C++用类实现角度画圆和中点画圆

以下是C++用类实现角度画圆和中点画圆的示例代码：

#include <graphics.h>
#include <math.h>

class Circle {
private:
    int x, y, r;
public:
    Circle(int x, int y, int r) {
 this->x = x;
        this->y = y;
        this->r = r;
    }
    void drawMidPointCircle() {
        int x0 = 0, y0 = r;
        int d = 1 - r;
        while (x0 <= y0) {
            putpixel(x + x0, y + y0, WHITE);
            putpixel(x + y0, y + x0, WHITE);
            putpixel(x + y0, y - x0, WHITE);
            putpixel(x + x0, y - y0, WHITE);
            putpixel(x - x0, y - y0, WHITE);
            putpixel(x - y0, y - x0, WHITE);
            putpixel(x - y0, y + x0, WHITE);
            putpixel(x - x0, y + y0, WHITE);
            if (d < 0) {
                d += 2 * x0 + 3;
            } else {
                d += 2 * (x0 - y0) + 5;
                y0--;
            }
            x0++;
        }
    }
    void drawAngleCircle(int angle) {
        int x0 = 0, y0 = r;
        int d = 1 - r;
        while (x0 <= y0) {
            double rad = atan2(y0, x0);
            int deg = (int)(rad * 180 / M_PI);
            if (deg % angle == 0) {
                putpixel(x + x0, y + y0, WHITE);
                putpixel(x + y0, y + x0, WHITE);
                putpixel(x + y0, y - x0, WHITE);
                putpixel(x + x0, y - y0, WHITE);
                putpixel(x - x0, y - y0, WHITE);
                putpixel(x - y0, y - x0, WHITE);
                putpixel(x - y0, y + x0, WHITE);
                putpixel(x - x0, y + y0, WHITE);
            }
            if (d < 0) {
                d += 2 * x0 + 3;
            } else {
                d += 2 * (x0 - y0) + 5;
                y0--;
            }
            x0++;
        }
    }
};

int main() {
    initgraph(640, 480);
    Circle c1(200, 200, 100);
    c1.drawMidPointCircle();
    Circle c2(400, 200, 100);
    c2.drawAngleCircle(30);
    getch();
    closegraph();
    return 0;
}

其中，`Circle`类表示一个圆，包含圆心坐标和半径。`drawMidPointCircle`方法使用中点画圆算法绘制圆，`drawAngleCircle`方法使用角度画圆算法绘制圆，其中`angle`参数表示每隔多少度绘制一个点。在`main`函数中，我们创建了两个圆对象，一个使用中点画圆算法绘制，一个使用角度画圆算法绘制。