Refactor ScreenUtilities

Source/Engine/Platform/Linux/LinuxScreenUtilities.cpp

@@ -0,0 +1,94 @@
+// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
+
+#if USE_EDITOR && 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 USE_EDITOR && 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