Re: [Mesa3d-dev] RE: [Dri-devel] Mesa glTexEnv bug (Was: S3TC and ut2k)

[Ian R. <id...@us...>]

Brian Paul wrote:
> Leif Delgass wrote:
> 
>> On Thu, 2 Jan 2003, Daniel Vogel wrote:
 >>
>>> glTexEnvi( GL_TEXTURE_ENV, GL_OPERAND2_RGB, GL_SRC_COLOR );
>>
>>
>>
>> This is indeed one of the sources of the GL_INVALID_ENUMs; however, it
>> appears to be a bug in Mesa.  There seems to be a missing break after
>> texstate.c:423 :
>>
>> --- texstate.c  Tue Jan 21 17:10:15 2003
>> +++ texstate.fixed.c    Tue Jan 21 17:11:19 2003
>> @@ -421,6 +421,7 @@
>>                   return;
>>                FLUSH_VERTICES(ctx, _NEW_TEXTURE);
>>                texUnit->CombineOperandRGB[2] = operand;
>> +              break;
>>             default:
>>                 TE_ERROR(GL_INVALID_ENUM, "glTexEnv(param=%s)", operand);
>>                return;
>>
>> Brian, does that look right to you?
> 
> 
> Yes.  There should be a break there.  I'm surprised this wasn't found 
> when running the texcombine conformance test or Glean test.  Hmmm.

Glean didn't catch it because it only ever sets GL_OPERAND2_{RGB,ALPHA} 
to the default state.  This ends up taking the early-out path in 
texstate.c.  Just dumb luck.

[snip]

>> However, I still see the same corruption reported before.  This could 
>> be in part because of the missing cube map support, but it looks to me 
>> like something is causing vertex data corruption.  Just a guess.
> 
> Cube mapping works in the R200 driver with one caveat: glTexCoord3*() 
> commands don't work.  Normally, a texgen mode like GL_REFLECT is used 
> with cube maps so the texcoords are generated in hardware.  The h/w 
> vertex setup code needs to be updated to handle 3-component texture coords.
> 
> Not sure if this is the problem you're seeing though.  The 
> Mesa/demos/cubemap program shows the problem.

How exactly does this problem look?  This might be exactly the problem 
that I'm geting on r100.  Could you put a screenshot up somewhere?  If 
it is the same thing on r100, I'll go ahead and commit my cube map 
changes, and we'll have to hope someone figures out how to setup the 
hardware for the R coord. :/