摘要
由Weiler-Atherton和Cohen-Sutherland算法思想,提出一种基于交点和区域特征的线段裁剪算法。算法将矩形窗口按水平方向和竖直方向各划分成三个区域,并从线段的有向性出发,根据起点和终点的不同给出-1、0和1的编码值,从而简化了"弃之"情况的判断。在求交中,为了避免直线段与裁剪边的多次求交,充分利用直线段"入点"和"出点"的唯一性和成对存在的性质,使得该算法具有较强的稳定性和较高的裁剪效率。
Proposes a new algorithm of straight-line segment clipping against rectangular window based on the thought of Weiler-Atherton and Co-hen-Sutherland algorithm. In this algorithm, divides the rectangular window into three regions by the horizontal and vertical direction each other. To reserve the straight-line directionality, every line endpoint in a region code is assigned a different value of-1, 0 or 1, and it can easily determine the“whole out” situation by code operations. To reduce the number of intersection computed, it takes full advan-tage of the properties that the line segment has only “in” and “out” point and exist in pairs. As a result, the application proves that this algorithm has the strong stability and high clipping efficiency.
关键词
裁剪
线段
交点特征
区域编码
Clipping
Straight-Line Segment
Intersection Features
Region Code
