Implement GetPixelAt and GetCursorPosition.

Source/Editor/Utilities/ScreenUtilities/ScreenUtilitiesLinux.cpp

@@ -6,12 +6,53 @@
 #include "Engine/Core/Delegate.h"
 #include "Engine/Core/Log.h"
 
+#include "Engine/Platform/Linux/IncludeX11.h"
+
 Color32 ScreenUtilities::GetPixelAt(int32 x, int32 y)
 {
+    X11::XColor color;
+    Color32 outputColor;
+    
+    X11::Display* display = X11::XOpenDisplay((char *) NULL);
+    int defaultScreen = X11::XDefaultScreen(display);
+
+    X11::XImage* image;
+    image = X11::XGetImage(display, X11::XRootWindow(display, defaultScreen), x, y, 1, 1, AllPlanes, XYPixmap);
+    color.pixel = XGetPixel(image, 0, 0);
+    X11::XFree(image);
+
+    X11::XQueryColor(display, X11::XDefaultColormap(display, defaultScreen), &color);
+    outputColor.R = color.red / 256;
+    outputColor.G = color.green / 256;
+    outputColor.B = color.blue / 256;
+
+    X11::XCloseDisplay(display);
+    return outputColor;
 }
 
 Int2 ScreenUtilities::GetScreenCursorPosition()
 {
+    Int2 cursorPosition = { 0, 0 };
+    X11::Display* display = X11::XOpenDisplay(NULL);
+    X11::Window rootWindow = X11::XRootWindow(display, X11::XDefaultScreen(display));
+
+    // Buffers (Some useful, some not.)
+    X11::Window rootWindowBuffer;
+    int rootX, rootY;
+    int winXBuffer, winYBuffer;
+    uint maskBuffer;
+
+    int gotPointer = X11::XQueryPointer(display, rootWindow, &rootWindowBuffer, &rootWindowBuffer, &rootX, &rootY, &winXBuffer, &winYBuffer, &maskBuffer);
+    if (!gotPointer) {
+        LOG(Error, "Failed to read mouse pointer (Are you using multiple displays?)");
+        return cursorPosition;
+    }
+
+    cursorPosition.X = rootX;
+    cursorPosition.Y = rootY;
+
+    X11::XCloseDisplay(display);
+    return cursorPosition;
 }
 
 class ScreenUtilitiesLinux
@@ -22,12 +63,14 @@ public:
 
 void ScreenUtilitiesLinux::BlockAndReadMouse()
 {
+    return;
 }
 
 Delegate<Color32> ScreenUtilities::PickColorDone;
 
 void ScreenUtilities::PickColor()
 {
+    return;
 }
 
 #endif