editmesh_bvh.cc

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/* SPDX-FileCopyrightText: 2010 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#include "MEM_guardedalloc.h"
 
#include "BLI_kdopbvh.h"
#include "BLI_math_geom.h"
#include "BLI_math_vector.h"
 
#include "BKE_editmesh.hh"
 
#include "BKE_editmesh_bvh.hh" /* own include */
 
using blender::Span;
 
struct BMBVHTree {
  BVHTree *tree;
 
  Span<std::array<BMLoop *, 3>> looptris;
 
  BMesh *bm;
 
  const blender::float3 *cos_cage;
  bool cos_cage_free;
 
  int flag;
};
 
BMBVHTree *BKE_bmbvh_new_from_editmesh(BMEditMesh *em,
                                       int flag,
                                       const blender::float3 *cos_cage,
                                       const bool cos_cage_free)
{
  return BKE_bmbvh_new(em->bm, em->looptris, flag, cos_cage, cos_cage_free);
}
 
BMBVHTree *BKE_bmbvh_new_ex(BMesh *bm,
                            const Span<std::array<BMLoop *, 3>> looptris,
                            int flag,
                            const blender::float3 *cos_cage,
                            const bool cos_cage_free,
                            bool (*test_fn)(BMFace *, void *user_data),
                            void *user_data)
{
  /* could become argument */
  const float epsilon = FLT_EPSILON * 2.0f;
 
  BMBVHTree *bmtree = static_cast<BMBVHTree *>(MEM_callocN(sizeof(*bmtree), "BMBVHTree"));
  float cos[3][3];
  int tottri;
 
  /* avoid testing every tri */
  BMFace *f_test, *f_test_prev;
  bool test_fn_ret;
 
  /* BKE_editmesh_looptris_calc() must be called already */
  BLI_assert(looptris.size() != 0 || bm->totface == 0);
 
  if (cos_cage) {
    BM_mesh_elem_index_ensure(bm, BM_VERT);
  }
 
  bmtree->looptris = looptris;
  bmtree->bm = bm;
  bmtree->cos_cage = cos_cage;
  bmtree->cos_cage_free = cos_cage_free;
  bmtree->flag = flag;
 
  if (test_fn) {
    /* callback must do... */
    BLI_assert(!(flag & (BMBVH_RESPECT_SELECT | BMBVH_RESPECT_HIDDEN)));
 
    f_test_prev = nullptr;
    test_fn_ret = false;
 
    tottri = 0;
    for (const int i : looptris.index_range()) {
      f_test = looptris[i][0]->f;
      if (f_test != f_test_prev) {
        test_fn_ret = test_fn(f_test, user_data);
        f_test_prev = f_test;
      }
 
      if (test_fn_ret) {
        tottri++;
      }
    }
  }
  else {
    tottri = looptris.size();
  }
 
  bmtree->tree = BLI_bvhtree_new(tottri, epsilon, 8, 8);
 
  f_test_prev = nullptr;
  test_fn_ret = false;
 
  for (const int i : looptris.index_range()) {
    if (test_fn) {
      /* NOTE: the arrays won't align now! Take care. */
      f_test = looptris[i][0]->f;
      if (f_test != f_test_prev) {
        test_fn_ret = test_fn(f_test, user_data);
        f_test_prev = f_test;
      }
 
      if (!test_fn_ret) {
        continue;
      }
    }
 
    if (cos_cage) {
      copy_v3_v3(cos[0], cos_cage[BM_elem_index_get(looptris[i][0]->v)]);
      copy_v3_v3(cos[1], cos_cage[BM_elem_index_get(looptris[i][1]->v)]);
      copy_v3_v3(cos[2], cos_cage[BM_elem_index_get(looptris[i][2]->v)]);
    }
    else {
      copy_v3_v3(cos[0], looptris[i][0]->v->co);
      copy_v3_v3(cos[1], looptris[i][1]->v->co);
      copy_v3_v3(cos[2], looptris[i][2]->v->co);
    }
 
    BLI_bvhtree_insert(bmtree->tree, i, (float *)cos, 3);
  }
 
  BLI_bvhtree_balance(bmtree->tree);
 
  return bmtree;
}
 
static bool bm_face_is_select(BMFace *f, void * /*user_data*/)
{
  return (BM_elem_flag_test(f, BM_ELEM_SELECT) != 0);
}
 
static bool bm_face_is_not_hidden(BMFace *f, void * /*user_data*/)
{
  return (BM_elem_flag_test(f, BM_ELEM_HIDDEN) == 0);
}
 
