Merge remote-tracking branch 'origin/1.10' into sdl_platform_1.10

# Conflicts:
#	Source/Editor/GUI/ContextMenu/ContextMenuBase.cs
#	Source/Engine/Platform/Linux/LinuxPlatform.cpp

.github/workflows/build_linux.yml

@@ -16,7 +16,7 @@ jobs:
       uses: actions/checkout@v3
     - name: Install dependencies
       run: |
-        sudo apt-get install libx11-dev libxcursor-dev libxinerama-dev build-essential gettext libtool libtool-bin libpulse-dev libasound2-dev libjack-dev portaudio19-dev
+        sudo apt-get install libx11-dev libxcursor-dev libxinerama-dev build-essential gettext libtool libtool-bin libpulse-dev libasound2-dev libjack-dev portaudio19-dev libwayland-dev
     - name: Setup Vulkan
       uses: ./.github/actions/vulkan
     - name: Setup .NET
@@ -44,7 +44,7 @@ jobs:
       uses: actions/checkout@v3
     - name: Install dependencies
       run: |
-        sudo apt-get install libx11-dev libxcursor-dev libxinerama-dev
+        sudo apt-get install libx11-dev libxcursor-dev libxinerama-dev libwayland-dev
     - name: Setup Vulkan
       uses: ./.github/actions/vulkan
     - name: Setup .NET

.github/workflows/tests.yml

@@ -28,7 +28,7 @@ jobs:
         git lfs pull
     - name: Install dependencies
       run: |
-        sudo apt-get install libx11-dev libxcursor-dev libxinerama-dev build-essential gettext libtool libtool-bin libpulse-dev libasound2-dev libjack-dev portaudio19-dev
+        sudo apt-get install libx11-dev libxcursor-dev libxinerama-dev build-essential gettext libtool libtool-bin libpulse-dev libasound2-dev libjack-dev portaudio19-dev libwayland-dev
     - name: Build
       run: |
         ./GenerateProjectFiles.sh -vs2022 -log -verbose -printSDKs -dotnet=8

Flax.flaxproj

@@ -13,6 +13,7 @@
   "Configuration": {
     "UseCSharp": true,
     "UseLargeWorlds": false,
-    "UseDotNet": true
+    "UseDotNet": true,
+    "UseSDL": true
   }
 }

Source/Editor/Content/Items/CppScriptItem.cs

@@ -20,7 +20,7 @@ namespace FlaxEditor.Content
         }
 
         /// <inheritdoc />
-        public override string TypeDescription => Path.EndsWith(".h") ? "C++ Header File" : "C++ Source Code";
+        public override string TypeDescription => Path.EndsWith(".h") || Path.EndsWith(".hpp") ? "C++ Header File" : "C++ Source Code";
 
         /// <inheritdoc />
         public override SpriteHandle DefaultThumbnail => Editor.Instance.Icons.CPPScript128;

Source/Editor/CustomEditors/Dedicated/LocalizationSettingsEditor.cs

@@ -186,12 +186,12 @@ namespace FlaxEditor.CustomEditors.Dedicated
                     foreach (var file in files)
                         FindNewKeysCSharp(file, newKeys, allKeys);
 
-                    // C++
-                    files = Directory.GetFiles(Globals.ProjectSourceFolder, "*.cpp", SearchOption.AllDirectories);
+                    // C/C++
+                    files = Directory.GetFiles(Globals.ProjectSourceFolder, "*.cpp", SearchOption.AllDirectories).Concat(Directory.GetFiles(Globals.ProjectSourceFolder, "*.c", SearchOption.AllDirectories)).ToArray();
                     filesCount += files.Length;
                     foreach (var file in files)
                         FindNewKeysCpp(file, newKeys, allKeys);
-                    files = Directory.GetFiles(Globals.ProjectSourceFolder, "*.h", SearchOption.AllDirectories);
+                    files = Directory.GetFiles(Globals.ProjectSourceFolder, "*.h", SearchOption.AllDirectories).Concat(Directory.GetFiles(Globals.ProjectSourceFolder, "*.hpp", SearchOption.AllDirectories)).ToArray();;
                     filesCount += files.Length;
                     foreach (var file in files)
                         FindNewKeysCpp(file, newKeys, allKeys);

Source/Editor/GUI/ContextMenu/ContextMenuBase.cs

@@ -1,7 +1,10 @@
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
 #define USE_IS_FOREGROUND
 #else
 #endif
+#if PLATFORM_SDL
+#define USE_SDL_WORKAROUNDS
+#endif
 // Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
 
 using System.Collections.Generic;
@@ -121,7 +124,7 @@ namespace FlaxEditor.GUI.ContextMenu
         }
 
         /// <summary>
-        /// Shows the empty menu popup o na screen.
+        /// Shows the empty menu popup on a screen.
         /// </summary>
         /// <param name="control">The target control.</param>
         /// <param name="area">The target control area to cover.</param>
@@ -256,7 +259,9 @@ namespace FlaxEditor.GUI.ContextMenu
                 desc.AllowMaximize = false;
                 desc.AllowDragAndDrop = false;
                 desc.IsTopmost = true;
-                desc.IsRegularWindow = false;
+                desc.Type = WindowType.Popup;
+                desc.Parent = parentWin.Window;
+                desc.Title = "ContextMenu";
                 desc.HasSizingFrame = false;
                 OnWindowCreating(ref desc);
                 _window = Platform.CreateWindow(ref desc);
@@ -266,16 +271,22 @@ namespace FlaxEditor.GUI.ContextMenu
                     _window.LostFocus += OnWindowLostFocus;
                 }
 
+#if USE_IS_FOREGROUND && USE_SDL_WORKAROUNDS
+                // The focus between popup and parent windows doesn't change, force hide the popup when clicked on parent
+                parentWin.Window.MouseDown += OnWindowMouseDown;
+                _window.Closed += () => parentWin.Window.MouseDown -= OnWindowMouseDown;
+#endif
+
                 // Attach to the window
                 _parentCM = parent as ContextMenuBase;
                 Parent = _window.GUI;
-
-                // Show
-                Visible = true;
-                if (_window == null)
-                    return;
-                _window.Show();
             }
+
+            // Show
+            Visible = true;
+            if (_window == null)
+                return;
+            _window.Show();
             PerformLayout();
             if (UseVisibilityControl)
             {
@@ -426,6 +437,17 @@ namespace FlaxEditor.GUI.ContextMenu
             }
         }
 
+#if USE_SDL_WORKAROUNDS
+        private void OnWindowGotFocus()
+        {
+        }
+        
+        private void OnWindowMouseDown(ref Float2 mousePosition, MouseButton button, ref bool handled)
+        {
+            // The user clicked outside the popup window
+            Hide();
+        }
+#else
         private void OnWindowGotFocus()
         {
             var child = _childCM;
@@ -439,6 +461,7 @@ namespace FlaxEditor.GUI.ContextMenu
                 });
             }
         }
+#endif
 
         private void OnWindowLostFocus()
         {
@@ -537,7 +560,12 @@ namespace FlaxEditor.GUI.ContextMenu
             // Let root context menu to check if none of the popup windows
             if (_parentCM == null && UseVisibilityControl && !IsForeground)
             {
+#if USE_SDL_WORKAROUNDS
+                if (!IsMouseOver)
+                    Hide();
+#else
                 Hide();
+#endif
             }
         }
 #endif

Source/Editor/GUI/Docking/DockHintWindow.cs

@@ -1,529 +0,0 @@
-// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
-
-using System;
-using FlaxEngine;
-using FlaxEngine.GUI;
-
-namespace FlaxEditor.GUI.Docking
-{
-    /// <summary>
-    /// Helper class used to handle docking windows dragging and docking.
-    /// </summary>
-    public class DockHintWindow
-    {
-        private FloatWindowDockPanel _toMove;
-
-        private Float2 _dragOffset;
-        private Float2 _defaultWindowSize;
-        private Rectangle _rectDock;
-        private Rectangle _rectWindow;
-        private Float2 _mouse;
-        private DockState _toSet;
-        private DockPanel _toDock;
-        private bool _lateDragOffsetUpdate;
-
-        private Rectangle _rLeft, _rRight, _rBottom, _rUpper, _rCenter;
-
-        private DockHintWindow(FloatWindowDockPanel toMove)
-        {
-            _toMove = toMove;
-            _toSet = DockState.Float;
-            var window = toMove.Window.Window;
-
-            // Remove focus from drag target
-            _toMove.Focus();
-            _toMove.Defocus();
-
-            // Focus window
-            window.Focus();
-
-            // Check if window is maximized and restore window.
-            if (window.IsMaximized)
-            {
-                // Restore window and set position to mouse.
-                var mousePos = window.MousePosition;
-                var previousSize = window.Size;
-                window.Restore();
-                window.Position = Platform.MousePosition - mousePos * window.Size / previousSize;
-            }
-
-            // Calculate dragging offset and move window to the destination position
-            var mouseScreenPosition = Platform.MousePosition;
-
-            // If the _toMove window was not focused when initializing this window, the result vector only contains zeros
-            // and to prevent a failure, we need to perform an update for the drag offset at later time which will be done in the OnMouseMove event handler.
-            if (mouseScreenPosition != Float2.Zero)
-                CalculateDragOffset(mouseScreenPosition);
-            else
-                _lateDragOffsetUpdate = true;
-
-            // Get initial size
-            _defaultWindowSize = window.Size;
-
-            // Init proxy window
-            Proxy.Init(ref _defaultWindowSize);
-
-            // Bind events
-            Proxy.Window.MouseUp += OnMouseUp;
-            Proxy.Window.MouseMove += OnMouseMove;
-            Proxy.Window.LostFocus += OnLostFocus;
-
-            // Start tracking mouse
-            Proxy.Window.StartTrackingMouse(false);
-
-            // Update window GUI
-            Proxy.Window.GUI.PerformLayout();
-
-            // Update rectangles
-            UpdateRects();
-
-            // Hide base window
-            window.Hide();
-
-            // Enable hit window presentation
-            Proxy.Window.RenderingEnabled = true;
-            Proxy.Window.Show();
-            Proxy.Window.Focus();
-        }
-
-        /// <summary>
-        /// Releases unmanaged and - optionally - managed resources.
-        /// </summary>
-        public void Dispose()
-        {
-            // End tracking mouse
-            Proxy.Window.EndTrackingMouse();
-
-            // Disable rendering
-            Proxy.Window.RenderingEnabled = false;
-
-            // Unbind events
-            Proxy.Window.MouseUp -= OnMouseUp;
-            Proxy.Window.MouseMove -= OnMouseMove;
-            Proxy.Window.LostFocus -= OnLostFocus;
-
-            // Hide the proxy
-            Proxy.Hide();
-
-            if (_toMove == null)
-                return;
-
-            // Check if window won't be docked
-            if (_toSet == DockState.Float)
-            {
-                var window = _toMove.Window?.Window;
-                if (window == null)
-                    return;
-                var mouse = Platform.MousePosition;
-
-                // Move base window
-                window.Position = mouse - _dragOffset;
-
-                // Show base window
-                window.Show();
-            }
-            else
-            {
-                bool hasNoChildPanels = _toMove.ChildPanelsCount == 0;
-
-                // Check if window has only single tab
-                if (hasNoChildPanels && _toMove.TabsCount == 1)
-                {
-                    // Dock window
-                    _toMove.GetTab(0).Show(_toSet, _toDock);
-                }
-                // Check if dock as tab and has no child panels
-                else if (hasNoChildPanels && _toSet == DockState.DockFill)
-                {
-                    // Dock all tabs
-                    while (_toMove.TabsCount > 0)
-                    {
-                        _toMove.GetTab(0).Show(DockState.DockFill, _toDock);
-                    }
-                }
-                else
-                {
-                    var selectedTab = _toMove.SelectedTab;
-
-                    // Dock the first tab into the target location
-                    var firstTab = _toMove.GetTab(0);
-                    firstTab.Show(_toSet, _toDock);
-
-                    // Dock rest of the tabs
-                    while (_toMove.TabsCount > 0)
-                    {
-                        _toMove.GetTab(0).Show(DockState.DockFill, firstTab);
-                    }
-
-                    // Keep selected tab being selected
-                    selectedTab?.SelectTab();
-                }
-
-                // Focus target window
-                _toDock.Root.Focus();
-            }
-
-            _toMove = null;
-        }
-
-        /// <summary>
-        /// Creates the new dragging hit window.
-        /// </summary>
-        /// <param name="toMove">Floating dock panel to move.</param>
-        /// <returns>The dock hint window object.</returns>
-        public static DockHintWindow Create(FloatWindowDockPanel toMove)
-        {
-            if (toMove == null)
-                throw new ArgumentNullException();
-
-            return new DockHintWindow(toMove);
-        }
-
-        /// <summary>
-        /// Creates the new dragging hit window.
-        /// </summary>
-        /// <param name="toMove">Dock window to move.</param>
-        /// <returns>The dock hint window object.</returns>
-        public static DockHintWindow Create(DockWindow toMove)
-        {
-            if (toMove == null)
-                throw new ArgumentNullException();
-
-            // Show floating
-            toMove.ShowFloating();
-
-            // Move window to the mouse position (with some offset for caption bar)
-            var window = (WindowRootControl)toMove.Root;
-            var mouse = Platform.MousePosition;
-            window.Window.Position = mouse - new Float2(8, 8);
-
-            // Get floating panel
-            var floatingPanelToMove = window.GetChild(0) as FloatWindowDockPanel;
-
-            return new DockHintWindow(floatingPanelToMove);
-        }
-
-        /// <summary>
-        /// Calculates window rectangle in the dock window.
-        /// </summary>
-        /// <param name="state">Window dock state.</param>
-        /// <param name="rect">Dock panel rectangle.</param>
-        /// <returns>Calculated window rectangle.</returns>
-        public static Rectangle CalculateDockRect(DockState state, ref Rectangle rect)
-        {
-            Rectangle result = rect;
-            switch (state)
-            {
-            case DockState.DockFill:
-                result.Location.Y += DockPanel.DefaultHeaderHeight;
-                result.Size.Y -= DockPanel.DefaultHeaderHeight;
-                break;
-            case DockState.DockTop:
-                result.Size.Y *= DockPanel.DefaultSplitterValue;
-                break;
-            case DockState.DockLeft:
-                result.Size.X *= DockPanel.DefaultSplitterValue;
-                break;
-            case DockState.DockBottom:
-                result.Location.Y += result.Size.Y * (1 - DockPanel.DefaultSplitterValue);
-                result.Size.Y *= DockPanel.DefaultSplitterValue;
-                break;
-            case DockState.DockRight:
-                result.Location.X += result.Size.X * (1 - DockPanel.DefaultSplitterValue);
-                result.Size.X *= DockPanel.DefaultSplitterValue;
-                break;
-            }
-            return result;
-        }
-
-        private void CalculateDragOffset(Float2 mouseScreenPosition)
-        {
-            var baseWinPos = _toMove.Window.Window.Position;
-            _dragOffset = mouseScreenPosition - baseWinPos;
-        }
-
-        private void UpdateRects()
-        {
-            // Cache mouse position
-            _mouse = Platform.MousePosition;
-
-            // Check intersection with any dock panel
-            var uiMouse = _mouse;
-            _toDock = _toMove.MasterPanel.HitTest(ref uiMouse, _toMove);
-
-            // Check dock state to use
-            bool showProxyHints = _toDock != null;
-            bool showBorderHints = showProxyHints;
-            bool showCenterHint = showProxyHints;
-            if (showProxyHints)
-            {
-                // If moved window has not only tabs but also child panels disable docking as tab
-                if (_toMove.ChildPanelsCount > 0)
-                    showCenterHint = false;
-
-                // Disable docking windows with one or more dock panels inside
-                if (_toMove.ChildPanelsCount > 0)
-                    showBorderHints = false;
-
-                // Get dock area
-                _rectDock = _toDock.DockAreaBounds;
-
-                // Cache dock rectangles
-                var size = _rectDock.Size;
-                var offset = _rectDock.Location;
-                var borderMargin = 4.0f;
-                var hintWindowsSize = Proxy.HintWindowsSize * Platform.DpiScale;
-                var hintWindowsSize2 = hintWindowsSize * 0.5f;
-                var centerX = size.X * 0.5f;
-                var centerY = size.Y * 0.5f;
-                _rUpper = new Rectangle(centerX - hintWindowsSize2, borderMargin, hintWindowsSize, hintWindowsSize) + offset;
-                _rBottom = new Rectangle(centerX - hintWindowsSize2, size.Y - hintWindowsSize - borderMargin, hintWindowsSize, hintWindowsSize) + offset;
-                _rLeft = new Rectangle(borderMargin, centerY - hintWindowsSize2, hintWindowsSize, hintWindowsSize) + offset;
-                _rRight = new Rectangle(size.X - hintWindowsSize - borderMargin, centerY - hintWindowsSize2, hintWindowsSize, hintWindowsSize) + offset;
-                _rCenter = new Rectangle(centerX - hintWindowsSize2, centerY - hintWindowsSize2, hintWindowsSize, hintWindowsSize) + offset;
-
-                // Hit test
-                DockState toSet = DockState.Float;
-                if (showBorderHints)
-                {
-                    if (_rUpper.Contains(_mouse))
-                        toSet = DockState.DockTop;
-                    else if (_rBottom.Contains(_mouse))
-                        toSet = DockState.DockBottom;
-                    else if (_rLeft.Contains(_mouse))
-                        toSet = DockState.DockLeft;
-                    else if (_rRight.Contains(_mouse))
-                        toSet = DockState.DockRight;
-                }
-                if (showCenterHint && _rCenter.Contains(_mouse))
-                    toSet = DockState.DockFill;
-                _toSet = toSet;
-
-                // Show proxy hint windows
-                Proxy.Down.Position = _rBottom.Location;
-                Proxy.Left.Position = _rLeft.Location;
-                Proxy.Right.Position = _rRight.Location;
-                Proxy.Up.Position = _rUpper.Location;
-                Proxy.Center.Position = _rCenter.Location;
-            }
-            else
-            {
-                _toSet = DockState.Float;
-            }
-
-            // Update proxy hint windows visibility
-            Proxy.Down.IsVisible = showProxyHints & showBorderHints;
-            Proxy.Left.IsVisible = showProxyHints & showBorderHints;
-            Proxy.Right.IsVisible = showProxyHints & showBorderHints;
-            Proxy.Up.IsVisible = showProxyHints & showBorderHints;
-            Proxy.Center.IsVisible = showProxyHints & showCenterHint;
-
-            // Calculate proxy/dock/window rectangles
-            if (_toDock == null)
-            {
-                // Floating window over nothing
-                _rectWindow = new Rectangle(_mouse - _dragOffset, _defaultWindowSize);
-            }
-            else
-            {
-                if (_toSet == DockState.Float)
-                {
-                    // Floating window over dock panel
-                    _rectWindow = new Rectangle(_mouse - _dragOffset, _defaultWindowSize);
-                }
-                else
-                {
-                    // Use only part of the dock panel to show hint
-                    _rectWindow = CalculateDockRect(_toSet, ref _rectDock);
-                }
-            }
-
-            // Update proxy window
-            Proxy.Window.ClientBounds = _rectWindow;
-        }
-
-        private void OnMouseUp(ref Float2 location, MouseButton button, ref bool handled)
-        {
-            if (button == MouseButton.Left)
-            {
-                Dispose();
-            }
-        }
-
-        private void OnMouseMove(ref Float2 mousePos)
-        {
-            // Recalculate the drag offset because the current mouse screen position was invalid when we initialized the window
-            if (_lateDragOffsetUpdate)
-            {
-                // Calculate dragging offset and move window to the destination position
-                CalculateDragOffset(mousePos);
-
-                // Reset state
-                _lateDragOffsetUpdate = false;
-            }
-
-            UpdateRects();
-        }
-
-        private void OnLostFocus()
-        {
-            Dispose();
-        }
-
-        /// <summary>
-        /// Contains helper proxy windows shared across docking panels. They are used to visualize docking window locations.
-        /// </summary>
-        public static class Proxy
-        {
-            /// <summary>
-            /// The drag proxy window.
-            /// </summary>
-            public static Window Window;
-
-            /// <summary>
-            /// The left hint proxy window.
-            /// </summary>
-            public static Window Left;
-
-            /// <summary>
-            /// The right hint proxy window.
-            /// </summary>
-            public static Window Right;
-
-            /// <summary>
-            /// The up hint proxy window.
-            /// </summary>
-            public static Window Up;
-
-            /// <summary>
-            /// The down hint proxy window.
-            /// </summary>
-            public static Window Down;
-
-            /// <summary>
-            /// The center hint proxy window.
-            /// </summary>
-            public static Window Center;
-
-            /// <summary>
-            /// The hint windows size.
-            /// </summary>
-            public const float HintWindowsSize = 32.0f;
-
-            /// <summary>
-            /// Initializes the hit proxy windows. Those windows are used to indicate drag target areas (left, right, top, bottom, etc.).
-            /// </summary>
-            public static void InitHitProxy()
-            {
-                CreateProxy(ref Left, "DockHint.Left");
-                CreateProxy(ref Right, "DockHint.Right");
-                CreateProxy(ref Up, "DockHint.Up");
-                CreateProxy(ref Down, "DockHint.Down");
-                CreateProxy(ref Center, "DockHint.Center");
-            }
-
-            /// <summary>
-            /// Initializes the hint window.
-            /// </summary>
-            /// <param name="initSize">Initial size of the proxy window.</param>
-            public static void Init(ref Float2 initSize)
-            {
-                if (Window == null)
-                {
-                    var settings = CreateWindowSettings.Default;
-                    settings.Title = "DockHint.Window";
-                    settings.Size = initSize;
-                    settings.AllowInput = true;
-                    settings.AllowMaximize = false;
-                    settings.AllowMinimize = false;
-                    settings.HasBorder = false;
-                    settings.HasSizingFrame = false;
-                    settings.IsRegularWindow = false;
-                    settings.SupportsTransparency = true;
-                    settings.ShowInTaskbar = false;
-                    settings.ShowAfterFirstPaint = false;
-                    settings.IsTopmost = true;
-
-                    Window = Platform.CreateWindow(ref settings);
-                    Window.Opacity = 0.6f;
-                    Window.GUI.BackgroundColor = Style.Current.DragWindow;
-                }
-                else
-                {
-                    // Resize proxy
-                    Window.ClientSize = initSize;
-                }
-
-                InitHitProxy();
-            }
-
-            private static void CreateProxy(ref Window win, string name)
-            {
-                if (win != null)
-                    return;
-
-                var settings = CreateWindowSettings.Default;
-                settings.Title = name;
-                settings.Size = new Float2(HintWindowsSize * Platform.DpiScale);
-                settings.AllowInput = false;
-                settings.AllowMaximize = false;
-                settings.AllowMinimize = false;
-                settings.HasBorder = false;
-                settings.HasSizingFrame = false;
-                settings.IsRegularWindow = false;
-                settings.SupportsTransparency = true;
-                settings.ShowInTaskbar = false;
-                settings.ActivateWhenFirstShown = false;
-                settings.IsTopmost = true;
-                settings.ShowAfterFirstPaint = false;
-
-                win = Platform.CreateWindow(ref settings);
-                win.Opacity = 0.6f;
-                win.GUI.BackgroundColor = Style.Current.DragWindow;
-            }
-
-            /// <summary>
-            /// Hides proxy windows.
-            /// </summary>
-            public static void Hide()
-            {
-                HideProxy(ref Window);
-                HideProxy(ref Left);
-                HideProxy(ref Right);
-                HideProxy(ref Up);
-                HideProxy(ref Down);
-                HideProxy(ref Center);
-            }
-
-            private static void HideProxy(ref Window win)
-            {
-                if (win)
-                {
-                    win.Hide();
-                }
-            }
-
-            /// <summary>
-            /// Releases proxy data and windows.
-            /// </summary>
-            public static void Dispose()
-            {
-                DisposeProxy(ref Window);
-                DisposeProxy(ref Left);
-                DisposeProxy(ref Right);
-                DisposeProxy(ref Up);
-                DisposeProxy(ref Down);
-                DisposeProxy(ref Center);
-            }
-
-            private static void DisposeProxy(ref Window win)
-            {
-                if (win)
-                {
-                    win.Close(ClosingReason.User);
-                    win = null;
-                }
-            }
-        }
-    }
-}

Source/Editor/GUI/Docking/DockPanelProxy.cs

@@ -49,6 +49,11 @@ namespace FlaxEditor.GUI.Docking
         /// The mouse position.
         /// </summary>
         public Float2 MousePosition = Float2.Minimum;
+        
+        /// <summary>
+        /// The mouse position.
+        /// </summary>
+        public Float2 MouseStartPosition = Float2.Minimum;
 
         /// <summary>
         /// The start drag asynchronous window.
@@ -165,7 +170,7 @@ namespace FlaxEditor.GUI.Docking
                 if (_panel.ChildPanelsCount == 0 && _panel.TabsCount == 1 && _panel.IsFloating)
                 {
                     // Create docking hint window but in an async manner
-                    DockHintWindow.Create(_panel as FloatWindowDockPanel);
+                    WindowDragHelper.StartDragging(_panel as FloatWindowDockPanel);
                 }
                 else
                 {
@@ -176,7 +181,7 @@ namespace FlaxEditor.GUI.Docking
                     _panel.SelectTab(index - 1);
 
                     // Create docking hint window
-                    DockHintWindow.Create(win);
+                    WindowDragHelper.StartDragging(win, _panel.RootWindow.Window);
                 }
             }
         }
@@ -355,6 +360,7 @@ namespace FlaxEditor.GUI.Docking
             if (IsSingleFloatingWindow)
                 return base.OnMouseDown(location, button);
             MouseDownWindow = GetTabAtPos(location, out IsMouseDownOverCross);
+            MouseStartPosition = location;
 
             // Check buttons
             if (button == MouseButton.Left)
@@ -441,6 +447,20 @@ namespace FlaxEditor.GUI.Docking
                         StartDrag(MouseDownWindow);
                     MouseDownWindow = null;
                 }
+                // Check if single tab is tried to be moved
+                else if (MouseDownWindow != null && _panel.TabsCount <= 1)
+                {
+                    if ((MousePosition - MouseStartPosition).Length > 3)
+                    {
+                        // Clear flag
+                        IsMouseLeftButtonDown = false;
+
+                        // Check tab under the mouse
+                        if (!IsMouseDownOverCross && MouseDownWindow != null)
+                            StartDrag(MouseDownWindow);
+                        MouseDownWindow = null;
+                    }
+                }
                 // Check if has more than one tab to change order
                 else if (MouseDownWindow != null && _panel.TabsCount > 1)
                 {

Source/Editor/GUI/Docking/DockWindow.cs

@@ -182,6 +182,25 @@ namespace FlaxEditor.GUI.Docking
         /// <param name="size">Window size, set <see cref="Float2.Zero"/> to use default.</param>
         /// <param name="position">Window location.</param>
         public void ShowFloating(Float2 location, Float2 size, WindowStartPosition position = WindowStartPosition.CenterParent)
+        {
+            CreateFloating(location, size, position, true);
+        }
+
+        /// <summary>
+        /// Creates the window in a floating state.
+        /// </summary>
+        public void CreateFloating()
+        {
+            CreateFloating(Float2.Zero, Float2.Zero);
+        }
+        /// <summary>
+        /// Creates the window in a floating state.
+        /// </summary>
+        /// <param name="location">Window location.</param>
+        /// <param name="size">Window size, set <see cref="Float2.Zero"/> to use default.</param>
+        /// <param name="position">Window location.</param>
+        /// <param name="showWindow">Window visibility.</param>
+        public void CreateFloating(Float2 location, Float2 size, WindowStartPosition position = WindowStartPosition.CenterParent, bool showWindow = false)
         {
             Undock();
 
@@ -199,14 +218,17 @@ namespace FlaxEditor.GUI.Docking
             windowGUI.UnlockChildrenRecursive();
             windowGUI.PerformLayout();
 
-            // Show
-            window.Show();
-            window.BringToFront();
-            window.Focus();
-            OnShow();
+            if (showWindow)
+            {
+                // Show
+                window.Show();
+                window.BringToFront();
+                window.Focus();
+                OnShow();
 
-            // Perform layout again
-            windowGUI.PerformLayout();
+                // Perform layout again
+                windowGUI.PerformLayout();
+            }
         }
 
         /// <summary>

Source/Editor/GUI/Docking/FloatWindowDockPanel.cs

@@ -52,7 +52,7 @@ namespace FlaxEditor.GUI.Docking
                 return;
 
             // Create docking hint window
-            DockHintWindow.Create(this);
+            WindowDragHelper.StartDragging(this);
         }
 
         /// <summary>
@@ -75,14 +75,14 @@ namespace FlaxEditor.GUI.Docking
             settings.MaximumSize = Float2.Zero; // Unlimited size
             settings.Fullscreen = false;
             settings.HasBorder = true;
-            settings.SupportsTransparency = false;
+            settings.SupportsTransparency = true;
             settings.ActivateWhenFirstShown = true;
             settings.AllowInput = true;
             settings.AllowMinimize = true;
             settings.AllowMaximize = true;
             settings.AllowDragAndDrop = true;
             settings.IsTopmost = false;
-            settings.IsRegularWindow = true;
+            settings.Type = WindowType.Regular;
             settings.HasSizingFrame = true;
             settings.ShowAfterFirstPaint = false;
             settings.ShowInTaskbar = true;

Source/Editor/GUI/Docking/MasterDockPanel.cs

@@ -81,7 +81,6 @@ namespace FlaxEditor.GUI.Docking
         public DockPanel HitTest(ref Float2 position, FloatWindowDockPanel excluded)
         {
             // Check all floating windows
-            // TODO: gather windows order and take it into account when performing test
             for (int i = 0; i < FloatingPanels.Count; i++)
             {
                 var win = FloatingPanels[i];
@@ -94,9 +93,44 @@ namespace FlaxEditor.GUI.Docking
             }
 
             // Base
+            //if (!Root?.RootWindow.Window.IsFocused ?? false)
+            //    return null;
             return base.HitTest(ref position);
         }
 
+        /// <summary>
+        /// Performs hit test over dock panel.
+        /// </summary>
+        /// <param name="position">Window space position to test.</param>
+        /// <param name="excluded">Floating window to omit during searching (and all docked to that one).</param>
+        /// <param name="hitResults">Results of the hit test</param>
+        /// <returns>True if any dock panels were hit, otherwise false.</returns>
+        public bool HitTest(ref Float2 position, FloatWindowDockPanel excluded, out DockPanel[] hitResults)
+        {
+            // Check all floating windows
+            List<DockPanel> results = new(FloatingPanels.Count);
+            for (int i = 0; i < FloatingPanels.Count; i++)
+            {
+                var win = FloatingPanels[i];
+                if (win.Visible && win != excluded)
+                {
+                    var result = win.HitTest(ref position);
+                    if (result != null)
+                        results.Add(result);
+                }
+            }
+
+            // Base
+            //if (!Root?.RootWindow.Window.IsFocused ?? false)
+            //    return null;
+            var baseResult = base.HitTest(ref position);
+            if (baseResult != null)
+                results.Add(baseResult);
+
+            hitResults = results.ToArray();
+            return hitResults.Length > 0;
+        }
+
         internal void LinkWindow(DockWindow window)
         {
             // Add to the windows list

Source/Editor/GUI/Docking/WindowDragHelper.cs

@@ -0,0 +1,448 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+using System;
+using FlaxEngine;
+using FlaxEngine.GUI;
+
+namespace FlaxEditor.GUI.Docking
+{
+    /// <summary>
+    /// Helper class used to handle docking windows dragging and docking.
+    /// </summary>
+    public class WindowDragHelper
+    {
+        private FloatWindowDockPanel _toMove;
+
+        private Float2 _dragOffset;
+        private Rectangle _rectDock;
+        private Float2 _mouse;
+        private DockState _toSet;
+        private DockPanel _toDock;
+        private Window _dragSourceWindow;
+
+        private Rectangle _rLeft, _rRight, _rBottom, _rUpper, _rCenter;
+        private Control _dockHintDown, _dockHintUp, _dockHintLeft, _dockHintRight, _dockHintCenter;
+
+        /// <summary>
+        /// The hint control size.
+        /// </summary>
+        public const float HintControlSize = 32.0f;
+
+        /// <summary>
+        /// The opacity of the dragged window when hint controls are shown.
+        /// </summary>
+        public const float DragWindowOpacity = 0.4f;
+
+        private WindowDragHelper(FloatWindowDockPanel toMove, Window dragSourceWindow)
+        {
+            _toMove = toMove;
+            _toSet = DockState.Float;
+            var window = toMove.Window.Window;
+
+            // Check if window is maximized and restore window.
+            if (window.IsMaximized)
+            {
+                // Restore window and set position to mouse.
+                var mousePos = window.MousePosition;
+                var previousSize = window.Size;
+                window.Restore();
+                window.Position = Platform.MousePosition - mousePos * window.Size / previousSize;
+            }
+
+            // Bind events
+            FlaxEngine.Scripting.Update += OnUpdate;
+            window.MouseUp += OnMouseUp;
+            
+            // Update rectangles
+            UpdateRects(Platform.MousePosition);
+
+            _dragSourceWindow = dragSourceWindow;
+            if (_dragSourceWindow != null) // Detaching a tab from existing window
+            {
+                _dragOffset = new Float2(window.Size.X / 2, 10.0f);
+
+                // TODO: when detaching tab in floating window (not main window), the drag source window is still main window?
+                var dragSourceWindowWayland = toMove.MasterPanel?.RootWindow.Window ?? Editor.Instance.Windows.MainWindow;
+                window.DoDragDrop(window.Title, _dragOffset, dragSourceWindowWayland);
+
+                _dragSourceWindow.MouseUp += OnMouseUp; // The mouse up event is sent to the source window on Windows
+            }
+            else
+            {
+                _dragOffset = window.MousePosition;
+                window.DoDragDrop(window.Title, _dragOffset, window);
+            }
+
+            // Ensure the dragged window stays on top of every other window
+            window.IsAlwaysOnTop = true;
+        }
+
+        /// <summary>
+        /// Releases unmanaged and - optionally - managed resources.
+        /// </summary>
+        public void Dispose()
+        {
+            var window = _toMove?.Window?.Window;
+
+            // Unbind events
+            FlaxEngine.Scripting.Update -= OnUpdate;
+            if (window != null)
+                window.MouseUp -= OnMouseUp;
+            if (_dragSourceWindow != null)
+                _dragSourceWindow.MouseUp -= OnMouseUp;
+
+            RemoveDockHints();
+
+            if (_toMove == null)
+                return;
+
+            if (window != null)
+            {
+                window.Opacity = 1.0f;
+                window.IsAlwaysOnTop = false;
+                window.BringToFront();
+            }
+
+            // Check if window won't be docked
+            if (_toSet == DockState.Float)
+            {
+                if (window == null)
+                    return;
+
+                // Show base window
+                window.Show();
+            }
+            else
+            {
+                bool hasNoChildPanels = _toMove.ChildPanelsCount == 0;
+
+                // Check if window has only single tab
+                if (hasNoChildPanels && _toMove.TabsCount == 1)
+                {
+                    // Dock window
+                    _toMove.GetTab(0).Show(_toSet, _toDock);
+                }
+                // Check if dock as tab and has no child panels
+                else if (hasNoChildPanels && _toSet == DockState.DockFill)
+                {
+                    // Dock all tabs
+                    while (_toMove.TabsCount > 0)
+                    {
+                        _toMove.GetTab(0).Show(DockState.DockFill, _toDock);
+                    }
+                }
+                else
+                {
+                    var selectedTab = _toMove.SelectedTab;
+
+                    // Dock the first tab into the target location
+                    if (_toMove.TabsCount > 0)
+                    {
+                        var firstTab = _toMove.GetTab(0);
+                        firstTab.Show(_toSet, _toDock);
+
+                        // Dock rest of the tabs
+                        while (_toMove.TabsCount > 0)
+                        {
+                            _toMove.GetTab(0).Show(DockState.DockFill, firstTab);
+                        }
+                    }
+
+                    // Keep selected tab being selected
+                    selectedTab?.SelectTab();
+                }
+
+                // Focus target window
+                _toDock.Root.Focus();
+            }
+
+            _toMove = null;
+        }
+
+        /// <summary>
+        /// Start dragging a floating dock panel.
+        /// </summary>
+        /// <param name="toMove">Floating dock panel to move.</param>
+        /// <returns>The window drag helper object.</returns>
+        public static WindowDragHelper StartDragging(FloatWindowDockPanel toMove)
+        {
+            if (toMove == null)
+                throw new ArgumentNullException();
+
+            return new WindowDragHelper(toMove, null);
+        }
+
+        /// <summary>
+        /// Start dragging a docked panel into a floating window.
+        /// </summary>
+        /// <param name="toMove">Dock window to move.</param>
+        /// <param name="dragSourceWindow">The window where dragging started from.</param>
+        /// <returns>The window drag helper object.</returns>
+        public static WindowDragHelper StartDragging(DockWindow toMove, Window dragSourceWindow)
+        {
+            if (toMove == null)
+                throw new ArgumentNullException();
+
+            // Create floating window
+            toMove.CreateFloating();
+
+            // Get floating panel
+            var window = (WindowRootControl)toMove.Root;
+            var floatingPanelToMove = window.GetChild(0) as FloatWindowDockPanel;
+
+            return new WindowDragHelper(floatingPanelToMove, dragSourceWindow);
+        }
+
+        private void AddDockHints()
+        {
+            if (_toDock == null)
+                return;
+
+            if (_toDock.RootWindow.Window != _dragSourceWindow)
+                _toDock.RootWindow.Window.MouseUp += OnMouseUp;
+
+            _dockHintDown = AddHintControl(new Float2(0.5f, 1));
+            _dockHintUp = AddHintControl(new Float2(0.5f, 0));
+            _dockHintLeft = AddHintControl(new Float2(0, 0.5f));
+            _dockHintRight = AddHintControl(new Float2(1, 0.5f));
+            _dockHintCenter = AddHintControl(new Float2(0.5f, 0.5f));
+
+            Control AddHintControl(Float2 pivot)
+            {
+                Control hintControl = _toDock.AddChild<Control>();
+                hintControl.AnchorPreset = AnchorPresets.StretchAll;
+                hintControl.Offsets = Margin.Zero;
+                hintControl.Size = new Float2(HintControlSize);
+                hintControl.BackgroundColor = Style.Current.DragWindow.AlphaMultiplied(0.6f);
+                hintControl.Pivot = pivot;
+                hintControl.PivotRelative = true;
+                return hintControl;
+            }
+        }
+        
+        private void RemoveDockHints()
+        {
+            if (_toDock == null)
+                return;
+
+            if (_toDock.RootWindow.Window != _dragSourceWindow)
+                _toDock.RootWindow.Window.MouseUp -= OnMouseUp;
+
+            _dockHintDown?.Parent.RemoveChild(_dockHintDown);
+            _dockHintUp?.Parent.RemoveChild(_dockHintUp);
+            _dockHintLeft?.Parent.RemoveChild(_dockHintLeft);
+            _dockHintRight?.Parent.RemoveChild(_dockHintRight);
+            _dockHintCenter?.Parent.RemoveChild(_dockHintCenter);
+            _dockHintDown = _dockHintUp = _dockHintLeft = _dockHintRight = _dockHintCenter = null;
+        }
+
+        private void UpdateRects(Float2 mousePos)
+        {
+            // Cache mouse position
+            _mouse = mousePos;
+
+            // Check intersection with any dock panel
+            DockPanel dockPanel = null;
+            if (_toMove.MasterPanel.HitTest(ref _mouse, _toMove, out var hitResults))
+            {
+                dockPanel = hitResults[0];
+
+                // Prefer panel which currently has focus
+                foreach (var hit in hitResults)
+                {
+                    if (hit.RootWindow.Window.IsFocused)
+                    {
+                        dockPanel = hit;
+                        break;
+                    }
+                }
+
+                // Prefer panel in the same window we hit earlier
+                if (dockPanel?.RootWindow != _toDock?.RootWindow)
+                {
+                    foreach (var hit in hitResults)
+                    {
+                        if (hit.RootWindow == _toDock?.RootWindow)
+                        {
+                            dockPanel = _toDock;
+                            break;
+                        }
+                    }
+                }
+            }
+            
+            if (dockPanel != _toDock)
+            {
+                RemoveDockHints();
+                _toDock = dockPanel;
+                AddDockHints();
+
+                // Make sure the all the dock hint areas are not under other windows
+                _toDock?.RootWindow.Window.BringToFront();
+                //_toDock?.RootWindow.Window.Focus();
+
+                // Make the dragged window transparent when dock hints are visible
+                _toMove.Window.Window.Opacity = _toDock == null ? 1.0f : DragWindowOpacity;
+            }
+            
+            // Check dock state to use
+            bool showProxyHints = _toDock != null;
+            bool showBorderHints = showProxyHints;
+            bool showCenterHint = showProxyHints;
+            Control hoveredHintControl = null;
+            Float2 hoveredSizeOverride = Float2.Zero;
+            if (showProxyHints)
+            {
+                // If moved window has not only tabs but also child panels disable docking as tab
+                if (_toMove.ChildPanelsCount > 0)
+                    showCenterHint = false;
+
+                // Disable docking windows with one or more dock panels inside
+                if (_toMove.ChildPanelsCount > 0)
+                    showBorderHints = false;
+
+                // Get dock area
+                _rectDock = _toDock.DockAreaBounds;
+
+                // Cache dock rectangles
+                var size = _rectDock.Size / Platform.DpiScale;
+                var offset = _toDock.PointFromScreen(_rectDock.Location);
+                var borderMargin = 4.0f;
+                var hintWindowsSize = HintControlSize;
+                var hintWindowsSize2 = hintWindowsSize * 0.5f;
+                var hintPreviewSize = new Float2(Math.Max(HintControlSize * 2, size.X * 0.5f), Math.Max(HintControlSize * 2, size.Y * 0.5f));
+                var centerX = size.X * 0.5f;
+                var centerY = size.Y * 0.5f;
+                _rUpper = new Rectangle(centerX - hintWindowsSize2, borderMargin, hintWindowsSize, hintWindowsSize) + offset;
+                _rBottom = new Rectangle(centerX - hintWindowsSize2, size.Y - hintWindowsSize - borderMargin, hintWindowsSize, hintWindowsSize) + offset;
+                _rLeft = new Rectangle(borderMargin, centerY - hintWindowsSize2, hintWindowsSize, hintWindowsSize) + offset;
+                _rRight = new Rectangle(size.X - hintWindowsSize - borderMargin, centerY - hintWindowsSize2, hintWindowsSize, hintWindowsSize) + offset;
+                _rCenter = new Rectangle(centerX - hintWindowsSize2, centerY - hintWindowsSize2, hintWindowsSize, hintWindowsSize) + offset;
+
+                // Hit test, and calculate the approximation for filled area when hovered over the hint
+                DockState toSet = DockState.Float;
+                if (showBorderHints)
+                {
+                    if (_rUpper.Contains(_toDock.PointFromScreen(_mouse)))
+                    {
+                        toSet = DockState.DockTop;
+                        hoveredHintControl = _dockHintUp;
+                        hoveredSizeOverride = new Float2(size.X, hintPreviewSize.Y);
+                    }
+                    else if (_rBottom.Contains(_toDock.PointFromScreen(_mouse)))
+                    {
+                        toSet = DockState.DockBottom;
+                        hoveredHintControl = _dockHintDown;
+                        hoveredSizeOverride = new Float2(size.X, hintPreviewSize.Y);
+                    }
+                    else if (_rLeft.Contains(_toDock.PointFromScreen(_mouse)))
+                    {
+                        toSet = DockState.DockLeft;
+                        hoveredHintControl = _dockHintLeft;
+                        hoveredSizeOverride = new Float2(hintPreviewSize.X, size.Y);
+                    }
+                    else if (_rRight.Contains(_toDock.PointFromScreen(_mouse)))
+                    {
+                        toSet = DockState.DockRight;
+                        hoveredHintControl = _dockHintRight;
+                        hoveredSizeOverride = new Float2(hintPreviewSize.X, size.Y);
+                    }
+                }
+                if (showCenterHint && _rCenter.Contains(_toDock.PointFromScreen(_mouse)))
+                {
+                    toSet = DockState.DockFill;
+                    hoveredHintControl = _dockHintCenter;
+                    hoveredSizeOverride = new Float2(size.X, size.Y);
+                }
+
+                _toSet = toSet;
+            }
+            else
+            {
+                _toSet = DockState.Float;
+            }
+            
+            // Update sizes and opacity of hint controls
+            if (_toDock != null)
+            {
+                if (hoveredHintControl != _dockHintDown)
+                {
+                    _dockHintDown.Size = new Float2(HintControlSize);
+                    _dockHintDown.BackgroundColor = Style.Current.DragWindow.AlphaMultiplied(0.6f);
+                }
+                if (hoveredHintControl != _dockHintLeft)
+                {
+                    _dockHintLeft.Size = new Float2(HintControlSize);
+                    _dockHintLeft.BackgroundColor = Style.Current.DragWindow.AlphaMultiplied(0.6f);
+                }
+                if (hoveredHintControl != _dockHintRight)
+                {
+                    _dockHintRight.Size = new Float2(HintControlSize);
+                    _dockHintRight.BackgroundColor = Style.Current.DragWindow.AlphaMultiplied(0.6f);
+                }
+                if (hoveredHintControl != _dockHintUp)
+                {
+                    _dockHintUp.Size = new Float2(HintControlSize);
+                    _dockHintUp.BackgroundColor = Style.Current.DragWindow.AlphaMultiplied(0.6f);
+                }
+                if (hoveredHintControl != _dockHintCenter)
+                {
+                    _dockHintCenter.Size = new Float2(HintControlSize);
+                    _dockHintCenter.BackgroundColor = Style.Current.DragWindow.AlphaMultiplied(0.6f);
+                }
+
+                if (_toSet != DockState.Float)
+                {
+                    if (hoveredHintControl != null)
+                    {
+                        hoveredHintControl.BackgroundColor = Style.Current.DragWindow.AlphaMultiplied(1.0f);
+                        hoveredHintControl.Size = hoveredSizeOverride;
+                    }
+                }
+            }
+
+            // Update hint controls visibility and location
+            if (showProxyHints)
+            {
+                if (hoveredHintControl != _dockHintDown)
+                    _dockHintDown.Location = _rBottom.Location;
+                if (hoveredHintControl != _dockHintLeft)
+                    _dockHintLeft.Location = _rLeft.Location;
+                if (hoveredHintControl != _dockHintRight)
+                    _dockHintRight.Location = _rRight.Location;
+                if (hoveredHintControl != _dockHintUp)
+                    _dockHintUp.Location = _rUpper.Location;
+                if (hoveredHintControl != _dockHintCenter)
+                    _dockHintCenter.Location = _rCenter.Location;
+                
+                _dockHintDown.Visible = showProxyHints & showBorderHints;
+                _dockHintLeft.Visible = showProxyHints & showBorderHints;
+                _dockHintRight.Visible = showProxyHints & showBorderHints;
+                _dockHintUp.Visible = showProxyHints & showBorderHints;
+                _dockHintCenter.Visible = showProxyHints & showCenterHint;
+            }
+        }
+
+        private void OnMouseUp(ref Float2 location, MouseButton button, ref bool handled)
+        {
+            if (button == MouseButton.Left)
+                Dispose();
+        }
+
+        private void OnUpdate()
+        {
+            var mousePos = Platform.MousePosition;
+
+            if (_mouse != mousePos)
+                OnMouseMove(mousePos);
+        }
+        
+        private void OnMouseMove(Float2 mousePos)
+        {
+            if (_dragSourceWindow != null)
+                _toMove.Window.Window.Position = mousePos - _dragOffset;
+
+            UpdateRects(mousePos);
+        }
+    }
+}

