An apparatus of drawing graphics includes an edge coefficient calculator calculating, from vertex data on vertices of a triangle, edge coefficients of edge functions used to determine whether a pixel is present in an inside region of the triangle, and a bounding box calculator calculating a bounding box of projected images of the triangle on a projection plane based on the edge coefficients. The apparatus also includes a starting point determiner and a traverser. The starting point determiner classifies the projected images of the triangle based on a combination of the edge coefficients for respective sides of the triangle, and determines a scan starting point from a corner of the bounding box based on classification of the projected images. The traverser generates pixel data used in rasterization by scanning the bounding box from the scan starting point.