la soluce avec des gl_quads

j'ai du faire une erreur dans les naths mais la c'est sur que ça marche

void Sphere(int a,int b) { 
float da = ( M_PI / a ); 
float db = ( 2.0f * M_PI / b ); 
glBegin(GL_QUADS); 
glColor3f(1.0,0.0,0.0);
glNormal3f(0,0,1); 
for( int i = 0; i < a + 1 ; i++ ) { 
 float r0 = sin ( i * da ); 
 float y0 = cos ( i * da ); 
 float r1 = sin ( (i+1) * da ); 
 float y1 = cos ( (i+1) * da ); 
 for( int j = 0; j < b + 1 ; j++ ) { 
 float x0 = r0 * sin( j * db ); 
 float z0 = r0 * cos( j * db ); 
 float x1 = r0 * sin( (j+1) * db ); 
 float z1 = r0 * cos( (j+1) * db ); 
 float x2 = r1 * sin( j * db ); 
 float z2 = r1 * cos( j * db ); 
 float x3 = r1 * sin( (j+1) * db ); 
 float z3 = r1 * cos( (j+1) * db ); 
 glColor3f((x0+x1+x2+x3)/4.0,(y0+y1)/2.0,(z0+z1+z2+z3)/4.0);
 glVertex3f(x0,y0,z0); 
 glVertex3f(x1,y0,z1); 
 glVertex3f(x3,y1,z3); 
 glVertex3f(x2,y1,z2); 
 } 
} 
glEnd(); 
}