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

#include <GL/glut.h>




void display( void ) {

  glClear( GL_COLOR_BUFFER_BIT );
  glColor3f( 1.0, 1.0, 1.0 );
  glBegin( GL_POLYGON );
  glVertex3f( 0.25, 0.25, 0.0 );
  glVertex3f( 0.75, 0.25, 0.0 );
  glVertex3f( 0.75, 0.75, 0.0 );
  glVertex3f( 0.25, 0.75, 0.0 );
  glEnd();

  glFlush();
}



void init( void ) {

  glClearColor( 0.0, 0.0, 0.0, 0.0 );
  glMatrixMode( GL_PROJECTION );
  glLoadIdentity();
  glOrtho( 0.0, 1.0, 0.0, 1.0, -1.0, 1.0 );
  
}




int main( int argc, char** argv ) {
  
  glutInit( &argc, argv );
  glutInitDisplayMode( GLUT_SINGLE | GLUT_RGB );
  glutInitWindowSize( 250, 250 );
  glutInitWindowPosition( 100, 100);
  glutCreateWindow( "hello" );
  init();
  glutDisplayFunc( display );
  glutMainLoop();

  return 0;
}