134.沙丘图案

/* Sandhill */
#include <graphics.h>
#include <math.h>
#define PI 3.1415926
void main()
{
  double a,b,c;
  int x,y,py;
  int gdriver=DETECT,gmode;
  initgraph(&gdriver,&gmode,"c:\\tc");
  cleardevice();
  setbkcolor(9);
  setcolor(14);
  outtextxy(80,3,"This program show the Sandhill picture.");
  for(py=20;py<=380;py+=3)
  {
    c=(py-20)*4*PI/360;
    b=PI*cos(c);
    for(a=0;a<=6*PI;a+=PI/7)
    {
      x=600/(6*PI)*a+20;
      y=10*sin(a+cos(a)*PI-b)*cos(c)+py;
      if(a==0)
        moveto(x,y);
      else
        lineto(x,y);
    }
  }
  outtextxy(80,460,"Press any key to quit...");
  getch();
  closegraph();
}