/*
 * 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.
 */

#pragma once

/** \file
 * \ingroup bke
 * \brief A BVH for high poly meshes.
 */

#include "BLI_bitmap.h"
#include "BLI_ghash.h"

/* For embedding CCGKey in iterator. */
#include "BKE_ccg.h"

#ifdef __cplusplus
extern "C" {
#endif

struct BMLog;
struct BMesh;
struct CCGElem;
struct CCGKey;
struct CustomData;
struct DMFlagMat;
struct GPU_PBVH_Buffers;
struct IsectRayPrecalc;
struct MLoop;
struct MLoopTri;
struct MPoly;
struct MVert;
struct Mesh;
struct PBVH;
struct PBVHNode;
struct SubdivCCG;
struct TaskParallelSettings;

typedef struct PBVH PBVH;
typedef struct PBVHNode PBVHNode;

typedef struct {
  float (*co)[3];
} PBVHProxyNode;

typedef struct {
  float (*color)[4];
} PBVHColorBufferNode;

typedef enum {
  PBVH_Leaf = 1 << 0,

  PBVH_UpdateNormals = 1 << 1,
  PBVH_UpdateBB = 1 << 2,
  PBVH_UpdateOriginalBB = 1 << 3,
  PBVH_UpdateDrawBuffers = 1 << 4,
  PBVH_UpdateRedraw = 1 << 5,
  PBVH_UpdateMask = 1 << 6,
  PBVH_UpdateVisibility = 1 << 8,

  PBVH_RebuildDrawBuffers = 1 << 9,
  PBVH_FullyHidden = 1 << 10,
  PBVH_FullyMasked = 1 << 11,
  PBVH_FullyUnmasked = 1 << 12,

  PBVH_UpdateTopology = 1 << 13,
  PBVH_UpdateColor = 1 << 14,
} PBVHNodeFlags;

typedef struct PBVHFrustumPlanes {
  float (*planes)[4];
  int num_planes;
} PBVHFrustumPlanes;

void BKE_pbvh_set_frustum_planes(PBVH *pbvh, PBVHFrustumPlanes *planes);
void BKE_pbvh_get_frustum_planes(PBVH *pbvh, PBVHFrustumPlanes *planes);

/* Callbacks */

/**
 * Returns true if the search should continue from this node, false otherwise.
 */
typedef bool (*BKE_pbvh_SearchCallback)(PBVHNode *node, void *data);

typedef void (*BKE_pbvh_HitCallback)(PBVHNode *node, void *data);
typedef void (*BKE_pbvh_HitOccludedCallback)(PBVHNode *node, void *data, float *tmin);

typedef void (*BKE_pbvh_SearchNearestCallback)(PBVHNode *node, void *data, float *tmin);

/* Building */

PBVH *BKE_pbvh_new(void);
/**
 * Do a full rebuild with on Mesh data structure.
 *
 * \note Unlike mpoly/mloop/verts, looptri is *totally owned* by PBVH
 * (which means it may rewrite it if needed, see #BKE_pbvh_vert_coords_apply().
 */
void BKE_pbvh_build_mesh(PBVH *pbvh,
                         struct Mesh *mesh,
                         const struct MPoly *mpoly,
                         const struct MLoop *mloop,
                         struct MVert *verts,
                         int totvert,
                         struct CustomData *vdata,
                         struct CustomData *ldata,
                         struct CustomData *pdata,
                         const struct MLoopTri *looptri,
                         int looptri_num);
/**
 * Do a full rebuild with on Grids data structure.
 */
void BKE_pbvh_build_grids(PBVH *pbvh,
                          struct CCGElem **grids,
                          int totgrid,
                          struct CCGKey *key,
                          void **gridfaces,
                          struct DMFlagMat *flagmats,
                          unsigned int **grid_hidden);
/**
 * Build a PBVH from a BMesh.
 */
void BKE_pbvh_build_bmesh(PBVH *pbvh,
                          struct BMesh *bm,
                          bool smooth_shading,
                          struct BMLog *log,
                          int cd_vert_node_offset,
                          int cd_face_node_offset);
void BKE_pbvh_free(PBVH *pbvh);

