[Mesa-dev] [PATCH] softpipe: fix clamping when using unormalized coordinates

[Morgan Armand]

On 11/14/2011 3:44 PM, Brian Paul wrote:
> On 11/13/2011 03:24 AM, Morgan Armand wrote:
>> ---
>>   src/gallium/drivers/softpipe/sp_tex_sample.c |    7 ++++---
>>   1 files changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/src/gallium/drivers/softpipe/sp_tex_sample.c b/src/gallium/drivers/softpipe/sp_tex_sample.c
>> index 72629a0..9b0e54e1 100644
>> --- a/src/gallium/drivers/softpipe/sp_tex_sample.c
>> +++ b/src/gallium/drivers/softpipe/sp_tex_sample.c
>> @@ -491,7 +491,8 @@ wrap_linear_unorm_clamp(const float s[4], unsigned size,
>>      uint ch;
>>      for (ch = 0; ch<  4; ch++) {
>>         /* Not exactly what the spec says, but it matches NVIDIA output */
>> -      float u = CLAMP(s[ch] - 0.5F, 0.0f, (float) size - 1.0f);
>> +      float u = CLAMP(s[ch], 0.0f, (float) size);
>> +      u -= 0.5F;
>>         icoord0[ch] = util_ifloor(u);
> 
> If s=0, then icoord0 = -1 and that's not right.  The 'i' coordinates must be in the range [0,size-1].
> 
> Are you trying to fix a specific bug or piglit test?
> 
> 
>>         icoord1[ch] = icoord0[ch] + 1;
>>         w[ch] = frac(u);
>> @@ -512,8 +513,8 @@ wrap_linear_unorm_clamp_to_border(const float s[4], unsigned size,
>>         u -= 0.5F;
>>         icoord0[ch] = util_ifloor(u);
>>         icoord1[ch] = icoord0[ch] + 1;
>> -      if (icoord1[ch]>  (int) size - 1)
>> -         icoord1[ch] = size - 1;
>> +      if (icoord1[ch]>  (int) size)
>> +         icoord1[ch] = size;
>>         w[ch] = frac(u);
>>      }
>>   }
> 
> -Brian

Yes, sorry, I forgot to mention it. This patch fixes texwrap-RECT-bordercolor and texwrap-RECT-proj-bordercolor.