Merge branch 'fix-per-window-dpi' of git://github.com/stefnotch/FlaxEngine into stefnotch-fix-per-window-dpi

# Conflicts:
#	Source/Editor/Utilities/Utils.cs
#	Source/Editor/Windows/Assets/MaterialWindow.cs
#	Source/Editor/Windows/Assets/ParticleEmitterWindow.cs
#	Source/Engine/Platform/Linux/LinuxWindow.cpp
#	Source/Engine/Platform/Windows/WindowsWindow.cpp

Source/Editor/Content/Proxy/ShaderProxy.cs

@@ -29,7 +29,7 @@ namespace FlaxEditor.Content
             if (asset)
             {
                 var source = Editor.GetShaderSourceCode(asset);
-                Utilities.Utils.ShowSourceCodeWindow(source, "Shader Source");
+                Utilities.Utils.ShowSourceCodeWindow(source, "Shader Source", item.RootWindow.Window);
             }
             return null;
         }

Source/Editor/Editor.cs

@@ -1181,7 +1181,7 @@ namespace FlaxEditor
                 var win = Windows.GameWin.Root;
                 if (win != null && win.RootWindow is WindowRootControl root && root.Window.IsFocused)
                 {
-                    pos = Vector2.Round(Windows.GameWin.Viewport.PointFromWindow(root.Window.ScreenToClient(pos)));
+                    pos = Vector2.Round(Windows.GameWin.Viewport.PointFromScreen(pos) * root.DpiScale);
                 }
                 else
                 {
@@ -1201,7 +1201,7 @@ namespace FlaxEditor
                 var win = Windows.GameWin.Root;
                 if (win != null && win.RootWindow is WindowRootControl root && root.Window.IsFocused)
                 {
-                    pos = Vector2.Round(root.Window.ClientToScreen(Windows.GameWin.Viewport.PointToWindow(pos)));
+                    pos = Vector2.Round(Windows.GameWin.Viewport.PointToScreen(pos / root.DpiScale));
                 }
                 else
                 {
@@ -1231,13 +1231,18 @@ namespace FlaxEditor
             var gameWin = Windows.GameWin;
             if (gameWin != null)
             {
-                // Handle case when Game window is not selected in tab view
+                var win = gameWin.Root;
-                var dockedTo = gameWin.ParentDockPanel;
+                if (win != null && win.RootWindow is WindowRootControl root)
-                if (dockedTo != null && dockedTo.SelectedTab != gameWin && dockedTo.SelectedTab != null)
+                {
-                    resultAsRef = dockedTo.SelectedTab.Size;
+                    // Handle case when Game window is not selected in tab view
-                else
+                    var dockedTo = gameWin.ParentDockPanel;
-                    resultAsRef = gameWin.Size;
+                    if (dockedTo != null && dockedTo.SelectedTab != gameWin && dockedTo.SelectedTab != null)
-                resultAsRef = Vector2.Round(resultAsRef);
+                        resultAsRef = dockedTo.SelectedTab.Size * root.DpiScale;
+                    else
+                        resultAsRef = gameWin.Size * root.DpiScale;
+
+                    resultAsRef = Vector2.Round(resultAsRef);
+                }
             }
         }
 

Source/Editor/GUI/ContextMenu/ContextMenuBase.cs

@@ -124,7 +124,7 @@ namespace FlaxEditor.GUI.ContextMenu
             PerformLayout();
 
             // Calculate popup direction and initial location (fit on a single monitor)
-            var dpiScale = Platform.DpiScale;
+            var dpiScale = parentWin.DpiScale;
             Vector2 dpiSize = Size * dpiScale;
             Vector2 locationWS = parent.PointToWindow(location);
             Vector2 locationSS = parentWin.PointToScreen(locationWS);
@@ -275,7 +275,7 @@ namespace FlaxEditor.GUI.ContextMenu
         {
             if (_window != null)
             {
-                _window.ClientSize = Size * Platform.DpiScale;
+                _window.ClientSize = Size * _window.DpiScale;
             }
         }
 

