CG to GLSL: f3texRECT equivalent?

Question

I'm trying to convert a CG program to a GLSL program.

What I've done so far seems correct, but the GLSL shader outputs an incorrect output. The incorrect behavior is defined by a set of test images.

The only dark point on which I'm investigating is the function f3texRECT, which I've translated in texture. However, I cannot find any documentation about f3texRECT.

Can somebody put some light about?

Answer 1

f3texRECT() looks like it would map to texture() with a sampler2DRect instead of a sampler2D -- meaning the texture coordinates are unnormalized ([0..textureSize-1] instead of [0..1]). The "f3" prefix means the result is a three-channel color. Older versions of GLSL had a textureRect() function for this purpose, but it's been deprecated.