i have a problem with glClear(GL_COLOR_BUFFER_BIT); the program crash when it arrives at glClear(GL_COLOR_BUFFER_BIT); and when i change a little the function which compute normal it works

Strange. You''re not going into much detail - what do you change exactly?

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at what point in the program are calling "glClear"?

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here is the display function

void display ( void )
{
glClear(GL_COLOR_BUFFER_BIT); // crash here
glLightfv ( GL_LIGHT0,GL_POSITION,light_pos );
glPushMatrix ( );
//glTranslatef ( -700.0, 800.0, -2500.0 ); //pour courbe
if (mode==1)
glTranslatef ( -700.0, 800.0, -2500.0 );
if (mode==2)
glTranslatef ( -700.0, 800.0, -2500.0 );
if (mode==3)
glTranslatef ( -100.0, 150.0, -300.0 );
if (mode==4)
glTranslatef ( -100.0, 150.0, -300.0 );

//glTranslatef ( -100.0, 150.0, -300.0 );
glRotatef ( angle2, 1.0, 0.0, 0.0 );
glRotatef ( angle, 0.0, 1.0, 0.0 );

if (mode==1)
dessin_3d_sans_moyenne ();
if (mode==2)
dessin_3d_avec_moyenne ();
if (mode==3)
dessin_3d_avec_pxyz1 ();
if (mode==4)
dessin_3d_avec_pxyz1_moyenne ();

//dessiner_courbe();
//dessin_3d_sans_moyenne ();
//dessin_3d_avec_moyenne ();
//dessin_3d_avec_pxyz1 ();
printf("coucou3 et mode=%d\n", mode);

glPopMatrix ( );
glutSwapBuffers ( );
}


here is the main function (it crashs when menu==4, but works when menu==1 2 or 3)

int main ( int argc, char** argv )
{
int menu;

initialise_tableau1 (); //pxyz et pxyz1 rempli
enleve_chiffre_apres_virgule ();

printf("\nEntrer \t1.pour dessin 3d\n\t2.pour courbes de niveaux\n");
scanf("%d", &menu);

if(menu==1)
{
printf("Entrer \t1.pour en entier\n\t2.pour en entier moyenne\n\t3.pour tous les chiffres\n\t4.pour tous les chiffres avec moyenne");
scanf("%d", &menu);
if (menu==1)
mode=1;
else
if (menu==2)
mode=2;
else
if (menu==3)
mode=3;
else
mode=4;
printf("mode=%d\n", mode);
}
if (mode==1)
calcul_normales_pxyz ();
if (mode==2)
{
moyenne_point_pxyz();
calcul_normales_moyenne ();
}
if(mode==3)
calcul_normales_pxyz1 ();
if (mode==4)
{
moyenne_point_pxyz1();
calcul_normales_moyenne ();
}

glutInit ( &argc, argv );
glutInitDisplayMode ( GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
glutInitWindowSize ( 640, 480 );
glutCreateWindow ( argv[0] );
init ( );
glutReshapeFunc ( reshape );
glutMouseFunc ( mouse );
glutMotionFunc ( motion );
glutKeyboardFunc ( keyboard );

glutSpecialFunc (vSpecial );

glutDisplayFunc ( display );
glutIdleFunc ( idle_func );
glutMainLoop ( );
return 0;
}

the only difference between what i do when menu==2 that when menu==4 is that i compute the z of each point of a matrix by the average of the points near it. but when menu==2, the points are integer and became double because of the average and when menu==4 the points are double and stay double.
and then i compute normal with this z.

i don''t see what can do this crash, there is almost no difference.

here is the 3 functions in information that i call when menu=2 and when menu=4

void calcul_normales_moyenne ()
{
long int i;
long int stop;
double normalisation;

if ((normale = (XYZ1 *)malloc((nv)*sizeof(XYZ1))) == NULL) { //changer long.... attention remettre comme avant?
fprintf(stderr,"TRIANGULATE - Unable to allocate enough memory\n");
return;
}


