The GL extension GL_EXT_texture_sRGB (which is in OpenGL 2.1 core) defines the texture formats GL_SRGB and friends and specifies that sampling such a texture automatically converts the values from non-linear RGB (sRGB) to linear RGB. However, this conversion is not performed; the textures are sampled as if they were normal GL_RGB textures. This results in wrong colors (e.g. in the Bino 3D video player: far too bright). I'm running Ubuntu 11.04 on x86_64 and get the following version info from GL: OpenGL version: 2.1 Mesa 7.10.2 OpenGL renderer: Gallium 0.4 on AMD RV710 OpenGL vendor: X.Org If you need more information, please let me know. [This is the same as bug 32323, but re-reported for newer Mesa versions]
I see similar problems in Starcraft 2, there are also over bright textures which go away when MESA_EXTENSION_OVERRIDE="-GL_EXT_texture_sRGB_decode" is set. OpenGL renderer string: Gallium 0.4 on ATI RV530 OpenGL version string: 2.1 Mesa 7.11-devel (git-32a95cb)
BTW this should be probably a mesa core bug, right?
(In reply to comment #2) > BTW this should be probably a mesa core bug, right? There is code in Mesa to handle SRGB textures correctly, see http://cgit.freedesktop.org/mesa/mesa/tree/src/mesa/main/texgetimage.c lines 223-301. I guess drivers can override this, but I don't know the internal structure of Mesa.
There is a lot of other code which plays role in handling sRGB textures. I don't think getteximage.c is relevant to this issue(s). Nevertheless, it looks like Pavel's and Martin's issues are different bugs. Pavel reported that GL_EXT_texture_sRGB_decode, which is only in 7.11, is broken specifically on r300g, but other drivers might be affected as well and it definitely looks like a Mesa core bug. Pavel, could you please add it as a new bug against Mesa core? Martin's issue is likely related to the fact that piglit/glean/texture_srgb fails on r600g. Taking a look at it might be a good start.
(In reply to comment #4) > There is a lot of other code which plays role in handling sRGB textures. I > don't think getteximage.c is relevant to this issue(s). > > Nevertheless, it looks like Pavel's and Martin's issues are different bugs. > > Pavel reported that GL_EXT_texture_sRGB_decode, which is only in 7.11, is > broken specifically on r300g, but other drivers might be affected as well and > it definitely looks like a Mesa core bug. Pavel, could you please add it as a > new bug against Mesa core? > Reported against mesa core as bug 37150.
(In reply to comment #4) > There is a lot of other code which plays role in handling sRGB textures. I > don't think getteximage.c is relevant to this issue(s). > > Nevertheless, it looks like Pavel's and Martin's issues are different bugs. > > Pavel reported that GL_EXT_texture_sRGB_decode, which is only in 7.11, is > broken specifically on r300g, but other drivers might be affected as well > and it definitely looks like a Mesa core bug. Pavel, could you please add it > as a new bug against Mesa core? > > Martin's issue is likely related to the fact that piglit/glean/texture_srgb > fails on r600g. Taking a look at it might be a good start. the piglit passes for me on my rv770 with mesa from git (470952f) @Martin: Can you test with a newer version of mesa (9.0 or mesa from git)?
I don't have access anymore to the AMD graphics card that originally exposed the problem for me. I can only confirm that the problem does not exist with Mesa 9.0 (from Ubuntu 12.10) with an Intel Sandybridge GPU: OpenGL Version: 3.0 Mesa 9.0 OpenGL Renderer: Mesa DRI Intel(R) Sandybridge Mobile OpenGL Vendor: Intel Open Source Technology Center Thanks for your work. Martin
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