Function compute_faces_mapping

editor/Read3ds.cpp:642–683

int this_vertex(reading_face *f, int v) { return f->face_verts[v]; }

int compute_faces_mapping(reading_face *f, vector *out_norm, float *out_d) {
  int i;
  float ut, vt, len;
  vector point, u, v;
  vector normal;

  vm_MakeZero(&point);
  vm_MakeZero(&normal);

  ut = vt = 0.0f;

  for (i = 0; i < f->num_verts; i++) {
    u.x = f->face_uvls[i].u;
    u.y = f->face_uvls[i].v;
    u.z = 1.0f;

    v.x = f->face_uvls[(i + 1) % f->num_verts].u;
    v.y = f->face_uvls[(i + 1) % f->num_verts].v;
    v.z = 1.0f;

    ut += (float)fabs(u.x - v.x);
    vt += (float)fabs(u.y - v.y);

    normal.x += (u.y - v.y) * (u.z + v.z);
    normal.y += (u.z - v.z) * (u.x + v.x);
    normal.z += (u.x - v.x) * (u.y + v.y);
    point += u;
  }

  len = vm_GetMagnitude(&normal);

  out_norm->x = normal.x / len;
  out_norm->y = normal.y / len;
  out_norm->z = normal.z / len;
  len *= f->num_verts;
  *out_d = (vm_DotProduct(&point, &normal) / len);
  point.x /= f->num_verts;
  point.y /= f->num_verts;
  point.z /= f->num_verts;

  return 0;
}

// Returns 1 if the uv's match
int uvs_match(reading_face *a, int va, reading_face *b, int vb) {