Announcement

Collapse
No announcement yet.

Mesa Can Do EXT_texture_compression_RGTC

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Mesa Can Do EXT_texture_compression_RGTC

    Phoronix: Mesa Can Do EXT_texture_compression_RGTC

    In Mesa's quest to catch up to the proprietary Linux drivers (and the graphics drivers available under Windows), they are now a tiny bit closer. David Airlie has announced on the Mesa mailing list that he has implemented support for the EXT_texture_compression_RGTC extension into Mesa...

    http://www.phoronix.com/vr.php?view=OTEzNA

  • #2
    Needs to be updated on this page: http://cgit.freedesktop.org/mesa/mesa/tree/docs/GL3.txt under GL 3.0.

    Comment


    • #3
      Hey, at least we recently moved up to 2.1 instead of 1.4...

      Comment


      • #4
        I believe S3TC is DXT3, and these are DXT4 and 5.

        Does anyone know what they're used by? Does this help WINE apps?

        Comment


        • #5
          Originally posted by smitty3268 View Post
          I believe S3TC is DXT3, and these are DXT4 and 5.

          Does anyone know what they're used by? Does this help WINE apps?
          All DXT compressions are "S3TC". RGTC was designed for compressing normal maps, and can replace DXT5.

          Comment


          • #6
            Correction: it can replace DirectX's 3Dc/BC5 (which is better than DXT5).

            Comment


            • #7
              Totally wrong, RGTC is red+green block texture compression. S3TC is RGB and RGBA block compression. How is BC5 (which is a RG compression formats) supposed to replace DXT5 (which is a RGBA compression format) if BC5 can only handle two color channels?!

              Comment


              • #8
                Originally posted by LiquidAcid View Post
                Totally wrong, RGTC is red+green block texture compression. S3TC is RGB and RGBA block compression. How is BC5 (which is a RG compression formats) supposed to replace DXT5 (which is a RGBA compression format) if BC5 can only handle two color channels?!
                Better for normal maps. Based that claim on the research presented in my second link:
                [3Dc] produces much better quality than DXT1 or DXT5 normal map compression.
                (...)
                The [3Dc] format can be loaded in OpenGL as LATC or RGTC.

                Comment


                • #9
                  Your statement is still wrong though. An RG format can never replace an RGB/RGBA format. Using DXTn formats for normal compression was always kind of a hack.

                  Comment


                  • #10
                    Addition to last post:
                    The very nVidia article you quote explains why using DXTn for encoding normal/tangent data is a hack.
                    If anything, then texture_RG and texture_RGTC are the proper ways to store such information.

                    Comment


                    • #11
                      Michael, I know it's easy to write articles about how far behind the free software drivers are, with statements like

                      Too bad though it will still be a long time before Mesa reaches any sort of parity in terms of OpenGL extension support or even provides proper OpenGL 3.x/4.x support, with the Gallium3D/Mesa drivers still effectively living in the OpenGL 2.1 world.
                      but honestly, look at GL3.txt and then tell me how far off OpenGL 3 is.

                      There are not that many items left on that list, and most of what is left is there because of patent concerns.

                      And, does anyone even care about OpenGL 4 yet anyway?

                      Comment


                      • #12
                        I think the changes to GLSL and the support for integer texture formats is probably the largest work that remains.

                        Comment


                        • #13
                          Originally posted by LiquidAcid View Post
                          I think the changes to GLSL and the support for integer texture formats is probably the largest work that remains.
                          Didn't intel FOSS devs develop support for next GLSL version?

                          Comment


                          • #14
                            Originally posted by mattst88 View Post
                            And, does anyone even care about OpenGL 4 yet anyway?
                            No, probably not yet, at least not to a big extent, but OpenGL3.3 is extremely interesting, and full support (albeit slow) for it would be great. Especially for the home-hackers, so we can test out OpenGL 3 and learn all the "new" stuff.

                            Comment


                            • #15
                              Originally posted by Drago View Post
                              Didn't intel FOSS devs develop support for next GLSL version?
                              Specify "next version".

                              Intel devs coded an entirely new GLSL compiler, that is certainly true. However this doesn't automatically give you support for every GLSL version out there.

                              Comment

                              Working...
                              X