Source/Editor/GUI/Input/ValueBox.cs

@@ -266,6 +266,7 @@ namespace FlaxEditor.GUI.Input
             return base.OnMouseDown(location, button);
         }
 
+#if !PLATFORM_SDL
         /// <inheritdoc />
         public override void OnMouseMove(Float2 location)
         {
@@ -292,13 +293,45 @@ namespace FlaxEditor.GUI.Input
             base.OnMouseMove(location);
         }
 
+#else
+
+        /// <inheritdoc />
+        public override void OnMouseMoveRelative(Float2 mouseMotion)
+        {
+            var location = Root.TrackingMouseOffset;
+            if (_isSliding)
+            {
+                // Update sliding
+                ApplySliding(Root.TrackingMouseOffset.X * _slideSpeed);
+                return;
+            }
+
+            // Update cursor type so user knows they can slide value
+            if (CanUseSliding && SlideRect.Contains(location) && !_isSliding)
+            {
+                Cursor = CursorType.SizeWE;
+                _cursorChanged = true;
+            }
+            else if (_cursorChanged && !_isSliding)
+            {
+                Cursor = CursorType.Default;
+                _cursorChanged = false;
+            }
+
+            base.OnMouseMoveRelative(mouseMotion);
+        }
+
+#endif
+
         /// <inheritdoc />
         public override bool OnMouseUp(Float2 location, MouseButton button)
         {
             if (button == MouseButton.Left && _isSliding)
             {
+#if !PLATFORM_SDL
                 // End sliding and return mouse to original location
                 RootWindow.MousePosition = _mouseClickedPosition;
+#endif
                 EndSliding();
                 return true;
             }

Source/Editor/GUI/MainMenu.cs

@@ -12,7 +12,7 @@ namespace FlaxEditor.GUI
     /// <seealso cref="FlaxEngine.GUI.ContainerControl" />
     public sealed class MainMenu : ContainerControl
     {
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
         private bool _useCustomWindowSystem;
         private Image _icon;
         private Label _title;
@@ -67,7 +67,7 @@ namespace FlaxEditor.GUI
             AutoFocus = false;
             AnchorPreset = AnchorPresets.HorizontalStretchTop;
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
             _useCustomWindowSystem = !Editor.Instance.Options.Options.Interface.UseNativeWindowSystem;
             if (_useCustomWindowSystem)
             {
@@ -84,13 +84,15 @@ namespace FlaxEditor.GUI
 
                 ScriptsBuilder.GetBinariesConfiguration(out _, out _, out _, out var configuration);
 
+                var driver = Platform.DisplayServer;
+
                 _icon = new Image
                 {
                     Margin = new Margin(6, 6, 6, 6),
                     Brush = new TextureBrush(windowIcon),
                     Color = Style.Current.Foreground,
                     KeepAspectRatio = false,
-                    TooltipText = string.Format("{0}\nVersion {1}\nConfiguration {3}\nGraphics {2}", _window.Title, Globals.EngineVersion, GPUDevice.Instance.RendererType, configuration),
+                    TooltipText = string.Format("{0}\nVersion {1}\nConfiguration {3}\nGraphics {2} {4}", _window.Title, Globals.EngineVersion, GPUDevice.Instance.RendererType, configuration, driver),
                     Parent = this,
                 };
 
@@ -166,7 +168,7 @@ namespace FlaxEditor.GUI
             }
         }
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
         /// <inheritdoc />
         public override void Update(float deltaTime)
         {
@@ -291,7 +293,7 @@ namespace FlaxEditor.GUI
             if (base.OnMouseDoubleClick(location, button))
                 return true;
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
             var child = GetChildAtRecursive(location);
             if (_useCustomWindowSystem && child is not Button && child is not MainMenuButton)
             {
@@ -321,7 +323,7 @@ namespace FlaxEditor.GUI
         {
             float x = 0;
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
             if (_useCustomWindowSystem)
             {
                 // Icon
@@ -349,7 +351,7 @@ namespace FlaxEditor.GUI
                 }
             }
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
             if (_useCustomWindowSystem)
             {
                 // Buttons
@@ -367,7 +369,7 @@ namespace FlaxEditor.GUI
 #endif
         }
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
         /// <inheritdoc />
         public override void OnDestroy()
         {

Source/Editor/GUI/MainMenuButton.cs

@@ -42,7 +42,7 @@ namespace FlaxEditor.GUI
             Text = text;
 
             var style = Style.Current;
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
             if (Editor.Instance.Options.Options.Interface.UseNativeWindowSystem)
             {
                 BackgroundColorMouseOver = style.BackgroundHighlighted;

Source/Editor/Managed/ManagedEditor.Internal.cpp

@@ -435,6 +435,9 @@ DEFINE_INTERNAL_CALL(void) EditorInternal_RunVisualScriptBreakpointLoopTick(floa
             case InputDevice::EventType::MouseMove:
                 window->OnMouseMove(window->ScreenToClient(e.MouseData.Position));
                 break;
+            case InputDevice::EventType::MouseMoveRelative:
+                window->OnMouseMoveRelative(e.MouseMovementData.PositionRelative);
+                break;
             case InputDevice::EventType::MouseLeave:
                 window->OnMouseLeave();
                 break;

Source/Editor/Modules/ContentDatabaseModule.cs

@@ -1008,7 +1008,7 @@ namespace FlaxEditor.Modules
                     ContentItem item;
                     if (path.EndsWith(".cs"))
                         item = new CSharpScriptItem(path);
-                    else if (path.EndsWith(".cpp") || path.EndsWith(".h"))
+                    else if (path.EndsWith(".cpp") || path.EndsWith(".h") || path.EndsWith(".c") || path.EndsWith(".hpp"))
                         item = new CppScriptItem(path);
                     else if (path.EndsWith(".shader") || path.EndsWith(".hlsl"))
                         item = new ShaderSourceItem(path);

Source/Editor/Modules/ContentImportingModule.cs

@@ -222,7 +222,7 @@ namespace FlaxEditor.Modules
                 outputExtension = extension;
 
                 // Check if can place source files here
-                if (!targetLocation.CanHaveScripts && (extension == ".cs" || extension == ".cpp" || extension == ".h"))
+                if (!targetLocation.CanHaveScripts && (extension == ".cs" || extension == ".cpp" || extension == ".h" || extension == ".c" || extension == ".hpp"))
                 {
                     // Error
                     Editor.LogWarning(string.Format("Cannot import \'{0}\' to \'{1}\'. The target directory cannot have scripts.", inputPath, targetLocation.Node.Path));

Source/Editor/Modules/UIModule.cs

@@ -16,7 +16,7 @@ using FlaxEditor.Windows;
 using FlaxEngine;
 using FlaxEngine.GUI;
 using FlaxEngine.Json;
-using DockHintWindow = FlaxEditor.GUI.Docking.DockHintWindow;
+using WindowDragHelper = FlaxEditor.GUI.Docking.WindowDragHelper;
 using MasterDockPanel = FlaxEditor.GUI.Docking.MasterDockPanel;
 using FlaxEditor.Content.Settings;
 using FlaxEditor.Options;
@@ -381,7 +381,7 @@ namespace FlaxEditor.Modules
             Editor.Options.OptionsChanged += OnOptionsChanged;
 
             // Add dummy control for drawing the main window borders if using a custom style
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
             if (!Editor.Options.Options.Interface.UseNativeWindowSystem)
 #endif
             {
@@ -458,13 +458,6 @@ namespace FlaxEditor.Modules
             UpdateToolstrip();
         }
 
-        /// <inheritdoc />
-        public override void OnExit()
-        {
-            // Cleanup dock panel hint proxy windows (Flax will destroy them by var but it's better to clear them earlier)
-            DockHintWindow.Proxy.Dispose();
-        }
-
         private IColorPickerDialog ShowPickColorDialog(Control targetControl, Color initialValue, ColorValueBox.ColorPickerEvent colorChanged, ColorValueBox.ColorPickerClosedEvent pickerClosed, bool useDynamicEditing)
         {
             var dialog = new ColorPickerDialog(initialValue, colorChanged, pickerClosed, useDynamicEditing);

Source/Editor/Modules/WindowsModule.cs

@@ -760,8 +760,10 @@ namespace FlaxEditor.Modules
             {
                 settings.HasBorder = false;
 
+#if !PLATFORM_SDL
                 // Skip OS sizing frame and implement it using LeftButtonHit
                 settings.HasSizingFrame = false;
+#endif
             }
 #elif PLATFORM_LINUX
             settings.HasBorder = false;

Source/Editor/Options/InterfaceOptions.cs

@@ -167,7 +167,7 @@ namespace FlaxEditor.Options
         [EditorDisplay("Interface"), EditorOrder(10), Tooltip("Editor User Interface scale. Applied to all UI elements, windows and text. Can be used to scale the interface up on a bigger display. Editor restart required.")]
         public float InterfaceScale { get; set; } = 1.0f;
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS || PLATFORM_SDL
         /// <summary>
         /// Gets or sets a value indicating whether use native window title bar. Editor restart required.
         /// </summary>

Source/Editor/Scripting/ScriptsBuilder.cpp

@@ -120,9 +120,13 @@ void ScriptsBuilderImpl::sourceDirEvent(const String& path, FileSystemAction act
     // Discard non-source files or generated files
     if ((!path.EndsWith(TEXT(".cs")) &&
         !path.EndsWith(TEXT(".cpp")) &&
+        !path.EndsWith(TEXT(".c")) &&
+        !path.EndsWith(TEXT(".hpp")) &&
         !path.EndsWith(TEXT(".h"))) ||
         path.EndsWith(TEXT(".Gen.cs")))
+    {
         return;
+    }
 
     ScopeLock scopeLock(_locker);
     _lastSourceCodeEdited = DateTime::Now();

Source/Editor/Utilities/ScreenUtilities.cpp

@@ -1,131 +0,0 @@
-// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
-
-#include "ScreenUtilities.h"
-#include "Engine/Core/Math/Vector2.h"
-#include "Engine/Core/Delegate.h"
-#include "Engine/Core/Log.h"
-#include "Engine/Profiler/ProfilerCPU.h"
-
-Delegate<Color32> ScreenUtilities::PickColorDone;
-
-#if PLATFORM_WINDOWS
-
-#include <Windows.h>
-
-#pragma comment(lib, "Gdi32.lib")
-
-static HHOOK MouseCallbackHook;
-
-LRESULT CALLBACK OnScreenUtilsMouseCallback(_In_ int nCode, _In_ WPARAM wParam, _In_ LPARAM lParam)
-{
-    if (nCode >= 0 && wParam == WM_LBUTTONDOWN)
-    {
-        UnhookWindowsHookEx(MouseCallbackHook);
-
-        // Push event with the picked color
-        const Float2 cursorPos = Platform::GetMousePosition();
-        const Color32 colorPicked = ScreenUtilities::GetColorAt(cursorPos);
-        ScreenUtilities::PickColorDone(colorPicked);
-        return 1;
-    }
-    return CallNextHookEx(NULL, nCode, wParam, lParam);
-}
-
-Color32 ScreenUtilities::GetColorAt(const Float2& pos)
-{
-    PROFILE_CPU();
-    HDC deviceContext = GetDC(NULL);
-    COLORREF color = GetPixel(deviceContext, (int)pos.X, (int)pos.Y);
-    ReleaseDC(NULL, deviceContext);
-    return Color32(GetRValue(color), GetGValue(color), GetBValue(color), 255);
-}
-
-void ScreenUtilities::PickColor()
-{
-    MouseCallbackHook = SetWindowsHookEx(WH_MOUSE_LL, OnScreenUtilsMouseCallback, NULL, NULL);
-    if (MouseCallbackHook == NULL)
-    {
-        LOG(Warning, "Failed to set mouse hook.");
-        LOG(Warning, "Error: {0}", GetLastError());
-    }
-}
-
-#elif PLATFORM_LINUX
-
-#include "Engine/Platform/Linux/LinuxPlatform.h"
-#include "Engine/Platform/Linux/IncludeX11.h"
-
-Color32 ScreenUtilities::GetColorAt(const Float2& pos)
-{
-    X11::XColor color;
-    
-    X11::Display* display = (X11::Display*) LinuxPlatform::GetXDisplay();
-    int defaultScreen = X11::XDefaultScreen(display);
-
-    X11::XImage* image;
-    image = X11::XGetImage(display, X11::XRootWindow(display, defaultScreen), (int)pos.X, (int)pos.Y, 1, 1, AllPlanes, XYPixmap);
-    color.pixel = XGetPixel(image, 0, 0);
-    X11::XFree(image);
-
-    X11::XQueryColor(display, X11::XDefaultColormap(display, defaultScreen), &color);
-
-    Color32 outputColor;
-    outputColor.R = color.red / 256;
-    outputColor.G = color.green / 256;
-    outputColor.B = color.blue / 256;
-    outputColor.A = 255;
-    return outputColor;
-}
-
-void OnScreenUtilsXEventCallback(void* eventPtr)
-{
-    X11::XEvent* event = (X11::XEvent*) eventPtr;
-    X11::Display* display = (X11::Display*)LinuxPlatform::GetXDisplay();
-    if (event->type == ButtonPress)
-    {
-        const Float2 cursorPos = Platform::GetMousePosition();
-        const Color32 colorPicked = ScreenUtilities::GetColorAt(cursorPos);
-        X11::XUngrabPointer(display, CurrentTime);
-        ScreenUtilities::PickColorDone(colorPicked);
-        LinuxPlatform::xEventRecieved.Unbind(OnScreenUtilsXEventCallback);
-    }
-}
-
-void ScreenUtilities::PickColor()
-{
-    PROFILE_CPU();
-    X11::Display* display = (X11::Display*) LinuxPlatform::GetXDisplay();
-    X11::Window rootWindow = X11::XRootWindow(display, X11::XDefaultScreen(display));
-
-    X11::Cursor cursor = XCreateFontCursor(display, 130);
-    int grabbedPointer = X11::XGrabPointer(display, rootWindow, 0,  ButtonPressMask, GrabModeAsync, GrabModeAsync, rootWindow, cursor, CurrentTime);
-    if (grabbedPointer != GrabSuccess)
-    {
-        LOG(Error, "Failed to grab cursor for events.");
-        X11::XFreeCursor(display, cursor);
-        return;
-    }
-
-    X11::XFreeCursor(display, cursor);
-    LinuxPlatform::xEventRecieved.Bind(OnScreenUtilsXEventCallback);
-}
-
-#elif PLATFORM_MAC
-
-#include <Cocoa/Cocoa.h>
-#include <AppKit/AppKit.h>
-
-Color32 ScreenUtilities::GetColorAt(const Float2& pos)
-{
-    // TODO: implement ScreenUtilities for macOS
-    return { 0, 0, 0, 255 };
-}
-
-void ScreenUtilities::PickColor()
-{
-    // This is what C# calls to start the color picking sequence
-    // This should stop mouse clicks from working for one click, and that click is on the selected color
-    // There is a class called NSColorSample that might implement that for you, but maybe not.
-}
-
-#endif

Source/Editor/Utilities/ScreenUtilities.h

@@ -2,32 +2,4 @@
 
 #pragma once
 
-#include "Engine/Core/Types/BaseTypes.h"
-#include "Engine/Core/Math/Color32.h"
-#include "Engine/Core/Math/Vector2.h"
-#include "Engine/Core/Delegate.h"
-
-/// <summary>
-/// Platform-dependent screen utilities.
-/// </summary>
-API_CLASS(Static) class FLAXENGINE_API ScreenUtilities
-{
-    DECLARE_SCRIPTING_TYPE_MINIMAL(ScreenUtilities);
-
-    /// <summary>
-    /// Gets the pixel color at the specified coordinates.
-    /// </summary>
-    /// <param name="pos">Screen-space coordinate to read.</param>
-    /// <returns>Pixel color at the specified coordinates.</returns>
-    API_FUNCTION() static Color32 GetColorAt(const Float2& pos);
-
-    /// <summary>
-    /// Starts async color picking. Color will be returned through PickColorDone event when the actions ends (user selected the final color with a mouse). When action is active, GetColorAt can be used to read the current value.
-    /// </summary>
-    API_FUNCTION() static void PickColor();
-
-    /// <summary>
-    /// Called when PickColor action is finished.
-    /// </summary>
-    API_EVENT() static Delegate<Color32> PickColorDone;
-};
+#include "Engine/Platform/ScreenUtilities.h"

Source/Editor/Viewport/EditorGizmoViewport.cs

@@ -77,7 +77,7 @@ namespace FlaxEditor.Viewport
         public bool SnapToVertex => ContainsFocus && Editor.Instance.Options.Options.Input.SnapToVertex.Process(Root);
 
         /// <inheritdoc />
-        public Float2 MouseDelta => _mouseDelta;
+        public Float2 MouseDelta => FlaxEngine.Input.MousePositionDelta;
 
         /// <inheritdoc />
         public bool UseSnapping => Root?.GetKey(KeyboardKeys.Control) ?? false;

Source/Editor/Viewport/EditorViewport.cs

@@ -158,18 +158,22 @@ namespace FlaxEditor.Viewport
         private float _movementSpeed;
         private float _minMovementSpeed;
         private float _maxMovementSpeed;
+#if !PLATFORM_SDL
         private float _mouseAccelerationScale;
         private bool _useMouseFiltering;
         private bool _useMouseAcceleration;
+#endif
 
         // Input
 
         internal bool _disableInputUpdate;
         private bool _isControllingMouse, _isViewportControllingMouse, _wasVirtualMouseRightDown, _isVirtualMouseRightDown;
-        private int _deltaFilteringStep;
         private Float2 _startPos;
+#if !PLATFORM_SDL
         private Float2 _mouseDeltaLast;
+        private int _deltaFilteringStep;
         private Float2[] _deltaFilteringBuffer = new Float2[FpsCameraFilteringFrames];
+#endif
 
         /// <summary>
         /// The previous input (from the previous update).
@@ -522,10 +526,11 @@ namespace FlaxEditor.Viewport
         : base(task)
         {
             _editor = Editor.Instance;
-
+#if !PLATFORM_SDL
             _mouseAccelerationScale = 0.1f;
             _useMouseFiltering = false;
             _useMouseAcceleration = false;
+#endif
             _camera = camera;
             if (_camera != null)
                 _camera.Viewport = this;
@@ -1460,7 +1465,9 @@ namespace FlaxEditor.Viewport
             // Hide cursor and start tracking mouse movement
             win.StartTrackingMouse(false);
             win.Cursor = CursorType.Hidden;
+            win.MouseMoveRelative += OnMouseMoveRelative;
 
+#if !PLATFORM_SDL
             // Center mouse position if it's too close to the edge
             var size = Size;
             var center = Float2.Round(size * 0.5f);
@@ -1469,6 +1476,7 @@ namespace FlaxEditor.Viewport
                 _viewMousePos = center;
                 win.MousePosition = PointToWindow(_viewMousePos);
             }
+#endif
         }
 
         /// <summary>
@@ -1480,6 +1488,7 @@ namespace FlaxEditor.Viewport
             // Restore cursor and stop tracking mouse movement
             win.Cursor = CursorType.Default;
             win.EndTrackingMouse();
+            win.MouseMoveRelative -= OnMouseMoveRelative;
         }
 
         /// <summary>
@@ -1584,6 +1593,14 @@ namespace FlaxEditor.Viewport
                     else
                         EndMouseCapture();
                 }
+#if PLATFORM_SDL
+                bool useMouse = IsControllingMouse || true;
+                _prevInput = _input;
+                if (canUseInput && ContainsFocus)
+                    _input.Gather(win.Window, useMouse, ref _prevInput);
+                else
+                    _input.Clear();
+#else
                 bool useMouse = IsControllingMouse || (Mathf.IsInRange(_viewMousePos.X, 0, Width) && Mathf.IsInRange(_viewMousePos.Y, 0, Height));
                 _prevInput = _input;
                 var hit = GetChildAt(_viewMousePos, c => c.Visible && !(c is CanvasRootControl) && !(c is UIEditorRoot));
@@ -1591,6 +1608,7 @@ namespace FlaxEditor.Viewport
                     _input.Gather(win.Window, useMouse, ref _prevInput);
                 else
                     _input.Clear();
+#endif
 
                 // Track controlling mouse state change
                 bool wasControllingMouse = _prevInput.IsControllingMouse;
@@ -1699,6 +1717,10 @@ namespace FlaxEditor.Viewport
                 if (_input.IsControlDown)
                     moveDelta *= 0.3f;
 
+#if PLATFORM_SDL
+                var mouseDelta = _mouseDelta;
+                _mouseDelta = Float2.Zero;
+#else
                 // Calculate smooth mouse delta not dependant on viewport size
                 var offset = _viewMousePos - _startPos;
                 if (_input.IsZooming && !_input.IsMouseRightDown && !_input.IsMouseLeftDown && !_input.IsMouseMiddleDown && !_isOrtho && !rmbWheel && !_isVirtualMouseRightDown)
@@ -1740,6 +1762,7 @@ namespace FlaxEditor.Viewport
                     mouseDelta += _mouseDeltaLast * _mouseAccelerationScale;
                     _mouseDeltaLast = currentDelta;
                 }
+#endif
 
                 // Update
                 moveDelta *= dt * (60.0f * 4.0f);
@@ -1748,12 +1771,14 @@ namespace FlaxEditor.Viewport
                     mouseDelta *= new Float2(1, -1);
                 UpdateView(dt, ref moveDelta, ref mouseDelta, out var centerMouse);
 
+#if !PLATFORM_SDL
                 // Move mouse back to the root position
                 if (centerMouse && (_input.IsMouseRightDown || _input.IsMouseLeftDown || _input.IsMouseMiddleDown || _isVirtualMouseRightDown))
                 {
                     var center = PointToWindow(_startPos);
                     win.MousePosition = center;
                 }
+#endif
 
                 // Change Ortho size on mouse scroll
                 if (_isOrtho && !rmbWheel)
@@ -1765,6 +1790,8 @@ namespace FlaxEditor.Viewport
             }
             else
             {
+#if PLATFORM_SDL
+#else
                 if (_input.IsMouseLeftDown || _input.IsMouseRightDown || _isVirtualMouseRightDown)
                 {
                     // Calculate smooth mouse delta not dependant on viewport size
@@ -1779,6 +1806,7 @@ namespace FlaxEditor.Viewport
                     _mouseDelta = Float2.Zero;
                 }
                 _mouseDeltaLast = Float2.Zero;
+#endif
 
                 if (ContainsFocus)
                 {
@@ -1828,6 +1856,12 @@ namespace FlaxEditor.Viewport
             _input.MouseWheelDelta = 0;
         }
 
+        /// <inheritdoc />
+        public void OnMouseMoveRelative(ref Float2 mouseMotion)
+        {
+            _mouseDelta += mouseMotion;
+        }
+
         /// <inheritdoc />
         public override bool OnMouseDown(Float2 location, MouseButton button)
         {

Source/Editor/Windows/GameWindow.cs

@@ -1150,8 +1150,11 @@ namespace FlaxEditor.Windows
 
             if (Editor.StateMachine.IsPlayMode && !Editor.StateMachine.PlayingState.IsPaused)
             {
+                // Make sure the cursor is always in the viewport when cursor is locked
+                bool forceCenter = _cursorLockMode != CursorLockMode.None && !IsMouseOver;
+
                 // Center mouse in play mode
-                if (CenterMouseOnFocus)
+                if (CenterMouseOnFocus || forceCenter)
                 {
                     var center = PointToWindow(Size * 0.5f);
                     Root.MousePosition = center;

Source/Editor/Windows/SplashScreen.cpp

@@ -28,7 +28,7 @@ const Char* SplashScreenQuotes[] =
 #elif PLATFORM_LINUX
     TEXT("Try it on a Raspberry"),
     TEXT("Trying to exit vim"),
-    TEXT("Sudo flax --loadproject"),
+    TEXT("sudo flax --project HelloWorld.flaxproj"),
 #elif PLATFORM_MAC
     TEXT("don't compare Macbooks to oranges."),
     TEXT("Why does macbook heat up?\nBecause it doesn't have windows"),
@@ -104,6 +104,7 @@ const Char* SplashScreenQuotes[] =
     TEXT("You have my bow.\nAnd my axe!"),
     TEXT("To the bridge of Khazad-dum."),
     TEXT("One ring to rule them all.\nOne ring to find them."),
+    TEXT("Where there's a whip, there's a way."),
     TEXT("That's what she said"),
     TEXT("We could be compiling shaders here"),
     TEXT("Hello There"),
@@ -164,7 +165,7 @@ void SplashScreen::Show()
     settings.AllowMaximize = false;
     settings.AllowDragAndDrop = false;
     settings.IsTopmost = false;
-    settings.IsRegularWindow = false;
+    settings.Type = WindowType::Utility;
     settings.HasSizingFrame = false;
     settings.ShowAfterFirstPaint = true;
     settings.StartPosition = WindowStartPosition::CenterScreen;

Source/Engine/Engine/CommandLine.cpp

@@ -145,6 +145,12 @@ bool CommandLine::Parse(const Char* cmdLine)
     PARSE_BOOL_SWITCH("-monolog ", MonoLog);
     PARSE_BOOL_SWITCH("-mute ", Mute);
     PARSE_BOOL_SWITCH("-lowdpi ", LowDPI);
+
+#if PLATFORM_LINUX && PLATFORM_SDL
+    PARSE_BOOL_SWITCH("-wayland ", Wayland);
+    PARSE_BOOL_SWITCH("-x11 ", X11);
+#endif
+
 #if USE_EDITOR
     PARSE_BOOL_SWITCH("-clearcache ", ClearCache);
     PARSE_BOOL_SWITCH("-clearcooker ", ClearCookerCache);

Source/Engine/Engine/CommandLine.h

@@ -127,6 +127,20 @@ public:
         /// </summary>
         Nullable<bool> LowDPI;
 
+#if PLATFORM_LINUX && PLATFORM_SDL
+
+        /// <summary>
+        /// -wayland (prefer Wayland over X11 as display server)
+        /// </summary>
+        Nullable<bool> Wayland;
+
+        /// <summary>
+        /// -x11 (prefer X11 over Wayland as display server)
+        /// </summary>
+        Nullable<bool> X11;
+
+#endif
+
 #if USE_EDITOR
         /// <summary>
         /// -project !path! (Startup project path)

Source/Engine/Engine/Engine.cpp

@@ -99,13 +99,14 @@ int32 Engine::Main(const Char* cmdLine)
     CommandLine::Options.Std = true;
 #endif
 
+    Platform::SetHighDpiAwarenessEnabled(!CommandLine::Options.LowDPI.IsTrue());
+
     if (Platform::Init())
     {
         Platform::Fatal(TEXT("Cannot init platform."));
         return -1;
     }
 
-    Platform::SetHighDpiAwarenessEnabled(!CommandLine::Options.LowDPI.IsTrue());
     Time::StartupTime = DateTime::Now();
     Globals::StartupFolder = Globals::BinariesFolder = Platform::GetMainDirectory();
 #if USE_EDITOR

Source/Engine/Engine/Screen.cpp

@@ -6,6 +6,8 @@
 #include "Engine/Core/Types/Nullable.h"
 #include "Engine/Platform/Window.h"
 #include "Engine/Engine/EngineService.h"
+#include "Engine/Input/Input.h"
+#include "Engine/Input/Mouse.h"
 #if USE_EDITOR
 #include "Editor/Editor.h"
 #include "Editor/Managed/ManagedEditor.h"
@@ -13,10 +15,14 @@
 #include "Engine/Engine/Engine.h"
 #endif
 
-Nullable<bool> Fullscreen;
-Nullable<Float2> Size;
-bool CursorVisible = true;
-CursorLockMode CursorLock = CursorLockMode::None;
+namespace
+{
+    Nullable<bool> Fullscreen;
+    Nullable<Float2> Size;
+    bool CursorVisible = true;
+    CursorLockMode CursorLock = CursorLockMode::None;
+    bool LastGameViewportFocus = false;
+}
 
 class ScreenService : public EngineService
 {
@@ -100,11 +106,25 @@ void Screen::SetCursorVisible(const bool value)
 #else
 	const auto win = Engine::MainWindow;
 #endif
+    bool focused = false;
     if (win && Engine::HasGameViewportFocus())
     {
         win->SetCursor(value ? CursorType::Default : CursorType::Hidden);
+        focused = true;
     }
+    else if (win)
+        win->SetCursor(CursorType::Default);
     CursorVisible = value;
+
+    // Just enable relative mode when cursor is constrained and not visible
+    if (CursorLock != CursorLockMode::None && !CursorVisible && focused)
+    {
+        Input::Mouse->SetRelativeMode(true, win);
+    }
+    else if (CursorLock == CursorLockMode::None || CursorVisible || !focused)
+    {
+        Input::Mouse->SetRelativeMode(false, win);
+    }
 }
 
 CursorLockMode Screen::GetCursorLock()
@@ -133,6 +153,17 @@ void Screen::SetCursorLock(CursorLockMode mode)
         win->EndClippingCursor();
     }
     CursorLock = mode;
+
+    // Just enable relative mode when cursor is constrained and not visible
+    bool focused = win && Engine::HasGameViewportFocus();
+    if (CursorLock != CursorLockMode::None && !CursorVisible && focused)
+    {
+        Input::Mouse->SetRelativeMode(true, win);
+    }
+    else if (CursorLock == CursorLockMode::None || CursorVisible || !focused)
+    {
+        Input::Mouse->SetRelativeMode(false, win);
+    }
 }
 
 GameWindowMode Screen::GetGameWindowMode()
@@ -190,7 +221,11 @@ void ScreenService::Update()
 {
 #if USE_EDITOR
     // Sync current cursor state in Editor (eg. when viewport focus can change)
-    Screen::SetCursorVisible(CursorVisible);
+    const auto win = Editor::Managed->GetGameWindow(true);
+    bool gameViewportFocus = win && Engine::HasGameViewportFocus();
+    if (gameViewportFocus != LastGameViewportFocus)
+        Screen::SetCursorVisible(CursorVisible);
+    LastGameViewportFocus = gameViewportFocus;
 #endif
 }
 

Source/Engine/Engine/Time.h

@@ -16,6 +16,7 @@ API_CLASS(Static, Attributes="DebugCommand") class FLAXENGINE_API Time
     friend class Engine;
     friend class TimeService;
     friend class PhysicsSettings;
+    friend Window;
 
 public:
     /// <summary>

Source/Engine/GraphicsDevice/Vulkan/Android/AndroidVulkanPlatform.cpp

@@ -4,6 +4,7 @@
 
 #include "AndroidVulkanPlatform.h"
 #include "../RenderToolsVulkan.h"
+#include "Engine/Platform/Window.h"
 
 void AndroidVulkanPlatform::GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers)
 {
@@ -17,8 +18,10 @@ void AndroidVulkanPlatform::GetDeviceExtensions(Array<const char*>& extensions,
 	extensions.Add(VK_KHR_ANDROID_SURFACE_EXTENSION_NAME);
 }
 
-void AndroidVulkanPlatform::CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* surface)
+void AndroidVulkanPlatform::CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* surface)
 {
+    ASSERT(window);
+    void* windowHandle = window->GetNativePtr();
     ASSERT(windowHandle);
     VkAndroidSurfaceCreateInfoKHR surfaceCreateInfo;
     RenderToolsVulkan::ZeroStruct(surfaceCreateInfo, VK_STRUCTURE_TYPE_ANDROID_SURFACE_CREATE_INFO_KHR);

Source/Engine/GraphicsDevice/Vulkan/Android/AndroidVulkanPlatform.h

@@ -17,7 +17,7 @@ class AndroidVulkanPlatform : public VulkanPlatformBase
 public:
 	static void GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers);
 	static void GetDeviceExtensions(Array<const char*>& extensions, Array<const char*>& layers);
-	static void CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* surface);
+	static void CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* surface);
 };
 
 typedef AndroidVulkanPlatform VulkanPlatform;

Source/Engine/GraphicsDevice/Vulkan/GPUSwapChainVulkan.cpp

@@ -192,7 +192,7 @@ bool GPUSwapChainVulkan::CreateSwapChain(int32 width, int32 height)
     ASSERT_LOW_LAYER(_backBuffers.Count() == 0);
 