Source/Editor/GUI/Dialogs/Dialog.cs

@@ -143,7 +143,7 @@ namespace FlaxEditor.GUI.Dialogs
             // Setup initial window settings
             CreateWindowSettings settings = CreateWindowSettings.Default;
             settings.Title = _title;
-            settings.Size = _dialogSize * Platform.DpiScale;
+            settings.Size = _dialogSize * parentWindow.DpiScale;
             settings.AllowMaximize = false;
             settings.AllowMinimize = false;
             settings.HasSizingFrame = false;

Source/Editor/GUI/Docking/DockPanel.cs

@@ -123,9 +123,8 @@ namespace FlaxEditor.GUI.Docking
                 if (parentWin == null)
                     throw new InvalidOperationException("Missing parent window.");
                 var control = _tabsProxy != null ? (Control)_tabsProxy : this;
-                var dpiScale = Platform.DpiScale;
                 var clientPos = control.PointToWindow(Vector2.Zero);
-                return new Rectangle(parentWin.PointToScreen(clientPos), control.Size * dpiScale);
+                return new Rectangle(parentWin.PointToScreen(clientPos), control.Size * RootWindow.DpiScale);
             }
         }
 

Source/Editor/GUI/MainMenu.cs

@@ -190,15 +190,15 @@ namespace FlaxEditor.GUI
 
         private WindowHitCodes OnHitTest(ref Vector2 mouse)
         {
-            var pos = _window.ScreenToClient(mouse * Platform.DpiScale);
+            var dpiScale = _window.DpiScale;
 
             if (_window.IsMinimized)
                 return WindowHitCodes.NoWhere;
 
             if (!_window.IsMaximized)
             {
-                var dpiScale = Platform.DpiScale;
+                var pos = _window.ScreenToClient(mouse * dpiScale); // pos is not DPI adjusted
-                var winSize = RootWindow.Size * dpiScale;
+                var winSize = _window.Size;
 
                 // Distance from which the mouse is considered to be on the border/corner
                 float distance = 5.0f * dpiScale;
@@ -228,11 +228,11 @@ namespace FlaxEditor.GUI
                     return WindowHitCodes.Bottom;
             }
 
-            var menuPos = PointFromWindow(pos);
+            var mousePos = PointFromScreen(mouse * dpiScale);
-            var controlUnderMouse = GetChildAt(menuPos);
+            var controlUnderMouse = GetChildAt(mousePos);
             var isMouseOverSth = controlUnderMouse != null && controlUnderMouse != _title;
             var rb = GetRightButton();
-            if (rb != null && _minimizeButton != null && new Rectangle(rb.UpperRight * Platform.DpiScale, (_minimizeButton.BottomLeft - rb.UpperRight) * Platform.DpiScale).Contains(ref menuPos) && !isMouseOverSth)
+            if (rb != null && _minimizeButton != null && new Rectangle(rb.UpperRight, _minimizeButton.BottomLeft - rb.UpperRight).Contains(ref mousePos) && !isMouseOverSth)
                 return WindowHitCodes.Caption;
 
             return WindowHitCodes.Client;

Source/Editor/Modules/WindowsModule.cs

@@ -707,8 +707,9 @@ namespace FlaxEditor.Modules
             var dpiScale = Platform.DpiScale;
             var settings = CreateWindowSettings.Default;
             settings.Title = "Flax Editor";
-            settings.Size = new Vector2(1300 * dpiScale, 900 * dpiScale);
+            settings.Size = Platform.DesktopSize;
             settings.StartPosition = WindowStartPosition.CenterScreen;
+            settings.ShowAfterFirstPaint = true;
 
 #if PLATFORM_WINDOWS
             if (!Editor.Instance.Options.Options.Interface.UseNativeWindowSystem)

Source/Editor/Surface/ContextMenu/ContentFinder.cs

@@ -108,11 +108,13 @@ namespace FlaxEditor.Surface.ContextMenu
         {
             _resultPanel.DisposeChildren();
 