BMBVHTree *BKE_bmbvh_new(BMesh *bm,
                         const Span<std::array<BMLoop *, 3>> looptris,
                         int flag,
                         const blender::float3 *cos_cage,
                         const bool cos_cage_free)
{
  bool (*test_fn)(BMFace *, void *user_data);
 
  if (flag & BMBVH_RESPECT_SELECT) {
    test_fn = bm_face_is_select;
  }
  else if (flag & BMBVH_RESPECT_HIDDEN) {
    test_fn = bm_face_is_not_hidden;
  }
  else {
    test_fn = nullptr;
  }
 
  flag &= ~(BMBVH_RESPECT_SELECT | BMBVH_RESPECT_HIDDEN);
 
  return BKE_bmbvh_new_ex(bm, looptris, flag, cos_cage, cos_cage_free, test_fn, nullptr);
}
 
void BKE_bmbvh_free(BMBVHTree *bmtree)
{
  BLI_bvhtree_free(bmtree->tree);
 
  if (bmtree->cos_cage && bmtree->cos_cage_free) {
    MEM_freeN((void *)bmtree->cos_cage);
  }
 
  MEM_freeN(bmtree);
}
 
BVHTree *BKE_bmbvh_tree_get(BMBVHTree *bmtree)
{
  return bmtree->tree;
}
 
/* -------------------------------------------------------------------- */
/* Utility BMesh cast/intersect functions */
 
static void bmbvh_tri_from_face(const float *cos[3],
                                const std::array<BMLoop *, 3> &ltri,
                                const blender::float3 *cos_cage)
{
  if (cos_cage == nullptr) {
    cos[0] = ltri[0]->v->co;
    cos[1] = ltri[1]->v->co;
    cos[2] = ltri[2]->v->co;
  }
  else {
    cos[0] = cos_cage[BM_elem_index_get(ltri[0]->v)];
    cos[1] = cos_cage[BM_elem_index_get(ltri[1]->v)];
    cos[2] = cos_cage[BM_elem_index_get(ltri[2]->v)];
  }
}
 
/* Taken from `bvhutils.cc`. */
 
/* -------------------------------------------------------------------- */
/* BKE_bmbvh_ray_cast */
 
struct RayCastUserData {
  /* from the bmtree */
  Span<std::array<BMLoop *, 3>> looptris;
  const blender::float3 *cos_cage;
 
  /* from the hit */
  float uv[2];
};
 
static BMFace *bmbvh_ray_cast_handle_hit(const BMBVHTree *bmtree,
                                         RayCastUserData *bmcb_data,
                                         const BVHTreeRayHit *hit,
                                         float *r_dist,
                                         float r_hitout[3],
                                         float r_cagehit[3])
{
  if (r_hitout) {
    if (bmtree->flag & BMBVH_RETURN_ORIG) {
      const std::array<BMLoop *, 3> &ltri = bmtree->looptris[hit->index];
      interp_v3_v3v3v3_uv(r_hitout, ltri[0]->v->co, ltri[1]->v->co, ltri[2]->v->co, bmcb_data->uv);
    }
    else {
      copy_v3_v3(r_hitout, hit->co);
    }
 
    if (r_cagehit) {
      copy_v3_v3(r_cagehit, hit->co);
    }
  }
 
  if (r_dist) {
    *r_dist = hit->dist;
  }
 
  return bmtree->looptris[hit->index][0]->f;
}
 
static void bmbvh_ray_cast_cb(void *userdata, int index, const BVHTreeRay *ray, BVHTreeRayHit *hit)
{
  RayCastUserData *bmcb_data = static_cast<RayCastUserData *>(userdata);
  const std::array<BMLoop *, 3> &ltri = bmcb_data->looptris[index];
  float dist, uv[2];
  const float *tri_cos[3];
  bool isect;
 
  bmbvh_tri_from_face(tri_cos, ltri, bmcb_data->cos_cage);
 
