I''m using glRasterPos and glDrawPixels to write an bitmap directly in the frame buffer. When I''m using my program in software mode, everything runs fast, but when I''m telling my program to use my 3DFX card to render the scene, the program becomes really slow. The same thing happened when trying the 13th Tutorial (Bitmap Fonts) with my 3DFX card. Is there something I can do about it?
I have an Creative 3D Blaster 12MB and my program runs on the Win32 platform.
It has been largely discussed in a previous topic (Background... how?) about the ugly performances of rasterizing functions. It is also known that 3dFX OpenGL drivers are far from being perfect. That might explain some of your performances.
Yes, sadly, using these raster functions in your program is akin to taking a large blunt object and beating the living shite out of it... it will thrash and moan and kick and scream, and eventually limp off into a corner to lick it''s wounds.
Most OpenGL bandits will recommend you avoid them and use texture-mapped quads to show bitmaps instead.
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