/* Hierarchical Search in the BVH, two methods:
 * - For each hit calling a callback.
 * - Gather nodes in an array (easy to multi-thread). */

void BKE_pbvh_search_callback(PBVH *pbvh,
                              BKE_pbvh_SearchCallback scb,
                              void *search_data,
                              BKE_pbvh_HitCallback hcb,
                              void *hit_data);

void BKE_pbvh_search_gather(
    PBVH *pbvh, BKE_pbvh_SearchCallback scb, void *search_data, PBVHNode ***array, int *tot);

/* Ray-cast
 * the hit callback is called for all leaf nodes intersecting the ray;
 * it's up to the callback to find the primitive within the leaves that is
 * hit first */

void BKE_pbvh_raycast(PBVH *pbvh,
                      BKE_pbvh_HitOccludedCallback cb,
                      void *data,
                      const float ray_start[3],
                      const float ray_normal[3],
                      bool original);

bool BKE_pbvh_node_raycast(PBVH *pbvh,
                           PBVHNode *node,
                           float (*origco)[3],
                           bool use_origco,
                           const float ray_start[3],
                           const float ray_normal[3],
                           struct IsectRayPrecalc *isect_precalc,
                           float *depth,
                           int *active_vertex_index,
                           int *active_face_grid_index,
                           float *face_normal);

bool BKE_pbvh_bmesh_node_raycast_detail(PBVHNode *node,
                                        const float ray_start[3],
                                        struct IsectRayPrecalc *isect_precalc,
                                        float *depth,
                                        float *r_edge_length);

/**
 * For orthographic cameras, project the far away ray segment points to the root node so
 * we can have better precision.
 */
void BKE_pbvh_raycast_project_ray_root(
    PBVH *pbvh, bool original, float ray_start[3], float ray_end[3], float ray_normal[3]);

void BKE_pbvh_find_nearest_to_ray(PBVH *pbvh,
                                  BKE_pbvh_HitOccludedCallback cb,
                                  void *data,
                                  const float ray_start[3],
                                  const float ray_normal[3],
                                  bool original);

bool BKE_pbvh_node_find_nearest_to_ray(PBVH *pbvh,
                                       PBVHNode *node,
                                       float (*origco)[3],
                                       bool use_origco,
                                       const float ray_start[3],
                                       const float ray_normal[3],
                                       float *depth,
                                       float *dist_sq);

/* Drawing */

void BKE_pbvh_draw_cb(PBVH *pbvh,
                      bool update_only_visible,
                      PBVHFrustumPlanes *update_frustum,
                      PBVHFrustumPlanes *draw_frustum,
                      void (*draw_fn)(void *user_data, struct GPU_PBVH_Buffers *buffers),
                      void *user_data);

void BKE_pbvh_draw_debug_cb(
    PBVH *pbvh,
    void (*draw_fn)(void *user_data, const float bmin[3], const float bmax[3], PBVHNodeFlags flag),
    void *user_data);

/* PBVH Access */
typedef enum {
  PBVH_FACES,
  PBVH_GRIDS,
  PBVH_BMESH,
} PBVHType;

PBVHType BKE_pbvh_type(const PBVH *pbvh);
bool BKE_pbvh_has_faces(const PBVH *pbvh);

/**
 * Get the PBVH root's bounding box.
 */
void BKE_pbvh_bounding_box(const PBVH *pbvh, float min[3], float max[3]);

/**
 * Multi-res hidden data, only valid for type == PBVH_GRIDS.
 */
unsigned int **BKE_pbvh_grid_hidden(const PBVH *pbvh);

/**
 * Returns the number of visible quads in the nodes' grids.
 */
int BKE_pbvh_count_grid_quads(BLI_bitmap **grid_hidden,
                              const int *grid_indices,
                              int totgrid,
                              int gridsize);

void BKE_pbvh_sync_face_sets_to_grids(PBVH *pbvh);