+            var dpiScale = RootWindow.DpiScale;
+
             if (items.Count == 0)
             {
                 Height = _searchBox.Height + 1;
                 _resultPanel.ScrollBars = ScrollBars.None;
-                RootWindow.Window.ClientSize = new Vector2(RootWindow.Window.ClientSize.X, Height * Platform.DpiScale);
+                RootWindow.Window.ClientSize = new Vector2(RootWindow.Window.ClientSize.X, Height * dpiScale);
                 return;
             }
 
@@ -146,7 +148,7 @@ namespace FlaxEditor.Surface.ContextMenu
                 MatchedItems.Add(searchItem);
             }
 
-            RootWindow.Window.ClientSize = new Vector2(RootWindow.Window.ClientSize.X, Height * Platform.DpiScale);
+            RootWindow.Window.ClientSize = new Vector2(RootWindow.Window.ClientSize.X, Height * dpiScale);
 
             PerformLayout();
         }

Source/Editor/Utilities/Utils.cs

@@ -1646,8 +1646,8 @@ namespace FlaxEditor.Utilities
         /// </summary>
         /// <param name="source">The source code.</param>
         /// <param name="title">The window title.</param>
-        /// <param name="control">The context control used to show source code window popup in a proper location.</param>
+        /// <param name="parentWindow">The optional parent window.</param>
-        public static void ShowSourceCodeWindow(string source, string title, Control control = null)
+        public static void ShowSourceCodeWindow(string source, string title, Window parentWindow = null)
         {
             if (string.IsNullOrEmpty(source))
             {
@@ -1661,8 +1661,8 @@ namespace FlaxEditor.Utilities
             settings.AllowMinimize = false;
             settings.HasSizingFrame = false;
             settings.StartPosition = WindowStartPosition.CenterParent;
-            settings.Size = new Vector2(500, 600) * Platform.DpiScale;
+            settings.Size = new Vector2(500, 600) * (parentWindow?.DpiScale ?? Platform.DpiScale);
-            settings.Parent = control?.RootWindow?.Window ?? Editor.Instance.Windows.MainWindow;
+            settings.Parent = parentWindow;
             settings.Title = title;
             var dialog = Platform.CreateWindow(ref settings);
 

Source/Editor/Windows/Assets/MaterialWindow.cs

@@ -240,7 +240,7 @@ namespace FlaxEditor.Windows.Assets
         private void ShowSourceCode()
         {
             var source = Editor.GetShaderSourceCode(_asset);
-            Utilities.Utils.ShowSourceCodeWindow(source, "Material Source", this);
+            Utilities.Utils.ShowSourceCodeWindow(source, "Material Source", RootWindow.Window);
         }
 
         /// <summary>

Source/Editor/Windows/Assets/ParticleEmitterWindow.cs

@@ -146,7 +146,7 @@ namespace FlaxEditor.Windows.Assets
         private void ShowSourceCode()
         {
             var source = Editor.GetShaderSourceCode(_asset);
-            Utilities.Utils.ShowSourceCodeWindow(source, "Particle Emitter GPU Simulation Source", this);
+            Utilities.Utils.ShowSourceCodeWindow(source, "Particle Emitter GPU Simulation Source", RootWindow.Window);
         }
 
         /// <inheritdoc />

Source/Editor/Windows/ContentWindow.cs

@@ -371,7 +371,7 @@ namespace FlaxEditor.Windows
 
                 // Focus content window
                 Focus();
-                RootWindow?.Window.Focus();
+                RootWindow?.Focus();
             }
 
             // Refresh database and view now

Source/Engine/Platform/Android/AndroidWindow.cpp

@@ -6,10 +6,14 @@
 #include "Engine/Graphics/RenderTask.h"
 #include <Engine/Main/Android/android_native_app_glue.h>
 
+#define DefaultDPI 96
+
 AndroidWindow::AndroidWindow(const CreateWindowSettings& settings)
     : WindowBase(settings)
 {
     _clientSize = settings.Size;
+    _dpi = DefaultDPI;
+    _dpiScale = (float)_dpi / (float)DefaultDPI;
 }
 
