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blender-archive/source/blender/bmesh/operators/bmo_connect_pair.c

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C

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/** \file
* \ingroup bmesh
*
* Connect vertex pair across multiple faces (splits faces).
*/
#include "MEM_guardedalloc.h"
#include "BLI_heap_simple.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"
#include "bmesh.h"
#include "intern/bmesh_operators_private.h" /* own include */
#include "BLI_mempool.h"
/**
* Method for connecting across many faces.
*
* - use the line between both verts and their normal average to construct a matrix.
* - using the matrix, we can find all intersecting verts/edges.
* - walk the connected data and find the shortest path.
* - store a heap of paths which are being scanned (#PathContext.states).
* - continuously search the shortest path in the heap.
* - never step over the same element twice (tag elements as #ELE_TOUCHED).
* this avoids going into an eternal loop if there are many possible branches (see T45582).
* - when running into a branch, create a new #PathLinkState state and add to the heap.
* - when the target is reached,
* finish - since none of the other paths can be shorter than the one just found.
* - if the connection can't be found - fail.
* - with the connection found, split all edges tagging verts
* (or tag verts that sit on the intersection).
* - run the standard connect operator.
*/
#define CONNECT_EPS 0.0001f
#define VERT_OUT 1
#define VERT_EXCLUDE 2
/* typically hidden faces */
#define FACE_EXCLUDE 2
/* any element we've walked over (only do it once!) */
#define ELE_TOUCHED 4
#define FACE_WALK_TEST(f) \
(CHECK_TYPE_INLINE(f, BMFace *), BMO_face_flag_test(pc->bm_bmoflag, f, FACE_EXCLUDE) == 0)
#define VERT_WALK_TEST(v) \
(CHECK_TYPE_INLINE(v, BMVert *), BMO_vert_flag_test(pc->bm_bmoflag, v, VERT_EXCLUDE) == 0)
#if 0
# define ELE_TOUCH_TEST(e) \
(CHECK_TYPE_ANY(e, BMVert *, BMEdge *, BMElem *, BMElemF *), \
BMO_elem_flag_test(pc->bm_bmoflag, (BMElemF *)e, ELE_TOUCHED))
#endif
#define ELE_TOUCH_MARK(e) \
{ \
CHECK_TYPE_ANY(e, BMVert *, BMEdge *, BMElem *, BMElemF *); \
BMO_elem_flag_enable(pc->bm_bmoflag, (BMElemF *)e, ELE_TOUCHED); \
} \
((void)0)
#define ELE_TOUCH_TEST_VERT(v) BMO_vert_flag_test(pc->bm_bmoflag, v, ELE_TOUCHED)
// #define ELE_TOUCH_MARK_VERT(v) BMO_vert_flag_enable(pc->bm_bmoflag, (BMElemF *)v, ELE_TOUCHED)
#define ELE_TOUCH_TEST_EDGE(e) BMO_edge_flag_test(pc->bm_bmoflag, e, ELE_TOUCHED)
// #define ELE_TOUCH_MARK_EDGE(e) BMO_edge_flag_enable(pc->bm_bmoflag, (BMElemF *)e, ELE_TOUCHED)
// #define ELE_TOUCH_TEST_FACE(f) BMO_face_flag_test(pc->bm_bmoflag, f, ELE_TOUCHED)
// #define ELE_TOUCH_MARK_FACE(f) BMO_face_flag_enable(pc->bm_bmoflag, (BMElemF *)f, ELE_TOUCHED)
// #define DEBUG_PRINT
typedef struct PathContext {
HeapSimple *states;
float matrix[3][3];
float axis_sep;
/* only to access BMO flags */
BMesh *bm_bmoflag;
BMVert *v_a, *v_b;
BLI_mempool *link_pool;
} PathContext;
/**
* Single linked list where each item contains state and points to previous path item.
