#include <GL/gl.h>
#include <GL/glut.h>

void display(void)
{
    int i;

    for (i=0; i < 100; i++) {
	glBegin(GL_LINES);
	glEnd();
    }
    glFlush ();
}

void init (void) 
{
/*  select clearing (background) color       */
    glClearColor (0.0, 0.0, 0.0, 0.0);

/*  initialize viewing values  */
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
}

/* 
 *  Declare initial window size, position, and display mode
 *  (single buffer and RGBA).  Open window with "hello"
 *  in its title bar.  Call initialization routines.
 *  Register callback function to display graphics.
 *  Enter main loop and process events.
 */
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;   /* ISO C requires main to return int. */
}