1. A method for domain shading comprising: analyzing graphics state data; generating a first control signal when a blending operation is active; generating all first primitives through a single-pass domain shading based on a result of the analysis and when the first control signal is received by a domain shader; generating a second control signal when the blending operation is inactive; and generating only second primitives which are visible among the first primitives through a two-pass domain shading based on the result of the analysis and when the second control signal is received by the domain shader.