 AndroidWindow::~AndroidWindow()

Source/Engine/Platform/Base/PlatformBase.h

@@ -569,17 +569,17 @@ public:
     API_PROPERTY() static BatteryInfo GetBatteryInfo();
 
     /// <summary>
-    /// Gets the screen DPI setting.
+    /// Gets the primary monitor's DPI setting.
     /// </summary>
     API_PROPERTY() static int32 GetDpi();
 
     /// <summary>
-    /// Gets the screen DPI setting scale factor (1 is default). Includes custom DPI scale.
+    /// Gets the primary monitor's DPI setting scale factor (1 is default). Includes custom DPI scale.
     /// </summary>
     API_PROPERTY() static float GetDpiScale();
 
     /// <summary>
-    /// The custom screen DPI scale factor to apply globally. Can be used to adjust the User Interface scale (resolution).
+    /// The custom DPI scale factor to apply globally. Can be used to adjust the User Interface scale (resolution).
     /// </summary>
     API_FIELD() static float CustomDpiScale;
 

Source/Engine/Platform/Base/WindowBase.h

@@ -281,6 +281,8 @@ protected:
     String _title;
     CursorType _cursor;
     Vector2 _clientSize;
+    int _dpi;
+    float _dpiScale;
 
     Vector2 _trackingMouseOffset;
     bool _isUsingMouseOffset;
@@ -542,6 +544,21 @@ public:
     /// <returns>The screen space position.</returns>
     API_FUNCTION() virtual Vector2 ClientToScreen(const Vector2& clientPos) const = 0;
 
+    /// <summary>
+    /// Gets the window DPI setting.
+    /// </summary>
+    API_PROPERTY() int GetDpi() const
+    {
+        return _dpi;
+    }
+
+    /// <summary>
+    /// Gets the window DPI scale factor (1 is default). Includes custom DPI scale
+    /// </summary>
+    API_PROPERTY() float GetDpiScale() const
+    {
+        return Platform::CustomDpiScale * _dpiScale;
+    }
 public:
 
     /// <summary>

Source/Engine/Platform/Linux/LinuxWindow.cpp

@@ -31,6 +31,7 @@
 #define _NET_WM_STATE_REMOVE 0L // remove/unset property
 #define _NET_WM_STATE_ADD 1L // add/set property
 #define _NET_WM_STATE_TOGGLE 2L // toggle property
+#define DefaultDPI 96
 
 // Window routines function prolog
 #define LINUX_WINDOW_PROLOG X11::Display* display = (X11::Display*)LinuxPlatform::GetXDisplay(); X11::Window window =  (X11::Window)_window
@@ -150,7 +151,10 @@ LinuxWindow::LinuxWindow(const CreateWindowSettings& settings)
 		X11::XSetTransientForHint(display, window, (X11::Window)((LinuxWindow*)settings.Parent)->GetNativePtr());
 	}
 
-	// Set events mask
+    _dpi = Platform::GetDpi();
+    _dpiScale = (float)_dpi / (float)DefaultDPI;
+    
+	// Set input mask
 	long eventMask =
 			ExposureMask | FocusChangeMask |
 			KeyPressMask | KeyReleaseMask |

Source/Engine/Platform/UWP/UWPWindow.h

@@ -100,7 +100,6 @@ private:
 
     UWPWindowImpl* _impl;
 
-    float _dpi, _dpiScale;
     Vector2 _logicalSize;
 
 public:

Source/Engine/Platform/Window.cs

@@ -7,8 +7,6 @@ namespace FlaxEngine
 {
     partial class Window
     {
-        internal float _dpiScale;
-
         /// <summary>
         /// Window closing delegate.
         /// </summary>
@@ -176,7 +174,6 @@ namespace FlaxEngine
         private Window()
         {
             GUI = new WindowRootControl(this);
-            _dpiScale = Platform.DpiScale;
         }
 
