On 20.07.2008 17:10, Nicolai Hähnle wrote: > CC'ing mesa-devel, since I don't have a pre-R300 card. > > Am Sonntag 20 Juli 2008 11:35:26 schrieb Andrew Randrianasulu: >> Hello. Not sure if this bug has any impact outside artificial tests, but >> it is here ... >> >> Mesa commit b4b7326717d3253656f9702fc04f06f8d210a6aa >> Xserver commit b85392e66b4cbfcc95897ac342f19ac8ab04d4cc >> drm commit 04893aa99abfbed8eb6d7067a974fa1f31193c87 >> xf86-video-ati commit ecb6347a3d7071890600c98c2addef3a8ca260ee >> >> piglit - 76ca09aeaa38c7ea22ab397dc8358817ee3c9c6f > > The problem is that 1D textures are simulated using 2D textures that are only > 1 pixel high. If the user sets a clamp mode of GL_CLAMP or GL_CLAMP_TO_BORDER > for the t component (i.e. y direction) this causes incorrect results since > the hardware treats the texture as a flat 2D object, while the OpenGL spec > mandates them being treated as actual 1D objects that ignore the t component > entirely. > > (I first found this bug in Mesa's shadowtex sample, so yes, it might appear > in > serious applications as well.) > > I've attached a possible patch for this problem - please test / provide > feedback. I would imagine the R100 has a similar bug and needs a similar > patch.
Haven't tested yet, but looks good to me. I wonder though if not more drivers are affected? I think it's quite common for hardware to have no direct support for 1d textures (coincidentally, it would be possible on r200 to set texcoords to 1d mode, but I don't know if it would help, and it seems we couldn't do projected 1d which looks geared towards d3d usage, and probably would be problematic wrt ATI_fragment_shader). Roland ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
