| 摘要 |
PROBLEM TO BE SOLVED: To shorten the decision processing time and also to shorten rasterization processing time by efficiently deciding whether sides of a Y convex polygon mutually cross or not. SOLUTION: When a polygon is separated into two sets of continuous side groups by two vertexes that are located at both ends in prescribed directions, each vertex of the separated continuous side groups decides whether the sides of the polygon mutually cross or not along either of the prescribed directions about a polygon that is arranged according to an arrangement order of the sides of the polygon. In such cases, one side that includes two vertexes is selected from either of the separated continuous side groups, one vertex is also selected from the other continuous side group, and then, another side and one vertex are successively and repeatedly selected according to the arrangement order (S202 to S215). |
