void s4_scale(Stack4 *s, Vector3 v)
{
*s->mtop = m4_m4prod(*s->mtop, m4_scale(v.x, v.y, v.z));
if (REL_EQ(v.x, 0.0) || REL_EQ(v.y,0.0) || REL_EQ(v.z,0.0))
error("(s4_scale) unable to invert scale matrix");
else
*s->itop = m4_m4prod(m4_scale(1./v.x,1./v.y,1./v.z), *s->itop);
}
Prim *cylin_set(Prim *p, Vector3 bc, double h, double r)
{
Cylin *s = p->d;
s->bc = bc; s->h = h; s->r = r;
p->ti = p->td = m4_ident();
p = cylin_transform(p, m4_scale(r,r,h), m4_scale(1/r,1/r,1/h));
p = cylin_transform(p, m4_translate(bc.x,bc.y,bc.z), m4_translate(-bc.x,-bc.y,-bc.z));
p->b = cylin_bbox(p);
return p;
}
Matrix4 m4_compxform(int k, char *t, Real **p, int j)
{
int i;
Matrix4 m = m4_ident();
for (i = 0; i < k; i++) {
switch (t[i]) {
case G_TX: m = m4_m4prod(m4_translate(p[i][j], 0, 0), m); break;
case G_TY: m = m4_m4prod(m4_translate(0, p[i][j], 0), m); break;
case G_TZ: m = m4_m4prod(m4_translate(0, 0, p[i][j]), m); break;
case G_RX: m = m4_m4prod(m4_rotate('x', p[i][j]), m); break;
case G_RY: m = m4_m4prod(m4_rotate('y', p[i][j]), m); break;
case G_RZ: m = m4_m4prod(m4_rotate('z', p[i][j]), m); break;
case G_SX: m = m4_m4prod(m4_scale(p[i][j], 1, 1), m); break;
case G_SY: m = m4_m4prod(m4_scale(1, p[i][j], 1), m); break;
case G_SZ: m = m4_m4prod(m4_scale(1, 1, p[i][j]), m); break;
default: break;
}
}
return m;
}