//les 4 bords.
i=0;
while(i {
normale.x= 0.0;
normale.y= 0.0;<br> normale.z= 1.0;<br> i++;<br> }<br><br> i=resolution*(resolution-1);<br> stop=(resolution*resolution);<br> while(i<stop) //bord inferieur<br> {<br> normale.x= 0.0;<br> normale.y= 0.0;<br> normale.z= 1.0;<br> i++;<br> }<br><br> i=resolution;<br> stop=(((resolution-1)*resolution));<br> while(i<stop) //bord gauche et droit en meme temps + pas repeter les 4 coins.<br> {<br> normale.x= 0.0;<br> normale.y= 0.0;<br> normale.z= 1.0;<br><br> if ((i%resolution)==(resolution-1))<br> i++;<br> else<br> i=i+resolution-1;<br> }<br><br> i=resolution+1;<br> stop=(((resolution-1)*resolution)-1);<br> while(i<stop) //l''interieur de la matrice<br> {<br> normalisation=sqrt(4*0.25+(moyenne[i-1].z-moyenne[i+1].z)*(moyenne[i-1].z-moyenne[i+1].z) +<br> (moyenne[i-512].z-moyenne[i+512].z)*(moyenne[i-512].z-moyenne[i+512].z));<br><br> normale.x= ((moyenne[i-1].z-moyenne[i+1].z)/normalisation);<br> normale.y= ((moyenne[i+512].z-moyenne[i-512].z)/normalisation);<br> normale.z= ((2*0.5)/normalisation);<br><br> if ((i%resolution)==(resolution-2))<br> i=i+3; //ligne suivante apres le bord<br> else<br> i++;<br> }<br>}<br><br><br>void moyenne_point_pxyz()<br>{<br> int i, stop, normalisation;<br> if ((moyenne = (XYZ1 *)malloc((nv)*sizeof(XYZ1))) == NULL) {<br> fprintf(stderr,"TRIANGULATE - Unable to allocate enough memory\n");<br> return;<br> }<br><br> //les 4 coins<br> moyenne[0].z=((pxyz[1].z+pxyz[512].z+pxyz[513].z+pxyz[0].z)/4);<br> moyenne[511].z=((pxyz[510].z+pxyz[1022].z+pxyz[1023].z+pxyz[511].z)/4);<br> moyenne[511*512].z=((pxyz[511*512+1].z+pxyz[(511*512)-512].z+pxyz[(511*512)-511].z+pxyz[511*512].z)/4);<br> moyenne[(512*512)-1].z=((pxyz[(512*512)-2].z+pxyz[(512*512)-513].z+pxyz[(512*512)-514].z+pxyz[(512*512)-1].z)/4);<br><br> //les 4 bords.<br> i=1;<br> while(i<resolution-1) //bord superieur<br> {<br> moyenne.z= ( ((double) (pxyz.z+pxyz[i-1].z+pxyz[i+1].z+pxyz[i+512].z+pxyz[i-1+512].z+pxyz[i+1+512].z)/6) );<br>i++;<br> }<br><br> i=(resolution*(resolution-1))+1;<br> stop=(resolution*resolution)-1;<br> while(i<stop) //bord inferieur<br> {<br> moyenne.z= ((pxyz.z+pxyz[i-1].z+pxyz[i+1].z+pxyz[i-512].z+pxyz[i-1-512].z+pxyz[i+1-512].z)/6);<br> i++;<br> }<br><br> i=resolution;<br> stop=((resolution-1)*resolution);<br> while(i<stop) //bord gauche<br> {<br> moyenne.z= ((pxyz.z+pxyz[i+1].z+pxyz[i-512].z+pxyz[i+512].z+pxyz[i+1+512].z+pxyz[i+1-512].z)/6);<br> i++;<br> }<br><br> i=resolution+resolution-1;<br> stop=(resolution*resolution)-1;<br> while(i<stop) //bord