US Patent 7768512 System and method for rasterizing primitives using direct interpolation

A system and method for rendering a graphic primitive by linear or perspective interpolation from vertex points. An interpolation engine is employed to interpolate channel values along edges of the primitive to determine values along a scan line containing a selected point. The interpolation engine is then employed to interpolate along the scan line. Processing time may further be reduced by the use of an improved adder/subtractor as a component of the interpolation engine to reduce sequential steps and improve parallelism.