  isect =
      (ray->radius > 0.0f ?
           isect_ray_tri_epsilon_v3(ray->origin,
                                    ray->direction,
                                    tri_cos[0],
                                    tri_cos[1],
                                    tri_cos[2],
                                    &dist,
                                    uv,
                                    ray->radius) :
#ifdef USE_KDOPBVH_WATERTIGHT
           isect_ray_tri_watertight_v3(
               ray->origin, ray->isect_precalc, tri_cos[0], tri_cos[1], tri_cos[2], &dist, uv));
#else
           isect_ray_tri_v3(
               ray->origin, ray->direction, tri_cos[0], tri_cos[1], tri_cos[2], &dist, uv));
#endif
 
  if (isect && dist < hit->dist) {
    hit->dist = dist;
    hit->index = index;
 
    copy_v3_v3(hit->no, ltri[0]->f->no);
 
    madd_v3_v3v3fl(hit->co, ray->origin, ray->direction, dist);
 
    copy_v2_v2(bmcb_data->uv, uv);
  }
}
 
BMFace *BKE_bmbvh_ray_cast(const BMBVHTree *bmtree,
                           const float co[3],
                           const float dir[3],
                           const float radius,
                           float *r_dist,
                           float r_hitout[3],
                           float r_cagehit[3])
{
  BVHTreeRayHit hit;
  RayCastUserData bmcb_data;
  const float dist = r_dist ? *r_dist : FLT_MAX;
 
  if (bmtree->cos_cage) {
    BLI_assert(!(bmtree->bm->elem_index_dirty & BM_VERT));
  }
 
  hit.dist = dist;
  hit.index = -1;
 
  /* ok to leave 'uv' uninitialized */
  bmcb_data.looptris = bmtree->looptris;
  bmcb_data.cos_cage = bmtree->cos_cage;
 
  BLI_bvhtree_ray_cast(bmtree->tree, co, dir, radius, &hit, bmbvh_ray_cast_cb, &bmcb_data);
 
  if (hit.index != -1 && hit.dist != dist) {
    return bmbvh_ray_cast_handle_hit(bmtree, &bmcb_data, &hit, r_dist, r_hitout, r_cagehit);
  }
 
  return nullptr;
}
 
/* -------------------------------------------------------------------- */
/* bmbvh_ray_cast_cb_filter */
 
/* Same as BKE_bmbvh_ray_cast but takes a callback to filter out faces.
 */
 
struct RayCastUserData_Filter {
  RayCastUserData bmcb_data;
 
  BMBVHTree_FaceFilter filter_cb;
  void *filter_userdata;
};
 
static void bmbvh_ray_cast_cb_filter(void *userdata,
                                     int index,
                                     const BVHTreeRay *ray,
                                     BVHTreeRayHit *hit)
{
  RayCastUserData_Filter *bmcb_data_filter = static_cast<RayCastUserData_Filter *>(userdata);
  RayCastUserData *bmcb_data = &bmcb_data_filter->bmcb_data;
  const std::array<BMLoop *, 3> &ltri = bmcb_data->looptris[index];
  if (bmcb_data_filter->filter_cb(ltri[0]->f, bmcb_data_filter->filter_userdata)) {
    bmbvh_ray_cast_cb(bmcb_data, index, ray, hit);
  }
}
 
BMFace *BKE_bmbvh_ray_cast_filter(const BMBVHTree *bmtree,
                                  const float co[3],
                                  const float dir[3],
                                  const float radius,
                                  float *r_dist,
                                  float r_hitout[3],
                                  float r_cagehit[3],
                                  BMBVHTree_FaceFilter filter_cb,
                                  void *filter_userdata)
{
  BVHTreeRayHit hit;
  RayCastUserData_Filter bmcb_data_filter;
  RayCastUserData *bmcb_data = &bmcb_data_filter.bmcb_data;
 
  const float dist = r_dist ? *r_dist : FLT_MAX;
 
  bmcb_data_filter.filter_cb = filter_cb;
  bmcb_data_filter.filter_userdata = filter_userdata;
 
  if (bmtree->cos_cage) {
    BLI_assert(!(bmtree->bm->elem_index_dirty & BM_VERT));
  }
 
  hit.dist = dist;
  hit.index = -1;
 
  /* ok to leave 'uv' uninitialized */
  bmcb_data->looptris = bmtree->looptris;
  bmcb_data->cos_cage = bmtree->cos_cage;
 