         internal void Internal_OnShow()
@@ -192,7 +189,7 @@ namespace FlaxEngine
 
         internal void Internal_OnDraw()
         {
-            Matrix3x3.Scaling(_dpiScale, out var scale);
+            Matrix3x3.Scaling(DpiScale, out var scale);
             Render2D.PushTransform(ref scale);
             GUI.Draw();
             Render2D.PopTransform();
@@ -200,7 +197,7 @@ namespace FlaxEngine
 
         internal void Internal_OnResize(int width, int height)
         {
-            GUI.Size = new Vector2(width / _dpiScale, height / _dpiScale);
+            GUI.Size = new Vector2(width / DpiScale, height / DpiScale);
         }
 
         internal void Internal_OnCharInput(char c)
@@ -223,7 +220,7 @@ namespace FlaxEngine
 
         internal void Internal_OnMouseDown(ref Vector2 mousePos, MouseButton button)
         {
-            Vector2 pos = mousePos / _dpiScale;
+            Vector2 pos = mousePos / DpiScale;
 
             bool handled = false;
             MouseDown?.Invoke(ref pos, button, ref handled);
@@ -235,7 +232,7 @@ namespace FlaxEngine
 
         internal void Internal_OnMouseUp(ref Vector2 mousePos, MouseButton button)
         {
-            Vector2 pos = mousePos / _dpiScale;
+            Vector2 pos = mousePos / DpiScale;
 
             bool handled = false;
             MouseUp?.Invoke(ref pos, button, ref handled);
@@ -247,7 +244,7 @@ namespace FlaxEngine
 
         internal void Internal_OnMouseDoubleClick(ref Vector2 mousePos, MouseButton button)
         {
-            Vector2 pos = mousePos / _dpiScale;
+            Vector2 pos = mousePos / DpiScale;
 
             bool handled = false;
             MouseDoubleClick?.Invoke(ref pos, button, ref handled);
@@ -259,7 +256,7 @@ namespace FlaxEngine
 
         internal void Internal_OnMouseWheel(ref Vector2 mousePos, float delta)
         {
-            Vector2 pos = mousePos / _dpiScale;
+            Vector2 pos = mousePos / DpiScale;
 
             bool handled = false;
             MouseWheel?.Invoke(ref pos, delta, ref handled);
@@ -271,7 +268,7 @@ namespace FlaxEngine
 
         internal void Internal_OnMouseMove(ref Vector2 mousePos)
         {
-            Vector2 pos = mousePos / _dpiScale;
+            Vector2 pos = mousePos / DpiScale;
 
             MouseMove?.Invoke(ref pos);
             GUI.OnMouseMove(pos);
@@ -285,7 +282,7 @@ namespace FlaxEngine
 
         internal void Internal_OnTouchDown(ref Vector2 pointerPosition, int pointerId)
         {
-            Vector2 pos = pointerPosition / _dpiScale;
+            Vector2 pos = pointerPosition / DpiScale;
 
             bool handled = false;
             TouchDown?.Invoke(ref pos, pointerId, ref handled);
@@ -297,7 +294,7 @@ namespace FlaxEngine
 
         internal void Internal_OnTouchMove(ref Vector2 pointerPosition, int pointerId)
         {
-            Vector2 pos = pointerPosition / _dpiScale;
+            Vector2 pos = pointerPosition / DpiScale;
 
             bool handled = false;
             TouchMove?.Invoke(ref pos, pointerId, ref handled);
@@ -309,7 +306,7 @@ namespace FlaxEngine
 
         internal void Internal_OnTouchUp(ref Vector2 pointerPosition, int pointerId)
         {
-            Vector2 pos = pointerPosition / _dpiScale;
+            Vector2 pos = pointerPosition / DpiScale;
 
             bool handled = false;
             TouchUp?.Invoke(ref pos, pointerId, ref handled);
@@ -335,7 +332,7 @@ namespace FlaxEngine
         {
             if (HitTest != null)
             {
-                Vector2 pos = mousePos / _dpiScale;
+                Vector2 pos = mousePos / DpiScale;
                 result = HitTest(ref pos);
                 handled = true;
             }
@@ -356,7 +353,7 @@ namespace FlaxEngine
                 dragData = new DragDataText(data[0]);
             else
                 dragData = new DragDataFiles(data);
-            Vector2 pos = mousePos / _dpiScale;
+            Vector2 pos = mousePos / DpiScale;
             return GUI.OnDragEnter(ref pos, dragData);
         }
 
