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;
}