  BLI_bvhtree_ray_cast(
      bmtree->tree, co, dir, radius, &hit, bmbvh_ray_cast_cb_filter, &bmcb_data_filter);
  if (hit.index != -1 && hit.dist != dist) {
    return bmbvh_ray_cast_handle_hit(bmtree, bmcb_data, &hit, r_dist, r_hitout, r_cagehit);
  }
 
  return nullptr;
}
 
/* -------------------------------------------------------------------- */
/* BKE_bmbvh_find_vert_closest */
 
struct VertSearchUserData {
  /* from the bmtree */
  Span<std::array<BMLoop *, 3>> looptris;
  const blender::float3 *cos_cage;
 
  /* from the hit */
  float dist_max_sq;
  int index_tri;
};
 
static void bmbvh_find_vert_closest_cb(void *userdata,
                                       int index,
                                       const float co[3],
                                       BVHTreeNearest *hit)
{
  VertSearchUserData *bmcb_data = static_cast<VertSearchUserData *>(userdata);
  const std::array<BMLoop *, 3> &ltri = bmcb_data->looptris[index];
  const float dist_max_sq = bmcb_data->dist_max_sq;
 
  const float *tri_cos[3];
  bmbvh_tri_from_face(tri_cos, ltri, bmcb_data->cos_cage);
 
  for (int i = 0; i < 3; i++) {
    const float dist_sq = len_squared_v3v3(co, tri_cos[i]);
    if (dist_sq < hit->dist_sq && dist_sq < dist_max_sq) {
      copy_v3_v3(hit->co, tri_cos[i]);
      /* XXX, normal ignores cage */
      copy_v3_v3(hit->no, ltri[i]->v->no);
      hit->dist_sq = dist_sq;
      hit->index = index;
      bmcb_data->index_tri = i;
    }
  }
}
 
BMVert *BKE_bmbvh_find_vert_closest(const BMBVHTree *bmtree,
                                    const float co[3],
                                    const float dist_max)
{
  BVHTreeNearest hit;
  VertSearchUserData bmcb_data;
  const float dist_max_sq = dist_max * dist_max;
 
  if (bmtree->cos_cage) {
    BLI_assert(!(bmtree->bm->elem_index_dirty & BM_VERT));
  }
 
  hit.dist_sq = dist_max_sq;
  hit.index = -1;
 
  bmcb_data.looptris = bmtree->looptris;
  bmcb_data.cos_cage = bmtree->cos_cage;
  bmcb_data.dist_max_sq = dist_max_sq;
 
  BLI_bvhtree_find_nearest(bmtree->tree, co, &hit, bmbvh_find_vert_closest_cb, &bmcb_data);
  if (hit.index != -1) {
    const std::array<BMLoop *, 3> &ltri = bmtree->looptris[hit.index];
    return ltri[bmcb_data.index_tri]->v;
  }
 
  return nullptr;
}
 
struct FaceSearchUserData {
  /* from the bmtree */
  Span<std::array<BMLoop *, 3>> looptris;
  const blender::float3 *cos_cage;
 
  /* from the hit */
  float dist_max_sq;
};
 
static void bmbvh_find_face_closest_cb(void *userdata,
                                       int index,
                                       const float co[3],
                                       BVHTreeNearest *hit)
{
  FaceSearchUserData *bmcb_data = static_cast<FaceSearchUserData *>(userdata);
  const std::array<BMLoop *, 3> &ltri = bmcb_data->looptris[index];
  const float dist_max_sq = bmcb_data->dist_max_sq;
 
  const float *tri_cos[3];
 
  bmbvh_tri_from_face(tri_cos, ltri, bmcb_data->cos_cage);
 
  float co_close[3];
  closest_on_tri_to_point_v3(co_close, co, UNPACK3(tri_cos));
  const float dist_sq = len_squared_v3v3(co, co_close);
  if (dist_sq < hit->dist_sq && dist_sq < dist_max_sq) {
    /* XXX, normal ignores cage */
    copy_v3_v3(hit->no, ltri[0]->f->no);
    hit->dist_sq = dist_sq;
    hit->index = index;
  }
}
 