*/
typedef struct PathLink {
struct PathLink *next;
BMElem *ele; /* edge or vert */
BMElem *ele_from; /* edge or face we came from (not 'next->ele') */
} PathLink;
typedef struct PathLinkState {
/* chain of links */
struct PathLink *link_last;
/* length along links */
float dist;
float co_prev[3];
} PathLinkState;
/**
* \name Min Dist Dir Util
*
* Simply getting the closest intersecting vert/edge is _not_ good enough. see T43792
* we need to get the closest in both directions since the absolute closest may be a dead-end.
*
* Logic is simple:
*
* - first intersection, store the direction.
* - successive intersections will update the first distance if its aligned with the first hit.
* otherwise update the opposite distance.
* - caller stores best outcome in both directions.
*
* \{ */
typedef struct MinDistDir {
/* distance in both directions (FLT_MAX == uninitialized) */
float dist_min[2];
/* direction of the first intersection found */
float dir[3];
} MinDistDir;
#define MIN_DIST_DIR_INIT \
{ \
{ \
FLT_MAX, FLT_MAX \
} \
}
static int min_dist_dir_test(MinDistDir *mddir, const float dist_dir[3], const float dist_sq)
{
if (mddir->dist_min[0] == FLT_MAX) {
return 0;
}
if (dot_v3v3(dist_dir, mddir->dir) > 0.0f) {
if (dist_sq < mddir->dist_min[0]) {
return 0;
}
}
else {
if (dist_sq < mddir->dist_min[1]) {
return 1;
}
}
return -1;
}
static void min_dist_dir_update(MinDistDir *dist, const float dist_dir[3])
{
if (dist->dist_min[0] == FLT_MAX) {
copy_v3_v3(dist->dir, dist_dir);
}
}
/** \} */
static int state_isect_co_pair(const PathContext *pc, const float co_a[3], const float co_b[3])
{
const float diff_a = dot_m3_v3_row_x(pc->matrix, co_a) - pc->axis_sep;
const float diff_b = dot_m3_v3_row_x(pc->matrix, co_b) - pc->axis_sep;
const int test_a = (fabsf(diff_a) < CONNECT_EPS) ? 0 : (diff_a < 0.0f) ? -1 : 1;
const int test_b = (fabsf(diff_b) < CONNECT_EPS) ? 0 : (diff_b < 0.0f) ? -1 : 1;
if ((test_a && test_b) && (test_a != test_b)) {
return 1; /* on either side */
}
return 0;
}
static int state_isect_co_exact(const PathContext *pc, const float co[3])
{
const float diff = dot_m3_v3_row_x(pc->matrix, co) - pc->axis_sep;
return (fabsf(diff) <= CONNECT_EPS);
}
static float state_calc_co_pair_fac(const PathContext *pc,
const float co_a[3],
const float co_b[3])
{
float diff_a, diff_b, diff_tot;
diff_a = fabsf(dot_m3_v3_row_x(pc->matrix, co_a) - pc->axis_sep);
diff_b = fabsf(dot_m3_v3_row_x(pc->matrix, co_b) - pc->axis_sep);
diff_tot = (diff_a + diff_b);
return (diff_tot > FLT_EPSILON) ? (diff_a / diff_tot) : 0.5f;
}
static void state_calc_co_pair(const PathContext *pc,
const float co_a[3],
const float co_b[3],
float r_co[3])
{
const float fac = state_calc_co_pair_fac(pc, co_a, co_b);
interp_v3_v3v3(r_co, co_a, co_b, fac);
}
#ifndef NDEBUG
/**
* Ideally we wouldn't need this and for most cases we don't.
* But when a face has vertices that are on the boundary more than once this becomes tricky.
