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Loading alpha channels

Loading alpha channels

Loading alpha channels


I am writing a DirectDraw game in full screen exclusive mode using 32bpp.

I'd like to be able to load images in ARGB format onto an off-screen surface so that when I blit them they will blit using their alpha channel. This is so that i can do things like menus with drop shadows behind them and the like.

I understand it might need a little bit of Direct3D code in there somewhere but the impression I get from searching around is that I can still use DirectDraw as the basis for my app, although I can't find the exact answer.

Many thanks in advance,

Daniel Briley

RE: Loading alpha channels

I have the same question. Also, am I right in thinking that the alpha channel can blit things semi-transparently?


RE: Loading alpha channels

You might not like the answer.

The DirectDraw interfaces/drivers don't support alpha-channels on the textures/images themselves.

You'd have to use Direct3D to do that.

If you want to combo DirectDraw and Direct3D, you can do so (up to Direct3D8 I believe), but you STILL won't be able to use the alpha channel properly with DirectDraw.

In the past, most games used DirectDraw for the menus, and Direct3D for the actual game code...which it kinda sounds like you want to do the same.

Any problem with moving up to Direct3D8?? It's EXTREMELY easy to load up a texture with alpha channel support and rasterize it to your video device...


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