/* GENERATOR FOR HENON'S STRANGE ATTRACTOR
   A PC executable of this program can be downloaded by right-clicking
   henon.exe and then saving it to your local disk.

   October 1997 Robert John Morton */

#include <stdio.h>
#include <conio.h>
#include <graph.h>
#define XBIAS  320
#define YBIAS  240

main() {
  int c;
  float x = 0, y = 0, z, w;
  _setvideomode(_VRES16COLOR);
  _setcolor(7);
  _settextposition( 1, 27); printf("HERON'S STRANGE ATTRACTOR");
  _settextposition(29, 30); printf("Hit C/R key to halt");

  while(!kbhit()) {
    z = x;
    w = x * x;
    x = 1.4 * w;
    x = x + y - 1;
    y = .3 * z;
    _setpixel(XBIAS + (int)(x * 200), YBIAS - (int)(y * 200));
  }

  c = getchar();
  _settextposition(29, 30); printf("Hit C/R key to quit");
  c = getchar();
  _setvideomode(_DEFAULTMODE);
}

/* Author: Robert John Morton October 1997 */