Drawing processing apparatus and drawing processing method for multipass rendering

A drawing processing apparatus capable of executing a drawing processing program having conditional branches efficiently by multipass rendering. The drawing processing apparatus comprises arithmetic processing parts including an object input part, a primitive generating part, a raster part, a pixelation part, a distribution part, and a shader which constitute pipeline stages. The shader divides the program into and executes the same in a plurality of passes depending on conditional branches. The shader generates enable flags determining whether or not respective pixels satisfy branch conditions. The flag generating part generates bind enable flags which are the enable flags on the pixels bound into the processing granularities of the pipeline stages, and feeds back the same to the respective pipeline stages. The arithmetic processing parts in the individual pipeline stages refer to the bind enable flags and limit the submission of data not targeted for arithmetic processing in the branched passes.