一个计算机图形学相关的程序源代码，含二维线画图元、二维线填充图元、线段裁切、多边形裁切、二维图形变换、三维图形变换、凸多面体的建模、透视投影，隐藏面的消除及基本图形变换（平移、旋转、缩放）、曲线移动、曲线清除等 -A computer graphics-related source code, with two-dimensional line drawing element, two-dimensional line fill pixel, line cutting, polygonal