@@ -367,7 +364,7 @@ namespace FlaxEngine
                 dragData = new DragDataText(data[0]);
             else
                 dragData = new DragDataFiles(data);
-            Vector2 pos = mousePos / _dpiScale;
+            Vector2 pos = mousePos / DpiScale;
             return GUI.OnDragMove(ref pos, dragData);
         }
 
@@ -378,7 +375,7 @@ namespace FlaxEngine
                 dragData = new DragDataText(data[0]);
             else
                 dragData = new DragDataFiles(data);
-            Vector2 pos = mousePos / _dpiScale;
+            Vector2 pos = mousePos / DpiScale;
             return GUI.OnDragDrop(ref pos, dragData);
         }
 

Source/Engine/Platform/Windows/WindowsPlatform.cpp

@@ -673,7 +673,7 @@ void WindowsPlatform::SetHighDpiAwarenessEnabled(bool enable)
 
     if (setProcessDpiAwareness)
     {
-        setProcessDpiAwareness(enable ? PROCESS_SYSTEM_DPI_AWARE : PROCESS_DPI_UNAWARE);
+        setProcessDpiAwareness(enable ? PROCESS_PER_MONITOR_DPI_AWARE : PROCESS_DPI_UNAWARE);
     }
 
     SystemDpi = CalculateDpi(shCoreDll);

Source/Engine/Platform/Windows/WindowsWindow.cpp

@@ -13,6 +13,8 @@
 #include "../Win32/IncludeWindowsHeaders.h"
 #include <propidl.h>
 
+#define DefaultDPI 96
+
 // Use improved borderless window support for Editor
 #define WINDOWS_USE_NEW_BORDER_LESS USE_EDITOR && 0
 #if WINDOWS_USE_NEW_BORDER_LESS
@@ -123,6 +125,21 @@ WindowsWindow::WindowsWindow(const CreateWindowSettings& settings)
         (HINSTANCE)Platform::Instance,
         nullptr);
 
+    // Query DPI
+    _dpi = Platform::GetDpi();
+    const HMODULE user32Dll = LoadLibraryW(L"user32.dll");
+    if (user32Dll)
+    {
+        typedef UINT (STDAPICALLTYPE* GetDpiForWindowProc)(HWND hwnd);
+        const GetDpiForWindowProc getDpiForWindowProc = (GetDpiForWindowProc)GetProcAddress(user32Dll, "GetDpiForWindow");
+        if (getDpiForWindowProc)
+        {
+            _dpi = getDpiForWindowProc(_handle);
+        }
+        FreeLibrary(user32Dll);
+    }
+    _dpiScale = (float)_dpi / (float)DefaultDPI;
+
     // Validate result
     if (!HasHWND())
     {
@@ -1021,6 +1038,22 @@ LRESULT WindowsWindow::WndProc(UINT msg, WPARAM wParam, LPARAM lParam)
         }
         break;
     }
+    case WM_DPICHANGED:
+    {
+        // Maybe https://stackoverflow.com/a/45110656
+        _dpi = HIWORD(wParam);
+        _dpiScale = (float)_dpi / (float)DefaultDPI;
+        RECT* windowRect = (RECT*)lParam;
+        SetWindowPos(_handle,
+                     nullptr,
+                     windowRect->left,
+                     windowRect->top,
+                     windowRect->right - windowRect->left,
+                     windowRect->bottom - windowRect->top,
+                     SWP_NOZORDER | SWP_NOACTIVATE);
+        // TODO: Recalculate fonts
+        return 0;
+    }
     case WM_ENTERSIZEMOVE:
     {
         _isResizing = true;

Source/Engine/Render2D/FontManager.cpp

@@ -67,7 +67,7 @@ bool FontManagerService::Init()
     ASSERT(Library == nullptr);
 
