Getting screenshot of a child window running OpenGL in it (Windows)

Question

I have a main window with children. I need to take screenshots programmatically to crop and draw them back on my main window. The way I do this is:

HDC hDC =         


        

Answer 1

OpenGL might be rendering into a layered context; try

BitBlt(memDC, 0, 0, Width, Height , hDC, BEGINX, BEGINY, SRCCOPY | CAPTUREBLT);

instead.