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01-07-2004, 09:23 AM
Hi there,

I'm studying openGL as part of my degree and have been set some questions to answer - one of these is:
"what is the OpenGL native Type?"

I cant find this in my notes, textbook or on the net anywhere!

Any ideas?

dorbie
01-07-2004, 10:42 AM
The question doesn't make a lot of sense, even to OpenGl experts. It may be asking several things (none of them very precisely or clearly).

OpenGL native bindings are in the C language.

OpenGL defines some types like GLFloat GLuint etc so these are consistent in cross platform environments.

Obli
01-07-2004, 10:54 AM
Originally posted by Bobby:
"what is the OpenGL native Type?"
If you mean "OpenGL native type to store models on disk" (something like 3dstudio's .3ds) then you're out of luck. GL does not consider that problem and has no native format.

Depending from the implementation, GL may store some information in a specific (implementation-dependant) way.
Example: textures on GeForce may be stored as RGBA RGBA RGBA, textures on Radeon may be stored as four separate arrays
RRRR
GGGG
BBBB
AAAA

However, you are not allowed to know how this works for both industrial secret reasons and because you don't really need to know.

Other things to ask?

dorbie
01-07-2004, 11:10 AM
Yep it might be asking ABGR vs RGBA which actually DOES matter and makes a performance difference for example when doing a drawpixels but the native arrangement of these is platform dependent. It is useful to know and fairly standard to have one more optimal than the other.

I assume your question has some kind of additional context. Such as glDrawpixels etc.


[This message has been edited by dorbie (edited 01-07-2004).]