*/
static bool state_link_find(const PathLinkState *state, BMElem *ele)
{
PathLink *link = state->link_last;
BLI_assert(ELEM(ele->head.htype, BM_VERT, BM_EDGE, BM_FACE));
if (link) {
do {
if (link->ele == ele) {
return true;
}
} while ((link = link->next));
}
return false;
}
#endif
static void state_link_add(PathContext *pc, PathLinkState *state, BMElem *ele, BMElem *ele_from)
{
PathLink *step_new = BLI_mempool_alloc(pc->link_pool);
BLI_assert(ele != ele_from);
BLI_assert(state_link_find(state, ele) == false);
/* never walk onto this again */
ELE_TOUCH_MARK(ele);
#ifdef DEBUG_PRINT
printf("%s: adding to state %p, %.4f - ", __func__, state, state->dist);
if (ele->head.htype == BM_VERT) {
printf("vert %d, ", BM_elem_index_get(ele));
}
else if (ele->head.htype == BM_EDGE) {
printf("edge %d, ", BM_elem_index_get(ele));
}
else {
BLI_assert(0);
}
if (ele_from == NULL) {
printf("from NULL\n");
}
else if (ele_from->head.htype == BM_EDGE) {
printf("from edge %d\n", BM_elem_index_get(ele_from));
}
else if (ele_from->head.htype == BM_FACE) {
printf("from face %d\n", BM_elem_index_get(ele_from));
}
else {
BLI_assert(0);
}
#endif
/* track distance */
{
float co[3];
if (ele->head.htype == BM_VERT) {
copy_v3_v3(co, ((BMVert *)ele)->co);
}
else if (ele->head.htype == BM_EDGE) {
state_calc_co_pair(pc, ((BMEdge *)ele)->v1->co, ((BMEdge *)ele)->v2->co, co);
}
else {
BLI_assert(0);
}
/* tally distance */
if (ele_from) {
state->dist += len_v3v3(state->co_prev, co);
}
copy_v3_v3(state->co_prev, co);
}
step_new->ele = ele;
step_new->ele_from = ele_from;
step_new->next = state->link_last;
state->link_last = step_new;
}
static PathLinkState *state_dupe_add(PathLinkState *state, const PathLinkState *state_orig)
{
state = MEM_mallocN(sizeof(*state), __func__);
*state = *state_orig;
return state;
}
static PathLinkState *state_link_add_test(PathContext *pc,
PathLinkState *state,
const PathLinkState *state_orig,
BMElem *ele,
BMElem *ele_from)
{
const bool is_new = (state_orig->link_last != state->link_last);
if (is_new) {
state = state_dupe_add(state, state_orig);
}
state_link_add(pc, state, ele, ele_from);
/* after adding a link so we use the updated 'state->dist' */
if (is_new) {
BLI_heapsimple_insert(pc->states, state->dist, state);
}
return state;
}
/* walk around the face edges */
static PathLinkState *state_step__face_edges(PathContext *pc,
PathLinkState *state,
const PathLinkState *state_orig,
BMLoop *l_iter,
BMLoop *l_last,
MinDistDir *mddir)
{
BMLoop *l_iter_best[2] = {NULL, NULL};
int i;
do {
if (state_isect_co_pair(pc, l_iter->v->co, l_iter->next->v->co)) {
float dist_test;
float co_isect[3];
float dist_dir[3];
int index;
state_calc_co_pair(pc, l_iter->v->co, l_iter->next->v->co, co_isect);
sub_v3_v3v3(dist_dir, co_isect, state_orig->co_prev);
dist_test = len_squared_v3(dist_dir);
if ((index = min_dist_dir_test(mddir, dist_dir, dist_test)) != -1) {
BMElem *ele_next = (BMElem *)l_iter->e;
BMElem *ele_next_from = (BMElem *)l_iter->f;
if (FACE_WALK_TEST((BMFace *)ele_next_from) &&
(ELE_TOUCH_TEST_EDGE((BMEdge *)ele_next) == false)) {
min_dist_dir_update(mddir, dist_dir);
mddir->dist_min[index] = dist_test;
l_iter_best[index] = l_iter;
}
}
}
} while ((l_iter = l_iter->next) != l_last);