     // Create platform-dependent surface
-    VulkanPlatform::CreateSurface(windowHandle, GPUDeviceVulkan::Instance, &_surface);
+    VulkanPlatform::CreateSurface(_window, GPUDeviceVulkan::Instance, &_surface);
     if (_surface == VK_NULL_HANDLE)
     {
         LOG(Warning, "Failed to create Vulkan surface.");
@@ -374,7 +374,9 @@ bool GPUSwapChainVulkan::CreateSwapChain(int32 width, int32 height)
     swapChainInfo.presentMode = presentMode;
     swapChainInfo.clipped = VK_TRUE;
     swapChainInfo.compositeAlpha = VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR;
-    if (surfProperties.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR)
+    if (_window->GetSettings().SupportsTransparency && surfProperties.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR)
+        swapChainInfo.compositeAlpha = VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR;
+    else if (surfProperties.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR)
         swapChainInfo.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
 
     // Create swap chain

Source/Engine/GraphicsDevice/Vulkan/Linux/LinuxVulkanPlatform.cpp

@@ -4,62 +4,62 @@
 
 #include "LinuxVulkanPlatform.h"
 #include "../RenderToolsVulkan.h"
+#include "Engine/Platform/Window.h"
 
-// Contents of vulkan\vulkan_xlib.h inlined here to prevent typename collisions with engine types due to X11 types
 #include "Engine/Platform/Linux/IncludeX11.h"
-#ifdef __cplusplus
-extern "C" {
-#endif
-#define VK_KHR_xlib_surface 1
-#define VK_KHR_XLIB_SURFACE_SPEC_VERSION  6
-#define VK_KHR_XLIB_SURFACE_EXTENSION_NAME "VK_KHR_xlib_surface"
-typedef VkFlags VkXlibSurfaceCreateFlagsKHR;
+#define Display X11::Display
+#define Window X11::Window
+#define VisualID X11::VisualID
+#include "vulkan/vulkan_xlib.h"
+#undef Display
+#undef Window
+#undef VisualID
 
-typedef struct VkXlibSurfaceCreateInfoKHR
-{
-	VkStructureType sType;
-	const void* pNext;
-	VkXlibSurfaceCreateFlagsKHR flags;
-	X11::Display* dpy;
-	X11::Window window;
-} VkXlibSurfaceCreateInfoKHR;
+#include "vulkan/vulkan_wayland.h"
 
-typedef VkResult (VKAPI_PTR *PFN_vkCreateXlibSurfaceKHR)(VkInstance instance, const VkXlibSurfaceCreateInfoKHR* pCreateInfo, const VkAllocationCallbacks* pAllocator, VkSurfaceKHR* pSurface);
-typedef VkBool32 (VKAPI_PTR *PFN_vkGetPhysicalDeviceXlibPresentationSupportKHR)(VkPhysicalDevice physicalDevice, uint32_t queueFamilyIndex, X11::Display* dpy, X11::VisualID visualID);
-#ifndef VK_NO_PROTOTYPES
-VKAPI_ATTR VkResult VKAPI_CALL vkCreateXlibSurfaceKHR(
-    VkInstance                                  instance,
-    const VkXlibSurfaceCreateInfoKHR*           pCreateInfo,
-    const VkAllocationCallbacks*                pAllocator,
-    VkSurfaceKHR*                               pSurface);
-VKAPI_ATTR VkBool32 VKAPI_CALL vkGetPhysicalDeviceXlibPresentationSupportKHR(
-    VkPhysicalDevice                            physicalDevice,
-    uint32_t                                    queueFamilyIndex,
-    Display*                                    dpy,
-    VisualID                                    visualID);
-#endif
-#ifdef __cplusplus
-}
-#endif
-//
-
-// Export X11 surface extension from volk
+// Export extension from volk
 extern PFN_vkCreateXlibSurfaceKHR vkCreateXlibSurfaceKHR;
 extern PFN_vkGetPhysicalDeviceXlibPresentationSupportKHR vkGetPhysicalDeviceXlibPresentationSupportKHR;
+extern PFN_vkCreateWaylandSurfaceKHR vkCreateWaylandSurfaceKHR;
+extern PFN_vkGetPhysicalDeviceWaylandPresentationSupportKHR vkGetPhysicalDeviceWaylandPresentationSupportKHR;
 
 void LinuxVulkanPlatform::GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers)
 {
 	extensions.Add(VK_KHR_SURFACE_EXTENSION_NAME);
 	extensions.Add(VK_KHR_XLIB_SURFACE_EXTENSION_NAME);
+    extensions.Add(VK_KHR_WAYLAND_SURFACE_EXTENSION_NAME);
 }
 
-void LinuxVulkanPlatform::CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* surface)
+void LinuxVulkanPlatform::CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* surface)
 {
+#if !PLATFORM_SDL
+    void* windowHandle = window->GetNativePtr();
 	VkXlibSurfaceCreateInfoKHR surfaceCreateInfo;
 	RenderToolsVulkan::ZeroStruct(surfaceCreateInfo, VK_STRUCTURE_TYPE_XLIB_SURFACE_CREATE_INFO_KHR);
-	surfaceCreateInfo.dpy = (X11::Display*)LinuxPlatform::GetXDisplay();
+	surfaceCreateInfo.dpy = (X11::Display*)Platform::GetXDisplay();
 	surfaceCreateInfo.window = (X11::Window)windowHandle;
 	VALIDATE_VULKAN_RESULT(vkCreateXlibSurfaceKHR(instance, &surfaceCreateInfo, nullptr, surface));
+#else
+    SDLWindow* sdlWindow = static_cast<Window*>(window);
+    X11::Window x11Window = (X11::Window)sdlWindow->GetX11WindowHandle();
+    wl_surface* waylandSurface = (wl_surface*)sdlWindow->GetWaylandSurfacePtr();
+    if (waylandSurface != nullptr)
+    {
+        VkWaylandSurfaceCreateInfoKHR surfaceCreateInfo;
+        RenderToolsVulkan::ZeroStruct(surfaceCreateInfo, VK_STRUCTURE_TYPE_WAYLAND_SURFACE_CREATE_INFO_KHR);
+        surfaceCreateInfo.display = (wl_display*)sdlWindow->GetWaylandDisplay();
+        surfaceCreateInfo.surface = waylandSurface;
+        VALIDATE_VULKAN_RESULT(vkCreateWaylandSurfaceKHR(instance, &surfaceCreateInfo, nullptr, surface));
+    }
+    else if (x11Window != 0)
+    {
+        VkXlibSurfaceCreateInfoKHR surfaceCreateInfo;
+        RenderToolsVulkan::ZeroStruct(surfaceCreateInfo, VK_STRUCTURE_TYPE_XLIB_SURFACE_CREATE_INFO_KHR);
+        surfaceCreateInfo.dpy = (X11::Display*)sdlWindow->GetX11Display();
+        surfaceCreateInfo.window = x11Window;
+        VALIDATE_VULKAN_RESULT(vkCreateXlibSurfaceKHR(instance, &surfaceCreateInfo, nullptr, surface));
+    }
+#endif
 }
 
 #endif

Source/Engine/GraphicsDevice/Vulkan/Linux/LinuxVulkanPlatform.h

@@ -19,7 +19,7 @@ class LinuxVulkanPlatform : public VulkanPlatformBase
 {
 public:
 	static void GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers);
-	static void CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* outSurface);
+	static void CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* outSurface);
 };
 
 typedef LinuxVulkanPlatform VulkanPlatform;

Source/Engine/GraphicsDevice/Vulkan/Mac/MacVulkanPlatform.cpp

@@ -4,6 +4,7 @@
 
 #include "MacVulkanPlatform.h"
 #include "../RenderToolsVulkan.h"
+#include "Engine/Platform/Window.h"
 #include <Cocoa/Cocoa.h>
 
 void MacVulkanPlatform::GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers)
@@ -12,12 +13,13 @@ void MacVulkanPlatform::GetInstanceExtensions(Array<const char*>& extensions, Ar
 	extensions.Add(VK_MVK_MACOS_SURFACE_EXTENSION_NAME);
 }
 
-void MacVulkanPlatform::CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* surface)
+void MacVulkanPlatform::CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* surface)
 {
-    NSWindow* window = (NSWindow*)windowHandle;
+    void* windowHandle = window->GetNativePtr();
+    NSWindow* nswindow = (NSWindow*)windowHandle;
 	VkMacOSSurfaceCreateInfoMVK surfaceCreateInfo;
 	RenderToolsVulkan::ZeroStruct(surfaceCreateInfo, VK_STRUCTURE_TYPE_MACOS_SURFACE_CREATE_INFO_MVK);
-	surfaceCreateInfo.pView = (void*)window.contentView;
+	surfaceCreateInfo.pView = (void*)nswindow.contentView;
 	VALIDATE_VULKAN_RESULT(vkCreateMacOSSurfaceMVK(instance, &surfaceCreateInfo, nullptr, surface));
 }
 

Source/Engine/GraphicsDevice/Vulkan/Mac/MacVulkanPlatform.h

@@ -18,7 +18,7 @@ class MacVulkanPlatform : public VulkanPlatformBase
 {
 public:
 	static void GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers);
-	static void CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* outSurface);
+	static void CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* outSurface);
 };
 
 typedef MacVulkanPlatform VulkanPlatform;

Source/Engine/GraphicsDevice/Vulkan/Win32/Win32VulkanPlatform.cpp

@@ -6,6 +6,7 @@
 
 #include "../RenderToolsVulkan.h"
 #include "Engine/Graphics/GPUDevice.h"
+#include "Engine/Platform/Window.h"
 
 void Win32VulkanPlatform::GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers)
 {
@@ -13,8 +14,9 @@ void Win32VulkanPlatform::GetInstanceExtensions(Array<const char*>& extensions,
     extensions.Add(VK_KHR_WIN32_SURFACE_EXTENSION_NAME);
 }
 
-void Win32VulkanPlatform::CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* surface)
+void Win32VulkanPlatform::CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* surface)
 {
+    void* windowHandle = window->GetNativePtr();
     VkWin32SurfaceCreateInfoKHR surfaceCreateInfo;
     RenderToolsVulkan::ZeroStruct(surfaceCreateInfo, VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR);
     surfaceCreateInfo.hinstance = GetModuleHandle(nullptr);

Source/Engine/GraphicsDevice/Vulkan/Win32/Win32VulkanPlatform.h

@@ -17,7 +17,7 @@ class Win32VulkanPlatform : public VulkanPlatformBase
 {
 public:
     static void GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers);
-    static void CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* surface);
+    static void CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* surface);
 };
 
 typedef Win32VulkanPlatform VulkanPlatform;

Source/Engine/GraphicsDevice/Vulkan/iOS/iOSVulkanPlatform.cpp

@@ -5,6 +5,7 @@
 #include "iOSVulkanPlatform.h"
 #include "../RenderToolsVulkan.h"
 #include "Engine/Core/Delegate.h"
+#include "Engine/Platform/Window.h"
 #include <UIKit/UIKit.h>
 
 void iOSVulkanPlatform::GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers)
@@ -13,8 +14,9 @@ void iOSVulkanPlatform::GetInstanceExtensions(Array<const char*>& extensions, Ar
 	extensions.Add(VK_MVK_IOS_SURFACE_EXTENSION_NAME);
 }
 
-void iOSVulkanPlatform::CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* surface)
+void iOSVulkanPlatform::CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* surface)
 {
+    void* windowHandle = window->GetNativePtr();
 	// Create surface on a main UI Thread
 	Function<void()> func = [&windowHandle, &instance, &surface]()
 	{

Source/Engine/GraphicsDevice/Vulkan/iOS/iOSVulkanPlatform.h

@@ -18,7 +18,7 @@ class iOSVulkanPlatform : public VulkanPlatformBase
 {
 public:
 	static void GetInstanceExtensions(Array<const char*>& extensions, Array<const char*>& layers);
-	static void CreateSurface(void* windowHandle, VkInstance instance, VkSurfaceKHR* outSurface);
+	static void CreateSurface(Window* window, VkInstance instance, VkSurfaceKHR* outSurface);
 };
 
 typedef iOSVulkanPlatform VulkanPlatform;

Source/Engine/Input/Input.cpp

@@ -78,6 +78,7 @@ Delegate<const Float2&, MouseButton> Input::MouseUp;
 Delegate<const Float2&, MouseButton> Input::MouseDoubleClick;
 Delegate<const Float2&, float> Input::MouseWheel;
 Delegate<const Float2&> Input::MouseMove;
+Delegate<const Float2&> Input::MouseMoveRelative;
 Action Input::MouseLeave;
 Delegate<const Float2&, int32> Input::TouchDown;
 Delegate<const Float2&, int32> Input::TouchMove;
@@ -208,6 +209,14 @@ void Mouse::OnMouseMove(const Float2& position, Window* target)
     e.MouseData.Position = position;
 }
 
+void Mouse::OnMouseMoveRelative(const Float2& positionRelative, Window* target)
+{
+    Event& e = _queue.AddOne();
+    e.Type = EventType::MouseMoveRelative;
+    e.Target = target;
+    e.MouseMovementData.PositionRelative = positionRelative;
+}
+
 void Mouse::OnMouseLeave(Window* target)
 {
     Event& e = _queue.AddOne();
@@ -273,6 +282,11 @@ bool Mouse::Update(EventQueue& queue)
             _state.MousePosition = e.MouseData.Position;
             break;
         }
+        case EventType::MouseMoveRelative:
+        {
+            _state.MousePosition += e.MouseMovementData.PositionRelative;
+            break;
+        }
         case EventType::MouseLeave:
         {
             break;
@@ -933,6 +947,9 @@ void InputService::Update()
         case InputDevice::EventType::MouseMove:
             window->OnMouseMove(window->ScreenToClient(e.MouseData.Position));
             break;
+        case InputDevice::EventType::MouseMoveRelative:
+            window->OnMouseMoveRelative(e.MouseMovementData.PositionRelative);
+            break;
         case InputDevice::EventType::MouseLeave:
             window->OnMouseLeave();
             break;
@@ -989,6 +1006,9 @@ void InputService::Update()
         case InputDevice::EventType::MouseMove:
             Input::MouseMove(e.MouseData.Position);
             break;
+        case InputDevice::EventType::MouseMoveRelative:
+            Input::MouseMoveRelative(e.MouseMovementData.PositionRelative);
+            break;
         case InputDevice::EventType::MouseLeave:
             Input::MouseLeave();
             break;
@@ -1202,12 +1222,14 @@ void InputService::Update()
         }
     }
 
+#if !PLATFORM_SDL
     // Lock mouse if need to
     const auto lockMode = Screen::GetCursorLock();
     if (lockMode == CursorLockMode::Locked)
     {
         Input::SetMousePosition(Screen::GetSize() * 0.5f);
     }
+#endif
 
     // Send events for the active actions and axes (send events only in play mode)
     if (!Time::GetGamePaused())

Source/Engine/Input/Input.h

@@ -108,6 +108,11 @@ public:
     /// </summary>
     API_EVENT() static Delegate<const Float2&> MouseMove;
 
+    /// <summary>
+    /// Event fired when mouse moves while in relative mode.
+    /// </summary>
+    API_EVENT() static Delegate<const Float2&> MouseMoveRelative;
+
     /// <summary>
     /// Event fired when mouse leaves window.
     /// </summary>

Source/Engine/Input/InputDevice.h

@@ -25,6 +25,7 @@ public:
         MouseDoubleClick,
         MouseWheel,
         MouseMove,
+        MouseMoveRelative,
         MouseLeave,
         TouchDown,
         TouchMove,
@@ -54,6 +55,11 @@ public:
                 Float2 Position;
             } MouseData;
 
+            struct
+            {
+                Float2 PositionRelative;
+            } MouseMovementData;
+
             struct
             {
                 float WheelDelta;

Source/Engine/Input/Mouse.h

@@ -46,12 +46,14 @@ public:
 protected:
     State _state;
     State _prevState;
+    bool _relativeMode;
 
     explicit Mouse()
         : InputDevice(SpawnParams(Guid::New(), TypeInitializer), TEXT("Mouse"))
     {
         _state.Clear();
         _prevState.Clear();
+        _relativeMode = false;
     }
 
 public:
@@ -114,6 +116,14 @@ public:
         return !_state.MouseButtons[static_cast<int32>(button)] && _prevState.MouseButtons[static_cast<int32>(button)];
     }
 
+    /// <summary>
+    /// Gets the current state of mouse relative mode. 
+    /// </summary>
+    API_FUNCTION() FORCE_INLINE bool IsRelative() const
+    {
+        return _relativeMode;
+    }
+
 public:
     /// <summary>
     /// Sets the mouse position.
@@ -121,6 +131,17 @@ public:
     /// <param name="newPosition">The new position.</param>
     virtual void SetMousePosition(const Float2& newPosition) = 0;
 
+    /// <summary>
+    /// Sets the mouse relative mode state. While enabled, the mouse movement tracking becomes more accurate.
+    /// The cursor will be hidden while in relative mode.
+    /// </summary>
+    /// <param name="relativeMode">The new relative mode state.</param>
+    /// <param name="window">The window.</param>
+    virtual void SetRelativeMode(bool relativeMode, Window* window)
+    {
+        _relativeMode = relativeMode;
+    }
+
     /// <summary>
     /// Called when mouse cursor gets moved by the application. Invalidates the previous cached mouse position to prevent mouse jitter when locking the cursor programmatically.
     /// </summary>
@@ -158,6 +179,13 @@ public:
     /// <param name="target">The target window to receive this event, otherwise input system will pick the window automatically.</param>
     void OnMouseMove(const Float2& position, Window* target = nullptr);
 
+    /// <summary>
+    /// Called when mouse moves in relative mode.
+    /// </summary>
+    /// <param name="positionRelative">The mouse position change.</param>
+    /// <param name="target">The target window to receive this event, otherwise input system will pick the window automatically.</param>
+    void OnMouseMoveRelative(const Float2& positionRelative, Window* target = nullptr);
+
     /// <summary>
     /// Called when mouse leaves the input source area.
     /// </summary>

Source/Engine/Platform/Base/Enums.h

@@ -0,0 +1,251 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#include "Engine/Core/Config.h"
+
+/// <summary>
+/// Window closing reasons.
+/// </summary>
+API_ENUM() enum class ClosingReason
+{
+    /// <summary>
+    /// The unknown.
+    /// </summary>
+    Unknown = 0,
+
+    /// <summary>
+    /// The user.
+    /// </summary>
+    User,
+
+    /// <summary>
+    /// The engine exit.
+    /// </summary>
+    EngineExit,
+
+    /// <summary>
+    /// The close event.
+    /// </summary>
+    CloseEvent,
+};
+
+/// <summary>
+/// Types of default cursors.
+/// </summary>
+API_ENUM() enum class CursorType
+{
+    /// <summary>
+    /// The default.
+    /// </summary>
+    Default = 0,
+
+    /// <summary>
+    /// The cross.
+    /// </summary>
+    Cross,
+
+    /// <summary>
+    /// The hand.
+    /// </summary>
+    Hand,
+
+    /// <summary>
+    /// The help icon
+    /// </summary>
+    Help,
+
+    /// <summary>
+    /// The I beam.
+    /// </summary>
+    IBeam,
+
+    /// <summary>
+    /// The blocking image.
+    /// </summary>
+    No,
+
+    /// <summary>
+    /// The wait.
+    /// </summary>
+    Wait,
+
+    /// <summary>
+    /// The size all sides.
+    /// </summary>
+    SizeAll,
+
+    /// <summary>
+    /// The size NE-SW.
+    /// </summary>
+    SizeNESW,
+
+    /// <summary>
+    /// The size NS.
+    /// </summary>
+    SizeNS,
+
+    /// <summary>
+    /// The size NW-SE.
+    /// </summary>
+    SizeNWSE,
+
+    /// <summary>
+    /// The size WE.
+    /// </summary>
+    SizeWE,
+
+    /// <summary>
+    /// The cursor is hidden.
+    /// </summary>
+    Hidden,
+
+    MAX
+};
+
+/// <summary>
+/// Data drag and drop effects.
+/// </summary>
+API_ENUM() enum class DragDropEffect
+{
+    /// <summary>
+    /// The none.
+    /// </summary>
+    None = 0,
+
+    /// <summary>
+    /// The copy.
+    /// </summary>
+    Copy,
+
+    /// <summary>
+    /// The move.
+    /// </summary>
+    Move,
+
+    /// <summary>
+    /// The link.
+    /// </summary>
+    Link,
+};
+
+/// <summary>
+/// Window hit test codes. Note: they are 1:1 mapping for Win32 values.
+/// </summary>
+API_ENUM() enum class WindowHitCodes
+{
+    /// <summary>
+    /// The transparent area.
+    /// </summary>
+    Transparent = -1,
+
+    /// <summary>
+    /// The no hit.
+    /// </summary>
+    NoWhere = 0,
+
+    /// <summary>
+    /// The client area.
+    /// </summary>
+    Client = 1,
+
+    /// <summary>
+    /// The caption area.
+    /// </summary>
+    Caption = 2,
+
+    /// <summary>
+    /// The system menu.
+    /// </summary>
+    SystemMenu = 3,
+
+    /// <summary>
+    /// The grow box
+    /// </summary>
+    GrowBox = 4,
+
+    /// <summary>
+    /// The menu.
+    /// </summary>
+    Menu = 5,
+
+    /// <summary>
+    /// The horizontal scroll.
+    /// </summary>
+    HScroll = 6,
+
+    /// <summary>
+    /// The vertical scroll.
+    /// </summary>
+    VScroll = 7,
+
+    /// <summary>
+    /// The minimize button.
+    /// </summary>
+    MinButton = 8,
+
+    /// <summary>
+    /// The maximize button.
+    /// </summary>
+    MaxButton = 9,
+
+    /// <summary>
+    /// The left side;
+    /// </summary>
+    Left = 10,
+
+    /// <summary>
+    /// The right side.
+    /// </summary>
+    Right = 11,
+
+    /// <summary>
+    /// The top side.
+    /// </summary>
+    Top = 12,
+
+    /// <summary>
+    /// The top left corner.
+    /// </summary>
+    TopLeft = 13,
+
+    /// <summary>
+    /// The top right corner.
+    /// </summary>
+    TopRight = 14,
+
+    /// <summary>
+    /// The bottom side.
+    /// </summary>
+    Bottom = 15,
+
+    /// <summary>
+    /// The bottom left corner.
+    /// </summary>
+    BottomLeft = 16,
+
+    /// <summary>
+    /// The bottom right corner.
+    /// </summary>
+    BottomRight = 17,
+
+    /// <summary>
+    /// The border.
+    /// </summary>
+    Border = 18,
+
+    /// <summary>
+    /// The object.
+    /// </summary>
+    Object = 19,
+
+    /// <summary>
+    /// The close button.
+    /// </summary>
+    Close = 20,
+
+    /// <summary>
+    /// The help button.
+    /// </summary>
+    Help = 21,
+};

Source/Engine/Platform/Base/PlatformBase.cpp

@@ -45,6 +45,7 @@ static_assert(sizeof(double) == 8, "Invalid double type size.");
 static_assert((PLATFORM_THREADS_LIMIT & (PLATFORM_THREADS_LIMIT - 1)) == 0, "Threads limit must be power of two.");
 static_assert(PLATFORM_THREADS_LIMIT % 4 == 0, "Threads limit must be multiple of 4.");
 
+const Char* PlatformBase::ApplicationClassName = TEXT("FlaxWindow");
 float PlatformBase::CustomDpiScale = 1.0f;
 Array<User*, FixedAllocation<8>> PlatformBase::Users;
 Delegate<User*> PlatformBase::UserAdded;
@@ -261,6 +262,15 @@ PlatformType PlatformBase::GetPlatformType()
     return PLATFORM_TYPE;
 }
 
+#if !PLATFORM_SDL
+
+String PlatformBase::GetDisplayServer()
+{
+    return String::Empty;
+}
+
+#endif
+
 bool PlatformBase::Is64BitApp()
 {
 #if PLATFORM_64BITS

Source/Engine/Platform/Base/PlatformBase.h

@@ -190,6 +190,13 @@ DECLARE_SCRIPTING_TYPE_MINIMAL(PlatformBase);
     /// </summary>
     static void Exit();
 
+public:
+
+    /// <summary>
+    /// Application windows class name.
+    /// </summary>
+    static const Char* ApplicationClassName;
+
 public:
     /// <summary>
     /// Copy memory region
@@ -362,6 +369,11 @@ public:
     /// </summary>
     API_PROPERTY() static PlatformType GetPlatformType();
 
+    /// <summary>
+    /// Returns the display server name on Linux.
+    /// </summary>
+    API_PROPERTY() static String GetDisplayServer() = delete;
+
     /// <summary>
     /// Returns true if is running 64 bit application (otherwise 32 bit). It's compile-time constant.
     /// </summary>

Source/Engine/Platform/Base/ScreenUtilitiesBase.h

@@ -0,0 +1,42 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#include "Engine/Core/Types/BaseTypes.h"
+#include "Engine/Core/Math/Color32.h"
+#include "Engine/Core/Math/Vector2.h"
+#include "Engine/Core/Delegate.h"
+
+API_INJECT_CODE(cpp, "#include \"Engine/Platform/ScreenUtilities.h\"");
+
+/// <summary>
+/// Platform-dependent screen utilities.
+/// </summary>
+API_CLASS(Static, Name="ScreenUtilities", Tag="NativeInvokeUseName")
+class FLAXENGINE_API ScreenUtilitiesBase
+{
+public:
+    static struct FLAXENGINE_API ScriptingTypeInitializer TypeInitializer;
+    
+    /// <summary>
+    /// Gets the pixel color at the specified coordinates.
+    /// </summary>
+    /// <param name="pos">Screen-space coordinate to read.</param>
+    /// <returns>Pixel color at the specified coordinates.</returns>
+    API_FUNCTION() static Color32 GetColorAt(const Float2& pos)
+    {
+        return Color32::Transparent;
+    }
+
+    /// <summary>
+    /// Starts async color picking. Color will be returned through PickColorDone event when the actions ends (user selected the final color with a mouse). When action is active, GetColorAt can be used to read the current value.
+    /// </summary>
+    API_FUNCTION() static void PickColor()
+    {
+    }
+
+    /// <summary>
+    /// Called when PickColor action is finished.
+    /// </summary>
+    API_EVENT() static Delegate<Color32> PickColorDone;
+};

Source/Engine/Platform/Base/WindowBase.cpp

@@ -106,7 +106,7 @@ WindowBase::WindowBase(const CreateWindowSettings& settings)
     if (settings.StartPosition == WindowStartPosition::CenterParent
         || settings.StartPosition == WindowStartPosition::CenterScreen)
     {
-        Rectangle parentBounds = Rectangle(Float2::Zero, Platform::GetDesktopSize());
+        Rectangle parentBounds = Platform::GetMonitorBounds(Float2::Minimum);
         if (settings.Parent != nullptr && settings.StartPosition == WindowStartPosition::CenterParent)
             parentBounds = settings.Parent->GetClientBounds();
 
@@ -164,6 +164,15 @@ void WindowBase::SetIsVisible(bool isVisible)
     }
 }
 
+bool WindowBase::IsAlwaysOnTop() const
+{
+    return false;
+}
+
+void WindowBase::SetIsAlwaysOnTop(bool isAlwaysOnTop)
+{
+}
+
 String WindowBase::ToString() const
 {
     return GetTitle();
@@ -257,6 +266,13 @@ void WindowBase::OnMouseMove(const Float2& mousePosition)
     INVOKE_EVENT_PARAMS_1(OnMouseMove, (void*)&mousePosition);
 }
 
+void WindowBase::OnMouseMoveRelative(const Float2& mousePositionRelative)
+{
+    PROFILE_CPU_NAMED("GUI.OnMouseMoveRelative");
+    MouseMoveRelative(mousePositionRelative);
+    INVOKE_EVENT_PARAMS_1(OnMouseMoveRelative, (void*)&mousePositionRelative);
+}
+
 void WindowBase::OnMouseLeave()
 {
     PROFILE_CPU_NAMED("GUI.OnMouseLeave");

Source/Engine/Platform/Base/WindowBase.h

@@ -8,6 +8,7 @@
 #include "Engine/Scripting/ScriptingObject.h"
 #include "Engine/Input/KeyboardKeys.h"
 #include "Engine/Input/Enums.h"
+#include "Enums.h"
 
 class Input;
 class Engine;
@@ -17,252 +18,6 @@ class GPUSwapChain;
 class TextureData;
 class IGuiData;
 
-/// <summary>
-/// Window closing reasons.
-/// </summary>
-API_ENUM() enum class ClosingReason
-{
-    /// <summary>
-    /// The unknown.
-    /// </summary>
-    Unknown = 0,
-
-    /// <summary>
-    /// The user.
-    /// </summary>
-    User,
-
-    /// <summary>
-    /// The engine exit.
-    /// </summary>
-    EngineExit,
-
-    /// <summary>
-    /// The close event.
-    /// </summary>
-    CloseEvent,
-};
-
-/// <summary>
-/// Types of default cursors.
-/// </summary>
-API_ENUM() enum class CursorType
-{
-    /// <summary>
-    /// The default.
-    /// </summary>
-    Default = 0,
-
-    /// <summary>
-    /// The cross.
-    /// </summary>
-    Cross,
-
-    /// <summary>
-    /// The hand.
-    /// </summary>
-    Hand,
-
-    /// <summary>
-    /// The help icon
-    /// </summary>
-    Help,
-
-    /// <summary>
-    /// The I beam.
-    /// </summary>
-    IBeam,
-
-    /// <summary>
-    /// The blocking image.
-    /// </summary>
-    No,
-
-    /// <summary>
-    /// The wait.
-    /// </summary>
-    Wait,
-
-    /// <summary>
-    /// The size all sides.
-    /// </summary>
-    SizeAll,
-
-    /// <summary>
-    /// The size NE-SW.
-    /// </summary>
-    SizeNESW,
-
-    /// <summary>
-    /// The size NS.
-    /// </summary>
-    SizeNS,
-
-    /// <summary>
-    /// The size NW-SE.
-    /// </summary>
-    SizeNWSE,
-
-    /// <summary>
-    /// The size WE.
-    /// </summary>
-    SizeWE,
-
-    /// <summary>
-    /// The cursor is hidden.
-    /// </summary>
-    Hidden,
-
-    MAX
-};
-
-/// <summary>
-/// Data drag and drop effects.
-/// </summary>
-API_ENUM() enum class DragDropEffect
-{
-    /// <summary>
-    /// The none.
-    /// </summary>
-    None = 0,
-
-    /// <summary>
-    /// The copy.
-    /// </summary>
-    Copy,
-
-    /// <summary>
-    /// The move.
-    /// </summary>
-    Move,
-
-    /// <summary>
-    /// The link.
-    /// </summary>
-    Link,
-};
-
-/// <summary>
-/// Window hit test codes. Note: they are 1:1 mapping for Win32 values.
-/// </summary>
-API_ENUM() enum class WindowHitCodes
-{
-    /// <summary>
-    /// The transparent area.
-    /// </summary>
-    Transparent = -1,
-
-    /// <summary>
-    /// The no hit.
-    /// </summary>
-    NoWhere = 0,
-
-    /// <summary>
-    /// The client area.
-    /// </summary>
-    Client = 1,
-
-    /// <summary>
-    /// The caption area.
-    /// </summary>
-    Caption = 2,
-
-    /// <summary>
-    /// The system menu.
-    /// </summary>
-    SystemMenu = 3,
-
-    /// <summary>
-    /// The grow box
-    /// </summary>
-    GrowBox = 4,
-
-    /// <summary>
-    /// The menu.
-    /// </summary>
-    Menu = 5,
-
-    /// <summary>
-    /// The horizontal scroll.
-    /// </summary>
-    HScroll = 6,
-
-    /// <summary>
-    /// The vertical scroll.
-    /// </summary>
-    VScroll = 7,
-
-    /// <summary>
-    /// The minimize button.
-    /// </summary>
-    MinButton = 8,
-
-    /// <summary>
-    /// The maximize button.
-    /// </summary>
-    MaxButton = 9,
-
-    /// <summary>
-    /// The left side;
-    /// </summary>
-    Left = 10,
-
-    /// <summary>
-    /// The right side.
-    /// </summary>
-    Right = 11,
-
-    /// <summary>
-    /// The top side.
-    /// </summary>
-    Top = 12,
-
-    /// <summary>
-    /// The top left corner.
-    /// </summary>
-    TopLeft = 13,
-
-    /// <summary>
-    /// The top right corner.
-    /// </summary>
-    TopRight = 14,
-
-    /// <summary>
-    /// The bottom side.
-    /// </summary>
-    Bottom = 15,
-
-    /// <summary>
-    /// The bottom left corner.
-    /// </summary>
-    BottomLeft = 16,
-
-    /// <summary>
-    /// The bottom right corner.
-    /// </summary>
-    BottomRight = 17,
-
-    /// <summary>
-    /// The border.
-    /// </summary>
-    Border = 18,
-
-    /// <summary>
-    /// The object.
-    /// </summary>
-    Object = 19,
-
-    /// <summary>
-    /// The close button.
-    /// </summary>
-    Close = 20,
-
-    /// <summary>
-    /// The help button.
-    /// </summary>
-    Help = 21,
-};
-
 API_INJECT_CODE(cpp, "#include \"Engine/Platform/Window.h\"");
 
 /// <summary>
@@ -402,6 +157,17 @@ public:
         return _maximized;
     }
 
+    /// <summary>
+    /// Gets a value that indicates whether a window is always on top of other windows.
+    /// </summary>
+    API_PROPERTY() virtual bool IsAlwaysOnTop() const;
+
+    /// <summary>
+    /// Sets a value that indicates whether a window is always on top of other windows.
+    /// </summary>
+    /// <param name="isAlwaysOnTop">True if always on top.</param>
+    API_PROPERTY() virtual void SetIsAlwaysOnTop(bool isAlwaysOnTop);
+
     /// <summary>
     /// Gets the native window handle.
     /// </summary>
@@ -663,7 +429,7 @@ public:
 
 public:
     /// <summary>
-    /// Starts drag and drop operation
+    /// Starts a drag and drop operation.
     /// </summary>
     /// <param name="data">The data.</param>
     /// <returns>The result.</returns>
@@ -672,6 +438,18 @@ public:
         return DragDropEffect::None;
     }
 
+    /// <summary>
+    /// Starts a window drag and drop operation.
+    /// </summary>
+    /// <param name="data">The data.</param>
+    /// <param name="offset">The offset for positioning the window from cursor.</param>
+    /// <param name="dragSourceWindow">The window where dragging started.</param>
+    /// <returns>The result.</returns>
+    API_FUNCTION() virtual DragDropEffect DoDragDrop(const StringView& data, const Float2& offset, Window* dragSourceWindow)
+    {
+        return DragDropEffect::None;
+    }
+
     /// <summary>
     /// Starts the mouse tracking.
     /// </summary>
@@ -837,6 +615,12 @@ public:
     MouseDelegate MouseMove;
     void OnMouseMove(const Float2& mousePosition);
 
+    /// <summary>
+    /// Event fired when mouse moves in relative mode.
+    /// </summary>
+    MouseDelegate MouseMoveRelative;
+    void OnMouseMoveRelative(const Float2& mousePositionRelative);
+
     /// <summary>
     /// Event fired when mouse leaves window.
     /// </summary>

Source/Engine/Platform/Clipboard.h

@@ -2,7 +2,9 @@
 
 #pragma once
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_SDL && PLATFORM_LINUX
+#include "SDL/SDLClipboard.h"
+#elif PLATFORM_WINDOWS
 #include "Windows/WindowsClipboard.h"
 #elif PLATFORM_LINUX
 #include "Linux/LinuxClipboard.h"

Source/Engine/Platform/CreateWindowSettings.cs

@@ -21,7 +21,7 @@ namespace FlaxEngine
             AllowMinimize = true,
             AllowMaximize = true,
             AllowDragAndDrop = true,
-            IsRegularWindow = true,
+            Type = WindowType.Regular,
             HasSizingFrame = true,
             ShowAfterFirstPaint = true,
         };

Source/Engine/Platform/CreateWindowSettings.h

@@ -26,6 +26,32 @@ API_ENUM() enum class WindowStartPosition
     Manual,
 };
 
+/// <summary>
+/// Specifies the type of the window.
+/// </summary>
+API_ENUM() enum class WindowType
+{
+    /// <summary>
+    /// Regular window.
+    /// </summary>
+    Regular,
+
+    /// <summary>
+    /// Utility window.
+    /// </summary>
+    Utility,
+
+    /// <summary>
+    /// Tooltip window.
+    /// </summary>
+    Tooltip,
+
+    /// <summary>
+    /// Popup window.
+    /// </summary>
+    Popup,
+};
+
 /// <summary>
 /// Settings for new window.
 /// </summary>
@@ -119,9 +145,15 @@ DECLARE_SCRIPTING_TYPE_MINIMAL(CreateWindowSettings);
     API_FIELD() bool IsTopmost = false;
 
     /// <summary>
-    /// True if it's a regular window, false for tooltips, contextmenu and other utility windows.
+    /// True if it's a regular window, false for tooltips, context menu and other utility windows.
     /// </summary>
-    API_FIELD() bool IsRegularWindow = true;
+    API_FIELD() DEPRECATED("Use Type instead") bool IsRegularWindow = true;
+
+    /// <summary>
+    /// The type of window. The type affects the behaviour of the window in system level.
+    /// Note: Tooltip and Popup windows require Parent to be set.
+    /// </summary>
+    API_FIELD() WindowType Type = WindowType::Regular;
 
     /// <summary>
     /// Enable/disable window sizing frame.