/**
 * Multi-res level, only valid for type == #PBVH_GRIDS.
 */
const struct CCGKey *BKE_pbvh_get_grid_key(const PBVH *pbvh);

struct CCGElem **BKE_pbvh_get_grids(const PBVH *pbvh);
BLI_bitmap **BKE_pbvh_get_grid_visibility(const PBVH *pbvh);
int BKE_pbvh_get_grid_num_vertices(const PBVH *pbvh);
int BKE_pbvh_get_grid_num_faces(const PBVH *pbvh);

/**
 * Only valid for type == #PBVH_BMESH.
 */
struct BMesh *BKE_pbvh_get_bmesh(PBVH *pbvh);
void BKE_pbvh_bmesh_detail_size_set(PBVH *pbvh, float detail_size);

typedef enum {
  PBVH_Subdivide = 1,
  PBVH_Collapse = 2,
} PBVHTopologyUpdateMode;
/**
 * Collapse short edges, subdivide long edges.
 */
bool BKE_pbvh_bmesh_update_topology(PBVH *pbvh,
                                    PBVHTopologyUpdateMode mode,
                                    const float center[3],
                                    const float view_normal[3],
                                    float radius,
                                    bool use_frontface,
                                    bool use_projected);

/* Node Access */

void BKE_pbvh_node_mark_update(PBVHNode *node);
void BKE_pbvh_node_mark_update_mask(PBVHNode *node);
void BKE_pbvh_node_mark_update_color(PBVHNode *node);
void BKE_pbvh_node_mark_update_visibility(PBVHNode *node);
void BKE_pbvh_node_mark_rebuild_draw(PBVHNode *node);
void BKE_pbvh_node_mark_redraw(PBVHNode *node);
void BKE_pbvh_node_mark_normals_update(PBVHNode *node);
void BKE_pbvh_node_mark_topology_update(PBVHNode *node);
void BKE_pbvh_node_fully_hidden_set(PBVHNode *node, int fully_hidden);
bool BKE_pbvh_node_fully_hidden_get(PBVHNode *node);
void BKE_pbvh_node_fully_masked_set(PBVHNode *node, int fully_masked);
bool BKE_pbvh_node_fully_masked_get(PBVHNode *node);
void BKE_pbvh_node_fully_unmasked_set(PBVHNode *node, int fully_masked);
bool BKE_pbvh_node_fully_unmasked_get(PBVHNode *node);

void BKE_pbvh_node_get_grids(PBVH *pbvh,
                             PBVHNode *node,
                             int **grid_indices,
                             int *totgrid,
                             int *maxgrid,
                             int *gridsize,
                             struct CCGElem ***r_griddata);
void BKE_pbvh_node_num_verts(PBVH *pbvh, PBVHNode *node, int *r_uniquevert, int *r_totvert);
void BKE_pbvh_node_get_verts(PBVH *pbvh,
                             PBVHNode *node,
                             const int **r_vert_indices,
                             struct MVert **r_verts);

void BKE_pbvh_node_get_BB(PBVHNode *node, float bb_min[3], float bb_max[3]);
void BKE_pbvh_node_get_original_BB(PBVHNode *node, float bb_min[3], float bb_max[3]);

float BKE_pbvh_node_get_tmin(PBVHNode *node);

/**
 * Test if AABB is at least partially inside the #PBVHFrustumPlanes volume.
 */
bool BKE_pbvh_node_frustum_contain_AABB(PBVHNode *node, void *frustum);
/**
 * Test if AABB is at least partially outside the #PBVHFrustumPlanes volume.
 */
bool BKE_pbvh_node_frustum_exclude_AABB(PBVHNode *node, void *frustum);

struct GSet *BKE_pbvh_bmesh_node_unique_verts(PBVHNode *node);
struct GSet *BKE_pbvh_bmesh_node_other_verts(PBVHNode *node);
struct GSet *BKE_pbvh_bmesh_node_faces(PBVHNode *node);
/**
 * In order to perform operations on the original node coordinates
 * (currently just ray-cast), store the node's triangles and vertices.
 *
 * Skips triangles that are hidden.
 */
void BKE_pbvh_bmesh_node_save_orig(struct BMesh *bm, PBVHNode *node);
void BKE_pbvh_bmesh_after_stroke(PBVH *pbvh);

