#include <GLUT/GLUT.h>

void display()

{

glClear(GL_ENABLE_BIT);

glBegin(GL_POLYGON);

glVertex2f(-0.5, -0.5);

glVertex2f(-0.5, 0.5);

glVertex2f(0.5, 0.5);

glVertex2f(0.5, -0.5);

glEnd();

glFlush();

}

int main(int argc, char ** argv)

{

glutInit(&argc, argv);

glutInitWindowSize(400, 400);

glutCreateWindow("test");

glutDisplayFunc(display);

glutMainLoop();

}