XXX - Not complete yet!!! Name S3_s3tc Name Strings GL_S3_s3tc Contact Unknown. IP Status There is significant IP associated with the S3TC format. In 1999 S3 told the OpenGL ARB that they would not license it for general use in OpenGL. IHVs shipping this extension probably have executed licenses directly with S3 or its successors (Sonic Blue, S3 Graphics). The current ownership of the S3TC IP is unknown to the ARB. It is known that when S3 exited the graphics hardware business, part of their operations were sold to ATI and part were spun off to a joint Taiwanese venture with Via Technologies, called S3 Graphics. Status Shipping in several vendor drivers. Deprecated in favor of EXT_texture_compression_s3tc. Version Unknown Number 276 Dependencies OpenGL 1.1 is required. The extension is not specified; only the new tokens are known. Overview This extension allows specifying texture data in compressed S3TC format. Issues * Need a specification, at least at a functional level. No detailed online documentation can be found in Google, only enum values. New Procedures and Functions None. New Tokens Accepted by the ??? parameter of ??? (presumably by the argument of TexImage2D?): RGB_S3TC 0x83A0 RGB4_S3TC 0x83A1 RGBA_S3TC 0x83A2 RGBA4_S3TC 0x83A3 RGBA_DXT5_S3TC 0x83A4 RGBA4_DXT5_S3TC 0x83A5 Additions to Chapter 2 of the OpenGL 1.2 Specification (OpenGL Operation) Unknown. Additions to Chapter 3 of the OpenGL 1.2.1 Specification (Rasterization) Unknown. Probably only changes to accepted client texture formats for 2D textures. Additions to Chapter 4 of the OpenGL 1.2.1 Specification (Per-Fragment Operations and the Frame Buffer) Unknown. Additions to Chapter 5 of the OpenGL 1.2.1 Specification (Special Functions) Unknown. Additions to Chapter 6 of the OpenGL 1.2 Specification (State and State Requests) Unknown. Additions to Appendix A of the OpenGL 1.2.1 Specification (Invariance) Unknown. Additions to the GLX / WGL / AGL Specifications None GLX Protocol Unknown. Passing compressed data would affect the computed data size, so some enhancements to the existing TexImage2D protocol might be needed. Errors Unknown. New State Unknown. Revision History * Revision 2, January 17, 2003 (Mark Kilgard) - Document RGBA_DXT5_S3TC and RGBA4_DXT5_S3TC enumerants. Update status as deprecated in favor of EXT_texture_compression_s3tc spec. * Revision 1, December 18, 2002 (Jon Leech) - Minimal documentation on the extension based on public header files.