/* chaos1.c  interesting plots using chaos reather than fractals */
#include "GL/glut.h"
#include <stdio.h>

static float xmin = 0.0; /* minimum value */
static float xmax = 1.0; /* maximum value */
static float x;          /* working value */
static float rmin = 2.95; 
static float rmax = 3.95;
static float r;
static float dr;         /* r step size */

/* heading for plot */
static char head[] = " chaos1   x=r*x*(1.0-x) run 200, plot 300 $ " ;


void display(void)
{
  int i, j;
  
  glClear(GL_COLOR_BUFFER_BIT);
  glColor3f(0.0, 0.0, 1.0); /* blue */
  glBegin(GL_LINES);
  dr = (rmax-rmin)/200.0;
  r = rmin ;
  while(r <= rmax)
  {
    x = 0.3;
    for(i=1; i<=200; i++)
    {
      x = r * x * ( 1.0 - x ) ;
    }
    for(i=1; i<=300; i++)
    {
      x = r * x * ( 1.0 - x ) ;
      glVertex2f(x, r);
      glVertex2f(x, r+dr);
    }
    r = r + dr ;
  }
  glEnd();
  glFlush();
}

void reshape(int w, int h)
{
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D (xmin,  xmax, rmin,  rmax);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glClearColor(1.0, 1.0, 1.0, 1.0);
}

int main(int argc, char* argv[])
{
  glutInit(&argc,argv); 
  glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
  glutInitWindowSize(500,500);
  glutInitWindowPosition(100,100); 
  glutCreateWindow(argv[0]);
  glutDisplayFunc(display);
  glutReshapeFunc(reshape);
  glutMainLoop();
  return 0;
} /* end chaos1 */