#ifndef M_PI
#define M_PI 3.14159
#endif
#define EPSILON 1.0
/* Fonction executee lors d'un changement */
/* de la taille de la fenetre OpenGL */
/* -> Ajustement de la camera de visualisation */
static void reshape(int tx,int ty) {
glViewport(0,0,tx,ty);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
double ratio =(double) tx/ty;
gluPerspective(2.0*asin(5.0/15.0)*180/M_PI,ratio,10.0-EPSILON,20.0+EPSILON);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(-4.0,6.0,-5.0,-2.0,-4.0,6.0,0.0,1.0,0.0);
}