droit<br> {<br> moyenne.z= ((pxyz.z+pxyz[i-1].z+pxyz[i-512].z+pxyz[i+512].z+pxyz[i-1+512].z+pxyz[i-1-512].z)/6);<br> i++;<br> }<br><br> i=resolution+1;<br> stop=(((resolution-1)*resolution)-1);<br> while(i<stop) //l''interieur de la matrice<br> {<br> moyenne.z= ((pxyz.z+pxyz[i-1].z+pxyz[i+1].z+pxyz[i-512].z+pxyz[i+512].z+pxyz[i-512+1].z+pxyz[i-512-1].z+pxyz[i+512+1].z+pxyz[i-1+512].z)/9);<br><br> if ((i%resolution)==(resolution-2))<br> i=i+3; //ligne suivante apres le bord<br> else<br> i++;<br> }<br> <br><br>}<br><br><br><br>void moyenne_point_pxyz1()<br>{<br> int i, stop, normalisation;<br> if ((moyenne = (XYZ1 *)malloc((nv)*sizeof(XYZ1))) == NULL) {<br> fprintf(stderr,"TRIANGULATE - Unable to allocate enough memory\n");<br> return;<br> }<br><br> //les 4 coins<br> moyenne[0].z=((pxyz1[1].z+pxyz1[512].z+pxyz1[513].z+pxyz1[0].z)/4);<br> moyenne[511].z=((pxyz1[510].z+pxyz1[1022].z+pxyz1[1023].z+pxyz1[511].z)/4);<br> moyenne[511*512].z=((pxyz1[511*512+1].z+pxyz1[(511*512)-512].z+pxyz1[(511*512)-511].z+pxyz1[511*512].z)/4);<br> moyenne[(512*512)-1].z=((pxyz1[(512*512)-2].z+pxyz1[(512*512)-513].z+pxyz1[(512*512)-514].z+pxyz1[(512*512)-1].z)/4);<br><br> //les 4 bords.<br> i=1;<br> while(i<resolution-1) //bord superieur<br> {<br> moyenne.z= ( ((double) (pxyz1.z+pxyz1[i-1].z+pxyz1[i+1].z+pxyz1[i+512].z+pxyz1[i-1+512].z+pxyz1[i+1+512].z)/6) );<br> i++;<br> }<br><br> i=(resolution*(resolution-1))+1;<br> stop=(resolution*resolution)-1;<br> while(i<stop) //bord inferieur<br> {<br> moyenne.z= ((pxyz1.z+pxyz1[i-1].z+pxyz1[i+1].z+pxyz1[i-512].z+pxyz1[i-1-512].z+pxyz1[i+1-512].z)/6);<br> i++;<br> }<br><br> i=resolution;<br> stop=((resolution-1)*resolution);<br> while(i<stop) //bord gauche<br> {<br> moyenne.z= ((pxyz1.z+pxyz1[i+1].z+pxyz1[i-512].z+pxyz1[i+512].z+pxyz1[i+1+512].z+pxyz1[i+1-512].z)/6);<br> i++;<br> }<br><br> i=resolution+resolution-1;<br> stop=(resolution*resolution)-1;<br> while(i<stop) //bord droit<br> {<br> moyenne.z= ((pxyz1.z+pxyz1[i-1].z+pxyz1[i-512].z+pxyz1[i+512].z+pxyz1[i-1+512].z+pxyz1[i-1-512].z)/6);<br> i++;<br> }<br><br> i=resolution+1;<br> stop=(((resolution-1)*resolution)-1);<br> while(i<stop) //l''interieur de la matrice<br> {<br> moyenne.z= ((pxyz1.z+pxyz1[i-1].z+pxyz1[i+1].z+pxyz1[i-512].z+pxyz1[i+512].z+pxyz1[i-512+1].z+pxyz1[i-512-1].z+pxyz1[i+512+1].z+pxyz1[i-1+512].z)/9);<br><br> if ((i%resolution)==(resolution-2))<br> i=i+3; //ligne suivante apres le bord<br> else<br> i++;<br> }<br> }<br> </i>