Re: Patch for bug #901422 (CLAMP_TO_EDGE)

[Daniele C. <dca...@in...>]

I try function with Window 98 and Windows Xp
In Window 98 I obtain:
openGLVersion = "1.15"
majorVers=1
minorVers=15

In Window Xp
openGLVersion = "1.3.3966 winXP Release"
majorVers=1
minorVers=3

Daniele


At 20.26 29/09/04, you wrote:
>Hmmm, GLUtils_CheckExtensions looks like it has some problems...
>
>First, the version check is flawed:
>
>         if ( (majorVers >= 1) && (minorVers >= 2) )
>
>would make more sense as:
>
>         if ( (majorVers > 1) || ((majorVers == 1) && (minorVers >= 2)) )
>
>Or else a version like "2.0" will get bypassed. The minor version can
>easily be two digits though, and "15" shouldn't be greater than "2" in
>this case, so it's broken anyway...
>
>Apple's glCheck code converts the GL_VERSION string into a BCD for
>comparisons
><http://developer.apple.com/samplecode/Carbon_AGL_Full_Screen/ 
>listing2.html> Quesa should probably do the same, something like this:
>
>------
>void
>GLUtils_CheckExtensions( TQ3GLExtensions* featureFlags )
>{
>         const char*     openGLVersion = (const char*)glGetString( 
> GL_VERSION );
>         const char*     openGLExtensions = (const char*)glGetString( 
> GL_EXTENSIONS
>);
>
>         short j = 0;
>         short shiftVal = 8;
>         unsigned short glVersion = 0;
>
>         // Initialize to default value, all off.
>         memset( featureFlags, 0, sizeof(TQ3GLExtensions) );
>
>         if (openGLVersion != NULL)
>         {
>                 // Get BCD version.
>                 while (((openGLVersion[j] <= '9') && (openGLVersion[j] >= 
> '0')) ||
>(openGLVersion[j] == '.'))
>                 {
>                         if ((openGLVersion[j] <= '9') && 
> (openGLVersion[j] >= '0'))
>                         {
>                                 glVersion += (openGLVersion[j] - '0') << 
> shiftVal;
>                                 shiftVal -= 4;
>                         }
>                         j++;
>                 }
>
>                 // Check for extensions.
>                 if ( glVersion >= 0x0120 ||
>                         isOpenGLExtensionPresent( openGLExtensions,
>"GL_EXT_separate_specular_color" ) )
>                 {
>                         featureFlags->separateSpecularColor = kQ3True;
>                 }
>
>                 if ( glVersion >= 0x0120 ||
>                         isOpenGLExtensionPresent( openGLExtensions,
>"GL_EXT_texture_edge_clamp" ) ||
>                         isOpenGLExtensionPresent( openGLExtensions,
>"GL_SGIS_texture_edge_clamp" ) )
>                 {
>                         featureFlags->clampToEdge = kQ3True;
>                 }
>         }
>}
>------
>
>Note: I added the GL_SGIS_texture_edge_clamp check as well. I've
>updated my patch archive with these changes, but for some reason I'm
>not convinced GL_VERSION is always correct (though Apple seems to
>depend on it). What OS are you running that returns OpenGL 1.15?
>
>Thanks,
>Frank.
>
>On 29-Sep-04, at 12:42 PM, Daniele Cavallini wrote:
>
>>I am using  OpenGL 1.15. The value is obtained from glGetString(
>>GL_VERSION ).
>>When exit from  GLUtils_CheckExtensions featureFlags->clampToEdge is
>>set to kQ3True;
>>I obtain:
>>majorVers =  1
>>minorVers = 15
>>after the step
>>int             numScanned = sscanf( openGLVersion, "%d.%d",
>>&majorVers, &minorVers );
>>It is Correct?
>>Daniele
>>
>>At 18.06 29/09/04, you wrote:
>>>No, that'll break it...
>>>
>>>The value will be false to start (the struct is zeroed in the
>>>function) and is set to true if using OpenGL 1.2+. The extension may
>>>not exist in an OpenGL 1.2+ implementation though, so you'll be
>>>setting it back to false even though it can be handled just fine at
>>>that point. The extension check is strictly for older OpenGL versions
>>>before the ARB ratified the function.
>>>
>>>Frank.
>>>
>>>On 29-Sep-04, at 10:59 AM, Daniele Cavallini wrote:
>>>
>>>>Question:
>>>>Is It better add this "else" in function "GLUtils_CheckExtensions"?
>>>>
>>>>  if (isOpenGLExtensionPresent( openGLExtensions,
>>>>GL_EXT_texture_edge_clamp" ))
>>>>         {
>>>>                 featureFlags->clampToEdge = kQ3True;
>>>>         }
>>>>         else
>>>>                 featureFlags->clampToEdge = kQ3False;
>>>>Daniele
>>>>
>>>>At 01.50 29/09/04, you wrote:
>>>>>Here: <http://chaoticbox.com/quesa901422.zip> is a small patch that
>>>>>checks for CLAMP_TO_EDGE and uses it when available for texture
>>>>>shaders
>>>>>that have a kQ3ShaderUVBoundaryClamp setting. The original report is
>>>>>here:
>>>>><http://sourceforge.net/tracker/index.php?  >>>> 
>>>>>func=detail&aid=901422&group_id=45158&atid=442052>
>>>>>
>>>>>On a similar note; Is there a better way to submit patches? Do you
>>>>>guys
>>>>>prefer some sort of diff tool output? If so, please let me know...
>
>
>
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