[Mesa-dev] COMPSIZE function in OpenGL XML registry

[Ian Romanick]

On 06/10/2015 11:25 AM, Shervin Sharifi wrote:
> Hi,
>  
>  This may not be the right forum to ask this, but I didn't know of a
> better forum, so I thought I can ask here.
> 
>  I'm new to OpenGL. I am looking at XML registry for OpenGL and there
> are some parameters with attributes containing a function COMPSIZE (I've
> pasted an example below).
>  I tried to find information on what the COMPSIZE function is, where/how
> it is used, etc, but couldn't find documentation or credible information
> on the Internet.
>  Any information or pointer to that would be really helpful. 

It's a signal to code generation scripts that the size of the data
referenced by the "pointer" parameter depends on the values of "type"
and "stride".  For example, GLX protocol code uses this to know how much
image data to send to the server for glTexImage2D.

>  Thanks, 
>     Shervin
> 
> 
> 
> This example is from gl.xml in the OpenGL registry:
> 
>         <command>
>             <proto>void <name>glBinormalPointerEXT</name></proto>
>             <param group="BinormalPointerTypeEXT"><ptype>GLenum</ptype>
> <name>type</name></param>
>             <param><ptype>GLsizei</ptype> <name>stride</name></param>
>             <param len="COMPSIZE(type,stride)">const void
> *<name>pointer</name></param>
>         </command>
> 
> 
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev