كود المربع
#include <GL/glut.h>
void reshape(int w, int h)
{
  glClearColor(1.0,1.0,1.0,0.0);
  glViewport(0,0,w/2,h/2);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(0.0,1.0,0.0,1.0);
  glMatrixMode(GL_MODELVIEW);
}
void display(void)
{
  glClear(GL_COLOR_BUFFER_BIT);// clear all pixels
  glPolygonMode(GL_FRONT,GL_LINE);
  glColor3f(0.0,0.0,0.0);
  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();
}
int main (int argc, char **argv)
{ 
  glutInit (&argc, argv);   glutInitDisplayMode (GLUT_SINGLE); 
  glutInitWindowSize (500,500);    glutInitWindowPosition (100, 100); 
  glutCreateWindow ("SEGMENT B"); 
  glutDisplayFunc (display);
  glutReshapeFunc(reshape);
  glutMainLoop(); 
  return 0; 
}
 
كود المثلث
#include <GL/glut.h>
  void renderScene(void) 
  {
        glClear(GL_COLOR_BUFFER_BIT);  
        glBegin(GL_TRIANGLES);  
        glVertex3f(-0.5,-0.5,0.0);  
        glVertex3f(0.5,0.0,0.0);
        glVertex3f(0.0,0.5,0.0);
        glEnd();
        glFlush();
  }
  void main(int argc, char **argv)
   {
       glutInit(&argc, argv);
       glutInitDisplayMode(GLUT_DEPTH | GLUT_SINGLE |GLUT_RGBA);  
       glutInitWindowPosition(100,100);
       glutInitWindowSize(320,320);  
       glutCreateWindow(“WINDOW TRIANGLE");
       glutDisplayFunc(renderScene);
       glutMainLoop();
  }