/* *  simple.c *  This program draws a white rectangle on a black background. */
/* E. Angel, Interactive Computer Graphics */
/* A Top-Down Approach with OpenGL, Third Edition */
/* Addison-Wesley Longman, 2003 */
#include <GL/glut.h>         /* glut.h includes gl.h and glu.h*/void display(void){/* clear window */	 glClear(GL_COLOR_BUFFER_BIT); /* draw unit square polygon */	glBegin(GL_POLYGON);	 	glVertex2f(-0.5, -0.5);	 	glVertex2f(-0.5, 0.5);	 	glVertex2f(0.5, 0.5);	 	glVertex2f(0.5, -0.5);	glEnd();/* flush GL buffers */	glFlush(); }void init(){/* set clear color to black *//* 	glClearColor (0.0, 0.0, 0.0, 0.0); *//* set fill  color to white *//* 	glColor3f(1.0, 1.0, 1.0); *//* set up standard orthogonal view with clipping *//* box as cube of side 2 centered at origin *//* This is default view and these statement could be removed */	/* glMatrixMode (GL_PROJECTION);	glLoadIdentity ();	glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);  */}int main(int argc, char** argv){/* Initialize mode and open a window in upper left corner of screen *//* Window title is name of program (arg[0]) *//* 	glutInit(&argc,argv); */	/* glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);  	glutInitWindowSize(500,500);	glutInitWindowPosition(0,0); */	glutCreateWindow("simple"); 	glutDisplayFunc(display);	init();	glutMainLoop();}