If the application provides s3tc-encoded data through glCompressedTexImage (usually loaded from a pre-compressed texture stored on disk), Mesa will pass it unaltered to the graphics card (as long as the driver/card supports DXT* format ids) and will not need to use any encoding or decoding algorithms.
The problem is that if the application supplies uncompressed data, Mesa would need to run an encoding algorithm to be able to use compressed textures. Conversely, if software rendering is necessary, and the application provides compressed textures, Mesa will need to run a decoding algorithm to be able to sample from the texture. So the workaround (and what commercial games usually do) is to ship pre-compressed textures along with the game, as well as uncompressed textures in case the card/rendered do not support texture compression. An end-user side solution is to download, compile and install libtxc_dxtn.so, which Mesa will use if present to decode and encode compressed textures. Furthermore, a GPU can be used to do decoding using its native sampling support, and some may also support encoding. ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