Source/Engine/Platform/Defines.h

@@ -140,6 +140,9 @@ API_ENUM() enum class ArchitectureType
 #if !defined(PLATFORM_SWITCH)
 #define PLATFORM_SWITCH 0
 #endif
+#if !defined(PLATFORM_SDL)
+#define PLATFORM_SDL 0
+#endif
 
 #if PLATFORM_WINDOWS
 #include "Windows/WindowsDefines.h"

Source/Engine/Platform/GDK/GDKPlatform.cpp

@@ -30,7 +30,6 @@ inline bool operator==(const APP_LOCAL_DEVICE_ID& l, const APP_LOCAL_DEVICE_ID&
     return Platform::MemoryCompare(&l, &r, sizeof(APP_LOCAL_DEVICE_ID)) == 0;
 }
 
-const Char* GDKPlatform::ApplicationWindowClass = TEXT("FlaxWindow");
 void* GDKPlatform::Instance = nullptr;
 Delegate<> GDKPlatform::Suspended;
 Delegate<> GDKPlatform::Resumed;
@@ -317,7 +316,7 @@ void GDKPlatform::PreInit(void* hInstance)
     windowsClass.style = CS_HREDRAW | CS_VREDRAW;
     windowsClass.lpfnWndProc = WndProc;
     windowsClass.hInstance = (HINSTANCE)Instance;
-    windowsClass.lpszClassName = ApplicationWindowClass;
+    windowsClass.lpszClassName = ApplicationClassName;
     if (!RegisterClassW(&windowsClass))
     {
         Error(TEXT("Window class registration failed!"));
@@ -477,7 +476,7 @@ void GDKPlatform::Exit()
     if (PlmSignalResume)
         CloseHandle(PlmSignalResume);
 
-    UnregisterClassW(ApplicationWindowClass, nullptr);
+    UnregisterClassW(ApplicationClassName, nullptr);
 
     XGameRuntimeUninitialize();
 }

Source/Engine/Platform/GDK/GDKPlatform.h

@@ -13,11 +13,6 @@ class FLAXENGINE_API GDKPlatform : public Win32Platform
 {
 public:
 
-    /// <summary>
-    /// Win32 application windows class name.
-    /// </summary>
-    static const Char* ApplicationWindowClass;
-
     /// <summary>
     /// Handle to Win32 application instance.
     /// </summary>

Source/Engine/Platform/GDK/GDKWindow.cpp

@@ -71,7 +71,7 @@ GDKWindow::GDKWindow(const CreateWindowSettings& settings)
     // Creating the window
     _handle = CreateWindowExW(
         exStyle,
-        Platform::ApplicationWindowClass,
+        Platform::ApplicationClassName,
         settings.Title.GetText(),
         style,
         x,

Source/Engine/Platform/Linux/IncludeX11.h

@@ -21,6 +21,7 @@ namespace X11
 #include <X11/Xresource.h>
 #include <X11/extensions/Xinerama.h>
 #include <X11/Xcursor/Xcursor.h>
+#include <X11/extensions/Xfixes.h>
 }
 
 // Helper macros

Source/Engine/Platform/Linux/LinuxPlatform.cpp

@@ -96,7 +96,9 @@ X11::Cursor Cursors[(int32)CursorType::MAX];
 X11::XcursorImage* CursorsImg[(int32)CursorType::MAX];
 Dictionary<StringAnsi, X11::KeyCode> KeyNameMap;
 Array<KeyboardKeys> KeyCodeMap;
-Delegate<void*> LinuxPlatform::xEventRecieved;
+#if !PLATFORM_SDL
+Delegate<void*> LinuxPlatform::xEventReceived;
+#endif
 Window* MouseTrackingWindow = nullptr;
 
 // Message boxes configuration
@@ -654,7 +656,11 @@ static int X11_MessageBoxLoop(MessageBoxData* data)
 	return 0;
 }
 
+#if !PLATFORM_SDL
 DialogResult MessageBox::Show(Window* parent, const StringView& text, const StringView& caption, MessageBoxButtons buttons, MessageBoxIcon icon)
+#else
+DialogResult MessageBox::ShowFallback(Window* parent, const StringView& text, const StringView& caption, MessageBoxButtons buttons, MessageBoxIcon icon)
+#endif
 {
     if (CommandLine::Options.Headless.IsTrue())
         return DialogResult::None;
@@ -841,6 +847,8 @@ DialogResult MessageBox::Show(Window* parent, const StringView& text, const Stri
 	return data.resultButtonIndex == -1 ? DialogResult::None : data.buttons[data.resultButtonIndex].result;
 }
 
+#if !PLATFORM_SDL
+
 int X11ErrorHandler(X11::Display* display, X11::XErrorEvent* event)
 {
     if (event->error_code == 5)
@@ -851,6 +859,8 @@ int X11ErrorHandler(X11::Display* display, X11::XErrorEvent* event)
 	return 0;
 }
 
+#endif
+
 int32 CalculateDpi()
 {
 	int dpi = 96;
@@ -1206,17 +1216,20 @@ public:
     }
 };
 
+#if !PLATFORM_SDL
 struct Property
 {
-	unsigned char* data;
-	int format, nitems;
-	X11::Atom type;
+    unsigned char* data;
+    int format, nitems;
+    X11::Atom type;
 };
+#endif
 
 namespace Impl
 {
 	LinuxKeyboard* Keyboard;
 	LinuxMouse* Mouse;
+#if !PLATFORM_SDL
     StringAnsi ClipboardText;
 
     void ClipboardGetText(String& result, X11::Atom source, X11::Atom atom, X11::Window window)
@@ -1360,6 +1373,7 @@ namespace Impl
 	}
 }
 
+#if !PLATFORM_SDL
 class LinuxDropFilesData : public IGuiData
 {
 public:
@@ -1397,7 +1411,7 @@ public:
     }
 };
 
-DragDropEffect LinuxWindow::DoDragDrop(const StringView& data)
+DragDropEffect Window::DoDragDrop(const StringView& data)
 {
     if (CommandLine::Options.Headless.IsTrue())
         return DragDropEffect::None;
@@ -1411,13 +1425,14 @@ DragDropEffect LinuxWindow::DoDragDrop(const StringView& data)
     StringAnsi dataAnsi(data);
     LinuxDropTextData dropData;
     dropData.Text = data;
+    unsigned long mainWindow = _window;
 
     // Begin dragging
 	auto screen = X11::XDefaultScreen(xDisplay);
 	auto rootWindow = X11::XRootWindow(xDisplay, screen);
-    if (X11::XGrabPointer(xDisplay, _window, 1, Button1MotionMask | ButtonReleaseMask, GrabModeAsync, GrabModeAsync, rootWindow, cursorWrong, CurrentTime) != GrabSuccess)
+    if (X11::XGrabPointer(xDisplay, mainWindow, 1, Button1MotionMask | ButtonReleaseMask, GrabModeAsync, GrabModeAsync, rootWindow, cursorWrong, CurrentTime) != GrabSuccess)
 	    return DragDropEffect::None;
-    X11::XSetSelectionOwner(xDisplay, xAtomXdndSelection, _window, CurrentTime);
+    X11::XSetSelectionOwner(xDisplay, xAtomXdndSelection, mainWindow, CurrentTime);
 
     // Process events
     X11::XEvent event;
@@ -1525,7 +1540,7 @@ DragDropEffect LinuxWindow::DoDragDrop(const StringView& data)
                     m.window = previousWindow;
                     m.message_type = xAtomXdndLeave;
                     m.format = 32;
-                    m.data.l[0] = _window;
+                    m.data.l[0] = mainWindow;
                     m.data.l[1] = 0;
                     m.data.l[2] = 0;
                     m.data.l[3] = 0;
@@ -1554,7 +1569,7 @@ DragDropEffect LinuxWindow::DoDragDrop(const StringView& data)
                     m.window = window;
                     m.message_type = xAtomXdndEnter;
                     m.format = 32;
-                    m.data.l[0] = _window;
+                    m.data.l[0] = mainWindow;
                     m.data.l[1] = Math::Min(5, version) << 24  | (formats.Count() > 3);
                     m.data.l[2] = formats.Count() > 0 ? formats[0] : 0;
                     m.data.l[3] = formats.Count() > 1 ? formats[1] : 0;
@@ -1589,7 +1604,7 @@ DragDropEffect LinuxWindow::DoDragDrop(const StringView& data)
                     m.window = window;
                     m.message_type = xAtomXdndPosition;
                     m.format = 32;
-                    m.data.l[0] = _window;
+                    m.data.l[0] = mainWindow;
                     m.data.l[1] = 0;
                     m.data.l[2] = (x << 16) | y;
                     m.data.l[3] = CurrentTime;
@@ -1632,7 +1647,7 @@ DragDropEffect LinuxWindow::DoDragDrop(const StringView& data)
                     m.window = previousWindow;
                     m.message_type = xAtomXdndDrop;
                     m.format = 32;
-                    m.data.l[0] = _window;
+                    m.data.l[0] = mainWindow;
                     m.data.l[1] = 0;
                     m.data.l[2] = CurrentTime;
                     m.data.l[3] = 0;
@@ -1679,7 +1694,7 @@ DragDropEffect LinuxWindow::DoDragDrop(const StringView& data)
             m.window = previousWindow;
             m.message_type = xAtomXdndLeave;
             m.format = 32;
-            m.data.l[0] = _window;
+            m.data.l[0] = mainWindow;
             m.data.l[1] = 0;
             m.data.l[2] = 0;
             m.data.l[3] = 0;
@@ -1705,7 +1720,7 @@ void LinuxClipboard::SetText(const StringView& text)
 {
     if (CommandLine::Options.Headless.IsTrue())
         return;
-    auto mainWindow = (LinuxWindow*)Engine::MainWindow;
+    auto mainWindow = Engine::MainWindow;
     if (!mainWindow)
         return;
     X11::Window window = (X11::Window)mainWindow->GetNativePtr();
@@ -1728,7 +1743,7 @@ String LinuxClipboard::GetText()
     if (CommandLine::Options.Headless.IsTrue())
         return String::Empty;
     String result;
-    auto mainWindow = (LinuxWindow*)Engine::MainWindow;
+    auto mainWindow = Engine::MainWindow;
     if (!mainWindow)
         return result;
     X11::Window window = (X11::Window)mainWindow->GetNativePtr();
@@ -1757,9 +1772,11 @@ Array<String> LinuxClipboard::GetFiles()
     return Array<String>();
 }
 
+#endif
+
 void* LinuxPlatform::GetXDisplay()
 {
-	return xDisplay;
+    return xDisplay;
 }
 
 bool LinuxPlatform::CreateMutex(const Char* name)
@@ -2089,6 +2106,7 @@ bool LinuxPlatform::Init()
 
     UnixGetMacAddress(MacAddress);
 
+#if !PLATFORM_SDL
     // Get user locale string
     setlocale(LC_ALL, "");
     const char* locale = setlocale(LC_CTYPE, NULL);
@@ -2098,6 +2116,7 @@ bool LinuxPlatform::Init()
     UserLocale.Replace('_', '-');
     if (UserLocale == TEXT("C"))
         UserLocale = TEXT("en");
+#endif
 
     // Get computer name string
     gethostname(buffer, UNIX_APP_BUFF_SIZE);
@@ -2141,7 +2160,11 @@ bool LinuxPlatform::Init()
     // Skip setup if running in headless mode (X11 might not be available on servers)
     if (CommandLine::Options.Headless.IsTrue())
         return false;
-
+#if PLATFORM_SDL
+    xDisplay = X11::XOpenDisplay(nullptr);
+#endif
+    
+#if !PLATFORM_SDL
 	X11::XInitThreads();
 
 	xDisplay = X11::XOpenDisplay(nullptr);
@@ -2280,7 +2303,7 @@ bool LinuxPlatform::Init()
     Input::Mouse = Impl::Mouse = New<LinuxMouse>();
     Input::Keyboard = Impl::Keyboard = New<LinuxKeyboard>();
 	LinuxInput::Init();
-
+#endif
     return false;
 }
 
@@ -2290,6 +2313,7 @@ void LinuxPlatform::BeforeRun()
 
 void LinuxPlatform::Tick()
 {
+#if !PLATFORM_SDL
 	UnixPlatform::Tick();
 
 	LinuxInput::UpdateState();
@@ -2306,9 +2330,9 @@ void LinuxPlatform::Tick()
 			continue;
 
         // External event handling
-		xEventRecieved(&event);
+		xEventReceived(&event);
 
-		LinuxWindow* window;
+		Window* window;
 		switch (event.type)
 		{
 			case ClientMessage:
@@ -2640,6 +2664,7 @@ void LinuxPlatform::Tick()
 	}
 
 	//X11::XFlush(xDisplay);
+#endif
 }
 
 void LinuxPlatform::BeforeExit()
@@ -2648,6 +2673,7 @@ void LinuxPlatform::BeforeExit()
 
 void LinuxPlatform::Exit()
 {
+#if !PLATFORM_SDL
 	for (int32 i = 0; i < (int32)CursorType::MAX; i++)
 	{
 		if (Cursors[i])
@@ -2673,6 +2699,7 @@ void LinuxPlatform::Exit()
 		X11::XCloseDisplay(xDisplay);
 		xDisplay = nullptr;
 	}
+#endif
 }
 
 String LinuxPlatform::GetSystemName()
@@ -2694,6 +2721,7 @@ Version LinuxPlatform::GetSystemVersion()
     return Version(0, 0);
 }
 
+#if !PLATFORM_SDL
 int32 LinuxPlatform::GetDpi()
 {
     return SystemDpi;
@@ -2703,6 +2731,7 @@ String LinuxPlatform::GetUserLocaleName()
 {
     return UserLocale;
 }
+#endif
 
 String LinuxPlatform::GetComputerName()
 {
@@ -2910,10 +2939,12 @@ bool LinuxPlatform::SetWorkingDirectory(const String& path)
     return chdir(StringAsANSI<>(*path).Get()) != 0;
 }
 
+#if !PLATFORM_SDL
 Window* LinuxPlatform::CreateWindow(const CreateWindowSettings& settings)
 {
     return New<LinuxWindow>(settings);
 }
+#endif
 
 extern char **environ;
 

Source/Engine/Platform/Linux/LinuxPlatform.h

@@ -36,7 +36,7 @@ public:
     /// <summary>
     /// An event that is fired when an XEvent is received during platform tick.
     /// </summary>
-    static Delegate<void*> xEventRecieved;
+    static Delegate<void*> xEventReceived;
 
 public:
 
@@ -123,8 +123,10 @@ public:
     static void Tick();
     static void BeforeExit();
     static void Exit();
+#if !PLATFORM_SDL
     static int32 GetDpi();
     static String GetUserLocaleName();
+#endif
     static String GetComputerName();
     static bool GetHasFocus();
     static bool CanOpenUrl(const StringView& url);
@@ -139,7 +141,9 @@ public:
     static Guid GetUniqueDeviceId();
     static String GetWorkingDirectory();
     static bool SetWorkingDirectory(const String& path);
+#if !PLATFORM_SDL
     static Window* CreateWindow(const CreateWindowSettings& settings);
+#endif
     static void GetEnvironmentVariables(Dictionary<String, String, HeapAllocation>& result);
     static bool GetEnvironmentVariable(const String& name, String& value);
     static bool SetEnvironmentVariable(const String& name, const String& value);

Source/Engine/Platform/Linux/LinuxScreenUtilities.cpp

@@ -0,0 +1,94 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_LINUX
+
+#include "Engine/Platform/Types.h"
+#include "Engine/Platform/ScreenUtilities.h"
+#include "Engine/Core/Math/Vector2.h"
+#include "Engine/Core/Delegate.h"
+#include "Engine/Core/Log.h"
+#include "Engine/Profiler/ProfilerCPU.h"
+#include "Engine/Platform/Linux/LinuxPlatform.h"
+#include "Engine/Platform/Linux/IncludeX11.h"
+
+Delegate<Color32> ScreenUtilitiesBase::PickColorDone;
+
+Color32 LinuxScreenUtilities::GetColorAt(const Float2& pos)
+{
+    X11::Display* display = (X11::Display*)Platform::GetXDisplay();
+    if (display)
+    {
+        int defaultScreen = X11::XDefaultScreen(display);
+        X11::Window rootWindow = X11::XRootWindow(display, defaultScreen);
+        X11::XImage* image = X11::XGetImage(display, rootWindow, (int)pos.X, (int)pos.Y, 1, 1, AllPlanes, XYPixmap);
+        if (image)
+        {
+            X11::XColor color;
+            color.pixel = XGetPixel(image, 0, 0);
+            X11::XFree(image);
+
+            X11::XQueryColor(display, X11::XDefaultColormap(display, defaultScreen), &color);
+
+            Color32 outputColor;
+            outputColor.R = color.red / 256;
+            outputColor.G = color.green / 256;
+            outputColor.B = color.blue / 256;
+            outputColor.A = 255;
+            return outputColor;
+        }
+        else
+        {
+            // XWayland doesn't support XGetImage...
+            // TODO: Fallback to Wayland implementation here?
+            return Color32::Black;
+        }
+    }
+    else
+    {
+        // TODO: Wayland
+        ASSERT(false);
+    }
+}
+
+void OnScreenUtilsXEventCallback(void* eventPtr)
+{
+    X11::XEvent* event = (X11::XEvent*) eventPtr;
+    X11::Display* display = (X11::Display*)Platform::GetXDisplay();
+    if (event->type == ButtonPress)
+    {
+        const Float2 cursorPos = Platform::GetMousePosition();
+        const Color32 colorPicked = ScreenUtilities::GetColorAt(cursorPos);
+        X11::XUngrabPointer(display, CurrentTime);
+        ScreenUtilities::PickColorDone(colorPicked);
+        LinuxPlatform::xEventReceived.Unbind(OnScreenUtilsXEventCallback);
+    }
+}
+
+void LinuxScreenUtilities::PickColor()
+{
+    PROFILE_CPU();
+    X11::Display* display = (X11::Display*)Platform::GetXDisplay();
+    if (display)
+    {
+        X11::Window rootWindow = X11::XRootWindow(display, X11::XDefaultScreen(display));
+
+        X11::Cursor cursor = XCreateFontCursor(display, 130);
+        int grabbedPointer = X11::XGrabPointer(display, rootWindow, 0,  ButtonPressMask, GrabModeAsync, GrabModeAsync, rootWindow, cursor, CurrentTime);
+        if (grabbedPointer != GrabSuccess)
+        {
+            LOG(Error, "Failed to grab cursor for events.");
+            X11::XFreeCursor(display, cursor);
+            return;
+        }
+
+        X11::XFreeCursor(display, cursor);
+        LinuxPlatform::xEventReceived.Bind(OnScreenUtilsXEventCallback);
+    }
+    else
+    {
+        // TODO: Wayland
+        ASSERT(false);
+    }
+}
+
+#endif

Source/Engine/Platform/Linux/LinuxScreenUtilities.h

@@ -0,0 +1,25 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_LINUX
+
+#include "Engine/Platform/Base/ScreenUtilitiesBase.h"
+#include "Engine/Core/Types/BaseTypes.h"
+#include "Engine/Core/Math/Color32.h"
+#include "Engine/Core/Math/Vector2.h"
+#include "Engine/Core/Delegate.h"
+
+/// <summary>
+/// Platform-dependent screen utilities.
+/// </summary>
+class FLAXENGINE_API LinuxScreenUtilities : public ScreenUtilitiesBase
+{
+public:
+    
+    // [ScreenUtilitiesBase]
+    static Color32 GetColorAt(const Float2& pos);
+    static void PickColor();
+};
+
+#endif

Source/Engine/Platform/Linux/LinuxWindow.cpp

@@ -1,6 +1,6 @@
 // Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
 
-#if PLATFORM_LINUX
+#if PLATFORM_LINUX && !PLATFORM_SDL
 
 #include "../Window.h"
 #include "Engine/Input/Input.h"
@@ -616,7 +616,7 @@ void LinuxWindow::OnButtonPress(void* event)
 	}
 
 	// Handle double-click
-	if (buttonEvent->button == Button1)
+	if (buttonEvent->button == Button1 && !Input::Mouse->IsRelative())
 	{
 		if (
 			buttonEvent->time < (MouseLastButtonPressTime + MouseDoubleClickTime) &&

Source/Engine/Platform/Mac/MacScreenUtilities.cpp

@@ -0,0 +1,29 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if USE_EDITOR && PLATFORM_MAC
+
+#include "Engine/Platform/Types.h"
+#include "Engine/Platform/ScreenUtilities.h"
+#include "Engine/Core/Math/Vector2.h"
+#include "Engine/Core/Delegate.h"
+#include "Engine/Core/Log.h"
+
+#include <Cocoa/Cocoa.h>
+#include <AppKit/AppKit.h>
+
+Delegate<Color32> ScreenUtilitiesBase::PickColorDone;
+
+Color32 MacScreenUtilities::GetColorAt(const Float2& pos)
+{
+    // TODO: implement ScreenUtilities for macOS
+    return { 0, 0, 0, 255 };
+}
+
+void MacScreenUtilities::PickColor()
+{
+    // This is what C# calls to start the color picking sequence
+    // This should stop mouse clicks from working for one click, and that click is on the selected color
+    // There is a class called NSColorSample that might implement that for you, but maybe not.
+}
+
+#endif

Source/Engine/Platform/Mac/MacScreenUtilities.h

@@ -0,0 +1,25 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if USE_EDITOR && PLATFORM_MAC
+
+#include "Engine/Platform/Base/ScreenUtilitiesBase.h"
+#include "Engine/Core/Types/BaseTypes.h"
+#include "Engine/Core/Math/Color32.h"
+#include "Engine/Core/Math/Vector2.h"
+#include "Engine/Core/Delegate.h"
+
+/// <summary>
+/// Platform-dependent screen utilities.
+/// </summary>
+class FLAXENGINE_API MacScreenUtilities : public ScreenUtilitiesBase
+{
+public:
+
+    // [ScreenUtilitiesBase]
+    static Color32 GetColorAt(const Float2& pos);
+    static void PickColor();
+};
+
+#endif

Source/Engine/Platform/Mac/MacWindow.cpp

@@ -507,7 +507,7 @@ static void ConvertNSRect(NSScreen *screen, NSRect *r)
 	Float2 mousePos = GetMousePosition(Window, event);
     mousePos = Window->ClientToScreen(mousePos);
     MouseButton mouseButton = MouseButton::Left;
-    if ([event clickCount] == 2)
+    if ([event clickCount] == 2 && !Input::Mouse->IsRelative())
         Input::Mouse->OnMouseDoubleClick(mousePos, mouseButton, Window);
     else
 	    Input::Mouse->OnMouseDown(mousePos, mouseButton, Window);
@@ -544,7 +544,7 @@ static void ConvertNSRect(NSScreen *screen, NSRect *r)
     if (IsWindowInvalid(Window)) return;
 	Float2 mousePos = GetMousePosition(Window, event);
     MouseButton mouseButton = MouseButton::Right;
-    if ([event clickCount] == 2)
+    if ([event clickCount] == 2 && !Input::Mouse->IsRelative())
         Input::Mouse->OnMouseDoubleClick(Window->ClientToScreen(mousePos), mouseButton, Window);
     else
 	    Input::Mouse->OnMouseDown(Window->ClientToScreen(mousePos), mouseButton, Window);
@@ -582,7 +582,7 @@ static void ConvertNSRect(NSScreen *screen, NSRect *r)
     default:
         return;
     }
-    if ([event clickCount] == 2)
+    if ([event clickCount] == 2 && !Input::Mouse->IsRelative())
         Input::Mouse->OnMouseDoubleClick(Window->ClientToScreen(mousePos), mouseButton, Window);
     else
 	    Input::Mouse->OnMouseDown(Window->ClientToScreen(mousePos), mouseButton, Window);

Source/Engine/Platform/MessageBox.h

@@ -237,4 +237,9 @@ DECLARE_SCRIPTING_TYPE_NO_SPAWN(MessageBox);
     /// <param name="icon">One of the MessageBoxIcon values that specifies which icon to display in the message box.</param>
     /// <returns>The message box dialog result.</returns>
     API_FUNCTION() static DialogResult Show(Window* parent, const StringView& text, const StringView& caption, MessageBoxButtons buttons, MessageBoxIcon icon);
+
+private:
+#if PLATFORM_SDL && PLATFORM_LINUX
+    static DialogResult ShowFallback(Window* parent, const StringView& text, const StringView& caption, MessageBoxButtons buttons, MessageBoxIcon icon);
+#endif
 };

Source/Engine/Platform/Platform.Build.cs

@@ -89,6 +89,21 @@ public class Platform : EngineModule
             break;
         default: throw new InvalidPlatformException(options.Platform.Target);
         }
+
+        if (EngineConfiguration.WithSDL(options))
+        {
+            switch (options.Platform.Target)
+            {
+            case TargetPlatform.Windows:
+            case TargetPlatform.Linux:
+            case TargetPlatform.Mac:
+                options.PublicDependencies.Add("SDL");
+                options.SourcePaths.Add(Path.Combine(FolderPath, "SDL"));
+                break;
+            }
+            if (options.Platform.Target == TargetPlatform.Linux)
+                options.PublicDependencies.Add("Wayland");
+        }
         if (options.Target.IsEditor)
         {
             // Include platform settings headers

Source/Engine/Platform/Platform.h

@@ -8,7 +8,9 @@
 #include "Types.h"
 #include "Defines.h"
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_SDL
+#include "SDL/SDLPlatform.h"
+#elif PLATFORM_WINDOWS
 #include "Windows/WindowsPlatform.h"
 #elif PLATFORM_UWP
 #include "UWP/UWPPlatform.h"

Source/Engine/Platform/SDL/SDLClipboard.h

@@ -0,0 +1,26 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_SDL && PLATFORM_LINUX
+
+#include "Engine/Platform/Base/ClipboardBase.h"
+
+/// <summary>
+/// SDL implementation of the clipboard service for Linux platform.
+/// </summary>
+class FLAXENGINE_API SDLClipboard : public ClipboardBase
+{
+public:
+
+    // [ClipboardBase]
+    static void Clear();
+    static void SetText(const StringView& text);
+    static void SetRawData(const Span<byte>& data);
+    static void SetFiles(const Array<String>& files);
+    static String GetText();
+    static Array<byte> GetRawData();
+    static Array<String> GetFiles();
+};
+
+#endif

Source/Engine/Platform/SDL/SDLInput.cpp

@@ -0,0 +1,823 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_SDL
+
+#include "SDLInput.h"
+#include "SDLWindow.h"
+#include "Engine/Core/Collections/Dictionary.h"
+#include "Engine/Core/Log.h"
+#include "Engine/Input/Input.h"
+#include "Engine/Input/Mouse.h"
+#include "Engine/Input/Keyboard.h"
+#include "Engine/Input/Gamepad.h"
+#include "Engine/Engine/Engine.h"
+#include "Engine/Engine/Screen.h"
+#if USE_EDITOR
+#include "Editor/Editor.h"
+#include "Editor/Managed/ManagedEditor.h"
+#endif
+
+#include <SDL3/SDL_events.h>
+
+class SDLMouse;
+class SDLKeyboard;
+class SDLGamepad;
+
+// TODO: Turn these into customizable values
+#define TRIGGER_THRESHOLD 30
+#define LEFT_STICK_THRESHOLD 7849
+#define RIGHT_STICK_THRESHOLD 8689
+
+namespace SDLInputImpl
+{
+    SDLMouse* Mouse = nullptr;
+    SDLKeyboard* Keyboard = nullptr;
+    Dictionary<SDL_JoystickID, SDLGamepad*> Gamepads;
+}
+
+static const KeyboardKeys SDL_TO_FLAX_KEYS_MAP[] =
+{
+    KeyboardKeys::None, // SDL_SCANCODE_UNKNOWN
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::A,
+    KeyboardKeys::B,
+    KeyboardKeys::C,
+    KeyboardKeys::D,
+    KeyboardKeys::E,
+    KeyboardKeys::F,
+    KeyboardKeys::G,
+    KeyboardKeys::H,
+    KeyboardKeys::I,
+    KeyboardKeys::J,
+    KeyboardKeys::K,
+    KeyboardKeys::L,
+    KeyboardKeys::M,
+    KeyboardKeys::N,
+    KeyboardKeys::O,
+    KeyboardKeys::P,
+    KeyboardKeys::Q,
+    KeyboardKeys::R,
+    KeyboardKeys::S,
+    KeyboardKeys::T,
+    KeyboardKeys::U,
+    KeyboardKeys::V,
+    KeyboardKeys::W,
+    KeyboardKeys::X,
+    KeyboardKeys::Y,
+    KeyboardKeys::Z, // 29
+    KeyboardKeys::Alpha1,
+    KeyboardKeys::Alpha2,
+    KeyboardKeys::Alpha3,
+    KeyboardKeys::Alpha4,
+    KeyboardKeys::Alpha5,
+    KeyboardKeys::Alpha6,
+    KeyboardKeys::Alpha7,
+    KeyboardKeys::Alpha8,
+    KeyboardKeys::Alpha9,
+    KeyboardKeys::Alpha0, // 39
+    KeyboardKeys::Return,
+    KeyboardKeys::Escape,
+    KeyboardKeys::Backspace,
+    KeyboardKeys::Tab,
+    KeyboardKeys::Spacebar,
+    KeyboardKeys::Minus,
+    KeyboardKeys::None, //KeyboardKeys::Equals, // ?
+    KeyboardKeys::LeftBracket,
+    KeyboardKeys::RightBracket,
+    KeyboardKeys::Backslash, // SDL_SCANCODE_BACKSLASH ?
+    KeyboardKeys::Oem102, // SDL_SCANCODE_NONUSHASH ?
+    KeyboardKeys::Colon, // SDL_SCANCODE_SEMICOLON ?
+    KeyboardKeys::Quote, // SDL_SCANCODE_APOSTROPHE
+    KeyboardKeys::BackQuote, // SDL_SCANCODE_GRAVE
+    KeyboardKeys::Comma,
+    KeyboardKeys::Period,
+    KeyboardKeys::Slash,
+    KeyboardKeys::Capital,
+    KeyboardKeys::F1,
+    KeyboardKeys::F2,
+    KeyboardKeys::F3,
+    KeyboardKeys::F4,
+    KeyboardKeys::F5,
+    KeyboardKeys::F6,
+    KeyboardKeys::F7,
+    KeyboardKeys::F8,
+    KeyboardKeys::F9,
+    KeyboardKeys::F10,
+    KeyboardKeys::F11,
+    KeyboardKeys::F12,
+    KeyboardKeys::PrintScreen,
+    KeyboardKeys::Scroll,
+    KeyboardKeys::Pause,
+    KeyboardKeys::Insert,
+    KeyboardKeys::Home,
+    KeyboardKeys::PageUp,
+    KeyboardKeys::Delete,
+    KeyboardKeys::End,
+    KeyboardKeys::PageDown,
+    KeyboardKeys::ArrowRight,
+    KeyboardKeys::ArrowLeft,
+    KeyboardKeys::ArrowDown,
+    KeyboardKeys::ArrowUp,
+    KeyboardKeys::Numlock,
+    KeyboardKeys::NumpadDivide,
+    KeyboardKeys::NumpadMultiply,
+    KeyboardKeys::NumpadSubtract,
+    KeyboardKeys::NumpadAdd,
+    KeyboardKeys::Return, // SDL_SCANCODE_KP_ENTER ?
+    KeyboardKeys::Numpad1,
+    KeyboardKeys::Numpad2,
+    KeyboardKeys::Numpad3,
+    KeyboardKeys::Numpad4,
+    KeyboardKeys::Numpad5,
+    KeyboardKeys::Numpad6,
+    KeyboardKeys::Numpad7,
+    KeyboardKeys::Numpad8,
+    KeyboardKeys::Numpad9,
+    KeyboardKeys::Numpad0, //98
+    KeyboardKeys::NumpadDecimal, // SDL_SCANCODE_KP_PERIOD
+    KeyboardKeys::Backslash, // SDL_SCANCODE_NONUSBACKSLASH ?
+    KeyboardKeys::Applications,
+    KeyboardKeys::Sleep, // SDL_SCANCODE_POWER ?
+    KeyboardKeys::None, // SDL_SCANCODE_KP_EQUALS ?
+    KeyboardKeys::F13,
+    KeyboardKeys::F14,
+    KeyboardKeys::F15,
+    KeyboardKeys::F16,
+    KeyboardKeys::F17,
+    KeyboardKeys::F18,
+    KeyboardKeys::F19,
+    KeyboardKeys::F20,
+    KeyboardKeys::F21,
+    KeyboardKeys::F22,
+    KeyboardKeys::F23,
+    KeyboardKeys::F24,
+    KeyboardKeys::Execute,
+    KeyboardKeys::Help,
+    KeyboardKeys::LeftMenu, // SDL_SCANCODE_MENU ?
+    KeyboardKeys::Select,
+    KeyboardKeys::None, // SDL_SCANCODE_STOP
+    KeyboardKeys::None, // SDL_SCANCODE_AGAIN
+    KeyboardKeys::None, // SDL_SCANCODE_UNDO
+    KeyboardKeys::None, // SDL_SCANCODE_CUT
+    KeyboardKeys::None, // SDL_SCANCODE_COPY
+    KeyboardKeys::None, // SDL_SCANCODE_PASTE
+    KeyboardKeys::None, // SDL_SCANCODE_FIND
+    KeyboardKeys::None, // SDL_SCANCODE_MUTE
+    KeyboardKeys::None, // SDL_SCANCODE_VOLUMEUP
+    KeyboardKeys::None, // SDL_SCANCODE_VOLUMEDOWN
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::NumpadSeparator, // SDL_SCANCODE_KP_COMMA ?
+    KeyboardKeys::None, // SDL_SCANCODE_KP_EQUALSAS400
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL1
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL2
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL3
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL4
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL5
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL6
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL7
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL8
+    KeyboardKeys::None, // SDL_SCANCODE_INTERNATIONAL9
+    KeyboardKeys::None, // SDL_SCANCODE_LANG1
+    KeyboardKeys::None, // SDL_SCANCODE_LANG2
+    KeyboardKeys::None, // SDL_SCANCODE_LANG3
+    KeyboardKeys::None, // SDL_SCANCODE_LANG4
+    KeyboardKeys::None, // SDL_SCANCODE_LANG5
+    KeyboardKeys::None, // SDL_SCANCODE_LANG6
+    KeyboardKeys::None, // SDL_SCANCODE_LANG7
+    KeyboardKeys::None, // SDL_SCANCODE_LANG8
+    KeyboardKeys::None, // SDL_SCANCODE_LANG9
+    KeyboardKeys::None, // SDL_SCANCODE_ALTERASE
+    KeyboardKeys::None, // SDL_SCANCODE_SYSREQ
+    KeyboardKeys::None, // SDL_SCANCODE_CANCEL
+    KeyboardKeys::Clear, // SDL_SCANCODE_CLEAR
+    KeyboardKeys::None, // SDL_SCANCODE_PRIOR
+    KeyboardKeys::None, // SDL_SCANCODE_RETURN2
+    KeyboardKeys::None, // SDL_SCANCODE_SEPARATOR
+    KeyboardKeys::None, // SDL_SCANCODE_OUT
+    KeyboardKeys::None, // SDL_SCANCODE_OPER
+    KeyboardKeys::None, // SDL_SCANCODE_CLEARAGAIN
+    KeyboardKeys::None, // SDL_SCANCODE_CRSEL
+    KeyboardKeys::None, // SDL_SCANCODE_EXSEL
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_00
+    KeyboardKeys::None, // SDL_SCANCODE_KP_000
+    KeyboardKeys::None, // SDL_SCANCODE_THOUSANDSSEPARATOR
+    KeyboardKeys::None, // SDL_SCANCODE_DECIMALSEPARATOR
+    KeyboardKeys::None, // SDL_SCANCODE_CURRENCYUNIT
+    KeyboardKeys::None, // SDL_SCANCODE_CURRENCYSUBUNIT
+    KeyboardKeys::None, // SDL_SCANCODE_KP_LEFTPAREN = 182,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_RIGHTPAREN = 183,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_LEFTBRACE = 184,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_RIGHTBRACE = 185,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_TAB = 186,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_BACKSPACE = 187,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_A = 188,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_B = 189,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_C = 190,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_D = 191,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_E = 192,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_F = 193,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_XOR = 194,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_POWER = 195,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_PERCENT = 196,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_LESS = 197,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_GREATER = 198,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_AMPERSAND = 199,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_DBLAMPERSAND = 200,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_VERTICALBAR = 201,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_DBLVERTICALBAR = 202,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_COLON = 203,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_HASH = 204,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_SPACE = 205,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_AT = 206,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_EXCLAM = 207,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_MEMSTORE = 208,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_MEMRECALL = 209,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_MEMCLEAR = 210,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_MEMADD = 211,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_MEMSUBTRACT = 212,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_MEMMULTIPLY = 213,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_MEMDIVIDE = 214,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_PLUSMINUS = 215,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_CLEAR = 216,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_CLEARENTRY = 217,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_BINARY = 218,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_OCTAL = 219,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_DECIMAL = 220,
+    KeyboardKeys::None, // SDL_SCANCODE_KP_HEXADECIMAL = 221,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::Control, // SDL_SCANCODE_LCTRL = 224,
+    KeyboardKeys::Shift, // SDL_SCANCODE_LSHIFT = 225,
+    KeyboardKeys::Alt, // SDL_SCANCODE_LALT = 226,
+    KeyboardKeys::LeftMenu, // SDL_SCANCODE_LGUI = 227,
+    KeyboardKeys::Control, // SDL_SCANCODE_RCTRL = 228,
+    KeyboardKeys::Shift, // SDL_SCANCODE_RSHIFT = 229,
+    KeyboardKeys::Alt, // SDL_SCANCODE_RALT = 230,
+    KeyboardKeys::RightMenu, // SDL_SCANCODE_RGUI = 231,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::None,
+    KeyboardKeys::Modechange, // SDL_SCANCODE_MODE
+    KeyboardKeys::Sleep, // SDL_SCANCODE_SLEEP
+    KeyboardKeys::None, // SDL_SCANCODE_WAKE
+    KeyboardKeys::None, // SDL_SCANCODE_CHANNEL_INCREMENT = 260,
+    KeyboardKeys::None, // SDL_SCANCODE_CHANNEL_DECREMENT = 261,
+    KeyboardKeys::None, // SDL_SCANCODE_MEDIA_PLAY = 262,
+    KeyboardKeys::None, // SDL_SCANCODE_MEDIA_PAUSE = 263,
+    KeyboardKeys::None, // SDL_SCANCODE_MEDIA_RECORD = 264,
+    KeyboardKeys::None, // SDL_SCANCODE_MEDIA_FAST_FORWARD = 265,
+    KeyboardKeys::None, // SDL_SCANCODE_MEDIA_REWIND = 266,
+    KeyboardKeys::MediaNextTrack, // SDL_SCANCODE_MEDIA_NEXT_TRACK = 267,
+    KeyboardKeys::MediaPrevTrack, // SDL_SCANCODE_MEDIA_PREVIOUS_TRACK = 268,
+    KeyboardKeys::MediaStop, // SDL_SCANCODE_MEDIA_STOP = 269,
+    KeyboardKeys::None, // SDL_SCANCODE_MEDIA_EJECT = 270,
+    KeyboardKeys::MediaPlayPause, // SDL_SCANCODE_MEDIA_PLAY_PAUSE = 271,
+    KeyboardKeys::None, // SDL_SCANCODE_MEDIA_SELECT = 272,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_NEW = 273,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_OPEN = 274,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_CLOSE = 275,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_EXIT = 276,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_SAVE = 277,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_PRINT = 278,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_PROPERTIES = 279,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_SEARCH = 280,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_HOME = 281,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_BACK = 282,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_FORWARD = 283,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_STOP = 284,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_REFRESH = 285,
+    KeyboardKeys::None, // SDL_SCANCODE_AC_BOOKMARKS = 286,
+    KeyboardKeys::None, // SDL_SCANCODE_SOFTLEFT = 287,
+    KeyboardKeys::None, // SDL_SCANCODE_SOFTRIGHT = 288,
+    KeyboardKeys::None, // SDL_SCANCODE_CALL = 289,
+    KeyboardKeys::None, // SDL_SCANCODE_ENDCALL = 290
+};
+
+/// <summary>
+/// Implementation of the keyboard device for Windows platform.
+/// </summary>
+/// <seealso cref="Keyboard" />
+class SDLKeyboard : public Keyboard
+{
+public:
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SDLKeyboard"/> class.
+    /// </summary>
+    explicit SDLKeyboard()
+        : Keyboard()
+    {
+    }
+
+public:
+
+};
+
+/// <summary>
+/// Implementation of the mouse device for SDL platform.
+/// </summary>
+/// <seealso cref="Mouse" />
+class SDLMouse : public Mouse
+{
+private:
+    Float2 oldPosition = Float2::Zero;
+    Window* relativeModeWindow = nullptr;
+    const SDL_Rect* oldScreenRect = nullptr;
+public:
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SDLMouse"/> class.
+    /// </summary>
+    explicit SDLMouse()
+        : Mouse()
+    {
+    }
+
+public:
+
+    /// <summary>
+    /// Returns the previous known position of the mouse before entering relative mode.
+    /// </summary>
+    Float2 GetOldMousePosition() const
+    {
+        ASSERT(relativeModeWindow != nullptr);
+        return relativeModeWindow->ClientToScreen(oldPosition);
+    }
+
+    // [Mouse]
+    void SetMousePosition(const Float2& screenPosition) final override
+    {
+#if USE_EDITOR
+        auto window = Editor::Managed->GetGameWindow();
+        if (window == nullptr)
+            window = Engine::MainWindow;
+#else
+        auto window = Engine::MainWindow;
+#endif
+        Float2 position = window->ScreenToClient(screenPosition);
+        SDL_WarpMouseInWindow(static_cast<SDLWindow*>(window)->_window, position.X, position.Y);
+
+        OnMouseMoved(position);
+    }
+
+    void SetRelativeMode(bool relativeMode, Window* window) final override
+    {
+        if (relativeMode == _relativeMode)
+            return;
+
+        auto windowHandle = static_cast<SDLWindow*>(window)->_window;
+        if (relativeMode)
+        {
+            relativeModeWindow = window;
+            SDL_GetMouseState(&oldPosition.X, &oldPosition.Y);
+            if (!SDL_CursorVisible())
+            {
+                // Trap the cursor in current location
+                SDL_Rect clipRect = { (int)oldPosition.X, (int)oldPosition.Y, 1, 1 };
+                oldScreenRect = SDL_GetWindowMouseRect(windowHandle);
+                SDL_SetWindowMouseRect(windowHandle, &clipRect);
+            }
+        }
+        else
+        {
+            if (relativeModeWindow != window)
+            {
+                // FIXME: When floating game window is focused and editor viewport activated, the relative mode gets stuck
+                return;
+            }
+            SDL_SetWindowMouseRect(windowHandle, nullptr);//oldScreenRect);
+            SDL_WarpMouseInWindow(windowHandle, oldPosition.X, oldPosition.Y);
+            oldScreenRect = nullptr;
+            relativeModeWindow = nullptr;
+        }
+
+        Mouse::SetRelativeMode(relativeMode, window);
+        if (!SDL_SetWindowRelativeMouseMode(windowHandle, relativeMode))
+            LOG(Error, "Failed to set mouse relative mode: {0}", String(SDL_GetError()));
+    }
+};
+
+/// <summary>
+/// Implementation of the gamepad device for SDL platform.
+/// </summary>
+/// <seealso cref="Gamepad" />
+class SDLGamepad : public Gamepad
+{
+private:
+
+    SDL_Gamepad* _gamepad;
+    SDL_JoystickID _instanceId;
+
+public:
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SDLGamepad"/> class.
+    /// </summary>
+    /// <param name="userIndex">The joystick.</param>
+    explicit SDLGamepad(SDL_JoystickID instanceId);
+
+    /// <summary>
+    /// Finalizes an instance of the <see cref="SDLGamepad"/> class.
+    /// </summary>
+    ~SDLGamepad();
+
+private:
+
+    SDLGamepad(SDL_Gamepad* gamepad, SDL_JoystickID instanceId);
+
+public:
+
+    static SDLGamepad* GetGamepadById(SDL_JoystickID id)
+    {
+        SDLGamepad* gamepad = nullptr;
+        SDLInputImpl::Gamepads.TryGet(id, gamepad);
+        return gamepad;
+    }
+
+    SDL_JoystickID GetJoystickInstanceId() const
+    {
+        return _instanceId;
+    }
+
+    void OnAxisMotion(SDL_GamepadAxis axis, int16 value);
+
+    void OnButtonState(SDL_GamepadButton axis, bool pressed);
+
+    // [Gamepad]
+    void SetVibration(const GamepadVibrationState& state) override;
+
+protected:
+
+    // [Gamepad]
+    bool UpdateState() override;
+};
+
+void SDLInput::Init()
+{
+    Input::Mouse = SDLInputImpl::Mouse = New<SDLMouse>();
+    Input::Keyboard = SDLInputImpl::Keyboard = New<SDLKeyboard>();
+}
+
+void SDLInput::Update()
+{
+}
+
+float NormalizeAxisValue(const int16 axisVal)
+{
+    // Normalize [-32768..32767] -> [-1..1]
+    const float norm = axisVal <= 0 ? 32768.0f : 32767.0f;
+    return float(axisVal) / norm;
+}
+
+bool SDLInput::HandleEvent(SDLWindow* window, SDL_Event& event)
+{
+    switch (event.type)
+    {
+    case SDL_EVENT_MOUSE_MOTION:
+    {
+        if (Input::Mouse->IsRelative())
+        {
+            const Float2 mouseDelta(event.motion.xrel, event.motion.yrel);
+            Input::Mouse->OnMouseMoveRelative(mouseDelta, window);
+        }
+        else
+        {
+            const Float2 mousePos = window->ClientToScreen({ event.motion.x, event.motion.y });
+            Input::Mouse->OnMouseMove(mousePos, window);
+        }
+        return true;
+    }
+    case SDL_EVENT_WINDOW_MOUSE_LEAVE:
+    {
+        Input::Mouse->OnMouseLeave(window);
+        return true;
+    }
+    case SDL_EVENT_MOUSE_BUTTON_DOWN:
+    case SDL_EVENT_MOUSE_BUTTON_UP:
+    {
+        Float2 mousePos = window->ClientToScreen({ event.button.x, event.button.y });
+        MouseButton button = MouseButton::None;
+        if (event.button.button == SDL_BUTTON_LEFT)
+            button = MouseButton::Left;
+        else if (event.button.button == SDL_BUTTON_RIGHT)
+            button = MouseButton::Right;
+        else if (event.button.button == SDL_BUTTON_MIDDLE)
+            button = MouseButton::Middle;
+        else if (event.button.button == SDL_BUTTON_X1)
+            button = MouseButton::Extended1;
+        else if (event.button.button == SDL_BUTTON_X2)
+            button = MouseButton::Extended2;
+
+        if (Input::Mouse->IsRelative())
+        {
+            // Use the previous visible mouse position here, the event or global
+            // mouse position would cause input to trigger in other editor windows.
+            mousePos = SDLInputImpl::Mouse->GetOldMousePosition();
+        }
+
+        if (!event.button.down)
+            Input::Mouse->OnMouseUp(mousePos, button, window);
+        // Prevent sending multiple mouse down event when double-clicking UI elements
+        else if (event.button.clicks % 2 == 1)
+            Input::Mouse->OnMouseDown(mousePos, button, window);
+        else
+            Input::Mouse->OnMouseDoubleClick(mousePos, button, window);
+
+        return true;
+    }
+    case SDL_EVENT_MOUSE_WHEEL:
+    {
+        Float2 mousePos = window->ClientToScreen({ event.wheel.mouse_x, event.wheel.mouse_y });
+        const float delta = event.wheel.y;
+
+        if (Input::Mouse->IsRelative())
+        {
+            // Use the previous visible mouse position here, the event or global
+            // mouse position would cause input to trigger in other editor windows.
+            mousePos = SDLInputImpl::Mouse->GetOldMousePosition();
+        }
+
+        Input::Mouse->OnMouseWheel(mousePos, delta, window);
+        return true;
+    }
+    case SDL_EVENT_KEY_DOWN:
+    case SDL_EVENT_KEY_UP:
+    {
+        // TODO: scancode support
+        KeyboardKeys key = SDL_TO_FLAX_KEYS_MAP[event.key.scancode];
+        //event.key.mod
+        if (!event.key.down)
+            Input::Keyboard->OnKeyUp(key, window);
+        else
+            Input::Keyboard->OnKeyDown(key, window);
+        return true;
+    }
+    case SDL_EVENT_TEXT_EDITING:
+    {
+        auto edit = event.edit;
+        return true;
+    }
+    case SDL_EVENT_TEXT_INPUT:
+    {
+        String text(event.text.text);
+        for (int i = 0; i < text.Length(); i++)
+        {
+            Input::Keyboard->OnCharInput(text[i], window);
+        }
+        return true;
+    }
+    case SDL_EVENT_GAMEPAD_AXIS_MOTION:
+    {
+        SDLGamepad* gamepad = SDLGamepad::GetGamepadById(event.gaxis.which);
+        SDL_GamepadAxis axis = (SDL_GamepadAxis)event.gaxis.axis;
+        gamepad->OnAxisMotion(axis, event.gaxis.value);
+
+        LOG(Info, "SDL_EVENT_GAMEPAD_AXIS_MOTION");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_BUTTON_DOWN:
+    case SDL_EVENT_GAMEPAD_BUTTON_UP:
+    {
+        SDLGamepad* gamepad = SDLGamepad::GetGamepadById(event.gbutton.which);
+        SDL_GamepadButton button = (SDL_GamepadButton)event.gbutton.button;
+        gamepad->OnButtonState(button, event.gbutton.down);
+
+        LOG(Info, "SDL_EVENT_GAMEPAD_BUTTON_");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_ADDED:
+    {
+        Input::Gamepads.Add(New<SDLGamepad>(event.gdevice.which));
+        Input::OnGamepadsChanged();
+
+        LOG(Info, "SDL_EVENT_GAMEPAD_ADDED");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_REMOVED:
+    {
+        for (int i = 0; i < Input::Gamepads.Count(); i++)
+        {
+            SDLGamepad* gamepad = static_cast<SDLGamepad*>(Input::Gamepads[i]);
+            if (gamepad->GetJoystickInstanceId() == event.gdevice.which)
+            {
+                Input::Gamepads[i]->DeleteObject();
+                Input::Gamepads.RemoveAtKeepOrder(i);
+                Input::OnGamepadsChanged();
+                break;
+            }
+        }
+        
+        LOG(Info, "SDL_EVENT_GAMEPAD_REMOVED");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_REMAPPED:
+    {
+        auto ev = event.gdevice;
+        LOG(Info, "SDL_EVENT_GAMEPAD_REMAPPED");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_TOUCHPAD_DOWN:
+    {
+        LOG(Info, "SDL_EVENT_GAMEPAD_TOUCHPAD_DOWN");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_TOUCHPAD_MOTION:
+    {
+        LOG(Info, "SDL_EVENT_GAMEPAD_TOUCHPAD_MOTION");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_TOUCHPAD_UP:
+    {
+        LOG(Info, "SDL_EVENT_GAMEPAD_TOUCHPAD_UP");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_SENSOR_UPDATE:
+    {
+        LOG(Info, "SDL_EVENT_GAMEPAD_SENSOR_UPDATE");
+        break;
+    }
+    case SDL_EVENT_GAMEPAD_STEAM_HANDLE_UPDATED:
+    {
+        auto ev = event.gdevice;
+        LOG(Info, "SDL_EVENT_GAMEPAD_STEAM_HANDLE_UPDATED");
+        break;
+    }
+    }
+    return false;
+}
+
+Guid GetGamepadGuid(SDL_JoystickID instanceId)
+{
+    SDL_GUID joystickGuid = SDL_GetGamepadGUIDForID(instanceId);
+    Guid guid;
+    Platform::MemoryCopy(&guid.Raw, joystickGuid.data, sizeof(uint8) * 16);
+    return guid;
+}
+
+SDLGamepad::SDLGamepad(SDL_JoystickID instanceId)
+    : SDLGamepad(SDL_OpenGamepad(instanceId), instanceId)
+{
+}
+
+SDLGamepad::SDLGamepad(SDL_Gamepad* gamepad, SDL_JoystickID instanceId)
+    : Gamepad(GetGamepadGuid(instanceId), String(SDL_GetGamepadName(gamepad)))
+    , _gamepad(gamepad)
+    , _instanceId(instanceId)
+{
+    SDLInputImpl::Gamepads.Add(_instanceId, this);
+}
+
+SDLGamepad::~SDLGamepad()
+{
+    SDL_CloseGamepad(_gamepad);
+    SDLInputImpl::Gamepads.Remove(_instanceId);
+}
+
+void SDLGamepad::SetVibration(const GamepadVibrationState& state)
+{
+    Gamepad::SetVibration(state);
+}
+
+bool SDLGamepad::UpdateState()
+{
+    return false;
+}
+
+void SDLGamepad::OnAxisMotion(SDL_GamepadAxis sdlAxis, int16 value)
+{
+    GamepadAxis axis;
+    int16 deadzone = 1; // SDL reports -1 for centered axis?
+    float valueNormalized = NormalizeAxisValue(value);
+    switch (sdlAxis)
+    {
+    case SDL_GAMEPAD_AXIS_LEFTX:
+        axis = GamepadAxis::LeftStickX;
+        deadzone = LEFT_STICK_THRESHOLD;
+        _state.Buttons[(int32)GamepadButton::LeftStickLeft] = value > LEFT_STICK_THRESHOLD;
+        _state.Buttons[(int32)GamepadButton::LeftStickRight] = value < -LEFT_STICK_THRESHOLD;
+        break;
+    case SDL_GAMEPAD_AXIS_LEFTY:
+        axis = GamepadAxis::LeftStickY;
+        deadzone = LEFT_STICK_THRESHOLD;
+        _state.Buttons[(int32)GamepadButton::LeftStickUp] = value < -LEFT_STICK_THRESHOLD;
+        _state.Buttons[(int32)GamepadButton::LeftStickDown] = value > LEFT_STICK_THRESHOLD;
+        valueNormalized = -valueNormalized;
+        break;
+    case SDL_GAMEPAD_AXIS_RIGHTX:
+        deadzone = RIGHT_STICK_THRESHOLD;
+        axis = GamepadAxis::RightStickX;
+        _state.Buttons[(int32)GamepadButton::RightStickLeft] = value > RIGHT_STICK_THRESHOLD;
+        _state.Buttons[(int32)GamepadButton::RightStickRight] = value < -RIGHT_STICK_THRESHOLD;
+        break;
+    case SDL_GAMEPAD_AXIS_RIGHTY:
+        deadzone = RIGHT_STICK_THRESHOLD;
+        axis = GamepadAxis::RightStickY;
+        _state.Buttons[(int32)GamepadButton::RightStickUp] = value < -RIGHT_STICK_THRESHOLD;
+        _state.Buttons[(int32)GamepadButton::RightStickDown] = value > RIGHT_STICK_THRESHOLD;
+        valueNormalized = -valueNormalized;
+        break;
+    case SDL_GAMEPAD_AXIS_LEFT_TRIGGER:
+        deadzone = TRIGGER_THRESHOLD;
+        axis = GamepadAxis::LeftTrigger;
+        _state.Buttons[(int32)GamepadButton::LeftTrigger] = value > TRIGGER_THRESHOLD;
+        break;
+    case SDL_GAMEPAD_AXIS_RIGHT_TRIGGER:
+        deadzone = TRIGGER_THRESHOLD;
+        axis = GamepadAxis::RightTrigger;
+        _state.Buttons[(int32)GamepadButton::RightTrigger] = value > TRIGGER_THRESHOLD;
+        break;
+    default:
+        return;
+    }
+    if (value <= deadzone && value >= -deadzone)
+        valueNormalized = 0.0f;
+    _state.Axis[(int32)axis] = valueNormalized;
+}
+
+void SDLGamepad::OnButtonState(SDL_GamepadButton sdlButton, bool pressed)
+{
+    switch (sdlButton)
+    {
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_SOUTH:
+        _state.Buttons[(int32)GamepadButton::A] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_EAST:
+        _state.Buttons[(int32)GamepadButton::B] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_WEST:
+        _state.Buttons[(int32)GamepadButton::X] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_NORTH:
+        _state.Buttons[(int32)GamepadButton::Y] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_LEFT_SHOULDER:
+        _state.Buttons[(int32)GamepadButton::LeftShoulder] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_RIGHT_SHOULDER:
+        _state.Buttons[(int32)GamepadButton::RightShoulder] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_BACK:
+        _state.Buttons[(int32)GamepadButton::Back] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_START:
+        _state.Buttons[(int32)GamepadButton::Start] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_LEFT_STICK:
+        _state.Buttons[(int32)GamepadButton::LeftThumb] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_RIGHT_STICK:
+        _state.Buttons[(int32)GamepadButton::RightThumb] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_DPAD_UP:
+        _state.Buttons[(int32)GamepadButton::DPadUp] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_DPAD_DOWN:
+        _state.Buttons[(int32)GamepadButton::DPadDown] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_DPAD_LEFT:
+        _state.Buttons[(int32)GamepadButton::DPadLeft] = pressed;
+        break;
+    case SDL_GamepadButton::SDL_GAMEPAD_BUTTON_DPAD_RIGHT:
+        _state.Buttons[(int32)GamepadButton::DPadRight] = pressed;
+        break;
+    }
+}
+
+#endif

