Bug 7985

Summary: Bad texture rendering with gluOrtho2d()
Product: Mesa Reporter: Laurent carlier <lordheavym>
Component: Drivers/DRI/r200Assignee: Default DRI bug account <dri-devel>
Status: RESOLVED INVALID QA Contact:
Severity: normal    
Priority: high    
Version: 6.4   
Hardware: x86 (IA32)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments: capture of the problem

Description Laurent carlier 2006-08-24 10:41:50 UTC 
Texture rendering give a black line around the quad. The problem seem to come 
from the use of glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, 
GL_LINEAR), GL_NEAREST fix the problem.

No problem with fglrx or nvidia drivers.

OpenGL vendor string: Tungsten Graphics, Inc.
OpenGL renderer string: Mesa DRI R200 20041207 AGP 1x TCL
OpenGL version string: 1.3 Mesa 6.4.1

Under Ubuntu Dapper
Comment 1 Laurent carlier 2006-08-24 10:44:04 UTC 
Created attachment 6672 [details]
capture of the problem
Comment 2 Brian Paul 2006-08-24 12:29:03 UTC 
Looks like a border texel sampling issue.  You might try different texture wrap
modes, like GL_CLAMP_TO_EDGE to see what happens.
Comment 3 Laurent carlier 2006-08-24 13:42:49 UTC 
(In reply to comment #2)
> Looks like a border texel sampling issue.  You might try different texture 
wrap
> modes, like GL_CLAMP_TO_EDGE to see what happens.
> 

GL_CLAMP_TO_EDGE mode fix the problem too, like GL_NEAREST.
Comment 4 Roland Scheidegger 2006-08-24 18:19:22 UTC 
So that looks like the rendering is correct. nvidia's behaviour with treating
gl_clamp as gl_clamp_to_edge is non-conformant. Probably fglrx picked this up
too because some old apps expose bugs with conformant behaviour (the
non-conformant behaviour exists because old nvidia hardware can't handle gl_clamp).

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