[تنبيه - عدم تكرار المخالفة :]أرجوكم المساعده في البرنامج التالي عجزت عن عمله

#include<iostream.h>

#include<stdlib.h>

#include<GL/glut.h>

#include<GL/gl.h>

#include<math.h>

int nWidth=500;

int nHeight=500;

void init (void)

{

glClearColor(1.0,1.0,1.0,0.0); // set display window to white

glMatrixMode(GL_PROJECTION); // set projection parameter

// glOrtho(-200.0,200.0,-200.0,200.0,90,-90);

gluOrtho2D(0,nWidth,0,nHeight);

}

void lineSegment(void)

{

glClear(GL_COLOR_BUFFER_BIT); // clear display window

glMatrixMode (GL_MODELVIEW);

glLoadIdentity ( );

glFlush(); // process all openGL routines as quickly as possible

}

void drawSquare(int x, int y)

{

glClearColor(1.0,1.0,1.0,0.0);

glClear(GL_COLOR_BUFFER_BIT);

y=nHeight-y; /* invert y position */

glColor3f( 1.0,0.5, 1.0); /* a random color */

glTranslatef(x,y,0);

glRecti (0,0, 50, 50);

glTranslatef(-x,-y,0);

glFlush();

}

void mymouse(int btn, int state, int x, int y)

{

if(btn==GLUT_RIGHT_BUTTON && state==GLUT_DOWN)

exit(0);

if(btn==GLUT_LEFT_BUTTON && state==GLUT_DOWN)

drawSquare(x, y);

}

void main(int argc,char** argv)

{

glutInit(&argc,argv); // initialize GLUT

glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); // Set top-left display-window posision

glutInitWindowPosition(50,100); //set top left display windowposition

glutInitWindowSize(nWidth,nHeight); // set dosplay window width and height

glutCreateWindow("an example OpenGL program"); //create display window

init(); // execute initialization-procedure

glutDisplayFunc(lineSegment); // send graphics to display window

glutMouseFunc(mymouse);

glutMainLoop(); // display every thing and wait

}