1 #include <GL/gl.h>
      2 #include <GL/glu.h>
      3 #include <GL/glut.h>
      4
      5 void display();
      6
      7 int main( int argc, char * argv[]) {
      8     glutInit(&argc, argv);
      9     glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
     10
     11     glutInitWindowPosition( 10, 10);
     12     glutInitWindowSize(400, 400);
     13     glutCreateWindow("hello");
     14
     15     glClearColor(0.0, 0.0, 0.0, 0.0);
     16
     17     glMatrixMode(GL_PROJECTION);
     18     glLoadIdentity();
     19     glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
     20
     21     glutDisplayFunc(display);
     22
     23     glutMainLoop();
     24     return 0;
     25 }
     26
     27 void display(void) {
     28     glClear(GL_COLOR_BUFFER_BIT);
     29
     30     glColor3f(1.0, 1.0, 1.0);
     31     glBegin(GL_POLYGON);
     32         glVertex3f( 0.25, 0.25, 0.0);
     33         glVertex3f( 0.75, 0.25, 0.0);
     34         glVertex3f( 0.75, 0.75, 0.0);
     35         glVertex3f( 0.25, 0.75, 0.0);
     36     glEnd();
     37     glFlush();
     38 }