I saw a query posted regarding this in the
Graphics[
^] forum and thought it might be a good tip to add here.
So we start with creating a layered window:
Use the
CreateWindowEx[
^] function with the
dwExStyle parameter set to
WS_EX_LAYERED and the
dwStyle parameter set to
WS_POPUP.
CreateWindowEx(WS_EX_LAYERED,"OpenGL","OpenGL",WS_POPUP, ...);
Set the layered attributes of this window using the
SetLayeredWindowAttributes[
^] function. Use
LWA_COLORKEY as the
dwFlags parameter and 0 as the crKey parameter. Now, everything rendered in OpenGL with RGB 000 will be transparent.
SetLayeredWindowAttributes(hWnd, 0, 0, LWA_COLORKEY);
Only thing remaining is to make sure you clear your OpenGL background using 0x00000000 and that you don't have absolute 0 in any of your 3D models!
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
I hope this helps.
