#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>

#define WINDSIZEX 100
#define WINDSIZEY 100


void
init (void)
{
  int i;
  GLfloat white[] = { 1.0, 1.0, 1.0, 1.0 };

  glClearColor (0.0, 0.0, 0.0, 1.0);
  glColor4fv (white);
  glDisable (GL_DITHER);
}


static void
test (void)
{
  int i, j;
  GLfloat red[] = { 1.0, 0.0, 0.0, 1.0 };

  glDrawBuffer(GL_NONE);
  glClearColor (0.0, 0.0, 0.0, 1.0);
  glClear (GL_COLOR_BUFFER_BIT);
  
  glColor4fv (red);
  glBegin(GL_POLYGON);
	glVertex2f(0, 0);
	glVertex2f(50, 0);
	glVertex2f(50, 50);
	glVertex2f(0, 50);
  glEnd();
  glFlush ();
}

void
display (void)
{
  glMatrixMode (GL_PROJECTION);
  glLoadIdentity ();
  gluOrtho2D (0, WINDSIZEX, 0, WINDSIZEX);
  test ();
}

int
main (int argc, char **argv)
{
  glutInit (&argc, argv);
  glutInitDisplayMode (GLUT_SINGLE | GLUT_RGBA);
  glutInitWindowSize (WINDSIZEX, WINDSIZEY);
  glutInitWindowPosition (100, 100);
  glutCreateWindow (argv[0]);
  init ();
  glutDisplayFunc (display);
  glutMainLoop ();
  return 0;
}