摘要
从矩形窗口裁剪任意多边形的本质特征出发,提出多边形各边端点编码技术。通过对多边形各边端点的一次及二次编码,可快速得到所有窗内边并舍弃绝大部分窗外边,还可快速判断该端点是内点还是外点。在已获取的窗内边、相交边的交点以及交点编码的基础上,可以得到正确的裁剪结果。同时考虑了矩形窗口与多边形相互包容的特殊情形。实验结果表明,新算法稳定可靠,实现了对任意凹凸多边形的裁剪,具有通用性强、算法简捷、裁剪效率较高的优点。
Encoding technique for the edges＇ endpoints of a polygon is proposed based on the essential characteristic of the polygon clipping against rectangular window. Primary and secondary encoding techniques can rapidly identify all of the polygon＇s edges in the window and most of the polygon＇s edges outside the window as well as classifying the inner vertices and external vertices. Correct clipping result can be obtained based on the line segments in the window and the encoding of intersection-points of polygon edges with those in the window. The special situation that rectangular window and polygon are one containing another is also taken into consideration. Experimental results show that the new algorithm is stable and fast.
出处
《工程图学学报》
CSCD
北大核心
2006年第4期72-76,共5页
Journal of Engineering Graphics
基金
教育部高等学校博士学科点专项科研基金资助项目(20020335093)
关键词
计算机图形学
多边形裁剪
端点与交点编码
矩形窗口
内点
外点
computer graphics
polygon clipping
endpoint and intersection-point encoding
rectangular window
inner vertex
external vertex