Source/Engine/Platform/SDL/SDLInput.h

@@ -0,0 +1,22 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_SDL
+
+class SDLWindow;
+union SDL_Event;
+
+/// <summary>
+/// SDL specific implementation of the input system parts.
+/// </summary>
+class SDLInput
+{
+public:
+
+    static void Init();
+    static void Update();
+    static bool HandleEvent(SDLWindow* window, SDL_Event& event);
+};
+
+#endif

Source/Engine/Platform/SDL/SDLPlatform.Mac.cpp

@@ -0,0 +1,12 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_SDL && PLATFORM_MAC
+
+static_assert(false, "TODO");
+
+void SDLPlatform::SetHighDpiAwarenessEnabled(bool enable)
+{
+    // TODO: This is now called before Platform::Init, ensure the scaling is changed accordingly during Platform::Init (see ApplePlatform::SetHighDpiAwarenessEnabled)
+}
+
+#endif

Source/Engine/Platform/SDL/SDLPlatform.Windows.cpp

@@ -0,0 +1,292 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_SDL && PLATFORM_WINDOWS
+
+#define BORDERLESS_MAXIMIZE_WORKAROUND 2
+
+#include "SDLPlatform.h"
+#include "SDLInput.h"
+
+#include "Engine/Core/Collections/Array.h"
+#include "Engine/Platform/WindowsManager.h"
+#include "Engine/Platform/Win32/IncludeWindowsHeaders.h"
+#include "Engine/Input/Mouse.h"
+#include "Engine/Core/Log.h"
+#include "Engine/Engine/Engine.h"
+
+#include <SDL3/SDL_hints.h>
+#include <SDL3/SDL_init.h>
+#include <SDL3/SDL_system.h>
+#include <SDL3/SDL_timer.h>
+
+#if USE_EDITOR
+#include <oleidl.h>
+#endif
+
+#define STYLE_RESIZABLE (WS_THICKFRAME | WS_MAXIMIZEBOX)
+
+namespace WinImpl
+{
+    Window* DraggedWindow;
+    Float2 DraggedWindowStartPosition = Float2::Zero;
+    Float2 DraggedWindowMousePosition = Float2::Zero;
+}
+
+// The events for releasing the mouse during window dragging are missing, handle the mouse release event here
+bool SDLCALL SDLPlatform::EventMessageHook(void* userdata, MSG* msg)
+{
+#define GET_WINDOW_WITH_HWND(window, hwnd) \
+    do { \
+        (window) = nullptr; \
+        WindowsManager::WindowsLocker.Lock(); \
+        for (int32 i = 0; i < WindowsManager::Windows.Count(); i++) \
+        { \
+            if (WindowsManager::Windows[i]->GetNativePtr() == (hwnd)) \
+            { \
+                (window) = WindowsManager::Windows[i]; \
+                break; \
+            } \
+        } \
+        WindowsManager::WindowsLocker.Unlock(); \
+        ASSERT((window) != nullptr); \
+    } while (false)
+
+    if (msg->message == WM_NCLBUTTONDOWN)
+    {
+        Window* window;
+        GET_WINDOW_WITH_HWND(window, msg->hwnd);
+        WinImpl::DraggedWindow = window;
+
+        WinImpl::DraggedWindowStartPosition = WinImpl::DraggedWindow->GetClientPosition();
+        Float2 mousePos(static_cast<float>(static_cast<LONG>(WINDOWS_GET_X_LPARAM(msg->lParam))), static_cast<float>(static_cast<LONG>(WINDOWS_GET_Y_LPARAM(msg->lParam))));
+        WinImpl::DraggedWindowMousePosition = mousePos;
+        WinImpl::DraggedWindowMousePosition -= WinImpl::DraggedWindowStartPosition;
+
+        bool result = false;
+        WindowHitCodes hit = static_cast<WindowHitCodes>(msg->wParam);
+        window->OnHitTest(mousePos, hit, result);
+        //if (result && hit != WindowHitCodes::Caption)
+        //    return false;
+
+        if (hit == WindowHitCodes::Caption)
+        {
+            SDL_Event event{ 0 };
+            event.button.type = SDL_EVENT_MOUSE_BUTTON_DOWN;
+            event.button.down = true;
+            event.button.timestamp = SDL_GetTicksNS();
+            event.button.windowID = SDL_GetWindowID(window->GetSDLWindow());
+            event.button.button = SDL_BUTTON_LEFT;
+            event.button.clicks = 1;
+            event.button.x = WinImpl::DraggedWindowMousePosition.X;
+            event.button.y = WinImpl::DraggedWindowMousePosition.Y;
+
+            SDL_PushEvent(&event);
+        }
+    }
+    /*else if (msg->message == WM_NCLBUTTONUP || msg->message == WM_CAPTURECHANGED)
+    {
+        windowDragging = false;
+        Window* window;
+        GET_WINDOW_WITH_HWND(window, msg->hwnd);
+
+        SDL_Event event{ 0 };
+        event.button.type = SDL_EVENT_MOUSE_BUTTON_UP;
+        event.button.down = false;
+        event.button.timestamp = SDL_GetTicksNS();
+        event.button.windowID = SDL_GetWindowID(window->GetSDLWindow());
+        event.button.button = SDL_BUTTON_LEFT;
+        event.button.clicks = 1;
+        event.button.x = static_cast<float>(static_cast<LONG>(WINDOWS_GET_X_LPARAM(msg->lParam)));
+        event.button.y = static_cast<float>(static_cast<LONG>(WINDOWS_GET_Y_LPARAM(msg->lParam)));
+
+        SDL_PushEvent(&event);
+    }*/
+    return true;
+#undef GET_WINDOW_WITH_HWND
+}
+
+bool SDLPlatform::InitInternal()
+{
+    // Workaround required for handling window dragging events properly
+    SDL_SetWindowsMessageHook(&EventMessageHook, nullptr);
+
+    if (WindowsPlatform::Init())
+        return true;
+
+    return false;
+}
+
+bool SDLPlatform::EventFilterCallback(void* userdata, SDL_Event* event)
+{
+    Window* draggedWindow = *(Window**)userdata;
+    if (draggedWindow == nullptr)
+        return true;
+
+    // When the window is being dragged on Windows, the internal message loop is blocking
+    // the SDL event queue. We need to handle all relevant events in this event watch callback
+    // to ensure dragging related functionality doesn't break due to engine not getting updated.
+    // This also happens to fix the engine freezing during the dragging operation.
+
+    SDLWindow* window = SDLWindow::GetWindowFromEvent(*event);
+    if (event->type == SDL_EVENT_WINDOW_EXPOSED)
+    {
+        // The internal timer is sending exposed events every ~16ms
+        Engine::OnUpdate();//Scripting::Update(); // For docking updates
+        Engine::OnDraw();
+        return false;
+    }
+    else if (event->type == SDL_EVENT_MOUSE_BUTTON_DOWN)
+    {
+        SDLWindow* window = SDLWindow::GetWindowFromEvent(*event);
+        if (window)
+        {
+            bool result = false;
+            window->OnLeftButtonHit(WindowHitCodes::Caption, result);
+            //if (result)
+            //    return false;
+            window->HandleEvent(*event);
+        }
+
+        return false;
+    }
+    else if (event->type == SDL_EVENT_WINDOW_MOVED)
+    {
+        Float2 start = WinImpl::DraggedWindowStartPosition;
+        Float2 newPos = Float2(static_cast<float>(event->window.data1), static_cast<float>(event->window.data2));
+        Float2 offset = newPos - start;
+        Float2 mousePos = WinImpl::DraggedWindowMousePosition;
+
+        SDL_Event mouseMovedEvent { 0 };
+        mouseMovedEvent.motion.type = SDL_EVENT_MOUSE_MOTION;
+        mouseMovedEvent.motion.windowID = SDL_GetWindowID(WinImpl::DraggedWindow->GetSDLWindow());
+        mouseMovedEvent.motion.timestamp = SDL_GetTicksNS();
+        mouseMovedEvent.motion.state = SDL_BUTTON_LEFT;
+        mouseMovedEvent.motion.x = mousePos.X;
+        mouseMovedEvent.motion.y = mousePos.Y;
+        if (window)
+            window->HandleEvent(mouseMovedEvent);
+        if (window)
+            window->HandleEvent(*event);
+
+        return false;
+    }
+    if (window)
+        window->HandleEvent(*event);
+    
+    return true;
+}
+
+void SDLPlatform::PreHandleEvents()
+{
+    SDL_AddEventWatch(EventFilterCallback, &WinImpl::DraggedWindow);
+}
+
+void SDLPlatform::PostHandleEvents()
+{
+    SDL_RemoveEventWatch(EventFilterCallback, &WinImpl::DraggedWindow);
+
+    // Handle window dragging release here
+    if (WinImpl::DraggedWindow != nullptr)
+    {
+        Float2 mousePosition;
+        auto buttons = SDL_GetGlobalMouseState(&mousePosition.X, &mousePosition.Y);
+
+        // Send simulated mouse up event
+        SDL_Event buttonUpEvent { 0 };
+        buttonUpEvent.motion.type = SDL_EVENT_MOUSE_BUTTON_UP;
+        buttonUpEvent.button.down = false;
+        buttonUpEvent.motion.windowID = SDL_GetWindowID(WinImpl::DraggedWindow->GetSDLWindow());
+        buttonUpEvent.motion.timestamp = SDL_GetTicksNS();
+        buttonUpEvent.motion.state = SDL_BUTTON_LEFT;
+        buttonUpEvent.button.clicks = 1;
+        buttonUpEvent.motion.x = mousePosition.X;
+        buttonUpEvent.motion.y = mousePosition.Y;
+        WinImpl::DraggedWindow->HandleEvent(buttonUpEvent);
+        WinImpl::DraggedWindow = nullptr;
+    }
+}
+
+bool SDLWindow::HandleEventInternal(SDL_Event& event)
+{
+    switch (event.type)
+    {
+    case SDL_EVENT_WINDOW_DESTROYED:
+    {
+#if USE_EDITOR
+        // Disable file dropping
+        if (_settings.AllowDragAndDrop)
+        {
+            const auto result = RevokeDragDrop((HWND)_handle);
+            if (result != S_OK)
+                LOG(Warning, "Window drag and drop service error: 0x{0:x}:{1}", result, 2);
+        }
+#endif
+        break;
+    }
+    case SDL_EVENT_MOUSE_BUTTON_UP:
+    {
+        if (WinImpl::DraggedWindow != nullptr && WinImpl::DraggedWindow->_windowId != event.button.windowID)
+        {
+            // Send the button event to dragged window as well
+            Float2 mousePos = ClientToScreen({ event.button.x, event.button.y });
+            Float2 clientPos = WinImpl::DraggedWindow->ScreenToClient(mousePos);
+
+            SDL_Event event2 = event;
+            event2.button.windowID = WinImpl::DraggedWindow->_windowId;
+            event2.button.x = clientPos.X;
+            event2.button.y = clientPos.Y;
+
+            SDLInput::HandleEvent(WinImpl::DraggedWindow, event2);
+        }
+        break;
+    }
+    default:
+        break;
+    }
+    
+    return false;
+}
+
+bool SDLPlatform::UsesWindows()
+{
+    return true;
+}
+
+bool SDLPlatform::UsesWayland()
+{
+    return false;
+}
+
+bool SDLPlatform::UsesX11()
+{
+    return false;
+}
+
+void SDLWindow::Focus()
+{
+    auto activateWhenRaised = SDL_GetHint(SDL_HINT_WINDOW_ACTIVATE_WHEN_RAISED);
+    SDL_SetHint(SDL_HINT_WINDOW_ACTIVATE_WHEN_RAISED, "1");
+
+    // Forcing the window to focus causes issues with opening context menus while window is maximized
+    //auto forceRaiseWindow = SDL_GetHint(SDL_HINT_FORCE_RAISEWINDOW);
+    //SDL_SetHint(SDL_HINT_FORCE_RAISEWINDOW, "1");
+
+    SDL_RaiseWindow(_window);
+
+    SDL_SetHint(SDL_HINT_WINDOW_ACTIVATE_WHEN_RAISED, activateWhenRaised);
+    //SDL_SetHint(SDL_HINT_FORCE_RAISEWINDOW, forceRaiseWindow);
+}
+
+void SDLPlatform::SetHighDpiAwarenessEnabled(bool enable)
+{
+    // Other supported values: "permonitor", "permonitorv2"
+    SDL_SetHint("SDL_WINDOWS_DPI_AWARENESS", enable ? "system" : "unaware");
+}
+
+DragDropEffect SDLWindow::DoDragDrop(const StringView& data, const Float2& offset, Window* dragSourceWindow)
+{
+    Show();
+    return DragDropEffect::None;
+}
+
+#endif

Source/Engine/Platform/SDL/SDLPlatform.cpp

@@ -0,0 +1,288 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_SDL
+
+#include "SDLPlatform.h"
+#include "SDLWindow.h"
+#include "Engine/Core/Log.h"
+#include "Engine/Input/Input.h"
+#include "Engine/Input/Mouse.h"
+#include "Engine/Platform/BatteryInfo.h"
+#include "Engine/Platform/WindowsManager.h"
+#include "Engine/Platform/SDL/SDLInput.h"
+#include "Engine/Engine/Engine.h"
+
+#include <SDL3/SDL_hints.h>
+#include <SDL3/SDL_init.h>
+#include <SDL3/SDL_misc.h>
+#include <SDL3/SDL_power.h>
+#include <SDL3/SDL_revision.h>
+#include <SDL3/SDL_system.h>
+#include <SDL3/SDL_version.h>
+#include <SDL3/SDL_locale.h>
+
+#if PLATFORM_LINUX
+#include "Engine/Engine/CommandLine.h"
+#endif
+
+#define DefaultDPI 96
+
+namespace
+{
+    int32 SystemDpi = 96;
+    String UserLocale("en");
+}
+
+bool SDLPlatform::Init()
+{
+#if PLATFORM_LINUX
+    if (CommandLine::Options.X11)
+        SDL_SetHintWithPriority(SDL_HINT_VIDEO_DRIVER, "x11", SDL_HINT_OVERRIDE);
+    else if (CommandLine::Options.Wayland)
+        SDL_SetHintWithPriority(SDL_HINT_VIDEO_DRIVER, "wayland", SDL_HINT_OVERRIDE);
+    else
+    {
+        // Override the X11 preference when running in Wayland session
+        String waylandDisplayEnv;
+        if (!GetEnvironmentVariable(String("WAYLAND_DISPLAY"), waylandDisplayEnv))
+            SDL_SetHintWithPriority(SDL_HINT_VIDEO_DRIVER, "wayland", SDL_HINT_OVERRIDE);
+    }
+#endif
+
+#if PLATFORM_LINUX
+    // TODO: This should be read from the platform configuration (needed for desktop icon handling)
+#if USE_EDITOR
+    SDL_SetHint(SDL_HINT_APP_ID, StringAnsi("com.FlaxEngine.FlaxEditor").Get());
+#else
+    SDL_SetHint(SDL_HINT_APP_ID, StringAnsi("com.FlaxEngine.FlaxGame").Get());
+#endif
+#else
+    SDL_SetHint(SDL_HINT_APP_ID, StringAnsi(ApplicationClassName).Get());
+#endif
+
+    SDL_SetHint(SDL_HINT_WINDOW_ACTIVATE_WHEN_SHOWN, "0");
+    SDL_SetHint(SDL_HINT_WINDOW_ACTIVATE_WHEN_RAISED, "0");
+    SDL_SetHint(SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, "1"); // Fixes context menu focus issues when clicking unfocused menus
+    SDL_SetHint(SDL_HINT_WINDOWS_ERASE_BACKGROUND_MODE, "0");
+    SDL_SetHint(SDL_HINT_TIMER_RESOLUTION, "0"); // Already handled during platform initialization
+    SDL_SetHint("SDL_BORDERLESS_RESIZABLE_STYLE", "1"); // Allow borderless windows to be resizable on Windows
+    //SDL_SetHint("SDL_BORDERLESS_WINDOWED_STYLE", "1"); 
+    
+    SDL_SetHint(SDL_HINT_MOUSE_RELATIVE_WARP_MOTION, "0");
+    SDL_SetHint(SDL_HINT_MOUSE_RELATIVE_CURSOR_VISIBLE, "1"); // Needed for tracking mode
+    SDL_SetHint(SDL_HINT_MOUSE_RELATIVE_MODE_CENTER, "0"); // 
+    SDL_SetHint(SDL_HINT_MOUSE_DOUBLE_CLICK_RADIUS, "8"); // Reduce the default mouse double-click radius
+
+    //SDL_SetHint(SDL_HINT_MOUSE_RELATIVE_MODE_WARP, "1"); // Disables raw mouse input
+    SDL_SetHint(SDL_HINT_WINDOWS_RAW_KEYBOARD, "1");
+
+    SDL_SetHint(SDL_HINT_VIDEO_WAYLAND_SCALE_TO_DISPLAY, "1");
+
+    //if (InitInternal())
+    //    return true;
+
+    if (!SDL_InitSubSystem(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
+        Platform::Fatal(String::Format(TEXT("Failed to initialize SDL: {0}."), String(SDL_GetError())));
+
+    int localesCount = 0;
+    auto locales = SDL_GetPreferredLocales(&localesCount);
+    for (int i = 0; i < localesCount; i++)
+    {
+        auto language = StringAnsiView(locales[i]->language);
+        auto country = StringAnsiView(locales[i]->country);
+        if (language.StartsWith("en"))
+        {
+            if (country != nullptr)
+                UserLocale = String::Format(TEXT("{0}-{1}"), String(language), String(locales[i]->country));
+            else
+                UserLocale = String(language);
+            break;
+        }
+    }
+    SDL_free(locales);
+
+    if (InitInternal())
+        return true;
+
+    if (UsesWindows() || UsesX11())
+    {
+        // Disable SDL clipboard support
+        SDL_SetEventEnabled(SDL_EVENT_CLIPBOARD_UPDATE, false);
+
+        // Disable SDL drag and drop support
+        SDL_SetEventEnabled(SDL_EVENT_DROP_FILE, false);
+        SDL_SetEventEnabled(SDL_EVENT_DROP_TEXT, false);
+        SDL_SetEventEnabled(SDL_EVENT_DROP_BEGIN, false);
+        SDL_SetEventEnabled(SDL_EVENT_DROP_COMPLETE, false);
+        SDL_SetEventEnabled(SDL_EVENT_DROP_POSITION, false);
+    }
+
+    SDLInput::Init();
+
+    SystemDpi = (int)(SDL_GetDisplayContentScale(SDL_GetPrimaryDisplay()) * DefaultDPI);
+
+    //SDL_StartTextInput(); // TODO: Call this only when text input is expected (shows virtual keyboard in some cases)
+
+    return base::Init();
+}
+
+void SDLPlatform::LogInfo()
+{
+    base::LogInfo();
+
+    const int32 runtimeVersion = SDL_GetVersion();
+    LOG(Info, "Using SDL version {}.{}.{} ({}), runtime: {}.{}.{} ({})",
+        SDL_VERSIONNUM_MAJOR(SDL_VERSION), SDL_VERSIONNUM_MINOR(SDL_VERSION), SDL_VERSIONNUM_MICRO(SDL_VERSION), String(SDL_REVISION),
+        SDL_VERSIONNUM_MAJOR(runtimeVersion), SDL_VERSIONNUM_MINOR(runtimeVersion), SDL_VERSIONNUM_MICRO(runtimeVersion), String(SDL_GetRevision()));
+
+    LOG(Info, "SDL video driver: {}", String(SDL_GetCurrentVideoDriver()));
+}
+
+void SDLPlatform::Tick()
+{
+    SDLInput::Update();
+
+    PreHandleEvents();
+    
+    SDL_PumpEvents();
+    SDL_Event events[32];
+    int count = SDL_PeepEvents(events, SDL_arraysize(events), SDL_GETEVENT, SDL_EVENT_FIRST, SDL_EVENT_LAST);
+    for (int i = 0; i < count; ++i)
+    {
+        SDLWindow* window = SDLWindow::GetWindowFromEvent(events[i]);
+        if (window)
+            window->HandleEvent(events[i]);
+        else if (events[i].type >= SDL_EVENT_JOYSTICK_AXIS_MOTION && events[i].type <= SDL_EVENT_GAMEPAD_STEAM_HANDLE_UPDATED)
+            SDLInput::HandleEvent(nullptr, events[i]);
+        else
+            HandleEvent(events[i]);
+    }
+
+    PostHandleEvents();
+}
+
+bool SDLPlatform::HandleEvent(SDL_Event& event)
+{
+    return true;
+}
+
+String SDLPlatform::GetDisplayServer()
+{
+#if PLATFORM_LINUX
+    String driver(SDL_GetCurrentVideoDriver());
+    if (driver.Length() > 0)
+        driver[0] = StringUtils::ToUpper(driver[0]);
+    return driver;
+#else
+    return String::Empty;
+#endif
+}
+
+BatteryInfo SDLPlatform::GetBatteryInfo()
+{
+    BatteryInfo info;
+    int percentage;
+    SDL_PowerState powerState = SDL_GetPowerInfo(nullptr, &percentage);
+
+    if (percentage < 0)
+        info.BatteryLifePercent = 1.0f;
+    else
+        info.BatteryLifePercent = (float)percentage / 100.0f;
+
+    switch (powerState)
+    {
+    case SDL_POWERSTATE_CHARGING:
+        info.State = BatteryInfo::States::BatteryCharging;
+        break;
+    case SDL_POWERSTATE_ON_BATTERY:
+        info.State = BatteryInfo::States::BatteryDischarging;
+        break;
+    case SDL_POWERSTATE_CHARGED:
+        info.State = BatteryInfo::States::Connected;
+        break;
+    default:
+        info.State = BatteryInfo::States::Unknown;
+    }
+    return info;
+}
+
+int32 SDLPlatform::GetDpi()
+{
+    return SystemDpi;
+}
+
+String SDLPlatform::GetUserLocaleName()
+{
+    return UserLocale;
+}
+
+void SDLPlatform::OpenUrl(const StringView& url)
+{
+    StringAnsi urlStr(url);
+    SDL_OpenURL(urlStr.GetText());
+}
+
+Float2 SDLPlatform::GetMousePosition()
+{
+    Float2 pos;
+    if (UsesWayland())
+    {
+        // Wayland doesn't support reporting global mouse position,
+        // use the last known reported position we got from received window events.
+        pos = Input::GetMouseScreenPosition();
+        //if (!SDL_GetGlobalMouseState(&pos.X, &pos.Y))
+        //    LOG(Error, "SDL_GetGlobalMouseState() failed");
+    }
+    else if (UsesX11())
+        SDL_GetGlobalMouseState(&pos.X, &pos.Y);
+    else
+        pos = Input::GetMouseScreenPosition();
+    return pos;
+}
+
+void SDLPlatform::SetMousePosition(const Float2& pos)
+{
+    SDL_WarpMouseGlobal(pos.X, pos.Y);
+}
+
+Float2 SDLPlatform::GetDesktopSize()
+{
+    SDL_Rect rect;
+    SDL_GetDisplayBounds(SDL_GetPrimaryDisplay(), &rect);
+    return Float2(static_cast<float>(rect.w), static_cast<float>(rect.h));
+}
+
+Rectangle SDLPlatform::GetMonitorBounds(const Float2& screenPos)
+{
+    SDL_Point point{ (int32)screenPos.X, (int32)screenPos.Y };
+    SDL_DisplayID display = SDL_GetDisplayForPoint(&point);
+    SDL_Rect rect;
+    SDL_GetDisplayBounds(display, &rect);
+    return Rectangle(static_cast<float>(rect.x), static_cast<float>(rect.y), static_cast<float>(rect.w), static_cast<float>(rect.h));
+}
+
+Rectangle SDLPlatform::GetVirtualDesktopBounds()
+{
+    int count;
+    const SDL_DisplayID* displays = SDL_GetDisplays(&count);
+    if (displays == nullptr)
+        return Rectangle::Empty;
+
+    Rectangle bounds = Rectangle::Empty;
+    for (int i = 0; i < count; i++)
+    {
+        SDL_DisplayID display = displays[i];
+        SDL_Rect rect;
+        SDL_GetDisplayBounds(display, &rect);
+        bounds = Rectangle::Union(bounds, Rectangle(static_cast<float>(rect.x), static_cast<float>(rect.y), static_cast<float>(rect.w), static_cast<float>(rect.h)));
+    }
+    SDL_free((void*)displays);
+    return bounds;
+}
+
+Window* SDLPlatform::CreateWindow(const CreateWindowSettings& settings)
+{
+    return New<SDLWindow>(settings);
+}
+
+#endif

