ThumbnailOverlay

An example of using DwmRegisterThumbnail to completely replicate content from another window and overlay custom content on top of it.

1. Change the target window:

   CloneWindow cloneWindow((HWND)FindWindowA("UnrealWindow", NULL));

   Replace "UnrealWindow" with your target window class name.

2. Implement your custom drawing: Write your drawing code in the CustomDraw function:

   void CustomDraw(OverlayWindow* Overlay, int Width, int Height)

• Modify the window class name in step 1 to match the window you want to clone
• Implement your overlay graphics in the CustomDraw function where you have access to the overlay window object and dimensions