BMFace *BKE_bmbvh_find_face_closest(const BMBVHTree *bmtree,
                                    const float co[3],
                                    const float dist_max)
{
  BVHTreeNearest hit;
  FaceSearchUserData bmcb_data;
  const float dist_max_sq = dist_max * dist_max;
 
  if (bmtree->cos_cage) {
    BLI_assert(!(bmtree->bm->elem_index_dirty & BM_VERT));
  }
 
  hit.dist_sq = dist_max_sq;
  hit.index = -1;
 
  bmcb_data.looptris = bmtree->looptris;
  bmcb_data.cos_cage = bmtree->cos_cage;
  bmcb_data.dist_max_sq = dist_max_sq;
 
  BLI_bvhtree_find_nearest(bmtree->tree, co, &hit, bmbvh_find_face_closest_cb, &bmcb_data);
  if (hit.index != -1) {
    const std::array<BMLoop *, 3> &ltri = bmtree->looptris[hit.index];
    return ltri[0]->f;
  }
 
  return nullptr;
}
 
/* -------------------------------------------------------------------- */
/* BKE_bmbvh_overlap */
 
struct BMBVHTree_OverlapData {
  const BMBVHTree *tree_pair[2];
  float epsilon;
};
 
static bool bmbvh_overlap_cb(void *userdata, int index_a, int index_b, int /*thread*/)
{
  BMBVHTree_OverlapData *data = static_cast<BMBVHTree_OverlapData *>(userdata);
  const BMBVHTree *bmtree_a = data->tree_pair[0];
  const BMBVHTree *bmtree_b = data->tree_pair[1];
 
  const std::array<BMLoop *, 3> &ltri_a = bmtree_a->looptris[index_a];
  const std::array<BMLoop *, 3> &ltri_b = bmtree_b->looptris[index_b];
  const float *tri_a_co[3] = {ltri_a[0]->v->co, ltri_a[1]->v->co, ltri_a[2]->v->co};
  const float *tri_b_co[3] = {ltri_b[0]->v->co, ltri_b[1]->v->co, ltri_b[2]->v->co};
  float ix_pair[2][3];
  int verts_shared = 0;
 
  if (bmtree_a->looptris == bmtree_b->looptris) {
    if (UNLIKELY(ltri_a[0]->f == ltri_b[0]->f)) {
      return false;
    }
 
    verts_shared = (ELEM(tri_a_co[0], UNPACK3(tri_b_co)) + ELEM(tri_a_co[1], UNPACK3(tri_b_co)) +
                    ELEM(tri_a_co[2], UNPACK3(tri_b_co)));
 
    /* if 2 points are shared, bail out */
    if (verts_shared >= 2) {
      return false;
    }
  }
 
  return (isect_tri_tri_v3(UNPACK3(tri_a_co), UNPACK3(tri_b_co), ix_pair[0], ix_pair[1]) &&
          /* if we share a vertex, check the intersection isn't a 'point' */
          ((verts_shared == 0) || (len_squared_v3v3(ix_pair[0], ix_pair[1]) > data->epsilon)));
}
 
BVHTreeOverlap *BKE_bmbvh_overlap(const BMBVHTree *bmtree_a,
                                  const BMBVHTree *bmtree_b,
                                  uint *r_overlap_tot)
{
  BMBVHTree_OverlapData data;
 
  data.tree_pair[0] = bmtree_a;
  data.tree_pair[1] = bmtree_b;
  data.epsilon = max_ff(BLI_bvhtree_get_epsilon(bmtree_a->tree),
                        BLI_bvhtree_get_epsilon(bmtree_b->tree));
 
  return BLI_bvhtree_overlap(
      bmtree_a->tree, bmtree_b->tree, r_overlap_tot, bmbvh_overlap_cb, &data);
}
 
static bool bmbvh_overlap_self_cb(void *userdata, int index_a, int index_b, int thread)
{
  if (index_a < index_b) {
    return bmbvh_overlap_cb(userdata, index_a, index_b, thread);
  }
  return false;
}
 
BVHTreeOverlap *BKE_bmbvh_overlap_self(const BMBVHTree *bmtree, uint *r_overlap_tot)
{
  BMBVHTree_OverlapData data;
 
  data.tree_pair[0] = bmtree;
  data.tree_pair[1] = bmtree;
  data.epsilon = BLI_bvhtree_get_epsilon(bmtree->tree);
 
  return BLI_bvhtree_overlap(
      bmtree->tree, bmtree->tree, r_overlap_tot, bmbvh_overlap_self_cb, &data);
}