多边形裁剪的 Sutherland—Hodgman 算法的c++代码实现

以下是Sutherland-Hodgman算法的C++代码实现，假设多边形为poly，裁剪窗口为clip：

vector<Point> Sutherland_Hodgman(vector<Point> poly, vector<Point> clip) {
    int n = clip.size();
    for (int i = 0; i < n; i++) {
        int m = poly.size();
        vector<Point> newpoly;
        Point S = poly[m-1];
        for (int j = 0; j < m; j++) {
            Point E = poly[j];
            if (inside(E, clip[i])) {
                if (!inside(S, clip[i])) {
                    newpoly.push_back(intersect(S, E, clip[i]));
                }
                newpoly.push_back(E);
            } else if (inside(S, clip[i])) {
                newpoly.push_back(intersect(S, E, clip[i]));
            }
            S = E;
        }
        poly = newpoly;
    }
    return poly;
}

其中，inside函数用于判断点是否在裁剪窗口内，intersect函数用于求解直线与边界的交点。