GAMES101 Assignment4 (对应Lecture10-11)

课程作业框架来自GAMES

基础部分：

目标要求：需要实现de Casteljau 算法来绘制由4 个控制点表示的Bézier 曲线

main.cpp

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/**
*	贝塞尔递归
**/
cv::Point2f recursive_bezier(const std::vector<cv::Point2f> &control_points, float t) 
{
    // TODO: Implement de Casteljau's algorithm
    int control_points_num = control_points.size();

    if (control_points_num == 1)
    {
        cv::Point2f pix_center_point(0.5,0.5);
        pix_center_point += (cv::Point2f) control_points[0];
        return pix_center_point;
    }
    else
    {
        cv::Point2d left_bezier_point, right_bezier_point;
        std::vector<cv::Point2f> left_control_points(&(control_points[0]), &(control_points[control_points_num - 1]));
        std::vector<cv::Point2f> right_control_points(&(control_points[1]), &(control_points[control_points_num]));
        left_bezier_point = recursive_bezier(left_control_points, t);
        right_bezier_point = recursive_bezier(right_control_points, t);
        return left_bezier_point * (1-t) + right_bezier_point*t;    
    }
    
    

}

void bezier(const std::vector<cv::Point2f> &control_points, cv::Mat &window) 
{
    // TODO: Iterate through all t = 0 to t = 1 with small steps, and call de Casteljau's 
    // recursive Bezier algorithm.
    static cv::Point2f point;
    for (double t = 0.0; t <= 1.0; t+=0.005)
    {
        point = recursive_bezier(control_points, t);
        window.at<cv::Vec3b>(point.y, point.x)[1] = 255;
    }
    
}