Source/Engine/Platform/SDL/SDLPlatform.h

@@ -0,0 +1,80 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_SDL
+
+#include "Engine/Platform/Base/Enums.h"
+#if PLATFORM_WINDOWS
+#include "Engine/Platform/Windows/WindowsPlatform.h"
+typedef struct tagMSG MSG;
+#elif PLATFORM_LINUX
+#include "Engine/Platform/Linux/LinuxPlatform.h"
+union _XEvent;
+#else
+#endif
+
+class SDLWindow;
+union SDL_Event;
+
+/// <summary>
+/// The SDL platform implementation and application management utilities.
+/// </summary>
+class FLAXENGINE_API SDLPlatform
+#if PLATFORM_WINDOWS
+    : public WindowsPlatform
+{
+    using base = WindowsPlatform;
+#elif PLATFORM_LINUX
+    : public LinuxPlatform
+{
+    using base = LinuxPlatform;
+#else
+{
+#endif
+    friend SDLWindow;
+
+private:
+    static bool InitInternal();
+#if PLATFORM_LINUX
+    static bool InitX11(void* display);
+#endif
+    static bool HandleEvent(SDL_Event& event);
+#if PLATFORM_WINDOWS
+    static bool EventMessageHook(void* userdata, MSG* msg);
+    static bool SDLPlatform::EventFilterCallback(void* userdata, SDL_Event* event);
+#elif PLATFORM_LINUX
+    static bool X11EventHook(void* userdata, _XEvent* xevent);
+#endif
+    static void PreHandleEvents();
+    static void PostHandleEvents();
+
+public:
+#if PLATFORM_LINUX
+    static void* GetXDisplay();
+#endif
+    static bool UsesWindows();
+    static bool UsesWayland();
+    static bool UsesX11();
+
+public:
+
+    // [PlatformBase]
+    static bool Init();
+    static void LogInfo();
+    static void Tick();
+    static String GetDisplayServer();
+    static void SetHighDpiAwarenessEnabled(bool enable);
+    static BatteryInfo GetBatteryInfo();
+    static int32 GetDpi();
+    static String GetUserLocaleName();
+    static void OpenUrl(const StringView& url);
+    static Float2 GetMousePosition();
+    static void SetMousePosition(const Float2& pos);
+    static Float2 GetDesktopSize();
+    static Rectangle GetMonitorBounds(const Float2& screenPos);
+    static Rectangle GetVirtualDesktopBounds();
+    static Window* CreateWindow(const CreateWindowSettings& settings);
+};
+
+#endif

Source/Engine/Platform/SDL/SDLWindow.cpp

@@ -0,0 +1,917 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_SDL
+
+#include "SDLWindow.h"
+#include "SDLInput.h"
+#include "Engine/Core/Log.h"
+#include "Engine/Core/Math/Math.h"
+#include "Engine/Core/Math/Rectangle.h"
+#include "Engine/Engine/Engine.h"
+#include "Engine/Graphics/GPUDevice.h"
+#include "Engine/Graphics/GPUSwapChain.h"
+#include "Engine/Graphics/RenderTask.h"
+#include "Engine/Input/Input.h"
+#include "Engine/Input/Keyboard.h"
+#include "Engine/Input/Mouse.h"
+#include "Engine/Platform/WindowsManager.h"
+
+#define NOGDI
+#include <SDL3/SDL_events.h>
+#include <SDL3/SDL_hints.h>
+#include <SDL3/SDL_properties.h>
+#include <SDL3/SDL_video.h>
+#undef CreateWindow
+
+#if PLATFORM_WINDOWS
+#include "Engine/Platform/Win32/IncludeWindowsHeaders.h"
+#if USE_EDITOR
+#include <oleidl.h>
+#endif
+#elif PLATFORM_LINUX
+#include "Engine/Platform/Linux/IncludeX11.h"
+#endif
+
+#define DefaultDPI 96
+
+namespace WindowImpl
+{
+    SDLWindow* LastEventWindow = nullptr;
+    static SDL_Cursor* Cursors[SDL_SYSTEM_CURSOR_COUNT] = { nullptr };
+}
+using namespace WindowImpl;
+
+SDL_HitTestResult OnWindowHitTest(SDL_Window* win, const SDL_Point* area, void* data);
+void GetRelativeWindowOffset(WindowType type, SDLWindow* parentWindow, Int2& positionOffset);
+Int2 GetSDLWindowScreenPosition(const SDLWindow* window);
+void SetSDLWindowScreenPosition(const SDLWindow* window, const Int2 position);
+
+bool IsPopupWindow(WindowType type)
+{
+    return type == WindowType::Popup || type == WindowType::Tooltip;
+}
+
+void* GetNativeWindowPointer(SDL_Window* window)
+{
+    void* windowPtr;
+    auto props = SDL_GetWindowProperties(window);
+#if PLATFORM_WINDOWS
+    windowPtr = SDL_GetPointerProperty(props, SDL_PROP_WINDOW_WIN32_HWND_POINTER, nullptr);
+#elif PLATFORM_LINUX
+    windowPtr = SDL_GetPointerProperty(props, SDL_PROP_WINDOW_WAYLAND_SURFACE_POINTER, nullptr);
+    if (windowPtr == nullptr)
+        windowPtr = (void*)SDL_GetNumberProperty(props, SDL_PROP_WINDOW_X11_WINDOW_NUMBER, 0);
+#elif PLATFORM_MAC
+    windowPtr = SDL_GetPointerProperty(props, SDL_PROP_WINDOW_COCOA_WINDOW_POINTER, nullptr);
+#elif PLATFORM_ANDROID
+    windowPtr = SDL_GetPointerProperty(props, SDL_PROP_WINDOW_ANDROID_WINDOW_POINTER, nullptr);
+#elif PLATFORM_IOS
+    windowPtr = SDL_GetPointerProperty(props, SDL_PROP_WINDOW_UIKIT_WINDOW_POINTER, nullptr);
+#else
+    static_assert(false, "unsupported platform");
+#endif
+    return windowPtr;
+}
+
+SDLWindow::SDLWindow(const CreateWindowSettings& settings)
+    : WindowBase(settings)
+    , _handle(nullptr)
+    , _cachedClientRectangle(Rectangle())
+#if PLATFORM_LINUX
+    , _dragOver(false)
+#endif
+{
+    Int2 clientSize(Math::TruncToInt(settings.Size.X), Math::TruncToInt(settings.Size.Y));
+    _clientSize = Float2(clientSize);
+
+    if (SDLPlatform::UsesWayland())
+    {
+        // The compositor seems to crash when something is rendered to the hidden popup window surface
+        _settings.ShowAfterFirstPaint = _showAfterFirstPaint = false;
+    }
+    
+    uint32 flags = SDL_WINDOW_HIDDEN;
+    if (_settings.Type == WindowType::Utility)
+        flags |= SDL_WINDOW_UTILITY;
+    else if (_settings.Type == WindowType::Regular && !_settings.ShowInTaskbar)
+        flags |= SDL_WINDOW_UTILITY;
+    else if (_settings.Type == WindowType::Tooltip)
+        flags |= SDL_WINDOW_TOOLTIP;
+    else if (_settings.Type == WindowType::Popup)
+        flags |= SDL_WINDOW_POPUP_MENU;
+
+    if (!_settings.HasBorder)
+        flags |= SDL_WINDOW_BORDERLESS;
+    if (_settings.AllowInput)
+        flags |= SDL_WINDOW_INPUT_FOCUS;
+    else
+        flags |= SDL_WINDOW_NOT_FOCUSABLE;
+    if (_settings.HasSizingFrame)
+        flags |= SDL_WINDOW_RESIZABLE;
+    if (_settings.IsTopmost)
+        flags |= SDL_WINDOW_ALWAYS_ON_TOP;
+    if (_settings.SupportsTransparency)
+        flags |= SDL_WINDOW_TRANSPARENT;
+
+    // Disable parenting of child windows as those are always on top of the parent window and never show up in taskbar
+    if (_settings.Parent != nullptr && (_settings.Type != WindowType::Tooltip && _settings.Type != WindowType::Popup))
+        _settings.Parent = nullptr;
+
+    // The window position needs to be relative to the parent window
+    Int2 relativePosition(Math::TruncToInt(settings.Position.X), Math::TruncToInt(settings.Position.Y));
+    GetRelativeWindowOffset(_settings.Type, _settings.Parent, relativePosition);
+
+    SDL_PropertiesID props = SDL_CreateProperties();
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_FLAGS_NUMBER, flags);
+    SDL_SetStringProperty(props, SDL_PROP_WINDOW_CREATE_TITLE_STRING, settings.Title.ToStringAnsi().Get());
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_X_NUMBER, relativePosition.X);
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_Y_NUMBER, relativePosition.Y);
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_WIDTH_NUMBER, clientSize.X);
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_HEIGHT_NUMBER, clientSize.Y);
+    SDL_SetBooleanProperty(props, SDL_PROP_WINDOW_CREATE_EXTERNAL_GRAPHICS_CONTEXT_BOOLEAN, true);
+    if ((flags & SDL_WINDOW_TOOLTIP) != 0)
+        SDL_SetBooleanProperty(props, SDL_PROP_WINDOW_CREATE_TOOLTIP_BOOLEAN, true);
+    else if ((flags & SDL_WINDOW_POPUP_MENU) != 0)
+        SDL_SetBooleanProperty(props, SDL_PROP_WINDOW_CREATE_MENU_BOOLEAN, true);
+    if (_settings.Parent != nullptr)
+        SDL_SetPointerProperty(props, SDL_PROP_WINDOW_CREATE_PARENT_POINTER, _settings.Parent->_window);
+
+    _window = SDL_CreateWindowWithProperties(props);
+    SDL_DestroyProperties(props);
+    if (_window == nullptr)
+        Platform::Fatal(String::Format(TEXT("Cannot create SDL window: {0}"), String(SDL_GetError())));
+
+    _windowId = SDL_GetWindowID(_window);
+    _handle = GetNativeWindowPointer(_window);
+    ASSERT(_handle != nullptr);
+
+    SDL_DisplayID display = SDL_GetDisplayForWindow(_window);
+    _dpiScale = SDL_GetWindowDisplayScale(_window);
+    _dpi = Math::TruncToInt(_dpiScale * DefaultDPI);
+
+    SDL_SetWindowMinimumSize(_window, Math::TruncToInt(_settings.MinimumSize.X), Math::TruncToInt(_settings.MinimumSize.Y));
+    SDL_SetWindowMaximumSize(_window, Math::TruncToInt(_settings.MaximumSize.X), Math::TruncToInt(_settings.MaximumSize.Y));
+    
+    SDL_SetWindowHitTest(_window, &OnWindowHitTest, this);
+    InitSwapChain();
+
+#if USE_EDITOR
+    // Enable file drag & drop support
+    if (_settings.AllowDragAndDrop)
+    {
+#if PLATFORM_WINDOWS
+        const auto result = RegisterDragDrop((HWND)_handle, (LPDROPTARGET)(Windows::IDropTarget*)this);
+        if (result != S_OK)
+        {
+            LOG(Warning, "Window drag and drop service error: 0x{0:x}:{1}", result, 1);
+        }
+#elif PLATFORM_LINUX
+        auto xDisplay = (X11::Display*)GetX11Display();
+        if (xDisplay)
+        {
+            auto xdndVersion = 5;
+            auto xdndAware = X11::XInternAtom(xDisplay, "XdndAware", 0);
+            if (xdndAware != 0)
+                X11::XChangeProperty(xDisplay, (X11::Window)_handle, xdndAware, (X11::Atom)4, 32, PropModeReplace, (unsigned char*)&xdndVersion, 1);
+        }
+#endif
+    }
+#endif
+
+    LastEventWindow = this;
+
+#if PLATFORM_LINUX
+    // Initialize using the shared Display instance from SDL
+    if (SDLPlatform::UsesX11() && SDLPlatform::GetXDisplay() == nullptr)
+        SDLPlatform::InitX11(GetX11Display());
+
+    // Window focus changes breaks the text input for some reason, just keep it enabled for good
+    if (SDLPlatform::UsesX11() && _settings.AllowInput)
+        SDL_StartTextInput(_window);
+#endif
+}
+
+SDL_Window* SDLWindow::GetSDLWindow() const
+{
+    return _window;
+}
+
+#if PLATFORM_LINUX
+
+void* SDLWindow::GetWaylandSurfacePtr() const
+{
+    return SDL_GetPointerProperty(SDL_GetWindowProperties(_window), SDL_PROP_WINDOW_WAYLAND_SURFACE_POINTER, nullptr);
+}
+
+void* SDLWindow::GetWaylandDisplay() const
+{
+    return SDL_GetPointerProperty(SDL_GetWindowProperties(_window), SDL_PROP_WINDOW_WAYLAND_DISPLAY_POINTER, nullptr);
+}
+
+uintptr SDLWindow::GetX11WindowHandle() const
+{
+    return (uintptr)SDL_GetNumberProperty(SDL_GetWindowProperties(_window), SDL_PROP_WINDOW_X11_WINDOW_NUMBER, 0);
+}
+
+void* SDLWindow::GetX11Display() const
+{
+    return SDL_GetPointerProperty(SDL_GetWindowProperties(_window), SDL_PROP_WINDOW_X11_DISPLAY_POINTER, nullptr);
+}
+
+#endif
+
+SDLWindow::~SDLWindow()
+{
+    if (LastEventWindow == this)
+        LastEventWindow = nullptr;
+
+    if (_window == nullptr)
+        return;
+    
+    SDL_StopTextInput(_window);
+    SDL_DestroyWindow(_window);
+
+    _window = nullptr;
+    _handle = nullptr;
+    _windowId = 0;
+    _visible = false;
+}
+
+SDL_HitTestResult OnWindowHitTest(SDL_Window* win, const SDL_Point* area, void* data)
+{
+    SDLWindow* window = (SDLWindow*)data;
+    if (window->IsFullscreen())
+        return SDL_HITTEST_NORMAL;
+
+    Float2 clientPosition = Float2(static_cast<float>(area->x), static_cast<float>(area->y));
+    Float2 screenPosition = window->ClientToScreen(clientPosition);
+
+    WindowHitCodes hit = WindowHitCodes::Client;
+    bool handled = false;
+    window->OnHitTest(screenPosition, hit, handled);
+
+    if (!handled)
+    {
+        int margin = window->GetSettings().HasBorder ? 0 : 0;
+        auto size = window->GetClientSize();
+        //if (clientPosition.Y < 0)
+        //    return SDL_HITTEST_DRAGGABLE;
+        if (clientPosition.Y < margin && clientPosition.X < margin)
+            return SDL_HITTEST_RESIZE_TOPLEFT;
+        else if (clientPosition.Y < margin && clientPosition.X > size.X - margin)
+            return SDL_HITTEST_RESIZE_TOPRIGHT;
+        else if (clientPosition.Y < margin)
+            return SDL_HITTEST_RESIZE_TOP;
+        else if (clientPosition.X < margin && clientPosition.Y > size.Y - margin)
+            return SDL_HITTEST_RESIZE_BOTTOMLEFT;
+        else if (clientPosition.X < margin)
+            return SDL_HITTEST_RESIZE_LEFT;
+        else if (clientPosition.X > size.X - margin && clientPosition.Y > size.Y - margin)
+            return SDL_HITTEST_RESIZE_BOTTOMRIGHT;
+        else if (clientPosition.X > size.X - margin)
+            return SDL_HITTEST_RESIZE_RIGHT;
+        else if (clientPosition.Y > size.Y - margin)
+            return SDL_HITTEST_RESIZE_BOTTOM;
+        else
+            return SDL_HITTEST_NORMAL;
+    }
+
+    switch (hit)
+    {
+    case WindowHitCodes::Caption:
+        return SDL_HITTEST_DRAGGABLE;
+    case WindowHitCodes::TopLeft:
+        return SDL_HITTEST_RESIZE_TOPLEFT;
+    case WindowHitCodes::Top:
+        return SDL_HITTEST_RESIZE_TOP;
+    case WindowHitCodes::TopRight:
+        return SDL_HITTEST_RESIZE_TOPRIGHT;
+    case WindowHitCodes::Right:
+        return SDL_HITTEST_RESIZE_RIGHT;
+    case WindowHitCodes::BottomRight:
+        return SDL_HITTEST_RESIZE_BOTTOMRIGHT;
+    case WindowHitCodes::Bottom:
+        return SDL_HITTEST_RESIZE_BOTTOM;
+    case WindowHitCodes::BottomLeft:
+        return SDL_HITTEST_RESIZE_BOTTOMLEFT;
+    case WindowHitCodes::Left:
+        return SDL_HITTEST_RESIZE_LEFT;
+    default:
+        return SDL_HITTEST_NORMAL;
+    }
+}
+
+SDLWindow* SDLWindow::GetWindowFromEvent(const SDL_Event& event)
+{
+    SDL_Window* window = SDL_GetWindowFromEvent(&event);
+    if (window == nullptr)
+        return nullptr;
+    if (LastEventWindow == nullptr || window != LastEventWindow->_window)
+        LastEventWindow = GetWindowWithSDLWindow(window);
+    return LastEventWindow;
+}
+
+SDLWindow* SDLWindow::GetWindowWithSDLWindow(SDL_Window* window)
+{
+    WindowsManager::WindowsLocker.Lock();
+    for (auto win : WindowsManager::Windows)
+    {
+        if (win->_window == window)
+            return win;
+    }
+    WindowsManager::WindowsLocker.Unlock();
+    return nullptr;
+}
+
+void SDLWindow::HandleEvent(SDL_Event& event)
+{
+    if (_isClosing)
+        return;
+
+    // Platform specific event handling
+    if (HandleEventInternal(event))
+        return;
+
+    switch (event.type)
+    {
+    case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
+    {
+        Close(ClosingReason::User);
+        return;
+    }
+    case SDL_EVENT_WINDOW_DESTROYED:
+    {
+        // Quit
+#if PLATFORM_WINDOWS
+        PostQuitMessage(0);
+#endif
+        return;
+    }
+    case SDL_EVENT_MOUSE_MOTION:
+    {
+        if (_isTrackingMouse && _isUsingMouseOffset)
+        {
+            Float2 delta(event.motion.xrel, event.motion.yrel);
+            _trackingMouseOffset += delta;
+        }
+        break;
+    }
+    case SDL_EVENT_KEY_DOWN:
+    {
+        if (event.key.scancode == SDL_SCANCODE_RETURN && Input::Keyboard->GetKey(KeyboardKeys::Alt))
+        {
+            LOG(Info, "Alt+Enter pressed");
+            SetIsFullscreen(!IsFullscreen());
+            return;
+        }
+        break;
+    }
+    case SDL_EVENT_WINDOW_MOVED:
+    {
+        _cachedClientRectangle.Location = Float2(static_cast<float>(event.window.data1), static_cast<float>(event.window.data2));
+        return;
+    }
+    case SDL_EVENT_WINDOW_HIT_TEST:
+    {
+        return;
+    }
+    case SDL_EVENT_WINDOW_MINIMIZED:
+    {
+        _minimized = true;
+        _maximized = false;
+        return;
+    }
+    case SDL_EVENT_WINDOW_MAXIMIZED:
+    {
+        _minimized = false;
+        _maximized = true;
+        
+        CheckForWindowResize();
+        return;
+    }
+    case SDL_EVENT_WINDOW_RESTORED:
+    {
+        if (_maximized)
+        {
+            _maximized = false;
+            // We assume SDL_EVENT_WINDOW_RESIZED is called right afterwards, no need to check for resize here
+            //CheckForWindowResize();
+        }
+        else if (_minimized)
+        {
+            _minimized = false;
+            CheckForWindowResize();
+        }
+        return;
+    }
+    case SDL_EVENT_WINDOW_RESIZED:
+    {
+        int32 width = event.window.data1;
+        int32 height = event.window.data2;
+
+        _clientSize = Float2(static_cast<float>(width), static_cast<float>(height));
+        _cachedClientRectangle.Size = _clientSize;
+
+        // Check if window size has been changed
+        if (width > 0 && height > 0 && (_swapChain == nullptr || width != _swapChain->GetWidth() || height != _swapChain->GetHeight()))
+            OnResize(width, height);
+        return;
+    }
+    case SDL_EVENT_WINDOW_FOCUS_GAINED:
+    {
+        OnGotFocus();
+        if (IsPopupWindow(_settings.Type))
+            _window = _window;
+        if (_settings.AllowInput && !SDLPlatform::UsesX11())
+            SDL_StartTextInput(_window);
+        const SDL_Rect* currentClippingRect = SDL_GetWindowMouseRect(_window);
+        if (_isClippingCursor && currentClippingRect == nullptr)
+        {
+            SDL_Rect rect{ (int)_clipCursorRect.GetX(), (int)_clipCursorRect.GetY(), (int)_clipCursorRect.GetWidth(), (int)_clipCursorRect.GetHeight() };
+            SDL_SetWindowMouseRect(_window, &rect);
+        }
+        return;
+    }
+    case SDL_EVENT_WINDOW_FOCUS_LOST:
+    {
+        if (IsPopupWindow(_settings.Type))
+            _window = _window;
+        if (_settings.AllowInput && !SDLPlatform::UsesX11())
+            SDL_StopTextInput(_window);
+        const SDL_Rect* currentClippingRect = SDL_GetWindowMouseRect(_window);
+        if (currentClippingRect != nullptr)
+            SDL_SetWindowMouseRect(_window, nullptr);
+        OnLostFocus();
+        return;
+    }
+    case SDL_EVENT_WINDOW_DISPLAY_SCALE_CHANGED:
+    {
+        float scale = SDL_GetWindowDisplayScale(_window);
+        if (scale > 0.0f && _dpiScale != scale)
+        {
+            float oldScale = _dpiScale;
+            _dpiScale = scale;
+            _dpi = static_cast<int>(_dpiScale * DefaultDPI);
+            int w = static_cast<int>(_cachedClientRectangle.GetWidth() * (scale / oldScale));
+            int h = static_cast<int>(_cachedClientRectangle.GetHeight() * (scale / oldScale));
+            _cachedClientRectangle.Size = Float2(static_cast<float>(w), static_cast<float>(h));
+            SDL_SetWindowSize(_window, w, h);
+            // TODO: Recalculate fonts
+        }
+        return;
+    }
+    default:
+        break;
+    }
+
+    if (_settings.AllowInput)
+    {
+        if (SDLInput::HandleEvent(this, event))
+            return;
+    }
+}
+
+void* SDLWindow::GetNativePtr() const
+{
+    return _handle;
+}
+
+void SDLWindow::Show()
+{
+    if (_visible)
+        return;
+
+    if (_showAfterFirstPaint)
+    {
+        if (RenderTask)
+            RenderTask->Enabled = true;
+        return;
+    }
+
+    SDL_ShowWindow(_window);
+    if (_settings.AllowInput && _settings.ActivateWhenFirstShown)
+        Focus();
+    else if (_settings.Parent == nullptr)
+        BringToFront();
+    
+    // Reused top-most windows doesn't stay on top for some reason
+    if (_settings.IsTopmost && !IsPopupWindow(_settings.Type))
+        SetIsAlwaysOnTop(true);
+
+    if (_isTrackingMouse)
+    {
+        if (!SDL_CaptureMouse(true))
+        {
+            if (!SDLPlatform::UsesWayland()) // Suppress "That operation is not supported" errors
+                LOG(Warning, "SDL_CaptureMouse: {0}", String(SDL_GetError()));
+        }
+    }
+
+    WindowBase::Show();
+}
+
+void SDLWindow::Hide()
+{
+    if (!_visible)
+        return;
+
+    SDL_HideWindow(_window);
+
+    WindowBase::Hide();
+}
+
+void SDLWindow::Minimize()
+{
+    if (!_settings.AllowMinimize)
+        return;
+
+    SDL_MinimizeWindow(_window);
+}
+
+void SDLWindow::Maximize()
+{
+    if (!_settings.AllowMaximize)
+        return;
+
+    SDL_MaximizeWindow(_window);
+}
+
+void SDLWindow::SetBorderless(bool isBorderless, bool maximized)
+{
+    if (IsFullscreen())
+        SetIsFullscreen(false);
+
+    // Fixes issue of borderless window not going full screen
+    if (IsMaximized())
+        Restore();
+
+    _settings.HasBorder = !isBorderless;
+
+    BringToFront();
+
+    SDL_SetWindowBordered(_window, !isBorderless ? true : false);
+    if (maximized)
+        Maximize();
+    else
+        Focus();
+    
+    CheckForWindowResize();
+}
+
+void SDLWindow::Restore()
+{
+    SDL_RestoreWindow(_window);
+}
+
+bool SDLWindow::IsClosed() const
+{
+    return _handle == nullptr;
+}
+
+bool SDLWindow::IsForegroundWindow() const
+{
+    SDL_WindowFlags flags = SDL_GetWindowFlags(_window);
+    return (flags & SDL_WINDOW_INPUT_FOCUS) != 0;
+}
+
+void SDLWindow::BringToFront(bool force)
+{
+    SDL_RaiseWindow(_window);
+}
+
+void SDLWindow::SetClientBounds(const Rectangle& clientArea)
+{
+    Int2 newPos = Int2(clientArea.GetTopLeft());
+    int newW = static_cast<int>(clientArea.GetWidth());
+    int newH = static_cast<int>(clientArea.GetHeight());
+
+    SetSDLWindowScreenPosition(this, newPos);
+    SDL_SetWindowSize(_window, newW, newH);
+}
+
+void GetRelativeWindowOffset(WindowType type, SDLWindow* parentWindow, Int2& positionOffset)
+{
+    if (!IsPopupWindow(type))
+        return;
+
+    SDLWindow* window = parentWindow;
+    while (window != nullptr)
+    {
+        Int2 parentPosition;
+        SDL_GetWindowPosition(window->GetSDLWindow(), &parentPosition.X, &parentPosition.Y);
+        positionOffset -= parentPosition;
+
+        if (!IsPopupWindow(window->GetSettings().Type))
+            break;
+
+        window = window->GetSettings().Parent;
+    }
+}
+
+Int2 GetSDLWindowScreenPosition(const SDLWindow* window)
+{
+    Int2 relativeOffset(0, 0);
+    GetRelativeWindowOffset(window->GetSettings().Type, window->GetSettings().Parent, relativeOffset);
+    
+    Int2 position;
+    SDL_GetWindowPosition(window->GetSDLWindow(), &position.X, &position.Y);
+
+    return position - relativeOffset;
+}
+
+void SetSDLWindowScreenPosition(const SDLWindow* window, const Int2 position)
+{
+    Int2 relativePosition = position;
+    GetRelativeWindowOffset(window->GetSettings().Type, window->GetSettings().Parent, relativePosition);
+    SDL_SetWindowPosition(window->GetSDLWindow(), relativePosition.X, relativePosition.Y);
+}
+
+void SDLWindow::SetPosition(const Float2& position)
+{
+    Int2 topLeftBorder;
+    SDL_GetWindowBordersSize(_window, &topLeftBorder.Y, &topLeftBorder.X, nullptr, nullptr);
+
+    Int2 screenPosition(static_cast<int>(position.X), static_cast<int>(position.Y));
+    screenPosition += topLeftBorder;
+
+    if (false && SDLPlatform::UsesX11())
+    {
+        // TODO: is this needed?
+        auto monitorBounds = Platform::GetMonitorBounds(Float2::Minimum);
+        screenPosition += Int2(monitorBounds.GetTopLeft());
+    }
+    
+    SetSDLWindowScreenPosition(this, screenPosition);
+}
+
+void SDLWindow::SetClientPosition(const Float2& position)
+{
+    SetSDLWindowScreenPosition(this, Int2(position));
+}
+
+void SDLWindow::SetIsFullscreen(bool isFullscreen)
+{
+    SDL_SetWindowFullscreen(_window, isFullscreen ? true : false);
+    if (!isFullscreen)
+    {
+        // The window is set to always-on-top for some reason when leaving fullscreen
+        SetIsAlwaysOnTop(false);
+    }
+
+    WindowBase::SetIsFullscreen(isFullscreen);
+}
+
+bool SDLWindow::IsAlwaysOnTop() const
+{
+    SDL_WindowFlags flags = SDL_GetWindowFlags(_window);
+    return (flags & SDL_WINDOW_ALWAYS_ON_TOP) != 0;
+}
+
+void SDLWindow::SetIsAlwaysOnTop(bool isAlwaysOnTop)
+{
+    if (!SDL_SetWindowAlwaysOnTop(_window, isAlwaysOnTop))
+        LOG(Warning, "SDL_SetWindowAlwaysOnTop failed: {0}", String(SDL_GetError()));
+    // Not sure if this should change _settings.IsTopmost to reflect the new value?
+}
+
+Float2 SDLWindow::GetPosition() const
+{
+    Int2 topLeftBorder;
+    SDL_GetWindowBordersSize(_window, &topLeftBorder.Y, &topLeftBorder.X, nullptr, nullptr);
+
+    Int2 position = GetSDLWindowScreenPosition(this);
+    position -= topLeftBorder;
+    
+    return Float2(static_cast<float>(position.X), static_cast<float>(position.Y));
+}
+
+Float2 SDLWindow::GetSize() const
+{
+    int top, left, bottom, right;
+    SDL_GetWindowBordersSize(_window, &top, &left, &bottom, &right);
+    
+    int w, h;
+    SDL_GetWindowSizeInPixels(_window, &w, &h);
+    return Float2(static_cast<float>(w + left + right), static_cast<float>(h + top + bottom));
+}
+
+Float2 SDLWindow::GetClientSize() const
+{
+    int w, h;
+    SDL_GetWindowSizeInPixels(_window, &w, &h);
+
+    return Float2(static_cast<float>(w), static_cast<float>(h));;
+}
+
+Float2 SDLWindow::ScreenToClient(const Float2& screenPos) const
+{
+    Int2 position = GetSDLWindowScreenPosition(this);
+    return screenPos - Float2(static_cast<float>(position.X), static_cast<float>(position.Y));
+}
+
+Float2 SDLWindow::ClientToScreen(const Float2& clientPos) const
+{
+    Int2 position = GetSDLWindowScreenPosition(this);
+    return clientPos + Float2(static_cast<float>(position.X), static_cast<float>(position.Y));
+}
+
+void SDLWindow::FlashWindow()
+{
+    SDL_FlashWindow(_window, SDL_FLASH_UNTIL_FOCUSED);
+}
+
+float SDLWindow::GetOpacity() const
+{
+    float opacity = SDL_GetWindowOpacity(_window);
+    if (opacity < 0.0f)
+    {
+        LOG(Warning, "SDL_GetWindowOpacity failed: {0}", String(SDL_GetError()));
+        opacity = 1.0f;
+    }
+    return opacity;
+}
+
+void SDLWindow::SetOpacity(const float opacity)
+{
+    if (!SDL_SetWindowOpacity(_window, opacity))
+        LOG(Warning, "SDL_SetWindowOpacity failed: {0}", String(SDL_GetError()));
+}
+
+#if !PLATFORM_WINDOWS
+
+void SDLWindow::Focus()
+{
+    SDL_RaiseWindow(_window);
+}
+
+#endif
+
+String SDLWindow::GetTitle() const
+{
+    return String(SDL_GetWindowTitle(_window));
+}
+
+void SDLWindow::SetTitle(const StringView& title)
+{
+    SDL_SetWindowTitle(_window, title.ToStringAnsi().Get());
+}
+
+void SDLWindow::StartTrackingMouse(bool useMouseScreenOffset)
+{
+    if (_isTrackingMouse)
+        return;
+
+    _isTrackingMouse = true;
+    _trackingMouseOffset = Float2::Zero;
+    _isUsingMouseOffset = useMouseScreenOffset;
+
+    if (_visible)
+    {
+        if (!SDL_CaptureMouse(true))
+        {
+            if (!SDLPlatform::UsesWayland()) // Suppress "That operation is not supported" errors
+                LOG(Warning, "SDL_CaptureMouse: {0}", String(SDL_GetError()));
+        }
+
+        // For viewport camera mouse tracking we want to use relative mode for best precision
+        if (_cursor == CursorType::Hidden)
+            Input::Mouse->SetRelativeMode(true, this);
+    }
+}
+
+void SDLWindow::EndTrackingMouse()
+{
+    if (!_isTrackingMouse)
+        return;
+    
+    _isTrackingMouse = false;
+    _isHorizontalFlippingMouse = false;
+    _isVerticalFlippingMouse = false;
+
+    if (!SDL_CaptureMouse(false))
+    {
+        if (!SDLPlatform::UsesWayland()) // Suppress "That operation is not supported" errors
+            LOG(Warning, "SDL_CaptureMouse: {0}", String(SDL_GetError()));
+    }
+
+    Input::Mouse->SetRelativeMode(false, this);
+}
+
+void SDLWindow::StartClippingCursor(const Rectangle& bounds)
+{
+    if (!IsFocused())
+        return;
+
+    _isClippingCursor = true;
+    SDL_Rect rect{ (int)bounds.GetX(), (int)bounds.GetY(), (int)bounds.GetWidth(), (int)bounds.GetHeight() };
+    SDL_SetWindowMouseRect(_window, &rect);
+}
+
+void SDLWindow::EndClippingCursor()
+{
+    if (!_isClippingCursor)
+        return;
+
+    _isClippingCursor = false;
+    SDL_SetWindowMouseRect(_window, nullptr);
+}
+
+void SDLWindow::SetCursor(CursorType type)
+{
+    CursorType oldCursor = _cursor;
+    WindowBase::SetCursor(type);
+    if (oldCursor != type)
+        SDLWindow::UpdateCursor();
+}
+
+void SDLWindow::CheckForWindowResize()
+{
+    return;
+    // Cache client size
+    _clientSize = GetClientSize();
+    int32 width = (int32)(_clientSize.X);
+    int32 height = (int32)(_clientSize.Y);
+
+    // Check for windows maximized size and see if it needs to adjust position if needed
+    if (_maximized)
+    {
+        // Pick the current monitor data for sizing
+        SDL_Rect rect;
+        auto displayId = SDL_GetDisplayForWindow(_window);
+        SDL_GetDisplayUsableBounds(displayId, &rect);
+
+        if (width > rect.w && height > rect.h)
+        {
+            width = rect.w;
+            height = rect.h;
+            SDL_SetWindowSize(_window, width, height);
+        }
+    }
+    
+    // Check if window size has been changed
+    if (width > 0 && height > 0 && (_swapChain == nullptr || width != _swapChain->GetWidth() || height != _swapChain->GetHeight()))
+        OnResize(width, height);
+}
+
+void SDLWindow::UpdateCursor()
+{
+    if (_cursor == CursorType::Hidden)
+    {
+        SDL_HideCursor();
+
+        if (_isTrackingMouse)
+            Input::Mouse->SetRelativeMode(true, this);
+        return;
+    }
+    SDL_ShowCursor();
+    //if (_isTrackingMouse)
+    //    Input::Mouse->SetRelativeMode(false, this);
+    
+    int32 index = SDL_SYSTEM_CURSOR_DEFAULT;
+    switch (_cursor)
+    {
+    case CursorType::Cross:
+        index = SDL_SYSTEM_CURSOR_CROSSHAIR;
+        break;
+    case CursorType::Hand:
+        index = SDL_SYSTEM_CURSOR_POINTER;
+        break;
+    case CursorType::Help:
+        //index = SDL_SYSTEM_CURSOR_DEFAULT;
+        break;
+    case CursorType::IBeam:
+        index = SDL_SYSTEM_CURSOR_TEXT;
+        break;
+    case CursorType::No:
+        index = SDL_SYSTEM_CURSOR_NOT_ALLOWED;
+        break;
+    case CursorType::Wait:
+        index = SDL_SYSTEM_CURSOR_WAIT;
+        break;
+    case CursorType::SizeAll:
+        index = SDL_SYSTEM_CURSOR_MOVE;
+        break;
+    case CursorType::SizeNESW:
+        index = SDL_SYSTEM_CURSOR_NESW_RESIZE;
+        break;
+    case CursorType::SizeNS:
+        index = SDL_SYSTEM_CURSOR_NS_RESIZE;
+        break;
+    case CursorType::SizeNWSE:
+        index = SDL_SYSTEM_CURSOR_NWSE_RESIZE;
+        break;
+    case CursorType::SizeWE:
+        index = SDL_SYSTEM_CURSOR_EW_RESIZE;
+        break;
+    case CursorType::Default:
+    default:
+        break;
+    }
+
+    if (Cursors[index] == nullptr)
+        Cursors[index] = SDL_CreateSystemCursor(static_cast<SDL_SystemCursor>(index));
+    SDL_SetCursor(Cursors[index]);
+}
+
+#endif
+

Source/Engine/Platform/SDL/SDLWindow.h

@@ -0,0 +1,129 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_SDL
+
+#include "Engine/Platform/Base/WindowBase.h"
+
+struct SDL_Window;
+union SDL_Event;
+#if PLATFORM_LINUX
+class MessageBox;
+#endif
+
+/// <summary>
+/// Implementation of the window class for SDL platform
+/// </summary>
+class FLAXENGINE_API SDLWindow : public WindowBase
+#if USE_EDITOR && PLATFORM_WINDOWS
+    , public Windows::IDropTarget
+#endif
+{
+    friend SDLPlatform;
+    friend class SDLMouse;
+#if PLATFORM_LINUX
+    friend LinuxPlatform;
+    friend MessageBox;
+#endif
+    
+private:
+    void* _handle; // Opaque, platform specific window handle
+#if USE_EDITOR && PLATFORM_WINDOWS
+    Windows::ULONG _refCount;
+#endif
+#if PLATFORM_LINUX
+    bool _dragOver;
+#endif
+    SDL_Window* _window;
+    uint32 _windowId;
+    Rectangle _clipCursorRect;
+    Rectangle _cachedClientRectangle;
+
+public:
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SDLWindow"/> class.
+    /// </summary>
+    /// <param name="settings">The initial window settings.</param>
+    SDLWindow(const CreateWindowSettings& settings);
+
+    /// <summary>
+    /// Finalizes an instance of the <see cref="SDLWindow"/> class.
+    /// </summary>
+    ~SDLWindow();
+
+private:
+
+    static SDLWindow* GetWindowFromEvent(const SDL_Event& event);
+    static SDLWindow* GetWindowWithSDLWindow(SDL_Window* window);
+    void HandleEvent(SDL_Event& event);
+    bool HandleEventInternal(SDL_Event& event);
+    void CheckForWindowResize();
+    void UpdateCursor();
+
+#if PLATFORM_LINUX
+    DragDropEffect DoDragDropWayland(const StringView& data, Window* dragSourceWindow = nullptr, Float2 dragOffset = Float2::Zero);
+    DragDropEffect DoDragDropX11(const StringView& data);
+#endif
+
+public:
+
+    SDL_Window* GetSDLWindow() const;
+#if PLATFORM_LINUX
+    void* GetWaylandSurfacePtr() const;
+    void* GetWaylandDisplay() const;
+    uintptr GetX11WindowHandle() const;
+    void* GetX11Display() const;
+#endif
+
+    // [WindowBase]
+    void* GetNativePtr() const override;
+    void Show() override;
+    void Hide() override;
+    void Minimize() override;
+    void Maximize() override;
+    void SetBorderless(bool isBorderless, bool maximized = false) override;
+    void Restore() override;
+    bool IsClosed() const override;
+    bool IsForegroundWindow() const override;
+    void BringToFront(bool force = false) override;
+    void SetClientBounds(const Rectangle& clientArea) override;
+    void SetPosition(const Float2& position) override;
+    void SetClientPosition(const Float2& position) override;
+    void SetIsFullscreen(bool isFullscreen) override;
+    bool IsAlwaysOnTop() const override;
+    void SetIsAlwaysOnTop(bool isAlwaysOnTop) override;
+    Float2 GetPosition() const override;
+    Float2 GetSize() const override;
+    Float2 GetClientSize() const override;
+    Float2 ScreenToClient(const Float2& screenPos) const override;
+    Float2 ClientToScreen(const Float2& clientPos) const override;
+    void FlashWindow() override;
+    float GetOpacity() const override;
+    void SetOpacity(float opacity) override;
+    void Focus() override;
+    String GetTitle() const override;
+    void SetTitle(const StringView& title) override;
+    DragDropEffect DoDragDrop(const StringView& data) override;
+    DragDropEffect DoDragDrop(const StringView& data, const Float2& offset, Window* dragSourceWindow) override;
+    void StartTrackingMouse(bool useMouseScreenOffset) override;
+    void EndTrackingMouse() override;
+    void StartClippingCursor(const Rectangle& bounds) override;
+    void EndClippingCursor() override;
+    void SetCursor(CursorType type) override;
+
+#if USE_EDITOR && PLATFORM_WINDOWS
+    // [IUnknown]
+    Windows::HRESULT __stdcall QueryInterface(const Windows::IID& id, void** ppvObject) override;
+    Windows::ULONG __stdcall AddRef() override;
+    Windows::ULONG __stdcall Release() override;
+
+    // [Windows::IDropTarget]
+    Windows::HRESULT __stdcall DragEnter(Windows::IDataObject* pDataObj, Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect) override;
+    Windows::HRESULT __stdcall DragOver(Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect) override;
+    Windows::HRESULT __stdcall DragLeave() override;
+    Windows::HRESULT __stdcall Drop(Windows::IDataObject* pDataObj, Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect) override;
+#endif
+};
+
+#endif

