class BezierCurve { public: void add_control_point(const vec2& p) { control_points.push_back(p); } void deCastelijau(int resolution) { //todo... } void draw(device_t* device, const TGAColor& smp_color, const TGAColor& ctr_color = RED, bool drawControlPoints = true) { if (drawControlPoints) { for (int i = 0; i < control_points.size() - 1; ++i) { draw_line(control_points[i], control_points[i + 1], device, ctr_color); } } for (int i = 0; i < sample_points.size() - 1; ++i) { draw_line(sample_points[i], sample_points[i + 1], device, smp_color); } } private: vector<vec2> control_points; //控制点 vector<vec2> sample_points; //贝塞尔曲线上的点 };完善代码

以下是完整的BezierCurve类的代码，其中deCastelijau函数实现了贝塞尔曲线的生成算法：

#include <vector>
#include "geometry.h"
#include "tgaimage.h"

class BezierCurve {
public:
    void add_control_point(const vec2& p) {
        control_points.push_back(p);
    }

    void deCastelijau(int resolution) {
        sample_points.clear();
        if (control_points.size() < 2) {
            return;
        }

        for (int i = 0; i <= resolution; ++i) {
            float t = static_cast<float>(i) / static_cast<float>(resolution);
            vec2 p = deCastelijau(control_points, t);
            sample_points.push_back(p);
        }
    }

    void draw(device_t* device, const TGAColor& smp_color, const TGAColor& ctr_color = RED, bool drawControlPoints = true) {
        if (drawControlPoints) {
            for (int i = 0; i < control_points.size() - 1; ++i) {
                draw_line(control_points[i], control_points[i + 1], device, ctr_color);
            }
        }

        for (int i = 0; i < sample_points.size() - 1; ++i) {
            draw_line(sample_points[i], sample_points[i + 1], device, smp_color);
        }
    }

private:
    vector<vec2> control_points;  // 控制点
    vector<vec2> sample_points;   // 贝塞尔曲线上的点

    vec2 deCastelijau(const vector<vec2>& points, float t) {
        if (points.size() == 1) {
            return points[0];
        }

        vector<vec2> new_points(points.size() - 1);
        for (int i = 0; i < points.size() - 1; ++i) {
            new_points[i] = (1 - t) * points[i] + t * points[i + 1];
        }

        return deCastelijau(new_points, t);
    }
};

其中的deCastelijau函数是递归实现的，通过向下逐层迭代，生成贝塞尔曲线上的点。在draw函数中，如果drawControlPoints参数为true，则绘制出所有控制点之间的连线，否则仅绘制贝塞尔曲线上的点之间的连线。