for (i = 0; i < 2; i++) {
if ((l_iter = l_iter_best[i])) {
BMElem *ele_next = (BMElem *)l_iter->e;
BMElem *ele_next_from = (BMElem *)l_iter->f;
state = state_link_add_test(pc, state, state_orig, ele_next, ele_next_from);
}
}
return state;
}
/* walk around the face verts */
static PathLinkState *state_step__face_verts(PathContext *pc,
PathLinkState *state,
const PathLinkState *state_orig,
BMLoop *l_iter,
BMLoop *l_last,
MinDistDir *mddir)
{
BMLoop *l_iter_best[2] = {NULL, NULL};
int i;
do {
if (state_isect_co_exact(pc, l_iter->v->co)) {
float dist_test;
const float *co_isect = l_iter->v->co;
float dist_dir[3];
int index;
sub_v3_v3v3(dist_dir, co_isect, state_orig->co_prev);
dist_test = len_squared_v3(dist_dir);
if ((index = min_dist_dir_test(mddir, dist_dir, dist_test)) != -1) {
BMElem *ele_next = (BMElem *)l_iter->v;
BMElem *ele_next_from = (BMElem *)l_iter->f;
if (FACE_WALK_TEST((BMFace *)ele_next_from) &&
(ELE_TOUCH_TEST_VERT((BMVert *)ele_next) == false)) {
min_dist_dir_update(mddir, dist_dir);
mddir->dist_min[index] = dist_test;
l_iter_best[index] = l_iter;
}
}
}
} while ((l_iter = l_iter->next) != l_last);
for (i = 0; i < 2; i++) {
if ((l_iter = l_iter_best[i])) {
BMElem *ele_next = (BMElem *)l_iter->v;
BMElem *ele_next_from = (BMElem *)l_iter->f;
state = state_link_add_test(pc, state, state_orig, ele_next, ele_next_from);
}
}
return state;
}
static bool state_step(PathContext *pc, PathLinkState *state)
{
PathLinkState state_orig = *state;
BMElem *ele = state->link_last->ele;
const void *ele_from = state->link_last->ele_from;
if (ele->head.htype == BM_EDGE) {
BMEdge *e = (BMEdge *)ele;
BMIter liter;
BMLoop *l_start;
BM_ITER_ELEM (l_start, &liter, e, BM_LOOPS_OF_EDGE) {
if ((l_start->f != ele_from) && FACE_WALK_TEST(l_start->f)) {
MinDistDir mddir = MIN_DIST_DIR_INIT;
/* very similar to block below */
state = state_step__face_edges(pc, state, &state_orig, l_start->next, l_start, &mddir);
state = state_step__face_verts(
pc, state, &state_orig, l_start->next->next, l_start, &mddir);
}
}
}
else if (ele->head.htype == BM_VERT) {
BMVert *v = (BMVert *)ele;
/* vert loops */
{
BMIter liter;
BMLoop *l_start;
BM_ITER_ELEM (l_start, &liter, v, BM_LOOPS_OF_VERT) {
if ((l_start->f != ele_from) && FACE_WALK_TEST(l_start->f)) {
MinDistDir mddir = MIN_DIST_DIR_INIT;
/* very similar to block above */
state = state_step__face_edges(
pc, state, &state_orig, l_start->next, l_start->prev, &mddir);
if (l_start->f->len > 3) {
/* adjacent verts are handled in state_step__vert_edges */
state = state_step__face_verts(
pc, state, &state_orig, l_start->next->next, l_start->prev, &mddir);
}
}
}
}
/* vert edges */
{
BMIter eiter;
BMEdge *e;
BM_ITER_ELEM (e, &eiter, v, BM_EDGES_OF_VERT) {
BMVert *v_other = BM_edge_other_vert(e, v);
if (((BMElem *)e != ele_from) && VERT_WALK_TEST(v_other)) {
if (state_isect_co_exact(pc, v_other->co)) {
BMElem *ele_next = (BMElem *)v_other;
BMElem *ele_next_from = (BMElem *)e;
if (ELE_TOUCH_TEST_VERT((BMVert *)ele_next) == false) {
state = state_link_add_test(pc, state, &state_orig, ele_next, ele_next_from);
}
}
}
}
}
}
else {
BLI_assert(0);
}
return (state_orig.link_last != state->link_last);
}
/**
* Get a orientation matrix from 2 vertices.