/* Update Bounding Box/Redraw and clear flags. */

void BKE_pbvh_update_bounds(PBVH *pbvh, int flags);
void BKE_pbvh_update_vertex_data(PBVH *pbvh, int flags);
void BKE_pbvh_update_visibility(PBVH *pbvh);
void BKE_pbvh_update_normals(PBVH *pbvh, struct SubdivCCG *subdiv_ccg);
void BKE_pbvh_redraw_BB(PBVH *pbvh, float bb_min[3], float bb_max[3]);
void BKE_pbvh_get_grid_updates(PBVH *pbvh, bool clear, void ***r_gridfaces, int *r_totface);
void BKE_pbvh_grids_update(PBVH *pbvh,
                           struct CCGElem **grids,
                           void **gridfaces,
                           struct DMFlagMat *flagmats,
                           unsigned int **grid_hidden);
void BKE_pbvh_subdiv_cgg_set(PBVH *pbvh, struct SubdivCCG *subdiv_ccg);
void BKE_pbvh_face_sets_set(PBVH *pbvh, int *face_sets);

void BKE_pbvh_face_sets_color_set(PBVH *pbvh, int seed, int color_default);

void BKE_pbvh_respect_hide_set(PBVH *pbvh, bool respect_hide);

/* Vertex Deformer. */

float (*BKE_pbvh_vert_coords_alloc(struct PBVH *pbvh))[3];
void BKE_pbvh_vert_coords_apply(struct PBVH *pbvh, const float (*vertCos)[3], int totvert);
bool BKE_pbvh_is_deformed(struct PBVH *pbvh);

/* Vertex Iterator. */

/* This iterator has quite a lot of code, but it's designed to:
 * - allow the compiler to eliminate dead code and variables
 * - spend most of the time in the relatively simple inner loop */

/* NOTE: PBVH_ITER_ALL does not skip hidden vertices,
 * PBVH_ITER_UNIQUE does */
#define PBVH_ITER_ALL 0
#define PBVH_ITER_UNIQUE 1

typedef struct PBVHVertexIter {
  /* iteration */
  int g;
  int width;
  int height;
  int gx;
  int gy;
  int i;
  int index;
  bool respect_hide;

  /* grid */
  struct CCGKey key;
  struct CCGElem **grids;
  struct CCGElem *grid;
  BLI_bitmap **grid_hidden, *gh;
  int *grid_indices;
  int totgrid;
  int gridsize;

  /* mesh */
  struct MVert *mverts;
  float (*vert_normals)[3];
  int totvert;
  const int *vert_indices;
  struct MPropCol *vcol;
  float *vmask;

  /* bmesh */
  struct GSetIterator bm_unique_verts;
  struct GSetIterator bm_other_verts;
  struct CustomData *bm_vdata;
  int cd_vert_mask_offset;

  /* result: these are all computed in the macro, but we assume
   * that compiler optimization's will skip the ones we don't use */
  struct MVert *mvert;
  struct BMVert *bm_vert;
  float *co;
  float *no;
  float *fno;
  float *mask;
  float *col;
  bool visible;
} PBVHVertexIter;

void pbvh_vertex_iter_init(PBVH *pbvh, PBVHNode *node, PBVHVertexIter *vi, int mode);

