Can I tell direct3d to render with alpha channel?

Question

I need to composite direct3d renders on top of a video feed, the way i have it setup the format i get the data in is 32 bit xrgb with a byte for red green blue and a throw away. Can I get it to render with an alpha channel so i can use it for better blending?

Answer 1

You sure can. Use D3DFMT_A8R8G8B8 for your back buffer.

http://msdn.microsoft.com/en-us/library/bb172558(VS.85).aspx