Affine/Linear Texture Mapping

Is there any way to specify what algorithm opengl uses to texture map a texture onto an object? I would like to use Affine Texture mapping, but it looks like opengl only supports some form of perspective texture mapping. Any ideas?

It does perspective-correct texture mapping and plain texture far as I know. I guess that the exact way of doing it is implementation dependent, since the spec doesn’t specify more.

You can give it a hint to do affine texture mapping.


On some implementations this will give you affine texture mapping, on others it won’t. Use GL_NICEST to ask for perspective correct texture mapping.


What is exactly affine texture mapping?

Linear texture coords. interpolation, no perspective correction.

Why would one want that? It’s not gonna be faster …

“What is exactly affine texture mapping?”
I thought it was something new (english is not my native language).

Its faster only in software implementations. I’m 99% shure that no video card 2 years old or less will accelerate a bit by using linear texture mapping.

[This message has been edited by coco (edited 01-26-2001).]