1. A method for use in a computer graphics system for applying texture mapping in per-pixel operations, the method comprising: receiving at the computer graphics system a plurality of parameters that are used to define a pixel value at a pixel in a primitive; selecting by the computer graphics system parameters from the plurality of parameters to generate selected parameters and unselected parameters where the unselected parameters are the plurality of parameters that are not selected; substituting by the computer graphics system a texture value from a texture map in place of at least one selected parameter used in an algorithm that uses the selected parameters, the texture value varying over the primitive; determining by the computer graphics system the pixel value by using the unselected parameters and the texture value varying over the primitive, wherein the set of unselected parameters are not a texture value and the texture value is associated with the selected parameters; and storing the generated pixel value in a frame buffer of the computer graphics system.