Add Platform::GetMousePosition/WindowsPlatform::SetMousePosition for unified access to screen-space mouse position on all platforms

#1109

Source/Engine/Platform/Base/PlatformBase.cpp

@@ -5,6 +5,7 @@
 #include "Engine/Platform/MemoryStats.h"
 #include "Engine/Platform/MessageBox.h"
 #include "Engine/Platform/FileSystem.h"
+#include "Engine/Platform/Window.h"
 #include "Engine/Platform/User.h"
 #include "Engine/Core/Log.h"
 #include "Engine/Core/Types/DateTime.h"
@@ -520,6 +521,21 @@ void PlatformBase::CreateGuid(Guid& result)
     result = Guid(dateThingHigh, randomThing | (sequentialThing << 16), cyclesThing, dateThingLow);
 }
 
+Float2 PlatformBase::GetMousePosition()
+{
+    const Window* win = Engine::MainWindow;
+    if (win)
+        return win->ClientToScreen(win->GetMousePosition());
+    return Float2::Minimum;
+}
+
+void PlatformBase::SetMousePosition(const Float2& position)
+{
+    const Window* win = Engine::MainWindow;
+    if (win)
+        win->SetMousePosition(win->ScreenToClient(position));
+}
+
 Float2 PlatformBase::GetVirtualDesktopSize()
 {
     return Platform::GetVirtualDesktopBounds().Size;

Source/Engine/Platform/Base/PlatformBase.h

@@ -660,6 +660,18 @@ public:
 
 public:
 
+    /// <summary>
+    /// Gets the mouse cursor position in screen-space coordinates.
+    /// </summary>
+    /// <returns>Mouse cursor coordinates.</returns>
+    API_PROPERTY() static Float2 GetMousePosition();
+
+    /// <summary>
+    /// Sets the mouse cursor position in screen-space coordinates.
+    /// </summary>
+    /// <param name="position">Cursor position to set.</param>
+    API_PROPERTY() static void SetMousePosition(const Float2& position);
+
     /// <summary>
     /// Gets the origin position and size of the monitor at the given screen-space location.
     /// </summary>

Source/Engine/Platform/Linux/LinuxPlatform.cpp

@@ -2643,10 +2643,8 @@ Float2 LinuxPlatform::GetMousePosition()
 {
     if (!xDisplay)
         return Float2::Zero;
-
-	int32 x, y;
+	int32 x = 0, y = 0;
 	uint32 screenCount = (uint32)X11::XScreenCount(xDisplay);
-
 	for (uint32 i = 0; i < screenCount; i++)
 	{
 		X11::Window outRoot, outChild;
@@ -2655,7 +2653,6 @@ Float2 LinuxPlatform::GetMousePosition()
 		if (X11::XQueryPointer(xDisplay, X11::XRootWindow(xDisplay, i), &outRoot, &outChild, &x, &y, &childX, &childY, &mask))
 			break;
 	}
-
 	return Float2((float)x, (float)y);
 }
 

Source/Engine/Platform/UWP/UWPPlatform.cpp

@@ -158,27 +158,6 @@ void UWPPlatform::OpenUrl(const StringView& url)
     // TODO: add support for OpenUrl on UWP
 }
 
-Float2 UWPPlatform::GetMousePosition()
-{
-    // Use the main window
-    auto win = Engine::MainWindow;
-    if (win)
-    {
-        return win->ClientToScreen(win->GetMousePosition());
-    }
-    return Float2::Minimum;
-}
-
-void UWPPlatform::SetMousePosition(const Float2& pos)
-{
-    // Use the main window
-    auto win = Engine::MainWindow;
-    if (win)
-    {
-        win->SetMousePosition(win->ScreenToClient(pos));
-    }
-}
-
 Float2 UWPPlatform::GetDesktopSize()
 {
     Float2 result;

Source/Engine/Platform/UWP/UWPPlatform.h

@@ -37,8 +37,6 @@ public:
     static bool GetHasFocus();
     static bool CanOpenUrl(const StringView& url);
     static void OpenUrl(const StringView& url);
-    static Float2 GetMousePosition();
-    static void SetMousePosition(const Float2& pos);
     static Rectangle GetMonitorBounds(const Float2& screenPos);
     static Float2 GetDesktopSize();
     static Rectangle GetVirtualDesktopBounds();

Source/Engine/Platform/Win32/Win32Platform.h

@@ -109,7 +109,7 @@ public:
     static void CreateGuid(Guid& result);
     static String GetMainDirectory();
     static String GetExecutableFilePath();
-    static struct Guid GetUniqueDeviceId();
+    static Guid GetUniqueDeviceId();
     static String GetWorkingDirectory();
     static bool SetWorkingDirectory(const String& path);
     static void FreeLibrary(void* handle);

Source/Engine/Platform/Windows/WindowsPlatform.cpp

@@ -825,6 +825,18 @@ void WindowsPlatform::OpenUrl(const StringView& url)
     ::ShellExecuteW(nullptr, TEXT("open"), *url, nullptr, nullptr, SW_SHOWNORMAL);
 }
 
+Float2 WindowsPlatform::GetMousePosition()
+{
+    POINT cursorPos;
+    GetCursorPos(&cursorPos);
+    return Float2((float)cursorPos.x, (float)cursorPos.y);
+}
+
+void WindowsPlatform::SetMousePosition(const Float2& pos)
+{
+    ::SetCursorPos((int)pos.X, (int)pos.Y);
+}
+
 struct GetMonitorBoundsData
 {
     Float2 Pos;

Source/Engine/Platform/Windows/WindowsPlatform.h

@@ -71,6 +71,8 @@ public:
     static bool GetHasFocus();
     static bool CanOpenUrl(const StringView& url);
     static void OpenUrl(const StringView& url);
+    static Float2 GetMousePosition();
+    static void SetMousePosition(const Float2& pos);
     static Rectangle GetMonitorBounds(const Float2& screenPos);
     static Float2 GetDesktopSize();
     static Rectangle GetVirtualDesktopBounds();