Как на opengl реализовать премещение фигур по экрану?

#include <windows.h>
#include <math.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glaux.h>
 
 
 
void CALLBACK resize(int width,int height)
{
   glViewport(0,0,width,height);
   glMatrixMode( GL_PROJECTION );
   glLoadIdentity();
   glOrtho(-5,5, -5,5, 2,12);   
   gluLookAt( 0,0,5, 0,0,0, 0,1,0 );
   glMatrixMode( GL_MODELVIEW );
}    
 
 
 
void CALLBACK display(void)
{
static float time=0;
float n=0.25;
 glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
 
    /* remove next tree lines
     * and enter your code here
        */
 
glPushMatrix();
glTranslated( 0,0,cos(time));
 
 glColor3d(1,1,1);
 
 
//Б
glPushMatrix(); 
    glTranslated(-5*n,3*n,n);
    auxSolidBox( n,6*n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(-3*n,6.5*n,0);
    auxSolidBox( 3*n,n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(-3.5*n,0.5*n,0);
    auxSolidBox( 2*n,n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(-3.5*n,3.5*n,0);
    auxSolidBox( 2*n,n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(-2*n,2*n,0);
    auxSolidBox( n,2*n,n );
glPopMatrix();
 
//Д
glPushMatrix(); 
    glTranslated(5*n,3*n,0);
    auxSolidBox( n,6*n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(3*n,6.5*n,0);
    auxSolidBox( 3*n,n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(3.5*n,0.5*n,0);
    auxSolidBox( 2*n,n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(3.5*n,3.5*n,0);
    auxSolidBox( 2*n,n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(2*n,2*n,0);
    auxSolidBox( n,2*n,n );
glPopMatrix();
//М
glPushMatrix(); 
    glTranslated(-2*n,-4*n,0);
    auxSolidBox( n,6*n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(2*n,-4*n,0);
    auxSolidBox( n,6*n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(n,-2.5*n,0);
    auxSolidBox( n,n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(-1*n,-2.5*n,0);
    auxSolidBox( n,n,n );
glPopMatrix();
 
glPushMatrix(); 
    glTranslated(0,-5*n,0);
    auxSolidBox( n,4*n,n );
glPopMatrix();
glPopMatrix();
time=time+0.1;
 
 
 
 
auxSwapBuffers();
 
}
 
 
 
void main()
{
float pos[4] = {3,3,3,1};
float dir[3] = {-1,-1,-1};
 
    GLfloat mat_specular[] = {1,1,1,1};
 
    auxInitPosition( 50, 10, 800, 600);
    auxInitDisplayMode( AUX_RGB | AUX_DEPTH | AUX_DOUBLE );
    auxInitWindow( "Glaux Template" );
    auxIdleFunc(display);
    auxReshapeFunc(resize);
 
  
    glEnable(GL_DEPTH_TEST);
 
    glEnable(GL_COLOR_MATERIAL);
 
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
 
    glLightfv(GL_LIGHT0, GL_POSITION, pos);
    glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, dir);
 
    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialf(GL_FRONT, GL_SHININESS, 128.0);
 
 
    /*
    * Enter your cod here
    */
    auxMainLoop(display);
}