Bug 10907 - GLSL built-in exp function not functioning correctly
Summary: GLSL built-in exp function not functioning correctly
Status: RESOLVED FIXED
Alias: None
Product: Mesa
Classification: Unclassified
Component: Mesa core (show other bugs)
Version: 6.5
Hardware: All All
: medium major
Assignee: mesa-dev
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Reported: 2007-05-10 13:23 UTC by James Burns
Modified: 2007-05-11 09:25 UTC (History)
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Description James Burns 2007-05-10 13:23:11 UTC 
The GLSL exponential function does not generate the correct result.  Symptom - shader working on NV does not perform same on OSMESA.  The following line:

float f = exp(-k*gl_FogFragCoord);

was replaced with:

float f = pow(2.718281828, -k*gl_FogFragCoord);

After making the replacement, the shader performed correctly again.

Test codes have verified this problem.
Comment 1 Brian Paul 2007-05-10 13:50:38 UTC 
Fixed in git.  Thanks, Jamie.
Comment 2 James Burns 2007-05-11 09:25:37 UTC 
(In reply to comment #1)
> Fixed in git.  Thanks, Jamie.
> 

Tested fix in my application.   All works as expected.  Thanks so much!

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