     // Scale UI fonts to match the monitor DPI
-    FontManager::FontScale = (float)Platform::GetDpi() / (float)DefaultDPI;
+    FontManager::FontScale = (float)Platform::GetDpi() / (float)DefaultDPI; // TODO: Adjust this at runtime
 
     // Init Free Type
     FreeTypeMemory.user = nullptr;

Source/Engine/UI/GUI/Control.cs

@@ -310,7 +310,7 @@ namespace FlaxEngine.GUI
         /// <summary>
         /// Gets the GUI window root control which contains that control (or null if not linked to any).
         /// </summary>
-        public virtual WindowRootControl RootWindow => _parent?.RootWindow;
+        public virtual WindowRootControl RootWindow => _root?.RootWindow;
 
         /// <summary>
         /// Gets screen position of the control (upper left corner).

Source/Engine/UI/GUI/RenderOutputControl.cs

@@ -224,7 +224,7 @@ namespace FlaxEngine.GUI
         /// </summary>
         public void SyncBackbufferSize()
         {
-            float scale = ResolutionScale * Platform.DpiScale;
+            float scale = ResolutionScale * (RootWindow?.DpiScale ?? Platform.DpiScale);
             int width = Mathf.CeilToInt(Width * scale);
             int height = Mathf.CeilToInt(Height * scale);
             if (_customResolution.HasValue)

Source/Engine/UI/GUI/Tooltip.cs

@@ -68,7 +68,7 @@ namespace FlaxEngine.GUI
             var parentWin = target.Root;
             if (parentWin == null)
                 return;
-            float dpiScale = Platform.DpiScale;
+            float dpiScale = target.RootWindow.DpiScale;
             Vector2 dpiSize = Size * dpiScale;
             Vector2 locationWS = target.PointToWindow(location);
             Vector2 locationSS = parentWin.PointToScreen(locationWS);
@@ -183,7 +183,7 @@ namespace FlaxEngine.GUI
         {
             if (_window)
             {
-                _window.ClientSize = Size * Platform.DpiScale;
+                _window.ClientSize = Size * _window.DpiScale;
             }
         }
 

Source/Engine/UI/GUI/WindowRootControl.cs

@@ -55,6 +55,11 @@ namespace FlaxEngine.GUI
         /// </summary>
         public bool IsMaximized => _window.IsMaximized;
 
+        /// <summary>
+        /// Gets the window DPI scale factor (1 is default). Includes custom DPI scale
+        /// </summary>
+        public float DpiScale => _window.DpiScale;
+
         internal WindowRootControl(Window window)
         {
             _window = window;
@@ -151,7 +156,7 @@ namespace FlaxEngine.GUI
         }
 
         /// <inheritdoc />
-        public override Vector2 TrackingMouseOffset => _window.TrackingMouseOffset / _window._dpiScale;
+        public override Vector2 TrackingMouseOffset => _window.TrackingMouseOffset / _window.DpiScale;
 
         /// <inheritdoc />
         public override WindowRootControl RootWindow => this;
@@ -159,8 +164,8 @@ namespace FlaxEngine.GUI
         /// <inheritdoc />
         public override Vector2 MousePosition
         {
-            get => _window.MousePosition / _window._dpiScale;
+            get => _window.MousePosition / _window.DpiScale;
-            set => _window.MousePosition = value * _window._dpiScale;
+            set => _window.MousePosition = value * _window.DpiScale;
         }
 
         /// <inheritdoc />
@@ -234,13 +239,13 @@ namespace FlaxEngine.GUI
         /// <inheritdoc />
         public override Vector2 PointFromScreen(Vector2 location)
         {
-            return _window.ScreenToClient(location) / _window._dpiScale;
+            return _window.ScreenToClient(location) / _window.DpiScale;
         }
 
         /// <inheritdoc />
         public override Vector2 PointToScreen(Vector2 location)
         {
-            return _window.ClientToScreen(location * _window._dpiScale);
+            return _window.ClientToScreen(location * _window.DpiScale);
         }
 
         /// <inheritdoc />