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.
cu,
Nicolai
diff --git a/src/mesa/drivers/dri/r200/r200_tex.c b/src/mesa/drivers/dri/r200/r200_tex.c
index e7a37dd..24b9b3b 100644
--- a/src/mesa/drivers/dri/r200/r200_tex.c
+++ b/src/mesa/drivers/dri/r200/r200_tex.c
@@ -102,37 +102,39 @@ static void r200SetTexWrap( r200TexObjPtr t, GLenum swrap, GLenum twrap, GLenum
_mesa_problem(NULL, "bad S wrap mode in %s", __FUNCTION__);
}
- switch ( twrap ) {
- case GL_REPEAT:
- t->pp_txfilter |= R200_CLAMP_T_WRAP;
- break;
- case GL_CLAMP:
- t->pp_txfilter |= R200_CLAMP_T_CLAMP_GL;
- is_clamp = GL_TRUE;
- break;
- case GL_CLAMP_TO_EDGE:
- t->pp_txfilter |= R200_CLAMP_T_CLAMP_LAST;
- break;
- case GL_CLAMP_TO_BORDER:
- t->pp_txfilter |= R200_CLAMP_T_CLAMP_GL;
- is_clamp_to_border = GL_TRUE;
- break;
- case GL_MIRRORED_REPEAT:
- t->pp_txfilter |= R200_CLAMP_T_MIRROR;
- break;
- case GL_MIRROR_CLAMP_EXT:
- t->pp_txfilter |= R200_CLAMP_T_MIRROR_CLAMP_GL;
- is_clamp = GL_TRUE;
- break;
- case GL_MIRROR_CLAMP_TO_EDGE_EXT:
- t->pp_txfilter |= R200_CLAMP_T_MIRROR_CLAMP_LAST;
- break;
- case GL_MIRROR_CLAMP_TO_BORDER_EXT:
- t->pp_txfilter |= R200_CLAMP_T_MIRROR_CLAMP_GL;
- is_clamp_to_border = GL_TRUE;
- break;
- default:
- _mesa_problem(NULL, "bad T wrap mode in %s", __FUNCTION__);
+ if (t->base.tObj->Target != GL_TEXTURE_1D) {
+ switch ( twrap ) {
+ case GL_REPEAT:
+ t->pp_txfilter |= R200_CLAMP_T_WRAP;
+ break;
+ case GL_CLAMP:
+ t->pp_txfilter |= R200_CLAMP_T_CLAMP_GL;
+ is_clamp = GL_TRUE;
+ break;
+ case GL_CLAMP_TO_EDGE:
+ t->pp_txfilter |= R200_CLAMP_T_CLAMP_LAST;
+ break;
+ case GL_CLAMP_TO_BORDER:
+ t->pp_txfilter |= R200_CLAMP_T_CLAMP_GL;
+ is_clamp_to_border = GL_TRUE;
+ break;
+ case GL_MIRRORED_REPEAT:
+ t->pp_txfilter |= R200_CLAMP_T_MIRROR;
+ break;
+ case GL_MIRROR_CLAMP_EXT:
+ t->pp_txfilter |= R200_CLAMP_T_MIRROR_CLAMP_GL;
+ is_clamp = GL_TRUE;
+ break;
+ case GL_MIRROR_CLAMP_TO_EDGE_EXT:
+ t->pp_txfilter |= R200_CLAMP_T_MIRROR_CLAMP_LAST;
+ break;
+ case GL_MIRROR_CLAMP_TO_BORDER_EXT:
+ t->pp_txfilter |= R200_CLAMP_T_MIRROR_CLAMP_GL;
+ is_clamp_to_border = GL_TRUE;
+ break;
+ default:
+ _mesa_problem(NULL, "bad T wrap mode in %s", __FUNCTION__);
+ }
}
t->pp_txformat_x &= ~R200_CLAMP_Q_MASK;
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