| 摘要 |
PURPOSE:To reduce processing quantity, and to speed up processing by performing clipping processing for two clipping boundaries parallel with each other by the input of a vertex series of one time. CONSTITUTION:Positional relation between the coordinate of the inputted vertex of a polygon and two clipping boundaries parallel with each other is decided by an inside/outside decision circuit 105. By using this decided result and the decided result which is obtained for the vertex inputted earlier and held in a vertex register 102 and is held in an inside/outside decision result register 107, the positional relation between a segment of line connecting these two adjacent vertexes and two clipping boundaries is decided according to a clipping decided result 109. Then, the coordinates of the points of intersection of the segment calculated by an intersection calculation circuit 112 and the clipping boundaries and the coordinate of the inputted vertex are outputted correspondingly to the respective positional relations through a vertex output circuit 114. Thus, the processing for two clipping boundaries parallel with each other can be performed simultaneously, and the clipping processing can be speeded up. |
