Sorry this is a bit vague. I suppose you're using engine.d or screen.d directly right?Depending on your setup (OpenGL or Software) transparency will be different.For example take a look at line 733, putpixel function and you'll see that It handle Color differently if it's OpenGL x Software and for the latter it checks if 32bpp or less.Now if it's OpenGL take a look for "Alpha". Matheus.
Thanks for the reply. Do you know the arsd library?