Source/Engine/Platform/ScreenUtilities.h

@@ -0,0 +1,15 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_WINDOWS
+#include "Windows/WindowsScreenUtilities.h"
+#elif PLATFORM_LINUX
+#include "Linux/LinuxScreenUtilities.h"
+#elif PLATFORM_MAC
+#include "Mac/MacScreenUtilities.h"
+#else
+#include "Base/ScreenUtilitiesBase.h"
+#endif
+
+#include "Types.h"

Source/Engine/Platform/Types.h

@@ -4,8 +4,6 @@
 
 #if PLATFORM_WINDOWS
 
-class WindowsClipboard;
-typedef WindowsClipboard Clipboard;
 class Win32CriticalSection;
 typedef Win32CriticalSection CriticalSection;
 class Win32ConditionVariable;
@@ -16,21 +14,25 @@ class WindowsFileSystemWatcher;
 typedef WindowsFileSystemWatcher FileSystemWatcher;
 class Win32File;
 typedef Win32File File;
-class WindowsPlatform;
-typedef WindowsPlatform Platform;
 class Win32Thread;
 typedef Win32Thread Thread;
+class WindowsClipboard;
+typedef WindowsClipboard Clipboard;
+#if !PLATFORM_SDL
+class WindowsPlatform;
+typedef WindowsPlatform Platform;
 class WindowsWindow;
 typedef WindowsWindow Window;
+#endif
 class Win32Network;
 typedef Win32Network Network;
 class UserBase;
 typedef UserBase User;
+class WindowsScreenUtilities;
+typedef WindowsScreenUtilities ScreenUtilities;
 
 #elif PLATFORM_UWP
 
-class ClipboardBase;
-typedef ClipboardBase Clipboard;
 class Win32CriticalSection;
 typedef Win32CriticalSection CriticalSection;
 class Win32ConditionVariable;
@@ -41,21 +43,23 @@ class FileSystemWatcherBase;
 typedef FileSystemWatcherBase FileSystemWatcher;
 class Win32File;
 typedef Win32File File;
-class UWPPlatform;
-typedef UWPPlatform Platform;
 class Win32Thread;
 typedef Win32Thread Thread;
+class ClipboardBase;
+typedef ClipboardBase Clipboard;
+class UWPPlatform;
+typedef UWPPlatform Platform;
 class UWPWindow;
 typedef UWPWindow Window;
 class Win32Network;
 typedef Win32Network Network;
 class UserBase;
 typedef UserBase User;
+class ScreenUtilitiesBase;
+typedef ScreenUtilitiesBase ScreenUtilities;
 
 #elif PLATFORM_LINUX
 
-class LinuxClipboard;
-typedef LinuxClipboard Clipboard;
 class UnixCriticalSection;
 typedef UnixCriticalSection CriticalSection;
 class UnixConditionVariable;
@@ -66,21 +70,25 @@ class LinuxFileSystemWatcher;
 typedef LinuxFileSystemWatcher FileSystemWatcher;
 class UnixFile;
 typedef UnixFile File;
-class LinuxPlatform;
-typedef LinuxPlatform Platform;
 class LinuxThread;
 typedef LinuxThread Thread;
+#if !PLATFORM_SDL
+class LinuxClipboard;
+typedef LinuxClipboard Clipboard;
+class LinuxPlatform;
+typedef LinuxPlatform Platform;
 class LinuxWindow;
 typedef LinuxWindow Window;
+#endif
 class UnixNetwork;
 typedef UnixNetwork Network;
 class UserBase;
 typedef UserBase User;
+class LinuxScreenUtilities;
+typedef LinuxScreenUtilities ScreenUtilities;
 
 #elif PLATFORM_PS4
 
-class ClipboardBase;
-typedef ClipboardBase Clipboard;
 class UnixCriticalSection;
 typedef UnixCriticalSection CriticalSection;
 class UnixConditionVariable;
@@ -91,21 +99,23 @@ class FileSystemWatcherBase;
 typedef FileSystemWatcherBase FileSystemWatcher;
 class UnixFile;
 typedef UnixFile File;
-class PS4Platform;
-typedef PS4Platform Platform;
 class PS4Thread;
 typedef PS4Thread Thread;
+class ClipboardBase;
+typedef ClipboardBase Clipboard;
+class PS4Platform;
+typedef PS4Platform Platform;
 class PS4Window;
 typedef PS4Window Window;
 class PS4Network;
 typedef PS4Network Network;
 class PS4User;
 typedef PS4User User;
+class ScreenUtilitiesBase;
+typedef ScreenUtilitiesBase ScreenUtilities;
 
 #elif PLATFORM_PS5
 
-class ClipboardBase;
-typedef ClipboardBase Clipboard;
 class UnixCriticalSection;
 typedef UnixCriticalSection CriticalSection;
 class UnixConditionVariable;
@@ -116,21 +126,23 @@ class FileSystemWatcherBase;
 typedef FileSystemWatcherBase FileSystemWatcher;
 class UnixFile;
 typedef UnixFile File;
-class PS5Platform;
-typedef PS5Platform Platform;
+class ClipboardBase;
+typedef ClipboardBase Clipboard;
 class PS5Thread;
 typedef PS5Thread Thread;
+class PS5Platform;
+typedef PS5Platform Platform;
 class PS5Window;
 typedef PS5Window Window;
 class PS5Network;
 typedef PS5Network Network;
 class PS5User;
 typedef PS5User User;
+class ScreenUtilitiesBase;
+typedef ScreenUtilitiesBase ScreenUtilities;
 
 #elif PLATFORM_XBOX_ONE
 
-class ClipboardBase;
-typedef ClipboardBase Clipboard;
 class Win32CriticalSection;
 typedef Win32CriticalSection CriticalSection;
 class Win32ConditionVariable;
@@ -141,21 +153,23 @@ class FileSystemWatcherBase;
 typedef FileSystemWatcherBase FileSystemWatcher;
 class Win32File;
 typedef Win32File File;
-class XboxOnePlatform;
-typedef XboxOnePlatform Platform;
 class Win32Thread;
 typedef Win32Thread Thread;
+class ClipboardBase;
+typedef ClipboardBase Clipboard;
+class XboxOnePlatform;
+typedef XboxOnePlatform Platform;
 class GDKWindow;
 typedef GDKWindow Window;
 class Win32Network;
 typedef Win32Network Network;
 class GDKUser;
 typedef GDKUser User;
+class ScreenUtilitiesBase;
+typedef ScreenUtilitiesBase ScreenUtilities;
 
 #elif PLATFORM_XBOX_SCARLETT
 
-class ClipboardBase;
-typedef ClipboardBase Clipboard;
 class Win32CriticalSection;
 typedef Win32CriticalSection CriticalSection;
 class Win32ConditionVariable;
@@ -166,21 +180,23 @@ class FileSystemWatcherBase;
 typedef FileSystemWatcherBase FileSystemWatcher;
 class Win32File;
 typedef Win32File File;
-class XboxScarlettPlatform;
-typedef XboxScarlettPlatform Platform;
 class Win32Thread;
 typedef Win32Thread Thread;
+class ClipboardBase;
+typedef ClipboardBase Clipboard;
+class XboxScarlettPlatform;
+typedef XboxScarlettPlatform Platform;
 class GDKWindow;
 typedef GDKWindow Window;
 class Win32Network;
 typedef Win32Network Network;
 class GDKUser;
 typedef GDKUser User;
+class ScreenUtilitiesBase;
+typedef ScreenUtilitiesBase ScreenUtilities;
 
 #elif PLATFORM_ANDROID
 
-class ClipboardBase;
-typedef ClipboardBase Clipboard;
 class UnixCriticalSection;
 typedef UnixCriticalSection CriticalSection;
 class UnixConditionVariable;
@@ -191,21 +207,23 @@ class FileSystemWatcherBase;
 typedef FileSystemWatcherBase FileSystemWatcher;
 class AndroidFile;
 typedef AndroidFile File;
-class AndroidPlatform;
-typedef AndroidPlatform Platform;
 class AndroidThread;
 typedef AndroidThread Thread;
+class ClipboardBase;
+typedef ClipboardBase Clipboard;
+class AndroidPlatform;
+typedef AndroidPlatform Platform;
 class AndroidWindow;
 typedef AndroidWindow Window;
 class UnixNetwork;
 typedef UnixNetwork Network;
 class UserBase;
 typedef UserBase User;
+class ScreenUtilitiesBase;
+typedef ScreenUtilitiesBase ScreenUtilities;
 
 #elif PLATFORM_SWITCH
 
-class ClipboardBase;
-typedef ClipboardBase Clipboard;
 class SwitchCriticalSection;
 typedef SwitchCriticalSection CriticalSection;
 class SwitchConditionVariable;
@@ -216,21 +234,23 @@ class FileSystemWatcherBase;
 typedef FileSystemWatcherBase FileSystemWatcher;
 class SwitchFile;
 typedef SwitchFile File;
-class SwitchPlatform;
-typedef SwitchPlatform Platform;
 class SwitchThread;
 typedef SwitchThread Thread;
+class ClipboardBase;
+typedef ClipboardBase Clipboard;
+class SwitchPlatform;
+typedef SwitchPlatform Platform;
 class SwitchWindow;
 typedef SwitchWindow Window;
 class SwitchNetwork;
 typedef SwitchNetwork Network;
 class SwitchUser;
 typedef SwitchUser User;
+class ScreenUtilitiesBase;
+typedef ScreenUtilitiesBase ScreenUtilities;
 
 #elif PLATFORM_MAC
 
-class MacClipboard;
-typedef MacClipboard Clipboard;
 class UnixCriticalSection;
 typedef UnixCriticalSection CriticalSection;
 class UnixConditionVariable;
@@ -241,21 +261,23 @@ class MacFileSystemWatcher;
 typedef MacFileSystemWatcher FileSystemWatcher;
 class UnixFile;
 typedef UnixFile File;
-class MacPlatform;
-typedef MacPlatform Platform;
 class AppleThread;
 typedef AppleThread Thread;
+class MacClipboard;
+typedef MacClipboard Clipboard;
+class MacPlatform;
+typedef MacPlatform Platform;
 class MacWindow;
 typedef MacWindow Window;
 class UnixNetwork;
 typedef UnixNetwork Network;
 class UserBase;
 typedef UserBase User;
+class MacScreenUtilities;
+typedef MacScreenUtilities ScreenUtilities;
 
 #elif PLATFORM_IOS
 
-class ClipboardBase;
-typedef ClipboardBase Clipboard;
 class UnixCriticalSection;
 typedef UnixCriticalSection CriticalSection;
 class UnixConditionVariable;
@@ -266,19 +288,34 @@ class FileSystemWatcherBase;
 typedef FileSystemWatcherBase FileSystemWatcher;
 class iOSFile;
 typedef iOSFile File;
-class iOSPlatform;
-typedef iOSPlatform Platform;
 class AppleThread;
 typedef AppleThread Thread;
+class ClipboardBase;
+typedef ClipboardBase Clipboard;
+class iOSPlatform;
+typedef iOSPlatform Platform;
 class iOSWindow;
 typedef iOSWindow Window;
 class UnixNetwork;
 typedef UnixNetwork Network;
 class UserBase;
 typedef UserBase User;
+class ScreenUtilitiesBase;
+typedef ScreenUtilitiesBase ScreenUtilities;
 
 #else
 
 #error Missing Types implementation!
 
 #endif
+
+#if PLATFORM_SDL
+#if PLATFORM_LINUX
+class SDLClipboard;
+typedef SDLClipboard Clipboard;
+#endif
+class SDLPlatform;
+typedef SDLPlatform Platform;
+class SDLWindow;
+typedef SDLWindow Window;
+#endif

Source/Engine/Platform/Window.cs

@@ -17,31 +17,37 @@ namespace FlaxEngine
         /// <summary>
         /// Perform window hit test delegate.
         /// </summary>
-        /// <param name="mouse">The mouse position. The coordinate is relative to the upper-left corner of the screen. Use <see cref="ScreenToClient"/> to convert position into client space coordinates.</param>
+        /// <param name="mousePosition">The mouse position. The coordinate is relative to the upper-left corner of the screen. Use <see cref="ScreenToClient"/> to convert position into client space coordinates.</param>
         /// <returns>Hit result.</returns>
-        public delegate WindowHitCodes HitTestDelegate(ref Float2 mouse);
+        public delegate WindowHitCodes HitTestDelegate(ref Float2 mousePosition);
 
         /// <summary>
         /// Perform mouse buttons action.
         /// </summary>
-        /// <param name="mouse">The mouse position.</param>
+        /// <param name="mousePosition">The mouse position.</param>
         /// <param name="button">The mouse buttons state.</param>
         /// <param name="handled">The flag that indicated that event has been handled by the custom code and should not be passed further. By default it is set to false.</param>
-        public delegate void MouseButtonDelegate(ref Float2 mouse, MouseButton button, ref bool handled);
+        public delegate void MouseButtonDelegate(ref Float2 mousePosition, MouseButton button, ref bool handled);
 
         /// <summary>
         /// Perform mouse move action.
         /// </summary>
-        /// <param name="mouse">The mouse position.</param>
-        public delegate void MouseMoveDelegate(ref Float2 mouse);
+        /// <param name="mousePosition">The mouse position.</param>
+        public delegate void MouseMoveDelegate(ref Float2 mousePosition);
+        
+        /// <summary>
+        /// Perform mouse move action in relative mode.
+        /// </summary>
+        /// <param name="mouseMotion">The relative mouse motion.</param>
+        public delegate void MouseMoveRelativeDelegate(ref Float2 mouseMotion);
 
         /// <summary>
         /// Perform mouse wheel action.
         /// </summary>
-        /// <param name="mouse">The mouse position.</param>
+        /// <param name="mousePosition">The mouse position.</param>
         /// <param name="delta">The mouse wheel move delta (can be positive or negative; normalized to [-1;1] range).</param>
         /// <param name="handled">The flag that indicated that event has been handled by the custom code and should not be passed further. By default it is set to false.</param>
-        public delegate void MouseWheelDelegate(ref Float2 mouse, float delta, ref bool handled);
+        public delegate void MouseWheelDelegate(ref Float2 mousePosition, float delta, ref bool handled);
 
         /// <summary>
         /// Perform touch action.
@@ -99,9 +105,14 @@ namespace FlaxEngine
         public event MouseWheelDelegate MouseWheel;
 
         /// <summary>
-        /// Event fired when mouse moves
+        /// Event fired when mouse moves.
         /// </summary>
         public event MouseMoveDelegate MouseMove;
+        
+        /// <summary>
+        /// Event fired when mouse moves in relative mode.
+        /// </summary>
+        public event MouseMoveRelativeDelegate MouseMoveRelative;
 
         /// <summary>
         /// Event fired when mouse leaves window.
@@ -273,6 +284,12 @@ namespace FlaxEngine
             MouseMove?.Invoke(ref pos);
             GUI.OnMouseMove(pos);
         }
+        
+        internal void Internal_OnMouseMoveRelative(ref Float2 mouseMotion)
+        {
+            MouseMoveRelative?.Invoke(ref mouseMotion);
+            GUI.OnMouseMoveRelative(mouseMotion);
+        }
 
         internal void Internal_OnMouseLeave()
         {

Source/Engine/Platform/Window.h

@@ -2,7 +2,9 @@
 
 #pragma once
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_SDL
+#include "SDL/SDLWindow.h"
+#elif PLATFORM_WINDOWS
 #include "Windows/WindowsWindow.h"
 #elif PLATFORM_UWP
 #include "UWP/UWPWindow.h"

Source/Engine/Platform/Windows/WindowsFileSystem.cpp

@@ -2,6 +2,7 @@
 
 #if PLATFORM_WINDOWS
 
+#include "WindowsWindow.h"
 #include "WindowsFileSystem.h"
 #include "Engine/Platform/File.h"
 #include "Engine/Platform/Window.h"
@@ -317,7 +318,7 @@ bool WindowsFileSystem::ShowBrowseFolderDialog(Window* parentWindow, const Strin
         if (SUCCEEDED(SHCreateItemFromParsingName(initialDirectory.Get(), NULL, IID_PPV_ARGS(&defaultFolder))))
             fd->SetFolder(defaultFolder);
 
-        HWND hwndOwner = parentWindow ? parentWindow->GetHWND() : NULL;
+        HWND hwndOwner = parentWindow ? (HWND)parentWindow->GetNativePtr() : NULL;
         if (SUCCEEDED(fd->Show(hwndOwner)))
         {
             ComPtr<IShellItem> si;

Source/Engine/Platform/Windows/WindowsInput.cpp

@@ -1,6 +1,6 @@
 // Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS && !PLATFORM_SDL
 
 #include "WindowsInput.h"
 #include "WindowsWindow.h"
@@ -265,19 +265,38 @@ bool WindowsMouse::WndProc(Window* window, const UINT msg, WPARAM wParam, LPARAM
     }
     case WM_LBUTTONDBLCLK:
     {
-        OnMouseDoubleClick(mousePos, MouseButton::Left, window);
+        if (!Input::Mouse->IsRelative())
+            OnMouseDoubleClick(mousePos, MouseButton::Left, window);
+        else
+            OnMouseDown(mousePos, MouseButton::Left, window);
         result = true;
         break;
     }
     case WM_RBUTTONDBLCLK:
     {
-        OnMouseDoubleClick(mousePos, MouseButton::Right, window);
+        if (!Input::Mouse->IsRelative())
+            OnMouseDoubleClick(mousePos, MouseButton::Right, window);
+        else
+            OnMouseDown(mousePos, MouseButton::Right, window);
         result = true;
         break;
     }
     case WM_MBUTTONDBLCLK:
     {
-        OnMouseDoubleClick(mousePos, MouseButton::Middle, window);
+        if (!Input::Mouse->IsRelative())
+            OnMouseDoubleClick(mousePos, MouseButton::Middle, window);
+        else
+            OnMouseDown(mousePos, MouseButton::Middle, window);
+        result = true;
+        break;
+    }
+    case WM_XBUTTONDBLCLK:
+    {
+        const auto button = (HIWORD(wParam) & XBUTTON1) ? MouseButton::Extended1 : MouseButton::Extended2;
+        if (!Input::Mouse->IsRelative())
+            OnMouseDoubleClick(mousePos, button, window);
+        else
+            OnMouseDown(mousePos, button, window);
         result = true;
         break;
     }

Source/Engine/Platform/Windows/WindowsPlatform.cpp

@@ -4,6 +4,8 @@
 
 #include "Engine/Platform/Platform.h"
 #include "Engine/Platform/Window.h"
+#include "Engine/Platform/Windows/WindowsInput.h"
+#include "Engine/Platform/Windows/WindowsWindow.h"
 #include "Engine/Platform/FileSystem.h"
 #include "Engine/Platform/CreateWindowSettings.h"
 #include "Engine/Platform/CreateProcessSettings.h"
@@ -33,7 +35,6 @@
 #define CLR_EXCEPTION 0xE0434352
 #define VCPP_EXCEPTION 0xE06D7363
 
-const Char* WindowsPlatform::ApplicationWindowClass = TEXT("FlaxWindow");
 void* WindowsPlatform::Instance = nullptr;
 
 #if CRASH_LOG_ENABLE || TRACY_ENABLE
@@ -256,6 +257,8 @@ void GetWindowsVersion(String& windowsName, int32& versionMajor, int32& versionM
     RegCloseKey(hKey);
 }
 
+#if !PLATFORM_SDL
+
 LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 {
     // Find window to process that message
@@ -273,6 +276,8 @@ LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
     return DefWindowProc(hwnd, msg, wParam, lParam);
 }
 
+#endif
+
 long __stdcall WindowsPlatform::SehExceptionHandler(EXCEPTION_POINTERS* ep)
 {
     if (ep->ExceptionRecord->ExceptionCode == CLR_EXCEPTION)
@@ -437,11 +442,12 @@ DialogResult MessageBox::Show(Window* parent, const StringView& text, const Stri
         flags |= MB_ICONHAND;
         break;
     case MessageBoxIcon::Information:
+    case MessageBoxIcon::Question:
         flags |= MB_ICONINFORMATION;
         break;
-    case MessageBoxIcon::Question:
-        flags |= MB_ICONQUESTION;
-        break;
+    //case MessageBoxIcon::Question:
+    //    flags |= MB_ICONQUESTION;
+    //    break;
     case MessageBoxIcon::Stop:
         flags |= MB_ICONSTOP;
         break;
@@ -519,6 +525,7 @@ void WindowsPlatform::PreInit(void* hInstance)
     // Disable the process from being showing "ghosted" while not responding messages during slow tasks
     DisableProcessWindowsGhosting();
 
+#if !PLATFORM_SDL
     // Register window class
     WNDCLASS windowsClass;
     Platform::MemoryClear(&windowsClass, sizeof(WNDCLASS));
@@ -527,12 +534,13 @@ void WindowsPlatform::PreInit(void* hInstance)
     windowsClass.hInstance = (HINSTANCE)Instance;
     windowsClass.hIcon = LoadIconW(GetModuleHandle(nullptr), MAKEINTRESOURCE(IDR_MAINFRAME));
     windowsClass.hCursor = LoadCursor(nullptr, IDC_ARROW);
-    windowsClass.lpszClassName = ApplicationWindowClass;
+    windowsClass.lpszClassName = ApplicationClassName;
     if (!RegisterClassW(&windowsClass))
     {
         Error(TEXT("Window class registration failed!"));
         exit(-1);
     }
+#endif
 
     // Init OLE
     if (OleInitialize(nullptr) != S_OK)
@@ -681,11 +689,13 @@ bool WindowsPlatform::Init()
     DWORD tmp;
     Char buffer[256];
 
+#if !PLATFORM_SDL
     // Get user locale string
     if (GetUserDefaultLocaleName(buffer, LOCALE_NAME_MAX_LENGTH))
     {
         UserLocale = String(buffer);
     }
+#endif
 
     // Get computer name string
     if (GetComputerNameW(buffer, &tmp))
@@ -701,7 +711,9 @@ bool WindowsPlatform::Init()
     }
     OnPlatformUserAdd(New<User>(userName));
 
+#if !PLATFORM_SDL
     WindowsInput::Init();
+#endif
 
     return false;
 }
@@ -747,7 +759,9 @@ void WindowsPlatform::LogInfo()
 
 void WindowsPlatform::Tick()
 {
+#if !PLATFORM_SDL
     WindowsInput::Update();
+#endif
 
     // Check to see if any messages are waiting in the queue
     MSG msg;
@@ -778,8 +792,10 @@ void WindowsPlatform::Exit()
     DbgHelpUnlock();
 #endif
 
+#if !PLATFORM_SDL
     // Unregister app class
-    UnregisterClassW(ApplicationWindowClass, nullptr);
+    UnregisterClassW(ApplicationClassName, nullptr);
+#endif
 
     Win32Platform::Exit();
 }
@@ -856,6 +872,7 @@ BatteryInfo WindowsPlatform::GetBatteryInfo()
     return info;
 }
 
+#if !PLATFORM_SDL
 int32 WindowsPlatform::GetDpi()
 {
     return SystemDpi;
@@ -865,6 +882,7 @@ String WindowsPlatform::GetUserLocaleName()
 {
     return UserLocale;
 }
+#endif
 
 String WindowsPlatform::GetComputerName()
 {
@@ -1234,10 +1252,12 @@ int32 WindowsPlatform::CreateProcess(CreateProcessSettings& settings)
     return result;
 }
 
+#if !PLATFORM_SDL
 Window* WindowsPlatform::CreateWindow(const CreateWindowSettings& settings)
 {
     return New<WindowsWindow>(settings);
 }
+#endif
 
 void* WindowsPlatform::LoadLibrary(const Char* filename)
 {

Source/Engine/Platform/Windows/WindowsPlatform.h

@@ -13,11 +13,6 @@ class FLAXENGINE_API WindowsPlatform : public Win32Platform
 {
 public:
 
-    /// <summary>
-    /// Win32 application windows class name.
-    /// </summary>
-    static const Char* ApplicationWindowClass;
-
     /// <summary>
     /// Handle to Win32 application instance.
     /// </summary>
@@ -70,8 +65,10 @@ public:
     static String GetSystemName();
     static Version GetSystemVersion();
     static BatteryInfo GetBatteryInfo();
+#if !PLATFORM_SDL
     static int32 GetDpi();
     static String GetUserLocaleName();
+#endif
     static String GetComputerName();
     static bool GetHasFocus();
     static bool CanOpenUrl(const StringView& url);
@@ -85,7 +82,9 @@ public:
     static bool GetEnvironmentVariable(const String& name, String& value);
     static bool SetEnvironmentVariable(const String& name, const String& value);
     static int32 CreateProcess(CreateProcessSettings& settings);
+#if !PLATFORM_SDL
     static Window* CreateWindow(const CreateWindowSettings& settings);
+#endif
     static void* LoadLibrary(const Char* filename);
 #if CRASH_LOG_ENABLE
     static Array<StackFrame, HeapAllocation> GetStackFrames(int32 skipCount = 0, int32 maxDepth = 60, void* context = nullptr);

Source/Engine/Platform/Windows/WindowsScreenUtilities.cpp

@@ -0,0 +1,54 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_WINDOWS
+
+#include "Engine/Platform/Types.h"
+#include "Engine/Platform/ScreenUtilities.h"
+#include "Engine/Core/Math/Vector2.h"
+#include "Engine/Core/Delegate.h"
+#include "Engine/Core/Log.h"
+#include "Engine/Profiler/ProfilerCPU.h"
+
+#include <Windows.h>
+
+#pragma comment(lib, "Gdi32.lib")
+
+Delegate<Color32> ScreenUtilitiesBase::PickColorDone;
+
+static HHOOK MouseCallbackHook;
+
+LRESULT CALLBACK OnScreenUtilsMouseCallback(_In_ int nCode, _In_ WPARAM wParam, _In_ LPARAM lParam)
+{
+    if (nCode >= 0 && wParam == WM_LBUTTONDOWN)
+    {
+        UnhookWindowsHookEx(MouseCallbackHook);
+
+        // Push event with the picked color
+        const Float2 cursorPos = Platform::GetMousePosition();
+        const Color32 colorPicked = ScreenUtilities::GetColorAt(cursorPos);
+        ScreenUtilities::PickColorDone(colorPicked);
+        return 1;
+    }
+    return CallNextHookEx(NULL, nCode, wParam, lParam);
+}
+
+Color32 WindowsScreenUtilities::GetColorAt(const Float2& pos)
+{
+    PROFILE_CPU();
+    HDC deviceContext = GetDC(NULL);
+    COLORREF color = GetPixel(deviceContext, (int)pos.X, (int)pos.Y);
+    ReleaseDC(NULL, deviceContext);
+    return Color32(GetRValue(color), GetGValue(color), GetBValue(color), 255);
+}
+
+void WindowsScreenUtilities::PickColor()
+{
+    MouseCallbackHook = SetWindowsHookEx(WH_MOUSE_LL, OnScreenUtilsMouseCallback, NULL, NULL);
+    if (MouseCallbackHook == NULL)
+    {
+        LOG(Warning, "Failed to set mouse hook.");
+        LOG(Warning, "Error: {0}", GetLastError());
+    }
+}
+
+#endif

Source/Engine/Platform/Windows/WindowsScreenUtilities.h

@@ -0,0 +1,25 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_WINDOWS
+
+#include "Engine/Platform/Base/ScreenUtilitiesBase.h"
+#include "Engine/Core/Types/BaseTypes.h"
+#include "Engine/Core/Math/Color32.h"
+#include "Engine/Core/Math/Vector2.h"
+#include "Engine/Core/Delegate.h"
+
+/// <summary>
+/// Platform-dependent screen utilities.
+/// </summary>
+class FLAXENGINE_API WindowsScreenUtilities : public ScreenUtilitiesBase
+{
+public:
+    
+    // [ScreenUtilitiesBase]
+    static Color32 GetColorAt(const Float2& pos);
+    static void PickColor();
+};
+
+#endif

Source/Engine/Platform/Windows/WindowsWindow.DragDrop.cpp

@@ -0,0 +1,662 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if PLATFORM_WINDOWS
+
+#if PLATFORM_SDL
+#include "Engine/Platform/SDL/SDLWindow.h"
+#endif
+
+#include "Engine/Platform/Windows/WindowsWindow.h"
+
+#if USE_EDITOR
+#include "Engine/Core/Collections/Array.h"
+#include "Engine/Platform/IGuiData.h"
+#include "Engine/Platform/Base/DragDropHelper.h"
+#include "Engine/Input/Input.h"
+#include "Engine/Input/Mouse.h"
+#endif
+#include "../Win32/IncludeWindowsHeaders.h"
+#include <propidl.h>
+#if USE_EDITOR
+#include <oleidl.h>
+#include <shellapi.h>
+#endif
+
+#if USE_EDITOR
+
+Windows::HRESULT Window::QueryInterface(const Windows::IID& id, void** ppvObject)
+{
+    // Check to see what interface has been requested
+    if ((const IID&)id == IID_IUnknown || (const IID&)id == IID_IDropTarget)
+    {
+        AddRef();
+        *ppvObject = this;
+        return S_OK;
+    }
+
+    // No interface
+    *ppvObject = nullptr;
+    return E_NOINTERFACE;
+}
+
+Windows::ULONG Window::AddRef()
+{
+    _InterlockedIncrement(&_refCount);
+    return _refCount;
+}
+
+Windows::ULONG Window::Release()
+{
+    return _InterlockedDecrement(&_refCount);
+}
+
+HGLOBAL duplicateGlobalMem(HGLOBAL hMem)
+{
+    auto len = GlobalSize(hMem);
+    auto source = GlobalLock(hMem);
+    auto dest = GlobalAlloc(GMEM_FIXED, len);
+    Platform::MemoryCopy(dest, source, len);
+    GlobalUnlock(hMem);
+    return dest;
+}
+
+DWORD dropEffect2OleEnum(DragDropEffect effect)
+{
+    DWORD result;
+    switch (effect)
+    {
+    case DragDropEffect::None:
+        result = DROPEFFECT_NONE;
+        break;
+    case DragDropEffect::Copy:
+        result = DROPEFFECT_COPY;
+        break;
+    case DragDropEffect::Move:
+        result = DROPEFFECT_MOVE;
+        break;
+    case DragDropEffect::Link:
+        result = DROPEFFECT_LINK;
+        break;
+    default:
+        result = DROPEFFECT_NONE;
+        break;
+    }
+    return result;
+}
+
+DragDropEffect dropEffectFromOleEnum(DWORD effect)
+{
+    DragDropEffect result;
+    switch (effect)
+    {
+    case DROPEFFECT_NONE:
+        result = DragDropEffect::None;
+        break;
+    case DROPEFFECT_COPY:
+        result = DragDropEffect::Copy;
+        break;
+    case DROPEFFECT_MOVE:
+        result = DragDropEffect::Move;
+        break;
+    case DROPEFFECT_LINK:
+        result = DragDropEffect::Link;
+        break;
+    default:
+        result = DragDropEffect::None;
+        break;
+    }
+    return result;
+}
+
+HANDLE StringToHandle(const StringView& str)
+{
+    // Allocate and lock a global memory buffer.
+    // Make it fixed data so we don't have to use GlobalLock
+    const int32 length = str.Length();
+    char* ptr = static_cast<char*>(GlobalAlloc(GMEM_FIXED, length + 1));
+
+    // Copy the string into the buffer as ANSI text
+    StringUtils::ConvertUTF162ANSI(str.Get(), ptr, length);
+    ptr[length] = '\0';
+
+    return ptr;
+}
+
+void DeepCopyFormatEtc(FORMATETC* dest, FORMATETC* source)
+{
+    // Copy the source FORMATETC into dest
+    *dest = *source;
+
+    if (source->ptd)
+    {
+        // Allocate memory for the DVTARGETDEVICE if necessary
+        dest->ptd = static_cast<DVTARGETDEVICE*>(CoTaskMemAlloc(sizeof(DVTARGETDEVICE)));
+
+        // Copy the contents of the source DVTARGETDEVICE into dest->ptd
+        *(dest->ptd) = *(source->ptd);
+    }
+}
+
+HRESULT CreateEnumFormatEtc(UINT nNumFormats, FORMATETC* pFormatEtc, IEnumFORMATETC** ppEnumFormatEtc);
+
+/// <summary>
+/// GUI data for Windows platform
+/// </summary>
+class WindowsGuiData : public IGuiData
+{
+private:
+    Type _type;
+    Array<String> _data;
+
+public:
+    /// <summary>
+    /// Init
+    /// </summary>
+    WindowsGuiData()
+        : _type(Type::Unknown)
+        , _data(1)
+    {
+    }
+
+public:
+    /// <summary>
+    /// Init from Ole IDataObject
+    /// </summary>
+    /// <param name="pDataObj">Object</param>
+    void Init(IDataObject* pDataObj)
+    {
+        // Temporary data
+        FORMATETC fmtetc;
+        STGMEDIUM stgmed;
+
+        // Clear
+        _type = Type::Unknown;
+        _data.Clear();
+
+        // Check type
+        fmtetc = { CF_TEXT, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
+        if (pDataObj->GetData(&fmtetc, &stgmed) == S_OK)
+        {
+            // Text
+            _type = Type::Text;
+
+            // Get data
+            char* text = static_cast<char*>(GlobalLock(stgmed.hGlobal));
+            _data.Add(String(text));
+            GlobalUnlock(stgmed.hGlobal);
+            ReleaseStgMedium(&stgmed);
+        }
+        else
+        {
+            fmtetc = { CF_UNICODETEXT, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
+            if (pDataObj->GetData(&fmtetc, &stgmed) == S_OK)
+            {
+                // Unicode Text
+                _type = Type::Text;
+
+                // Get data
+                Char* text = static_cast<Char*>(GlobalLock(stgmed.hGlobal));
+                _data.Add(String(text));
+                GlobalUnlock(stgmed.hGlobal);
+                ReleaseStgMedium(&stgmed);
+            }
+            else
+            {
+                fmtetc = { CF_HDROP, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
+                if (pDataObj->GetData(&fmtetc, &stgmed) == S_OK)
+                {
+                    // Files
+                    _type = Type::Files;
+
+                    // Get data
+                    Char item[MAX_PATH];
+                    HDROP hdrop = static_cast<HDROP>(GlobalLock(stgmed.hGlobal));
+                    UINT filesCount = DragQueryFileW(hdrop, 0xFFFFFFFF, nullptr, 0);
+                    for (UINT i = 0; i < filesCount; i++)
+                    {
+                        if (DragQueryFileW(hdrop, i, item, MAX_PATH) != 0)
+                        {
+                            _data.Add(String(item));
+                        }
+                    }
+                    GlobalUnlock(stgmed.hGlobal);
+                    ReleaseStgMedium(&stgmed);
+                }
+            }
+        }
+    }
+
+public:
+    // [IGuiData]
+    Type GetType() const override
+    {
+        return _type;
+    }
+    String GetAsText() const override
+    {
+        String result;
+        if (_type == Type::Text)
+        {
+            result = _data[0];
+        }
+        return result;
+    }
+    void GetAsFiles(Array<String>* files) const override
+    {
+        if (_type == Type::Files)
+        {
+            files->Add(_data);
+        }
+    }
+};
+
+/// <summary>
+/// Tool class for Windows Ole support
+/// </summary>
+class WindowsEnumFormatEtc : public IEnumFORMATETC
+{
+private:
+    ULONG _refCount;
+    ULONG _index;
+    ULONG _formatsCount;
+    FORMATETC* _formatEtc;
+
+public:
+    WindowsEnumFormatEtc(FORMATETC* pFormatEtc, int32 nNumFormats)
+        : _refCount(1)
+        , _index(0)
+        , _formatsCount(nNumFormats)
+        , _formatEtc(nullptr)
+    {
+        // Allocate memory
+        _formatEtc = new FORMATETC[nNumFormats];
+
+        // Copy the FORMATETC structures
+        for (int32 i = 0; i < nNumFormats; i++)
+        {
+            DeepCopyFormatEtc(&_formatEtc[i], &pFormatEtc[i]);
+        }
+    }
+
+    ~WindowsEnumFormatEtc()
+    {
+        if (_formatEtc)
+        {
+            for (uint32 i = 0; i < _formatsCount; i++)
+            {
+                if (_formatEtc[i].ptd)
+                {
+                    CoTaskMemFree(_formatEtc[i].ptd);
+                }
+            }
+
+            delete[] _formatEtc;
+        }
+    }
+
+public:
+    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, _COM_Outptr_ void __RPC_FAR* __RPC_FAR* ppvObject) override
+    {
+        // Check to see what interface has been requested
+        if (riid == IID_IEnumFORMATETC || riid == IID_IUnknown)
+        {
+            AddRef();
+            *ppvObject = this;
+            return S_OK;
+        }
+
+        // No interface
+        *ppvObject = nullptr;
+        return E_NOINTERFACE;
+    }
+    ULONG STDMETHODCALLTYPE AddRef() override
+    {
+        _InterlockedIncrement(&_refCount);
+        return _refCount;
+    }
+    ULONG STDMETHODCALLTYPE Release() override
+    {
+        ULONG ulRefCount = _InterlockedDecrement(&_refCount);
+        if (_refCount == 0)
+        {
+            delete this;
+        }
+        return ulRefCount;
+    }
+
+    // [IEnumFormatEtc]
+    HRESULT STDMETHODCALLTYPE Next(ULONG celt, FORMATETC* pFormatEtc, ULONG* pceltFetched) override
+    {
+        ULONG copied = 0;
+
+        // validate arguments
+        if (celt == 0 || pFormatEtc == nullptr)
+            return E_INVALIDARG;
+
+        // copy FORMATETC structures into caller's buffer
+        while (_index < _formatsCount && copied < celt)
+        {
+            DeepCopyFormatEtc(&pFormatEtc[copied], &_formatEtc[_index]);
+            copied++;
+            _index++;
+        }
+
+        // store result
+        if (pceltFetched != nullptr)
+            *pceltFetched = copied;
+
+        // did we copy all that was requested?
+        return (copied == celt) ? S_OK : S_FALSE;
+    }
+    HRESULT STDMETHODCALLTYPE Skip(ULONG celt) override
+    {
+        _index += celt;
+        return (_index <= _formatsCount) ? S_OK : S_FALSE;
+    }
+    HRESULT STDMETHODCALLTYPE Reset() override
+    {
+        _index = 0;
+        return S_OK;
+    }
+    HRESULT STDMETHODCALLTYPE Clone(IEnumFORMATETC** ppEnumFormatEtc) override
+    {
+        HRESULT result;
+
+        // Make a duplicate enumerator
+        result = CreateEnumFormatEtc(_formatsCount, _formatEtc, ppEnumFormatEtc);
+
+        if (result == S_OK)
+        {
+            // Manually set the index state
+            static_cast<WindowsEnumFormatEtc*>(*ppEnumFormatEtc)->_index = _index;
+        }
+
+        return result;
+    }
+};
+
+HRESULT CreateEnumFormatEtc(UINT nNumFormats, FORMATETC* pFormatEtc, IEnumFORMATETC** ppEnumFormatEtc)
+{
+    if (nNumFormats == 0 || pFormatEtc == nullptr || ppEnumFormatEtc == nullptr)
+        return E_INVALIDARG;
+    *ppEnumFormatEtc = new WindowsEnumFormatEtc(pFormatEtc, nNumFormats);
+    return *ppEnumFormatEtc ? S_OK : E_OUTOFMEMORY;
+}
+
+/// <summary>
+/// Drag drop source and data container for Ole
+/// </summary>
+class WindowsDragSource : public IDataObject, public IDropSource
+{
+private:
+    ULONG _refCount;
+    int32 _formatsCount;
+    FORMATETC* _formatEtc;
+    STGMEDIUM* _stgMedium;
+
+public:
+    WindowsDragSource(FORMATETC* fmtetc, STGMEDIUM* stgmed, int32 count)
+        : _refCount(1)
+        , _formatsCount(count)
+        , _formatEtc(nullptr)
+        , _stgMedium(nullptr)
+    {
+        // Allocate memory
+        _formatEtc = new FORMATETC[count];
+        _stgMedium = new STGMEDIUM[count];
+
+        // Copy descriptors
+        for (int32 i = 0; i < count; i++)
+        {
+            _formatEtc[i] = fmtetc[i];
+            _stgMedium[i] = stgmed[i];
+        }
+    }
+
+    virtual ~WindowsDragSource()
+    {
+        delete[] _formatEtc;
+        delete[] _stgMedium;
+    }
+
+public:
+    // [IUnknown]
+    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, _COM_Outptr_ void __RPC_FAR* __RPC_FAR* ppvObject) override
+    {
+        // Check to see what interface has been requested
+        if (riid == IID_IDataObject || riid == IID_IUnknown || riid == IID_IDropSource)
+        {
+            AddRef();
+            *ppvObject = this;
+            return S_OK;
+        }
+
+        // No interface
+        *ppvObject = nullptr;
+        return E_NOINTERFACE;
+    }
+
+    ULONG STDMETHODCALLTYPE AddRef() override
+    {
+        _InterlockedIncrement(&_refCount);
+        return _refCount;
+    }
+
+    ULONG STDMETHODCALLTYPE Release() override
+    {
+        ULONG ulRefCount = _InterlockedDecrement(&_refCount);
+        if (_refCount == 0)
+        {
+            delete this;
+        }
+        return ulRefCount;
+    }
+
+    // [IDropSource]
+    HRESULT STDMETHODCALLTYPE QueryContinueDrag(_In_ BOOL fEscapePressed, _In_ DWORD grfKeyState) override
+    {
+        // If the Escape key has been pressed since the last call, cancel the drop
+        if (fEscapePressed == TRUE || grfKeyState & MK_RBUTTON)
+            return DRAGDROP_S_CANCEL;
+
+        // If the LeftMouse button has been released, then do the drop!
+        if ((grfKeyState & MK_LBUTTON) == 0)
+            return DRAGDROP_S_DROP;
+
+        // Continue with the drag-drop
+        return S_OK;
+    }
+    HRESULT STDMETHODCALLTYPE GiveFeedback(_In_ DWORD dwEffect) override
+    {
+        // TODO: allow to use custom mouse cursor during drop and drag operation
+        return DRAGDROP_S_USEDEFAULTCURSORS;
+    }
+
+    // [IDataObject]
+    HRESULT STDMETHODCALLTYPE GetData(_In_ FORMATETC* pformatetcIn, _Out_ STGMEDIUM* pmedium) override
+    {
+        if (pformatetcIn == nullptr || pmedium == nullptr)
+            return E_INVALIDARG;
+
+        // Try to match the specified FORMATETC with one of our supported formats
+        int32 index = lookupFormatEtc(pformatetcIn);
+        if (index == INVALID_INDEX)
+            return DV_E_FORMATETC;
+
+        // Found a match - transfer data into supplied storage medium
+        pmedium->tymed = _formatEtc[index].tymed;
+        pmedium->pUnkForRelease = nullptr;
+
+        // Copy the data into the caller's storage medium
+        switch (_formatEtc[index].tymed)
+        {
+        case TYMED_HGLOBAL:
+            pmedium->hGlobal = duplicateGlobalMem(_stgMedium[index].hGlobal);
+            break;
+
+        default:
+            return DV_E_FORMATETC;
+        }
+
+        return S_OK;
+    }
+    HRESULT STDMETHODCALLTYPE GetDataHere(_In_ FORMATETC* pformatetc, _Inout_ STGMEDIUM* pmedium) override
+    {
+        return DATA_E_FORMATETC;
+    }
+    HRESULT STDMETHODCALLTYPE QueryGetData(__RPC__in_opt FORMATETC* pformatetc) override
+    {
+        return lookupFormatEtc(pformatetc) == INVALID_INDEX ? DV_E_FORMATETC : S_OK;
+    }
+    HRESULT STDMETHODCALLTYPE GetCanonicalFormatEtc(__RPC__in_opt FORMATETC* pformatectIn, __RPC__out FORMATETC* pformatetcOut) override
+    {
+        // Apparently we have to set this field to NULL even though we don't do anything else
+        pformatetcOut->ptd = nullptr;
+        return E_NOTIMPL;
+    }
+    HRESULT STDMETHODCALLTYPE SetData(_In_ FORMATETC* pformatetc, _In_ STGMEDIUM* pmedium, BOOL fRelease) override
+    {
+        return E_NOTIMPL;
+    }
+    HRESULT STDMETHODCALLTYPE EnumFormatEtc(DWORD dwDirection, __RPC__deref_out_opt IEnumFORMATETC** ppenumFormatEtc) override
+    {
+        // Only the get direction is supported for OLE
+        if (dwDirection == DATADIR_GET)
+        {
+            // TODO: use SHCreateStdEnumFmtEtc API call
+            return CreateEnumFormatEtc(_formatsCount, _formatEtc, ppenumFormatEtc);
+        }
+
+        // The direction specified is not supported for drag+drop
+        return E_NOTIMPL;
+    }
+    HRESULT STDMETHODCALLTYPE DAdvise(__RPC__in FORMATETC* pformatetc, DWORD advf, __RPC__in_opt IAdviseSink* pAdvSink, __RPC__out DWORD* pdwConnection) override
+    {
+        return OLE_E_ADVISENOTSUPPORTED;
+    }
+    HRESULT STDMETHODCALLTYPE DUnadvise(DWORD dwConnection) override
+    {
+        return OLE_E_ADVISENOTSUPPORTED;
+    }
+    HRESULT STDMETHODCALLTYPE EnumDAdvise(__RPC__deref_out_opt IEnumSTATDATA** ppenumAdvise) override
+    {
+        return OLE_E_ADVISENOTSUPPORTED;
+    }
+
+private:
+    int32 lookupFormatEtc(FORMATETC* pFormatEtc) const
+    {
+        // Check each of our formats in turn to see if one matches
+        for (int32 i = 0; i < _formatsCount; i++)
+        {
+            if ((_formatEtc[i].tymed & pFormatEtc->tymed) &&
+                _formatEtc[i].cfFormat == pFormatEtc->cfFormat &&
+                _formatEtc[i].dwAspect == pFormatEtc->dwAspect)
+            {
+                // Return index of stored format
+                return i;
+            }
+        }
+
+        // Format not found
+        return INVALID_INDEX;
+    }
+};
+
+WindowsGuiData GuiDragDropData;
+
+DragDropEffect Window::DoDragDrop(const StringView& data)
+{
+    // Create background worker that will keep updating GUI (perform rendering)
+    const auto task = New<DoDragDropJob>();
+    Task::StartNew(task);
+    while (task->GetState() == TaskState::Queued)
+        Platform::Sleep(1);
+
+    // Create descriptors
+    FORMATETC fmtetc = { CF_TEXT, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
+    STGMEDIUM stgmed = { TYMED_HGLOBAL, { nullptr }, nullptr };
+
+    // Create a HGLOBAL inside the storage medium
+    stgmed.hGlobal = StringToHandle(data);
+
+    // Create drop source
+    auto dropSource = new WindowsDragSource(&fmtetc, &stgmed, 1);
+
+    // Do the drag drop operation
+    DWORD dwEffect;
+    HRESULT result = ::DoDragDrop(dropSource, dropSource, DROPEFFECT_COPY | DROPEFFECT_MOVE | DROPEFFECT_LINK | DROPEFFECT_SCROLL, &dwEffect);
+
+    // Wait for job end
+    Platform::AtomicStore(&task->ExitFlag, 1);
+    task->Wait();
+
+    // Release allocated data
+    dropSource->Release();
+    ReleaseStgMedium(&stgmed);
+
+    // Fix hanging mouse state (Windows doesn't send WM_LBUTTONUP when we end the drag and drop)
+    if (Input::GetMouseButton(MouseButton::Left))
+    {
+        ::POINT point;
+        ::GetCursorPos(&point);
+#if PLATFORM_SDL
+        // Reset the internal button state in SDL
+        SendMessageA((HWND)_handle, WM_LBUTTONUP, 0, MAKELPARAM(point.x, point.y));
+#else
+        Input::Mouse->OnMouseUp(Float2((float)point.x, (float)point.y), MouseButton::Left, this);
+#endif
+    }
+
+    return SUCCEEDED(result) ? dropEffectFromOleEnum(dwEffect) : DragDropEffect::None;
+}
+
+HRESULT Window::DragEnter(Windows::IDataObject* pDataObj, Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect)
+{
+    POINT p = { pt.x, pt.y };
+    ::ScreenToClient((HWND)_handle, &p);
+    GuiDragDropData.Init((IDataObject*)pDataObj);
+    DragDropEffect effect = DragDropEffect::None;
+    OnDragEnter(&GuiDragDropData, Float2(static_cast<float>(p.x), static_cast<float>(p.y)), effect);
+    Focus();
+    *pdwEffect = dropEffect2OleEnum(effect);
+    return S_OK;
+}
+
+HRESULT Window::DragOver(Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect)
+{
+    POINT p = { pt.x, pt.y };
+    ::ScreenToClient((HWND)_handle, &p);
+    DragDropEffect effect = DragDropEffect::None;
+    OnDragOver(&GuiDragDropData, Float2(static_cast<float>(p.x), static_cast<float>(p.y)), effect);
+    *pdwEffect = dropEffect2OleEnum(effect);
+    return S_OK;
+}
+
+HRESULT Window::DragLeave()
+{
+    OnDragLeave();
+    return S_OK;
+}
+
+HRESULT Window::Drop(Windows::IDataObject* pDataObj, Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect)
+{
+    POINT p = { pt.x, pt.y };
+    ::ScreenToClient((HWND)_handle, &p);
+    GuiDragDropData.Init((IDataObject*)pDataObj);
+    DragDropEffect effect = DragDropEffect::None;
+    OnDragDrop(&GuiDragDropData, Float2(static_cast<float>(p.x), static_cast<float>(p.y)), effect);
+    *pdwEffect = dropEffect2OleEnum(effect);
+    return S_OK;
+}
+
+#else
+
+DragDropEffect Window::DoDragDrop(const StringView& data)
+{
+    return DragDropEffect::None;
+}
+
+#endif
+
+#endif

