Re: Choosing Between Target Texture

Knockr wrote:

> Dear All,
> 
> I'm using rendering few textures in my OpenGL which is NPOT(non
> power of two).
> 
> I've tried using both GL_TEXTURE_RECTANGLE_ARB and
> GL_TEXTURE_RECTANGLE_NV as target texture. Bother are working
> fine in my nVidia Hardware. Is there any advantage for either
> of these over other? ARB is the standard format and NV is the
> nVidia format. Will I get any performance improvements for NV
> texture rectangle if I use it with nVidia Hardware?

It was NVidia who came up with NPO2 textures first, so that's why
there is the _NV extension. Then NPO2 textures got accepted as a
standard feature and they became _ARB.

Now if you looked into the specification of both extensions, then
you would have seen that the newly introduced tokens have the
same values:

~ $ grep TEXTURE_RECTANGLE /usr/include/GL/glext
#define GL_TEXTURE_RECTANGLE_ARB          0x84F5
#define GL_PROXY_TEXTURE_RECTANGLE_ARB    0x84F7
#define GL_TEXTURE_RECTANGLE_NV           0x84F5
#define GL_PROXY_TEXTURE_RECTANGLE_NV     0x84F7

So there's absolutely no difference. But for reasons of
****tability you should use the ARB variant in your code. The _NV
version might go away.

Wolfgang Draxinger
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