On Sat, Mar 09, 2002 at 11:41:02AM +0000, Jos� Fonseca wrote: > > VQ texture compression on Rage Pro? Now, they aren't talking about DXTC, > > are they? I wouldn't really call the VQ, but then again, I don't write > > press releases. :) So here's the question for the guys working on the > > mach64 driver: you guys know anything about this? It is mentioned in the > > product specs simply as "texture decompression," but they also mention > > mipmapping. :( > > > > http://www.ati.com/products/pc/xpert98/specs.html > > This is something interesting that I had also noticed when reading the > chip specs, a TEX_COMPRESS bit that enabled 4:1 VQ compression. (the 8:1 > must be with palletized textures simultaneously). At that time I didn't > fully understand what was the meaning of this so I left this for a later > time.
Might be interesting to try some experiments with this. Is code available to compress textures to their format? > With this we could compress the textures before feeding them into the > driver isn't it? Or must we rely on the client to give them compressed? I took a peek at the ARB_texture_compression extension. New internal format tokens would need to be created for each of the compressed formats available. So, if only compressed RGB textures are supported by the hardware, then something like GL_COMPRESSED_RGB_VQ1_MESA would need to be added. Then, when a texture is sent into the driver, if the texture format is non-compressed (i.e., GL_RGB) and the internal format is either GL_COMPRESSED_RGB_VQ1_MESA *or* GL_COMPRESSED_RGB, the driver would need to compress it. If the texture format is already GL_COMPRESSED_RGB_VQ1_MESA (very, very, very, unlikely), it would just get passed through. Now, the new token could probably be skipped. If the requested internal format is GL_COMPRESSED_RGB, just compress the texture and be done with it. Given the likely hood of ANYONE having pre-compressed textures for this format, this is probably both the easiest and best route to take. This is amplified by the fact that I don't think that even the ATI drivers export this functionality in OpenGL. Does anyone know any different? Perhaps we could discuss this more in the IRC chat today. http://oss.sgi.com/projects/ogl-sample/registry/ARB/texture_compression.txt http://oss.sgi.com/projects/ogl-sample/registry/3DFX/texture_compression_FXT1.txt http://oss.sgi.com/projects/ogl-sample/registry/EXT/texture_compression_s3tc.txt -- Tell that to the Marines! _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
