157 static void tri_intersect(tri *trn, ray *ry) {  in tri_intersect()  argument
162     CROSS(pvec, ry->d, trn->edge2);  in tri_intersect()
165     det = DOT(trn->edge1, pvec);  in tri_intersect()
173     SUB(tvec, ry->o, trn->v0);  in tri_intersect()
181     CROSS(qvec, tvec, trn->edge1);  in tri_intersect()
189     t = DOT(trn->edge2, qvec) * inv_det;  in tri_intersect()
191     add_intersection(t, (object *)trn, ry);  in tri_intersect()
194 static void tri_normal(tri *trn, vector *pnt, ray *incident, vector *N) {  in tri_normal()  argument
195     CROSS((*N), trn->edge1, trn->edge2);  in tri_normal()
206 static void stri_normal(stri *trn, vector *pnt, ray *incident, vector *N) {  in stri_normal()  argument
210     CROSS(norm, trn->edge1, trn->edge2);  in stri_normal()
213     VSUB((*pnt), trn->v0, P);  in stri_normal()
215     CROSS(tmp, P, trn->edge2);  in stri_normal()
218     CROSS(tmp, trn->edge1, P);  in stri_normal()
223     N->x = W * trn->n0.x + U * trn->n1.x + V * trn->n2.x;  in stri_normal()
224     N->y = W * trn->n0.y + U * trn->n1.y + V * trn->n2.y;  in stri_normal()
225     N->z = W * trn->n0.z + U * trn->n1.z + V * trn->n2.z;  in stri_normal()