ßÊÈÊ ãæÖæÚÇ ÞÈá ÝÊÑÉ Úä ÇáÜ game loop ÞÏãÊ Ýíå ÝßÑÉ ãÈÓØÉ Úä ÇáãæÖæÚ, æ ßÊÈÊ ÇíÖÇ ãæÖæÚ Úä ÇÓÊÎÏÇã glut ãÚ opengl æ åæ Ýí ÇáÍÞíÞÉ áã íÍÊæí Ôí ÌÏíÏ Óæì ÊÐßíÑ ÝÞØ ÈãÇ åæ ãæÌæÏ Ýí ãæÇÖíÚ ÇÎÑì Ýí ÇáãäÊÏì.

ØíÈ, ÇÐÇ ãÚ glut ÍáíäÇ ãÔßáÉ ÇáäæÇÝÐ .. æ ÇáÇä äÑíÏ Çä äÚãá ÈÑäÇãÌ ÕÛíÑ íÍÊæí Úáì loop ãä ÇÌá ÊÍÏíË ÇááÚÈÉ ÈÇÓÊãÑÇÑ .. ßíÝ äÞæã ÈÐáß¿

Ýí glut åäÇß function ÇÓãå glutMainLoop, ÚäÏ ÇÓÊÏÚÇÆå, ÓíÏÎá ÇáÈÑäÇãÌ Ýí ÍáÞÉ áÇ äåÇÆíÉ ÊÞæã ÈÊÔÛíá ÇáÈÑäÇãÌ æ ÇÏÇÑÉ ÇáãåÇã ÇáãÊÚáÞÉ ÈÇáäÇÝÐÉ æ ÇÓÊÞÈÇá ÇáãÏÎáÇÊ .. ÇáÎ!
ÇáãÔßáÉ Çä glut áÇ íæÝÑ áß ØÑíÞÉ ãä ÇÌá Úãá gameloop ... áÇäß ÚäÏãÇ ÊÓÊÏÚí glutMainLoop ÝÅäß ÊÝÞÏ ÇáÓíØÑÉ Úáì ÇáÈÑäÇãÌ æ íÕÈÍ ÊÍÊ ÓíØÑÉ glut æ áÇ ÊæÌÏ ØÑíÞÉ áßí ÊÞæã ÍÖÑÊß ÈÅÏÎÇá ßæÏ ãÚíä íÊã ÊäÝíÐå ßá ÝÑíã ..

åÐå ÇáãÔßáÉ íãßä ÍáåÇ Úä ØÑíÞ ÇÞÊÍÇã ÇáÓæÑÓ ßæÏ ÇáÎÇÕ ÈÜ glut æ ÊÚÏíá glutMainLoop æ åÐÇ ÓíÞæÏ Çáì ÚÏÉ ãÔÇßá ÊÍÊÇÌ áÍáæá, æ áßä áÇ ÏÇÚí áßá åÐÇ ÇáÚäÇÁ, ÝåäÇß ÇäÇÓ ÞÏ æÇÌåæÇ åÐå ÇáãÔÇßá ãä ÞÈá æ ÞÇãæÇ ÈÍáåÇ!!

æ ÇáÍá åæ ÇÓÊÎÏÇã freeglut
http://freeglut.sourceforge.net

ÍíË íæÝÑ áß function ÅÓãå
glutMainLoopEvent
ÍÊì ÊÞæã ÈÇÓÊÏÚÇÆå ÏÇÎá ÇáÜ loop ÇáÎÇÕÉ Èíß .. ÝÊÓÊÛäí ÈÐáß Úä glutMainLoop

íÚäí, äÍä äÍÊÇÌ glutMainLoop ãä ÇÌá ÇáÞíÇã ÈÎÏãÇÊ ÖÑæÑíÉ áÇ äÓÊØíÚ ÊÔÛíá ÇáÈÑäÇãÌ ãä ÏæäåÇ (ãËá ãÊÇÈÚÉ ÇáäÇÝÐÉ æ ÇÓÊÞÈÇá ÇáÑÓÇÆá .. ÇáÎ), íÚäí ãä ÇÌá Çä íÞæã ÈÇáãåÇã ÇááÊí ãä ÃÌáåÇ áÌÃäÇ Çáì glut ãä ÇáÃÓÇÓ.

Ýí ßá ÍáÞÉ ãä ÍáÞÇÊ glutMainLoop íÊã ÊäÝíÐ ßæÏ ãÚíä ... Ýáæ ÇÓÊØÚäÇ ÇÓÊÎáÇÕ åÐÇ ÇáßæÏ ææÖÚå Ýí ÏÇáÉ ãäÝÕáÉ (æ áíÓ ÍáÞÉ) Óíßæä ÈÅãßÇääÇ ÇÓÊÏÚÇÁ åÐå ÇáÏÇáÉ ÏÇÎá ÇáÍáÞÉ ÇáÎÇÕÉ ÈäÇ!

åÐå åí æÙíÝÉ glutMainLoopEvent ÍíË Çäß ãä ÇáãÝÑæÖ Çä ÊÓÊÏÚíå ãÑÉ æÇÍÏÉ ÏÇÎá ßá ÏæÑÉ ãä ÇáÜ gameloop ÇáÎÇÕÉ Èß,

while( true )
{
    glutMainLoopEvent();    
    //your code ..
}
glutLeaveMainLoop();

#include <windows.h>
#include <algorithm>
#include <ctime>
#include <GL/glut.h> 
#include <GL/freeglut_ext.h>

int gx, gy;
GLubyte * picture = 0;

GLubyte * getPicture( int w, int h )
{
    int length = w * h * 4;
    GLubyte * bytes = new GLubyte[length];
    for( int i = 0; i < length; i++ )
    {
        bytes[i] = 0;
    }
    int m = std::min(w,h);

    //draw a line!
    int c = 100;
    for( int i = 0; i < m; i++ )
    {
        int p = i*4;
        p = p+p*w;
        int pe = p + 4;
        while( p <= pe )
        {
            bytes[p] = c;
            p++;
            c++;
        }       
        c++;
    }

    return bytes;
}

void drawBox( int x, int y )
{
    glRasterPos2d( x, y );
    glDrawPixels( 20, 20, GL_RGBA, GL_UNSIGNED_BYTE, picture );
}

void myInit()
{
    glClearColor(0.3,0.3,0.3,0.0);
    glColor3f(1.0,1.0,0.5);
    glPointSize(2.0);
    glMatrixMode(GL_PROJECTION);
    gluOrtho2D(0.0,60.0,0.0,60.0);
}

void myMainLoop()
{
    int counter = 0;

    while(true)
    {
        glutMainLoopEvent();
        counter++;
        if( ! (counter % 50) )
        {
            gx++;
            gy++;
        }
        Sleep(20);

        glClear(GL_COLOR_BUFFER_BIT);
        drawBox( gx, gy );
        glFlush();
    }
    glutLeaveMainLoop();
}

int main(int argc, char** argv)
{
    gx = gy = 0;
    picture = getPicture( 20, 20 );

    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE |GLUT_RGB);
    glutInitWindowSize(400,400);
    glutInitWindowPosition(50,50);
    glutCreateWindow("Moving Box");
    myInit();
    myMainLoop();
    return 0;
}