*/
static void bm_vert_pair_to_matrix(BMVert *v_pair[2], float r_unit_mat[3][3])
{
const float eps = 1e-8f;
float basis_dir[3];
float basis_tmp[3];
float basis_nor[3];
sub_v3_v3v3(basis_dir, v_pair[0]->co, v_pair[1]->co);
normalize_v3(basis_dir);
#if 0
add_v3_v3v3(basis_nor, v_pair[0]->no, v_pair[1]->no);
cross_v3_v3v3(basis_tmp, basis_nor, basis_dir);
cross_v3_v3v3(basis_nor, basis_tmp, basis_dir);
#else
/* align both normals to the directions before combining */
{
float basis_nor_a[3];
float basis_nor_b[3];
/* align normal to direction */
project_plane_normalized_v3_v3v3(basis_nor_a, v_pair[0]->no, basis_dir);
project_plane_normalized_v3_v3v3(basis_nor_b, v_pair[1]->no, basis_dir);
/* Don't normalize before combining so as normals approach the direction,
* they have less effect (T46784). */
/* combine the normals */
/* for flipped faces */
if (dot_v3v3(basis_nor_a, basis_nor_b) < 0.0f) {
negate_v3(basis_nor_b);
}
add_v3_v3v3(basis_nor, basis_nor_a, basis_nor_b);
}
#endif
/* get third axis */
normalize_v3(basis_nor);
cross_v3_v3v3(basis_tmp, basis_dir, basis_nor);
/* Try get the axis from surrounding faces, fallback to 'ortho_v3_v3' */
if (UNLIKELY(normalize_v3(basis_tmp) < eps)) {
/* vertex normals are directly opposite */
/* find the loop with the lowest angle */
struct {
float nor[3];
float angle_cos;
} axis_pair[2];
int i;
for (i = 0; i < 2; i++) {
BMIter liter;
BMLoop *l;
zero_v2(axis_pair[i].nor);
axis_pair[i].angle_cos = -FLT_MAX;
BM_ITER_ELEM (l, &liter, v_pair[i], BM_LOOPS_OF_VERT) {
float basis_dir_proj[3];
float angle_cos_test;
/* project basis dir onto the normal to find its closest angle */
project_plane_normalized_v3_v3v3(basis_dir_proj, basis_dir, l->f->no);
if (normalize_v3(basis_dir_proj) > eps) {
angle_cos_test = dot_v3v3(basis_dir_proj, basis_dir);
if (angle_cos_test > axis_pair[i].angle_cos) {
axis_pair[i].angle_cos = angle_cos_test;
copy_v3_v3(axis_pair[i].nor, basis_dir_proj);
}
}
}
}
/* create a new 'basis_nor' from the best direction.
* note: we could add the directions,
* but this more often gives 45d rotated matrix, so just use the best one. */
copy_v3_v3(basis_nor, axis_pair[axis_pair[0].angle_cos < axis_pair[1].angle_cos].nor);
project_plane_normalized_v3_v3v3(basis_nor, basis_nor, basis_dir);
cross_v3_v3v3(basis_tmp, basis_dir, basis_nor);
/* last resort, pick _any_ ortho axis */
if (UNLIKELY(normalize_v3(basis_tmp) < eps)) {
ortho_v3_v3(basis_nor, basis_dir);
normalize_v3(basis_nor);
cross_v3_v3v3(basis_tmp, basis_dir, basis_nor);
normalize_v3(basis_tmp);
}
}
copy_v3_v3(r_unit_mat[0], basis_tmp);
copy_v3_v3(r_unit_mat[1], basis_dir);
copy_v3_v3(r_unit_mat[2], basis_nor);
if (invert_m3(r_unit_mat) == false) {
unit_m3(r_unit_mat);
}
}
void bmo_connect_vert_pair_exec(BMesh *bm, BMOperator *op)
{
BMOpSlot *op_verts_slot = BMO_slot_get(op->slots_in, "verts");
PathContext pc;
PathLinkState state_best = {NULL};
if (op_verts_slot->len != 2) {
/* fail! */
return;
}
pc.bm_bmoflag = bm;
pc.v_a = ((BMVert **)op_verts_slot->data.p)[0];