Source/Engine/Platform/Windows/WindowsWindow.cpp

@@ -1,6 +1,6 @@
 // Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS && !PLATFORM_SDL
 
 #include "WindowsWindow.h"
 #include "WindowsPlatform.h"
@@ -10,13 +10,6 @@
 #include "Engine/Graphics/GPUSwapChain.h"
 #include "Engine/Graphics/RenderTask.h"
 #include "Engine/Graphics/GPUDevice.h"
-#if USE_EDITOR
-#include "Engine/Core/Collections/Array.h"
-#include "Engine/Platform/IGuiData.h"
-#include "Engine/Platform/Base/DragDropHelper.h"
-#include "Engine/Input/Input.h"
-#include "Engine/Input/Mouse.h"
-#endif
 #include "../Win32/IncludeWindowsHeaders.h"
 #include <propidl.h>
 #if USE_EDITOR
@@ -118,7 +111,7 @@ WindowsWindow::WindowsWindow(const CreateWindowSettings& settings)
         if (settings.IsRegularWindow)
             style |= WS_BORDER | WS_CAPTION | WS_DLGFRAME | WS_SYSMENU | WS_THICKFRAME | WS_GROUP;
 #elif WINDOWS_USE_NEWER_BORDER_LESS
-        if (settings.IsRegularWindow)
+        if (settings.Type == WindowType::Regular)
             style |= WS_THICKFRAME | WS_SYSMENU | WS_CAPTION;
 #endif
         exStyle |= WS_EX_WINDOWEDGE;
@@ -127,7 +120,7 @@ WindowsWindow::WindowsWindow(const CreateWindowSettings& settings)
     // Creating the window
     _handle = CreateWindowExW(
         exStyle,
-        Platform::ApplicationWindowClass,
+        Platform::ApplicationClassName,
         settings.Title.GetText(),
         style,
         x,
@@ -162,7 +155,7 @@ WindowsWindow::WindowsWindow(const CreateWindowSettings& settings)
 
 #if WINDOWS_USE_NEWER_BORDER_LESS
     // Enable shadow
-    if (_settings.IsRegularWindow && !_settings.HasBorder && IsCompositionEnabled())
+    if (settings.Type == WindowType::Regular && !_settings.HasBorder && IsCompositionEnabled())
     {
         const int margin[4] = { 1, 1, 1, 1 };
         ::DwmExtendFrameIntoClientArea(_handle, margin);
@@ -295,7 +288,7 @@ void WindowsWindow::SetBorderless(bool isBorderless, bool maximized)
         if (_settings.IsRegularWindow)
             style |= WS_BORDER | WS_CAPTION | WS_DLGFRAME | WS_SYSMENU | WS_THICKFRAME | WS_GROUP;
 #elif WINDOWS_USE_NEWER_BORDER_LESS
-        if (_settings.IsRegularWindow)
+        if (_settings.Type == WindowType::Regular)
             lStyle |= WS_THICKFRAME | WS_SYSMENU;
 #endif
 
@@ -371,7 +364,7 @@ void WindowsWindow::BringToFront(bool force)
 {
     ASSERT(HasHWND());
 
-    if (_settings.IsRegularWindow)
+    if (_settings.Type == WindowType::Regular)
     {
         if (IsIconic(_handle))
         {
@@ -698,36 +691,6 @@ void WindowsWindow::SetCursor(CursorType type)
     UpdateCursor();
 }
 
-#if USE_EDITOR
-
-Windows::HRESULT WindowsWindow::QueryInterface(const Windows::IID& id, void** ppvObject)
-{
-    // Check to see what interface has been requested
-    if ((const IID&)id == IID_IUnknown || (const IID&)id == IID_IDropTarget)
-    {
-        AddRef();
-        *ppvObject = this;
-        return S_OK;
-    }
-
-    // No interface
-    *ppvObject = nullptr;
-    return E_NOINTERFACE;
-}
-
-Windows::ULONG WindowsWindow::AddRef()
-{
-    _InterlockedIncrement(&_refCount);
-    return _refCount;
-}
-
-Windows::ULONG WindowsWindow::Release()
-{
-    return _InterlockedDecrement(&_refCount);
-}
-
-#endif
-
 void WindowsWindow::CheckForWindowResize()
 {
     // Skip for minimized window (GetClientRect for minimized window returns 0)
@@ -1345,617 +1308,11 @@ LRESULT WindowsWindow::WndProc(UINT msg, WPARAM wParam, LPARAM lParam)
 
     if (_settings.AllowInput)
     {
-        if (WindowsInput::WndProc(this, msg, wParam, lParam))
+        if (WindowsInput::WndProc((Window*)this, msg, wParam, lParam))
             return true;
     }
 
     return DefWindowProc(_handle, msg, wParam, lParam);
 }
 
-#if USE_EDITOR
-
-HGLOBAL duplicateGlobalMem(HGLOBAL hMem)
-{
-    auto len = GlobalSize(hMem);
-    auto source = GlobalLock(hMem);
-    auto dest = GlobalAlloc(GMEM_FIXED, len);
-    Platform::MemoryCopy(dest, source, len);
-    GlobalUnlock(hMem);
-    return dest;
-}
-
-DWORD dropEffect2OleEnum(DragDropEffect effect)
-{
-    DWORD result;
-    switch (effect)
-    {
-    case DragDropEffect::None:
-        result = DROPEFFECT_NONE;
-        break;
-    case DragDropEffect::Copy:
-        result = DROPEFFECT_COPY;
-        break;
-    case DragDropEffect::Move:
-        result = DROPEFFECT_MOVE;
-        break;
-    case DragDropEffect::Link:
-        result = DROPEFFECT_LINK;
-        break;
-    default:
-        result = DROPEFFECT_NONE;
-        break;
-    }
-    return result;
-}
-
-DragDropEffect dropEffectFromOleEnum(DWORD effect)
-{
-    DragDropEffect result;
-    switch (effect)
-    {
-    case DROPEFFECT_NONE:
-        result = DragDropEffect::None;
-        break;
-    case DROPEFFECT_COPY:
-        result = DragDropEffect::Copy;
-        break;
-    case DROPEFFECT_MOVE:
-        result = DragDropEffect::Move;
-        break;
-    case DROPEFFECT_LINK:
-        result = DragDropEffect::Link;
-        break;
-    default:
-        result = DragDropEffect::None;
-        break;
-    }
-    return result;
-}
-
-HANDLE StringToHandle(const StringView& str)
-{
-    // Allocate and lock a global memory buffer.
-    // Make it fixed data so we don't have to use GlobalLock
-    const int32 length = str.Length();
-    char* ptr = static_cast<char*>(GlobalAlloc(GMEM_FIXED, length + 1));
-
-    // Copy the string into the buffer as ANSI text
-    StringUtils::ConvertUTF162ANSI(str.Get(), ptr, length);
-    ptr[length] = '\0';
-
-    return ptr;
-}
-
-void DeepCopyFormatEtc(FORMATETC* dest, FORMATETC* source)
-{
-    // Copy the source FORMATETC into dest
-    *dest = *source;
-
-    if (source->ptd)
-    {
-        // Allocate memory for the DVTARGETDEVICE if necessary
-        dest->ptd = static_cast<DVTARGETDEVICE*>(CoTaskMemAlloc(sizeof(DVTARGETDEVICE)));
-
-        // Copy the contents of the source DVTARGETDEVICE into dest->ptd
-        *(dest->ptd) = *(source->ptd);
-    }
-}
-
-HRESULT CreateEnumFormatEtc(UINT nNumFormats, FORMATETC* pFormatEtc, IEnumFORMATETC** ppEnumFormatEtc);
-
-/// <summary>
-/// GUI data for Windows platform
-/// </summary>
-class WindowsGuiData : public IGuiData
-{
-private:
-    Type _type;
-    Array<String> _data;
-
-public:
-    /// <summary>
-    /// Init
-    /// </summary>
-    WindowsGuiData()
-        : _type(Type::Unknown)
-        , _data(1)
-    {
-    }
-
-public:
-    /// <summary>
-    /// Init from Ole IDataObject
-    /// </summary>
-    /// <param name="pDataObj">Object</param>
-    void Init(IDataObject* pDataObj)
-    {
-        // Temporary data
-        FORMATETC fmtetc;
-        STGMEDIUM stgmed;
-
-        // Clear
-        _type = Type::Unknown;
-        _data.Clear();
-
-        // Check type
-        fmtetc = { CF_TEXT, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
-        if (pDataObj->GetData(&fmtetc, &stgmed) == S_OK)
-        {
-            // Text
-            _type = Type::Text;
-
-            // Get data
-            char* text = static_cast<char*>(GlobalLock(stgmed.hGlobal));
-            _data.Add(String(text));
-            GlobalUnlock(stgmed.hGlobal);
-            ReleaseStgMedium(&stgmed);
-        }
-        else
-        {
-            fmtetc = { CF_UNICODETEXT, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
-            if (pDataObj->GetData(&fmtetc, &stgmed) == S_OK)
-            {
-                // Unicode Text
-                _type = Type::Text;
-
-                // Get data
-                Char* text = static_cast<Char*>(GlobalLock(stgmed.hGlobal));
-                _data.Add(String(text));
-                GlobalUnlock(stgmed.hGlobal);
-                ReleaseStgMedium(&stgmed);
-            }
-            else
-            {
-                fmtetc = { CF_HDROP, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
-                if (pDataObj->GetData(&fmtetc, &stgmed) == S_OK)
-                {
-                    // Files
-                    _type = Type::Files;
-
-                    // Get data
-                    Char item[MAX_PATH];
-                    HDROP hdrop = static_cast<HDROP>(GlobalLock(stgmed.hGlobal));
-                    UINT filesCount = DragQueryFileW(hdrop, 0xFFFFFFFF, nullptr, 0);
-                    for (UINT i = 0; i < filesCount; i++)
-                    {
-                        if (DragQueryFileW(hdrop, i, item, MAX_PATH) != 0)
-                        {
-                            _data.Add(String(item));
-                        }
-                    }
-                    GlobalUnlock(stgmed.hGlobal);
-                    ReleaseStgMedium(&stgmed);
-                }
-            }
-        }
-    }
-
-public:
-    // [IGuiData]
-    Type GetType() const override
-    {
-        return _type;
-    }
-    String GetAsText() const override
-    {
-        String result;
-        if (_type == Type::Text)
-        {
-            result = _data[0];
-        }
-        return result;
-    }
-    void GetAsFiles(Array<String>* files) const override
-    {
-        if (_type == Type::Files)
-        {
-            files->Add(_data);
-        }
-    }
-};
-
-/// <summary>
-/// Tool class for Windows Ole support
-/// </summary>
-class WindowsEnumFormatEtc : public IEnumFORMATETC
-{
-private:
-    ULONG _refCount;
-    ULONG _index;
-    ULONG _formatsCount;
-    FORMATETC* _formatEtc;
-
-public:
-    WindowsEnumFormatEtc(FORMATETC* pFormatEtc, int32 nNumFormats)
-        : _refCount(1)
-        , _index(0)
-        , _formatsCount(nNumFormats)
-        , _formatEtc(nullptr)
-    {
-        // Allocate memory
-        _formatEtc = new FORMATETC[nNumFormats];
-
-        // Copy the FORMATETC structures
-        for (int32 i = 0; i < nNumFormats; i++)
-        {
-            DeepCopyFormatEtc(&_formatEtc[i], &pFormatEtc[i]);
-        }
-    }
-
-    ~WindowsEnumFormatEtc()
-    {
-        if (_formatEtc)
-        {
-            for (uint32 i = 0; i < _formatsCount; i++)
-            {
-                if (_formatEtc[i].ptd)
-                {
-                    CoTaskMemFree(_formatEtc[i].ptd);
-                }
-            }
-
-            delete[] _formatEtc;
-        }
-    }
-
-public:
-    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, _COM_Outptr_ void __RPC_FAR *__RPC_FAR * ppvObject) override
-    {
-        // Check to see what interface has been requested
-        if (riid == IID_IEnumFORMATETC || riid == IID_IUnknown)
-        {
-            AddRef();
-            *ppvObject = this;
-            return S_OK;
-        }
-
-        // No interface
-        *ppvObject = nullptr;
-        return E_NOINTERFACE;
-    }
-    ULONG STDMETHODCALLTYPE AddRef() override
-    {
-        _InterlockedIncrement(&_refCount);
-        return _refCount;
-    }
-    ULONG STDMETHODCALLTYPE Release() override
-    {
-        ULONG ulRefCount = _InterlockedDecrement(&_refCount);
-        if (_refCount == 0)
-        {
-            delete this;
-        }
-        return ulRefCount;
-    }
-
-    // [IEnumFormatEtc]
-    HRESULT STDMETHODCALLTYPE Next(ULONG celt, FORMATETC* pFormatEtc, ULONG* pceltFetched) override
-    {
-        ULONG copied = 0;
-
-        // validate arguments
-        if (celt == 0 || pFormatEtc == nullptr)
-            return E_INVALIDARG;
-
-        // copy FORMATETC structures into caller's buffer
-        while (_index < _formatsCount && copied < celt)
-        {
-            DeepCopyFormatEtc(&pFormatEtc[copied], &_formatEtc[_index]);
-            copied++;
-            _index++;
-        }
-
-        // store result
-        if (pceltFetched != nullptr)
-            *pceltFetched = copied;
-
-        // did we copy all that was requested?
-        return (copied == celt) ? S_OK : S_FALSE;
-    }
-    HRESULT STDMETHODCALLTYPE Skip(ULONG celt) override
-    {
-        _index += celt;
-        return (_index <= _formatsCount) ? S_OK : S_FALSE;
-    }
-    HRESULT STDMETHODCALLTYPE Reset() override
-    {
-        _index = 0;
-        return S_OK;
-    }
-    HRESULT STDMETHODCALLTYPE Clone(IEnumFORMATETC** ppEnumFormatEtc) override
-    {
-        HRESULT result;
-
-        // Make a duplicate enumerator
-        result = CreateEnumFormatEtc(_formatsCount, _formatEtc, ppEnumFormatEtc);
-
-        if (result == S_OK)
-        {
-            // Manually set the index state
-            static_cast<WindowsEnumFormatEtc*>(*ppEnumFormatEtc)->_index = _index;
-        }
-
-        return result;
-    }
-};
-
-HRESULT CreateEnumFormatEtc(UINT nNumFormats, FORMATETC* pFormatEtc, IEnumFORMATETC** ppEnumFormatEtc)
-{
-    if (nNumFormats == 0 || pFormatEtc == nullptr || ppEnumFormatEtc == nullptr)
-        return E_INVALIDARG;
-    *ppEnumFormatEtc = new WindowsEnumFormatEtc(pFormatEtc, nNumFormats);
-    return *ppEnumFormatEtc ? S_OK : E_OUTOFMEMORY;
-}
-
-/// <summary>
-/// Drag drop source and data container for Ole
-/// </summary>
-class WindowsDragSource : public IDataObject, public IDropSource
-{
-private:
-    ULONG _refCount;
-    int32 _formatsCount;
-    FORMATETC* _formatEtc;
-    STGMEDIUM* _stgMedium;
-
-public:
-    WindowsDragSource(FORMATETC* fmtetc, STGMEDIUM* stgmed, int32 count)
-        : _refCount(1)
-        , _formatsCount(count)
-        , _formatEtc(nullptr)
-        , _stgMedium(nullptr)
-    {
-        // Allocate memory
-        _formatEtc = new FORMATETC[count];
-        _stgMedium = new STGMEDIUM[count];
-
-        // Copy descriptors
-        for (int32 i = 0; i < count; i++)
-        {
-            _formatEtc[i] = fmtetc[i];
-            _stgMedium[i] = stgmed[i];
-        }
-    }
-
-    virtual ~WindowsDragSource()
-    {
-        delete[] _formatEtc;
-        delete[] _stgMedium;
-    }
-
-public:
-    // [IUnknown]
-    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, _COM_Outptr_ void __RPC_FAR *__RPC_FAR * ppvObject) override
-    {
-        // Check to see what interface has been requested
-        if (riid == IID_IDataObject || riid == IID_IUnknown || riid == IID_IDropSource)
-        {
-            AddRef();
-            *ppvObject = this;
-            return S_OK;
-        }
-
-        // No interface
-        *ppvObject = nullptr;
-        return E_NOINTERFACE;
-    }
-
-    ULONG STDMETHODCALLTYPE AddRef() override
-    {
-        _InterlockedIncrement(&_refCount);
-        return _refCount;
-    }
-
-    ULONG STDMETHODCALLTYPE Release() override
-    {
-        ULONG ulRefCount = _InterlockedDecrement(&_refCount);
-        if (_refCount == 0)
-        {
-            delete this;
-        }
-        return ulRefCount;
-    }
-
-    // [IDropSource]
-    HRESULT STDMETHODCALLTYPE QueryContinueDrag(_In_ BOOL fEscapePressed, _In_ DWORD grfKeyState) override
-    {
-        // If the Escape key has been pressed since the last call, cancel the drop
-        if (fEscapePressed == TRUE || grfKeyState & MK_RBUTTON)
-            return DRAGDROP_S_CANCEL;
-
-        // If the LeftMouse button has been released, then do the drop!
-        if ((grfKeyState & MK_LBUTTON) == 0)
-            return DRAGDROP_S_DROP;
-
-        // Continue with the drag-drop
-        return S_OK;
-    }
-    HRESULT STDMETHODCALLTYPE GiveFeedback(_In_ DWORD dwEffect) override
-    {
-        // TODO: allow to use custom mouse cursor during drop and drag operation
-        return DRAGDROP_S_USEDEFAULTCURSORS;
-    }
-
-    // [IDataObject]
-    HRESULT STDMETHODCALLTYPE GetData(_In_ FORMATETC* pformatetcIn, _Out_ STGMEDIUM* pmedium) override
-    {
-        if (pformatetcIn == nullptr || pmedium == nullptr)
-            return E_INVALIDARG;
-
-        // Try to match the specified FORMATETC with one of our supported formats
-        int32 index = lookupFormatEtc(pformatetcIn);
-        if (index == INVALID_INDEX)
-            return DV_E_FORMATETC;
-
-        // Found a match - transfer data into supplied storage medium
-        pmedium->tymed = _formatEtc[index].tymed;
-        pmedium->pUnkForRelease = nullptr;
-
-        // Copy the data into the caller's storage medium
-        switch (_formatEtc[index].tymed)
-        {
-        case TYMED_HGLOBAL:
-            pmedium->hGlobal = duplicateGlobalMem(_stgMedium[index].hGlobal);
-            break;
-
-        default:
-            return DV_E_FORMATETC;
-        }
-
-        return S_OK;
-    }
-    HRESULT STDMETHODCALLTYPE GetDataHere(_In_ FORMATETC* pformatetc, _Inout_ STGMEDIUM* pmedium) override
-    {
-        return DATA_E_FORMATETC;
-    }
-    HRESULT STDMETHODCALLTYPE QueryGetData(__RPC__in_opt FORMATETC* pformatetc) override
-    {
-        return lookupFormatEtc(pformatetc) == INVALID_INDEX ? DV_E_FORMATETC : S_OK;
-    }
-    HRESULT STDMETHODCALLTYPE GetCanonicalFormatEtc(__RPC__in_opt FORMATETC* pformatectIn, __RPC__out FORMATETC* pformatetcOut) override
-    {
-        // Apparently we have to set this field to NULL even though we don't do anything else
-        pformatetcOut->ptd = nullptr;
-        return E_NOTIMPL;
-    }
-    HRESULT STDMETHODCALLTYPE SetData(_In_ FORMATETC* pformatetc, _In_ STGMEDIUM* pmedium, BOOL fRelease) override
-    {
-        return E_NOTIMPL;
-    }
-    HRESULT STDMETHODCALLTYPE EnumFormatEtc(DWORD dwDirection, __RPC__deref_out_opt IEnumFORMATETC** ppenumFormatEtc) override
-    {
-        // Only the get direction is supported for OLE
-        if (dwDirection == DATADIR_GET)
-        {
-            // TODO: use SHCreateStdEnumFmtEtc API call
-            return CreateEnumFormatEtc(_formatsCount, _formatEtc, ppenumFormatEtc);
-        }
-
-        // The direction specified is not supported for drag+drop
-        return E_NOTIMPL;
-    }
-    HRESULT STDMETHODCALLTYPE DAdvise(__RPC__in FORMATETC* pformatetc, DWORD advf, __RPC__in_opt IAdviseSink* pAdvSink, __RPC__out DWORD* pdwConnection) override
-    {
-        return OLE_E_ADVISENOTSUPPORTED;
-    }
-    HRESULT STDMETHODCALLTYPE DUnadvise(DWORD dwConnection) override
-    {
-        return OLE_E_ADVISENOTSUPPORTED;
-    }
-    HRESULT STDMETHODCALLTYPE EnumDAdvise(__RPC__deref_out_opt IEnumSTATDATA** ppenumAdvise) override
-    {
-        return OLE_E_ADVISENOTSUPPORTED;
-    }
-
-private:
-    int32 lookupFormatEtc(FORMATETC* pFormatEtc) const
-    {
-        // Check each of our formats in turn to see if one matches
-        for (int32 i = 0; i < _formatsCount; i++)
-        {
-            if ((_formatEtc[i].tymed & pFormatEtc->tymed) &&
-                _formatEtc[i].cfFormat == pFormatEtc->cfFormat &&
-                _formatEtc[i].dwAspect == pFormatEtc->dwAspect)
-            {
-                // Return index of stored format
-                return i;
-            }
-        }
-
-        // Format not found
-        return INVALID_INDEX;
-    }
-};
-
-WindowsGuiData GuiDragDropData;
-
-DragDropEffect WindowsWindow::DoDragDrop(const StringView& data)
-{
-    // Create background worker that will keep updating GUI (perform rendering)
-    const auto task = New<DoDragDropJob>();
-    Task::StartNew(task);
-    while (task->GetState() == TaskState::Queued)
-        Platform::Sleep(1);
-
-    // Create descriptors
-    FORMATETC fmtetc = { CF_TEXT, nullptr, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
-    STGMEDIUM stgmed = { TYMED_HGLOBAL, { nullptr }, nullptr };
-
-    // Create a HGLOBAL inside the storage medium
-    stgmed.hGlobal = StringToHandle(data);
-
-    // Create drop source
-    auto dropSource = new WindowsDragSource(&fmtetc, &stgmed, 1);
-
-    // Do the drag drop operation
-    DWORD dwEffect;
-    HRESULT result = ::DoDragDrop(dropSource, dropSource, DROPEFFECT_COPY | DROPEFFECT_MOVE | DROPEFFECT_LINK | DROPEFFECT_SCROLL, &dwEffect);
-
-    // Wait for job end
-    Platform::AtomicStore(&task->ExitFlag, 1);
-    task->Wait();
-
-    // Release allocated data
-    dropSource->Release();
-    ReleaseStgMedium(&stgmed);
-
-    // Fix hanging mouse state (Windows doesn't send WM_LBUTTONUP when we end the drag and drop)
-    if (Input::GetMouseButton(MouseButton::Left))
-    {
-        ::POINT point;
-        ::GetCursorPos(&point);
-        Input::Mouse->OnMouseUp(Float2((float)point.x, (float)point.y), MouseButton::Left, this);
-    }
-
-    return SUCCEEDED(result) ? dropEffectFromOleEnum(dwEffect) : DragDropEffect::None;
-}
-
-HRESULT WindowsWindow::DragEnter(Windows::IDataObject* pDataObj, Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect)
-{
-    POINT p = { pt.x, pt.y };
-    ::ScreenToClient(_handle, &p);
-    GuiDragDropData.Init((IDataObject*)pDataObj);
-    DragDropEffect effect = DragDropEffect::None;
-    OnDragEnter(&GuiDragDropData, Float2(static_cast<float>(p.x), static_cast<float>(p.y)), effect);
-    Focus();
-    *pdwEffect = dropEffect2OleEnum(effect);
-    return S_OK;
-}
-
-HRESULT WindowsWindow::DragOver(Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect)
-{
-    POINT p = { pt.x, pt.y };
-    ::ScreenToClient(_handle, &p);
-    DragDropEffect effect = DragDropEffect::None;
-    OnDragOver(&GuiDragDropData, Float2(static_cast<float>(p.x), static_cast<float>(p.y)), effect);
-    *pdwEffect = dropEffect2OleEnum(effect);
-    return S_OK;
-}
-
-HRESULT WindowsWindow::DragLeave()
-{
-    OnDragLeave();
-    return S_OK;
-}
-
-HRESULT WindowsWindow::Drop(Windows::IDataObject* pDataObj, Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect)
-{
-    POINT p = { pt.x, pt.y };
-    ::ScreenToClient(_handle, &p);
-    GuiDragDropData.Init((IDataObject*)pDataObj);
-    DragDropEffect effect = DragDropEffect::None;
-    OnDragDrop(&GuiDragDropData, Float2(static_cast<float>(p.x), static_cast<float>(p.y)), effect);
-    *pdwEffect = dropEffect2OleEnum(effect);
-    return S_OK;
-}
-
-#else
-
-DragDropEffect WindowsWindow::DoDragDrop(const StringView& data)
-{
-	return DragDropEffect::None;
-}
-
-#endif
-
 #endif

Source/Engine/Platform/Windows/WindowsWindow.h

@@ -2,7 +2,7 @@
 
 #pragma once
 
-#if PLATFORM_WINDOWS
+#if PLATFORM_WINDOWS && !PLATFORM_SDL
 
 #include "Engine/Platform/Base/WindowBase.h"
 #include "Engine/Platform/Platform.h"
@@ -136,7 +136,7 @@ public:
     Windows::ULONG __stdcall AddRef() override;
     Windows::ULONG __stdcall Release() override;
 
-    // [IDropTarget]
+    // [Windows::IDropTarget]
     Windows::HRESULT __stdcall DragEnter(Windows::IDataObject* pDataObj, Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect) override;
     Windows::HRESULT __stdcall DragOver(Windows::DWORD grfKeyState, Windows::POINTL pt, Windows::DWORD* pdwEffect) override;
     Windows::HRESULT __stdcall DragLeave() override;

Source/Engine/UI/GUI/Control.cs

@@ -771,6 +771,15 @@ namespace FlaxEngine.GUI
                 Tooltip.OnMouseLeaveControl(this);
             }
         }
+        
+        /// <summary>
+        /// When mouse moves over control's area while mouse is in relative mode
+        /// </summary>
+        /// <param name="mouseMotion">Mouse relative motion</param>
+        [NoAnimate]
+        public virtual void OnMouseMoveRelative(Float2 mouseMotion)
+        {
+        }
 
         /// <summary>
         /// When mouse leaves control's area

Source/Engine/UI/GUI/Tooltip.cs

@@ -17,6 +17,11 @@ namespace FlaxEngine.GUI
         private string _currentText;
         private Window _window;
 
+        /// <summary>
+        /// The mouse offset from top-left corner of tooltip.
+        /// </summary>
+        private static readonly Float2 TooltipOffset = new Float2(15, 10);
+
         /// <summary>
         /// The horizontal alignment of the text.
         /// </summary>
@@ -69,16 +74,24 @@ namespace FlaxEngine.GUI
             UnlockChildrenRecursive();
             PerformLayout();
 
-            // Calculate popup direction and initial location
             var parentWin = target.Root;
             if (parentWin == null)
                 return;
+
+            // Showing a popup window might bring up the parent window on top
+            if (!parentWin.IsFocused)
+                return;
+
+            // Calculate popup direction and initial location
             var dpiScale = target.RootWindow.DpiScale;
             var dpiSize = Size * dpiScale;
             var locationWS = target.PointToWindow(location);
             var locationSS = parentWin.PointToScreen(locationWS);
+            var mousePos = Input.MouseScreenPosition;
             _showTarget = target;
-            WrapPosition(ref locationSS);
+            //WrapPosition(ref locationSS);
+            WrapPosition(ref mousePos, 10);
+            locationSS = mousePos + TooltipOffset;
 
             // Create window
             var desc = CreateWindowSettings.Default;
@@ -95,9 +108,11 @@ namespace FlaxEngine.GUI
             desc.AllowMaximize = false;
             desc.AllowDragAndDrop = false;
             desc.IsTopmost = true;
-            desc.IsRegularWindow = false;
+            desc.Type = WindowType.Tooltip;
+            desc.Title = "Tooltip";
             desc.HasSizingFrame = false;
             desc.ShowAfterFirstPaint = true;
+            desc.Parent = parentWin.RootWindow.Window;
             _window = Platform.CreateWindow(ref desc);
             if (_window == null)
                 throw new InvalidOperationException("Failed to create tooltip window.");
@@ -197,7 +212,7 @@ namespace FlaxEngine.GUI
             var rightBottomLocationSS = locationSS + dpiSize;
 
             // Prioritize tooltip placement within parent window, fall back to virtual desktop
-            if (rightBottomMonitorBounds.Y < rightBottomLocationSS.Y)
+            /*if (rightBottomMonitorBounds.Y < rightBottomLocationSS.Y)
             {
                 // Direction: up
                 locationSS.Y -= dpiSize.Y + flipOffset;
@@ -206,7 +221,7 @@ namespace FlaxEngine.GUI
             {
                 // Direction: left
                 locationSS.X -= dpiSize.X + flipOffset * 2;
-            }
+            }*/
         }
 
         /// <inheritdoc />
@@ -224,7 +239,7 @@ namespace FlaxEngine.GUI
                 // Position tooltip when mouse moves
                 WrapPosition(ref mousePos, 10);
                 if (_window)
-                    _window.Position = mousePos + new Float2(15, 10);
+                    _window.Position = mousePos + TooltipOffset;
             }
 
             base.Update(deltaTime);

Source/Engine/UI/GUI/WindowRootControl.cs

@@ -338,5 +338,17 @@ namespace FlaxEngine.GUI
 
             base.OnMouseMove(location);
         }
+
+        /// <inheritdoc />
+        public override void OnMouseMoveRelative(Float2 mouseMotion)
+        {
+            if (_trackingControl != null)
+            {
+                _trackingControl.OnMouseMoveRelative(mouseMotion);
+                return;
+            }
+
+            base.OnMouseMoveRelative(mouseMotion);
+        }
     }
 }

Source/ThirdParty/SDL/LICENSE.txt

@@ -0,0 +1,18 @@
+Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+  
+This software is provided 'as-is', without any express or implied
+warranty.  In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+  
+1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software. If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required. 
+2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+