[AlwaysOnTop] Proof of concept (#14360)

Co-authored-by: Niels Laute <niels.laute@live.nl>

src/modules/alwaysontop/AlwaysOnTop/FrameDrawer.h

@@ -0,0 +1,51 @@
+#pragma once
+
+#include <mutex>
+#include <d2d1.h>
+#include <dwrite.h>
+
+class FrameDrawer
+{
+public:
+    static std::unique_ptr<FrameDrawer> Create(HWND window);
+
+    FrameDrawer(HWND window);
+    FrameDrawer(FrameDrawer&& other);
+    ~FrameDrawer();
+
+    bool Init();
+
+    void Show();
+    void Hide();
+    void SetBorderRect(RECT windowRect, COLORREF color, float thickness);
+
+private:
+    struct DrawableRect
+    {
+        D2D1_RECT_F rect;
+        D2D1_COLOR_F borderColor;
+        float thickness;
+    };
+
+    enum struct RenderResult
+    {
+        Ok,
+        Failed,
+    };
+
+    static ID2D1Factory* GetD2DFactory();
+    static IDWriteFactory* GetWriteFactory();
+    static D2D1_COLOR_F ConvertColor(COLORREF color);
+    static D2D1_RECT_F ConvertRect(RECT rect);
+    RenderResult Render();
+    void RenderLoop();
+
+    HWND m_window = nullptr;
+    ID2D1HwndRenderTarget* m_renderTarget = nullptr;
+
+    std::mutex m_mutex;
+    DrawableRect m_sceneRect;
+
+    std::atomic<bool> m_abortThread = false;
+    std::thread m_renderThread;
+};