pc.v_b = ((BMVert **)op_verts_slot->data.p)[1];
/* fail! */
if (!(pc.v_a && pc.v_b)) {
return;
}
#ifdef DEBUG_PRINT
printf("%s: v_a: %d\n", __func__, BM_elem_index_get(pc.v_a));
printf("%s: v_b: %d\n", __func__, BM_elem_index_get(pc.v_b));
#endif
/* tag so we won't touch ever (typically hidden faces) */
BMO_slot_buffer_flag_enable(bm, op->slots_in, "faces_exclude", BM_FACE, FACE_EXCLUDE);
BMO_slot_buffer_flag_enable(bm, op->slots_in, "verts_exclude", BM_VERT, VERT_EXCLUDE);
/* setup context */
{
pc.states = BLI_heapsimple_new();
pc.link_pool = BLI_mempool_create(sizeof(PathLink), 0, 512, BLI_MEMPOOL_NOP);
}
/* calculate matrix */
{
bm_vert_pair_to_matrix(&pc.v_a, pc.matrix);
pc.axis_sep = dot_m3_v3_row_x(pc.matrix, pc.v_a->co);
}
/* add first vertex */
{
PathLinkState *state;
state = MEM_callocN(sizeof(*state), __func__);
state_link_add(&pc, state, (BMElem *)pc.v_a, NULL);
BLI_heapsimple_insert(pc.states, state->dist, state);
}
while (!BLI_heapsimple_is_empty(pc.states)) {
#ifdef DEBUG_PRINT
printf("\n%s: stepping %u\n", __func__, BLI_heapsimple_len(pc.states));
#endif
while (!BLI_heapsimple_is_empty(pc.states)) {
PathLinkState *state = BLI_heapsimple_pop_min(pc.states);
/* either we insert this into 'pc.states' or its freed */
bool continue_search;
if (state->link_last->ele == (BMElem *)pc.v_b) {
/* pass, wait until all are found */
#ifdef DEBUG_PRINT
printf("%s: state %p loop found %.4f\n", __func__, state, state->dist);
#endif
state_best = *state;
/* we're done, exit all loops */
BLI_heapsimple_clear(pc.states, MEM_freeN);
continue_search = false;
}
else if (state_step(&pc, state)) {
continue_search = true;
}
else {
/* didn't reach the end, remove it,
* links are shared between states so just free the link_pool at the end */
#ifdef DEBUG_PRINT
printf("%s: state %p removed\n", __func__, state);
#endif
continue_search = false;
}
if (continue_search) {
BLI_heapsimple_insert(pc.states, state->dist, state);
}
else {
MEM_freeN(state);
}
}
}
if (state_best.link_last) {
PathLink *link;
/* find the best state */
link = state_best.link_last;
do {
if (link->ele->head.htype == BM_EDGE) {
BMEdge *e = (BMEdge *)link->ele;
BMVert *v_new;
float e_fac = state_calc_co_pair_fac(&pc, e->v1->co, e->v2->co);
v_new = BM_edge_split(bm, e, e->v1, NULL, e_fac);
BMO_vert_flag_enable(bm, v_new, VERT_OUT);
}
else if (link->ele->head.htype == BM_VERT) {
BMVert *v = (BMVert *)link->ele;
BMO_vert_flag_enable(bm, v, VERT_OUT);
}
else {
BLI_assert(0);
}
} while ((link = link->next));
}
BMO_vert_flag_enable(bm, pc.v_a, VERT_OUT);
BMO_vert_flag_enable(bm, pc.v_b, VERT_OUT);
BLI_mempool_destroy(pc.link_pool);
BLI_heapsimple_free(pc.states, MEM_freeN);
#if 1
if (state_best.link_last) {
BMOperator op_sub;
BMO_op_initf(bm,
&op_sub,
0,
"connect_verts verts=%fv faces_exclude=%s check_degenerate=%b",
VERT_OUT,
op,
"faces_exclude",
true);
BMO_op_exec(bm, &op_sub);
BMO_slot_copy(&op_sub, slots_out, "edges.out", op, slots_out, "edges.out");
BMO_op_finish(bm, &op_sub);
}
#endif
}