Patent ID: 8154547

Claim:
An early Z test method, the method comprising: segmenting a scene into a plurality of tiles for performing a rendering with respect to a triangle; selecting a first tile of the plurality of tiles, which has a tile Z value less than a minimum Z value of the triangle; performing the rendering with respect to the triangle in remaining tiles excluding the selected first tile of the plurality of tiles, using a frame memory; and outputting a result of the rendering on a display device wherein the minimum Z value is a smallest Z value among Z values of three vertices of the triangle, and a maximum Z value is determined to be a determined greatest value of the Z values of the three vertices of the triangle, wherein the selecting the first tile comprises determining maximum Z values of any triangles which completely include the first tile, determining a smallest value of the determined maximum Z values, and determining the tile Z value to be equal to the determined smallest value, and wherein when at least two vertices of the triangle have different Z values, the maximum Z value is determined to be the determined greatest value of the Z values of the three vertices of the triangle.