void :: glClear(); void :: glBegin(); void :: glVertex3f(); void :: glEnd(); void :: glFlush(); void :: glutInit(); void :: glutInitDisplayMode(); void :: glutInitWindowPosition(); void :: glutInitWindowSize(); void :: glutCreateWindow(); void :: glutDisplayFunc(); void :: glutMainLoop(); void :: display() { glClear(16384); glBegin(9); glVertex3f(0, 0, 0); glVertex3f(1, 0, 0); glVertex3f(1, 1, 0); glVertex3f(0, 1, 0); glEnd(); glFlush(); } int :: main(int argc, char** argv) { glutInit(&argc, argv); glutInitDisplayMode(0); glutInitWindowSize(300, 300); glutInitWindowPosition(100, 100); glutCreateWindow("Hello"); glutDisplayFunc(display); glutMainLoop(); return (0); }