/*
 * simple2.c -- Angel, OpenGL: A Primer, p. 23
 */

#include <glut.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>


void display() {
 typedef GLfloat point2[2];
 point2 vertices[3] = { {0.0,0.0},{250.0,500.0},{500.0,0.0}};
 static point2 p = {75.0,50.0};
 int i,j,k;
 //fprintf(stderr,"Display\n");
 glClear(GL_COLOR_BUFFER_BIT);
 for(k=0;k<50000;k++) { 
  j=rand()%3;
  p[0] = (p[0]+vertices[j][0])/2.0;
  p[1] = (p[1]+vertices[j][1])/2.0;
  //fprintf(stderr,"%04d: %f %f\n",p[0],p[1]);
  glBegin(GL_POINTS);
   glVertex2fv(p);
  glEnd();
  }
 glFlush();
 }

void init() {
 glClearColor(1.0,1.0,1.0,0.0);
 glColor3f(1.0,0.0,0.0);
 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();
 gluOrtho2D(0.0,500.0,0.0,500.0);
 glMatrixMode(GL_MODELVIEW);
 }

int main(int argc,char *argv[]) {
 glutInit(&argc,argv);
 srand(time(0));
 glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
 glutInitWindowSize(500,500);
 glutInitWindowPosition(0,0);
 glutCreateWindow("simple");
 glutDisplayFunc(display);
 init();
 glutMainLoop();
 }