Vector3 torus_normal(Prim *p, Real u, Real v)
{
Vector3 w;
w.x = cos(u)*cos(v);
w.y = sin(u)*cos(v);
w.z = sin(v);
return v3_unit(v3_m3mult(w, m4_transpose(p->ti)));
}
Vector3 cylin_normal(Prim *p, Real u, Real v)
{
Vector3 w;
if (u < 0){
w.x = 0;
w.y = 0;
w.z = -1;
} else if (u > 1){
w.x = 0;
w.y = 0;
w.z = 1;
} else {
w.x = cos(v);
w.y = cos(v);
w.z = 0;
}
return v3_unit(v3_m3mult(w, m4_transpose(p->ti)));
}
Vector3 cylin_gradient(Prim *p, Vector3 q)
{
Vector3 w = v3_m4mult(q, p->ti);
w.z = 0;
return v3_m3mult(v3_scale(2., w), m4_transpose(p->ti));
}
void m4_adjoint(mat4_t res, mat4_t m)
{
int i, j;
mat4_t coef;
coef[0][0] = (m[1][1] * (m[2][2] * m[3][3] - m[3][2] * m[2][3])) -
(m[1][2] * (m[2][1] * m[3][3] - m[3][1] * m[2][3])) +
(m[1][3] * (m[2][1] * m[3][2] - m[3][1] * m[2][2]));
coef[0][1] = (m[1][0] * (m[2][2] * m[3][3] - m[3][2] * m[2][3])) -
(m[1][2] * (m[2][0] * m[3][3] - m[3][0] * m[2][3])) +
(m[1][3] * (m[2][0] * m[3][2] - m[3][0] * m[2][2]));
coef[0][2] = (m[1][0] * (m[2][1] * m[3][3] - m[3][1] * m[2][3])) -
(m[1][1] * (m[2][0] * m[3][3] - m[3][0] * m[2][3])) +
(m[1][3] * (m[2][0] * m[3][1] - m[3][0] * m[2][1]));
coef[0][3] = (m[1][0] * (m[2][1] * m[3][2] - m[3][1] * m[2][2])) -
(m[1][1] * (m[2][0] * m[3][2] - m[3][0] * m[2][2])) +
(m[1][2] * (m[2][0] * m[3][1] - m[3][0] * m[2][1]));
coef[1][0] = (m[0][1] * (m[2][2] * m[3][3] - m[3][2] * m[2][3])) -
(m[0][2] * (m[2][1] * m[3][3] - m[3][1] * m[2][3])) +
(m[0][3] * (m[2][1] * m[3][2] - m[3][1] * m[2][2]));
coef[1][1] = (m[0][0] * (m[2][2] * m[3][3] - m[3][2] * m[2][3])) -
(m[0][2] * (m[2][0] * m[3][3] - m[3][0] * m[2][3])) +
(m[0][3] * (m[2][0] * m[3][2] - m[3][0] * m[2][2]));
coef[1][2] = (m[0][0] * (m[2][1] * m[3][3] - m[3][1] * m[2][3])) -
(m[0][1] * (m[2][0] * m[3][3] - m[3][0] * m[2][3])) +
(m[0][3] * (m[2][0] * m[3][1] - m[3][0] * m[2][1]));
coef[1][3] = (m[0][0] * (m[2][1] * m[3][2] - m[3][1] * m[2][2])) -
(m[0][1] * (m[2][0] * m[3][2] - m[3][0] * m[2][2])) +
(m[0][2] * (m[2][0] * m[3][1] - m[3][0] * m[2][1]));
coef[2][0] = (m[0][1] * (m[1][2] * m[3][3] - m[3][2] * m[1][3])) -
(m[0][2] * (m[1][1] * m[3][3] - m[3][1] * m[1][3])) +
(m[0][3] * (m[1][1] * m[3][2] - m[3][1] * m[1][2]));
coef[2][1] = (m[0][0] * (m[1][2] * m[3][3] - m[3][2] * m[1][3])) -
(m[0][2] * (m[1][0] * m[3][3] - m[3][0] * m[1][3])) +
(m[0][3] * (m[1][0] * m[3][2] - m[3][0] * m[1][2]));
coef[2][2] = (m[0][0] * (m[1][1] * m[3][3] - m[3][1] * m[1][3])) -
(m[0][1] * (m[1][0] * m[3][3] - m[3][0] * m[1][3])) +
(m[0][3] * (m[1][0] * m[3][1] - m[3][0] * m[1][1]));
coef[2][3] = (m[0][0] * (m[1][1] * m[3][2] - m[3][1] * m[1][2])) -
(m[0][1] * (m[1][0] * m[3][2] - m[3][0] * m[1][2])) +
(m[0][2] * (m[1][0] * m[3][1] - m[3][0] * m[1][1]));
coef[3][0] = (m[0][1] * (m[1][2] * m[2][3] - m[2][2] * m[1][3])) -
(m[0][2] * (m[1][1] * m[2][3] - m[2][1] * m[1][3])) +
(m[0][3] * (m[1][1] * m[2][2] - m[2][1] * m[1][2]));
coef[3][1] = (m[0][0] * (m[1][2] * m[2][3] - m[2][2] * m[1][3])) -
(m[0][2] * (m[1][0] * m[2][3] - m[2][0] * m[1][3])) +
(m[0][3] * (m[1][0] * m[2][2] - m[2][0] * m[1][2]));
coef[3][2] = (m[0][0] * (m[1][1] * m[2][3] - m[2][1] * m[1][3])) -
(m[0][1] * (m[1][0] * m[2][3] - m[2][0] * m[1][3])) +
(m[0][3] * (m[1][0] * m[2][1] - m[2][0] * m[1][1]));
coef[3][3] = (m[0][0] * (m[1][1] * m[2][2] - m[2][1] * m[1][2])) -
(m[0][1] * (m[1][0] * m[2][2] - m[2][0] * m[1][2])) +
(m[0][2] * (m[1][0] * m[2][1] - m[2][0] * m[1][1]));
m4_transpose(res, coef);
for(i=0; i<4; i++) {
for(j=0; j<4; j++) {
res[i][j] = j % 2 ? -res[i][j] : res[i][j];
if(i % 2) res[i][j] = -res[i][j];
}
}
}
Vector3 s4_n3xform(Stack4 *s, Vector3 nv)
{
return v3_m4mult(nv, m4_transpose(*s->itop));
}
