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



// 定義全局變量
int rosesize = 500;
int h = -250;


// 定義結構體
struct DOT
{
 double x;
 double y;
 double z;
 double r; // 紅色
 double g; // 綠色
    // b(藍色) 通過 r 計算
};


// 計算點
bool calc(double a, double b, double c, DOT &d)
{
 double j, n, o, w, z;

 if (c > 60)    // 花柄
 {
  d.x = sin(a * 7) * (13 + 5 / (0.2 + pow(b * 4, 4))) - sin(b) * 50;
  d.y = b * rosesize + 50;
  d.z = 625 + cos(a * 7) * (13 + 5 / (0.2 + pow(b * 4, 4))) + b * 400;
  d.r = a * 1 - b / 2;
  d.g = a;
  return true;
 }

 double A = a * 2 - 1;
 double B = b * 2 - 1;
 if (A * A + B * B < 1)
 {
  if (c > 37)   // 葉
  {
   j = (int(c) & 1);
   n = j &#63; 6 : 4;
   o = 0.5 / (a + 0.01) + cos(b * 125) * 3 - a * 300;
   w = b * h;

   d.x = o * cos(n) + w * sin(n) + j * 610 - 390;
   d.y = o * sin(n) - w * cos(n) + 550 - j * 350;
   d.z = 1180 + cos(B + A) * 99 - j * 300;
   d.r = 0.4 - a * 0.1 + pow(1 - B * B, -h * 6) * 0.15 - a * b * 0.4 + cos(a + b) / 5 + pow(cos((o * (a + 1) + (B > 0 &#63; w : -w)) / 25), 30) * 0.1 * (1 - B * B);
   d.g = o / 1000 + 0.7 - o * w * 0.000003;
   return true;
  }
  if (c > 32)   // 花萼
  {
   c = c * 1.16 - 0.15;
   o = a * 45 - 20;
   w = b * b * h;
   z = o * sin(c) + w * cos(c) + 620;

   d.x = o * cos(c) - w * sin(c);
   d.y = 28 + cos(B * 0.5) * 99 - b * b * b * 60 - z / 2 - h;
   d.z = z;
   d.r = (b * b * 0.3 + pow((1 - (A * A)), 7) * 0.15 + 0.3) * b;
   d.g = b * 0.7;
   return true;
  }

  // 花
  o = A * (2 - b) * (80 - c * 2);
  w = 99 - cos(A) * 120 - cos(b) * (-h - c * 4.9) + cos(pow(1 - b, 7)) * 50 + c * 2;
  z = o * sin(c) + w * cos(c) + 700;

  d.x = o * cos(c) - w * sin(c);
  d.y = B * 99 - cos(pow(b, 7)) * 50 - c / 3 - z / 1.35 + 450;
  d.z = z;
  d.r = (1 - b / 1.2) * 0.9 + a * 0.1;
  d.g = pow((1 - b), 20) / 4 + 0.05;
  return true;
 }

 return false;
}


// 主函數
void main()
{
 // 定義變量
 short *zBuffer;
 int  x, y, z, zBufferIndex;
 DOT  dot;

 // 初始化
 initgraph(640, 480);    // 創建繪圖窗口
 setbkcolor(WHITE);     // 設置背景色為白色
 cleardevice();      // 清屏

          // 初始化 z-buffer
 zBuffer = new short[rosesize * rosesize];
 memset(zBuffer, 0, sizeof(short) * rosesize * rosesize);

 for (int j = 0; j < 2000 && !_kbhit(); j++) // 按任意鍵退出
 {
  for (int i = 0; i < 10000; i++)   // 減少是否有按鍵的判斷
   if (calc(double(rand()) / RAND_MAX, double(rand()) / RAND_MAX, rand() % 46 / 0.74, dot))
   {
    z = int(dot.z + 0.5);
    x = int(dot.x * rosesize / z - h + 0.5);
    y = int(dot.y * rosesize / z - h + 0.5);
    if (y >= rosesize) continue;

    zBufferIndex = y * rosesize + x;

    if (!zBuffer[zBufferIndex] || zBuffer[zBufferIndex] > z)
    {
     zBuffer[zBufferIndex] = z;

     // 畫點
     int r = ~int((dot.r * h));    if (r < 0) r = 0; if (r > 255) r = 255;
     int g = ~int((dot.g * h));    if (g < 0) g = 0; if (g > 255) g = 255;
     int b = ~int((dot.r * dot.r * -80)); if (b < 0) b = 0; if (b > 255) b = 255;
     putpixel(x + 50, y - 20, RGB(r, g, b));
    }
   }

  Sleep(1);
 }

 // 退出
 delete[]zBuffer;
 _getch();
 closegraph();
}