/**
* Given an array of faces, recalculate their normals.
* this functions assumes all faces in the array are connected by edges.
*
* \param bm:
* \param faces: Array of connected faces.
* \param faces_len: Length of \a faces
* \param oflag: Flag to check before doing the actual face flipping.
*/
static void bmo_recalc_face_normals_array(BMesh *bm,
BMFace **faces,
const int faces_len,
const short oflag)
{
int i, f_start_index;
const short oflag_flip = oflag | FACE_FLIP;
bool is_flip;
BMFace *f;
BLI_LINKSTACK_DECLARE(fstack, BMFace *);
f_start_index = recalc_face_normals_find_index(bm, faces, faces_len, &is_flip);
if (is_flip) {
BMO_face_flag_enable(bm, faces[f_start_index], FACE_FLIP);
}
/* now that we've found our starting face, make all connected faces
* have the same winding. this is done recursively, using a manual
* stack (if we use simple function recursion, we'd end up overloading
* the stack on large meshes). */
BLI_LINKSTACK_INIT(fstack);
BLI_LINKSTACK_PUSH(fstack, faces[f_start_index]);
BMO_face_flag_enable(bm, faces[f_start_index], FACE_TEMP);
while ((f = BLI_LINKSTACK_POP(fstack))) {
const bool flip_state = BMO_face_flag_test_bool(bm, f, FACE_FLIP);
BMLoop *l_iter, *l_first;
l_iter = l_first = BM_FACE_FIRST_LOOP(f);
do {
BMLoop *l_other = l_iter->radial_next;
if ((l_other != l_iter) && bmo_recalc_normal_loop_filter_cb(l_iter, NULL)) {
if (!BMO_face_flag_test(bm, l_other->f, FACE_TEMP)) {
BMO_face_flag_enable(bm, l_other->f, FACE_TEMP);
BMO_face_flag_set(bm, l_other->f, FACE_FLIP, (l_other->v == l_iter->v) != flip_state);
BLI_LINKSTACK_PUSH(fstack, l_other->f);
}
}
} while ((l_iter = l_iter->next) != l_first);
}
BLI_LINKSTACK_FREE(fstack);
/* apply flipping to oflag'd faces */
for (i = 0; i < faces_len; i++) {
if (BMO_face_flag_test(bm, faces[i], oflag_flip) == oflag_flip) {
BM_face_normal_flip(bm, faces[i]);
}
BMO_face_flag_disable(bm, faces[i], FACE_TEMP);
}
}
static PyObject *bpy_bm_utils_face_flip(PyObject *UNUSED(self), BPy_BMFace *value)
{
if (!BPy_BMFace_Check(value)) {
PyErr_Format(PyExc_TypeError,
"face_flip(face): BMFace expected, not '%.200s'",
Py_TYPE(value)->tp_name);
return NULL;
}
BPY_BM_CHECK_OBJ(value);
BM_face_normal_flip(value->bm, value->f);
Py_RETURN_NONE;
}
