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BaShildy

Alpha Blending + Rotation in DirectDraw

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I am currently working on a 2d multiplayer game, and i would like to be able to do special effects using alpha blending and rotation. The problem is I don''t know any way of doing this using hardware acccelerated calls. My sollution on my previous directX game was to do both of these through my own algorithms on the software side. The problem with this is that it was horribly slow no matter how much we optimized it (assembly level, MMX registers, etc.) it wasn''t fast enough to do anything but a small shape rotation. Alpha blending killed performance enough that we dropped it (Before Alpha blending: 65fps, after 25). I realize that DirectGraphics and D3D both support these calls, but i have very little time to spend researching new api''s, so I''m not sure if i would have time to do a 2d game entirely in D3D. I would prefer if there was some way to maintain the project in a 2D api. I am currently using DirectX 8, and using DirectDraw7, DirectInput7, and the current DirectSound COM versions. I wrote a wrapper for these so for blitting i would just call draw with an address of a bitmap structure, it would be nice if i could do the same with rotation and alpha blending without a huge loss of performance. Thanks - Kevin "BaShildy" King Game Programmer: DigiPen www.mpogd.com

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Since you''re already using DX 7 for everything you could easily initialize Direct3D 7 and solve all your problems without redoing all your code since with 7 you can keep your DDraw going while you work on D3D.

Teach Yourself DirectX 7 in 24 Hours will be a great help in getting it going. I have a tutorial at my site for getting the orthogonal view going with DX7.

Ben


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Ben, just went to your site and I must say you did a great job. Theres a lot of things on it I look forward to reading, and you have some nice selections in the downloads section. I have the golgotha zip here, but the music files are corrupt, and i was never able to find a non-corrupt zip! Glad to see your providing it

It just happens I borrowed a copy of Teach Yourself DirectX 7 in 24 Hours and have it right above my desk. I''m going to crack it open right now, didn''t even think about looking that up in there. Thanks for your quick reply, I didn''t think i''d get something that would help me solve this problem within minutes of posting!

- Kevin "BaShildy" King
Game Programmer: DigiPen
www.mpogd.com

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