MandelbrotSet 分形艺术（C++实现）

转自 EasyX，不过我重构了代码。

运行结果：

源程序：

// MandelbrotSet.cpp

#include "graphics.h"
#include <conio.h>

struct Complex
{
    double re;
    double im;

public:
    Complex operator * (const Complex &other) const
    {
        Complex c;
        c.re = this->re * other.re - this->im * other.im;
        c.im = this->im * other.re + this->re * other.im;
        return c;
    }

    Complex operator + (const Complex &other) const
    {
        Complex c;
        c.re = this->re + other.re;
        c.im = this->im + other.im;
        return c;
    }
};

void main()
{
    // 初始化绘图窗口
    initgraph(640, 480);

    /////////////////////////////////////////////////
    // 绘制 Mandelbrot Set (曼德布洛特集)
    /////////////////////////////////////////////////
    Complex z, c;
    for(int x = 0; x < 640; x++)
    {
        c.re = -2.1 + (1.1 - -2.1) * (x / 640.0);
        for(int y = 0; y < 480; y++)
        {
            c.im = -1.2 + (1.2 - -1.2) * (y / 480.0);
            z.re = z.im = 0;
            int k;
            for(k = 0; k < 180; k++)
            {
                if ( z.re * z.re + z.im * z.im > 4.0 )    break;
                z = z * z + c;
            }
            putpixel(x, y, (k >= 180) ? 0 : HSLtoRGB((float)((k << 5) % 360), 1.0, 0.5));
        }
    }

    // 按任意键退出
    _getch();
    closegraph();
}