#define BKE_pbvh_vertex_iter_begin(pbvh, node, vi, mode) \
  pbvh_vertex_iter_init(pbvh, node, &vi, mode); \
\
  for (vi.i = 0, vi.g = 0; vi.g < vi.totgrid; vi.g++) { \
    if (vi.grids) { \
      vi.width = vi.gridsize; \
      vi.height = vi.gridsize; \
      vi.index = vi.grid_indices[vi.g] * vi.key.grid_area - 1; \
      vi.grid = vi.grids[vi.grid_indices[vi.g]]; \
      if (mode == PBVH_ITER_UNIQUE) { \
        vi.gh = vi.grid_hidden[vi.grid_indices[vi.g]]; \
      } \
    } \
    else { \
      vi.width = vi.totvert; \
      vi.height = 1; \
    } \
\
    for (vi.gy = 0; vi.gy < vi.height; vi.gy++) { \
      for (vi.gx = 0; vi.gx < vi.width; vi.gx++, vi.i++) { \
        if (vi.grid) { \
          vi.co = CCG_elem_co(&vi.key, vi.grid); \
          vi.fno = CCG_elem_no(&vi.key, vi.grid); \
          vi.mask = vi.key.has_mask ? CCG_elem_mask(&vi.key, vi.grid) : NULL; \
          vi.grid = CCG_elem_next(&vi.key, vi.grid); \
          vi.index++; \
          vi.visible = true; \
          if (vi.gh) { \
            if (BLI_BITMAP_TEST(vi.gh, vi.gy * vi.gridsize + vi.gx)) { \
              continue; \
            } \
          } \
        } \
        else if (vi.mverts) { \
          vi.mvert = &vi.mverts[vi.vert_indices[vi.gx]]; \
          if (vi.respect_hide) { \
            vi.visible = !(vi.mvert->flag & ME_HIDE); \
            if (mode == PBVH_ITER_UNIQUE && !vi.visible) { \
              continue; \
            } \
          } \
          else { \
            BLI_assert(vi.visible); \
          } \
          vi.co = vi.mvert->co; \
          vi.no = vi.vert_normals[vi.vert_indices[vi.gx]]; \
          vi.index = vi.vert_indices[vi.i]; \
          if (vi.vmask) { \
            vi.mask = &vi.vmask[vi.index]; \
          } \
          if (vi.vcol) { \
            vi.col = vi.vcol[vi.index].color; \
          } \
        } \
        else { \
          if (!BLI_gsetIterator_done(&vi.bm_unique_verts)) { \
            vi.bm_vert = BLI_gsetIterator_getKey(&vi.bm_unique_verts); \
            BLI_gsetIterator_step(&vi.bm_unique_verts); \
          } \
          else { \
            vi.bm_vert = BLI_gsetIterator_getKey(&vi.bm_other_verts); \
            BLI_gsetIterator_step(&vi.bm_other_verts); \
          } \
          vi.visible = !BM_elem_flag_test_bool(vi.bm_vert, BM_ELEM_HIDDEN); \
          if (mode == PBVH_ITER_UNIQUE && !vi.visible) { \
            continue; \
          } \
          vi.co = vi.bm_vert->co; \
          vi.fno = vi.bm_vert->no; \
          vi.index = BM_elem_index_get(vi.bm_vert); \
          vi.mask = BM_ELEM_CD_GET_VOID_P(vi.bm_vert, vi.cd_vert_mask_offset); \
        }

#define BKE_pbvh_vertex_iter_end \
  } \
  } \
  } \
  ((void)0)

void BKE_pbvh_node_get_proxies(PBVHNode *node, PBVHProxyNode **proxies, int *proxy_count);
void BKE_pbvh_node_free_proxies(PBVHNode *node);
PBVHProxyNode *BKE_pbvh_node_add_proxy(PBVH *pbvh, PBVHNode *node);
void BKE_pbvh_gather_proxies(PBVH *pbvh, PBVHNode ***r_array, int *r_tot);
void BKE_pbvh_node_get_bm_orco_data(PBVHNode *node,
                                    int (**r_orco_tris)[3],
                                    int *r_orco_tris_num,
                                    float (**r_orco_coords)[3]);

/**
 * \note doing a full search on all vertices here seems expensive,
 * however this is important to avoid having to recalculate bound-box & sync the buffers to the
 * GPU (which is far more expensive!) See: T47232.
 */
bool BKE_pbvh_node_vert_update_check_any(PBVH *pbvh, PBVHNode *node);

// void BKE_pbvh_node_BB_reset(PBVHNode *node);
// void BKE_pbvh_node_BB_expand(PBVHNode *node, float co[3]);

bool pbvh_has_mask(const PBVH *pbvh);
void pbvh_show_mask_set(PBVH *pbvh, bool show_mask);

bool pbvh_has_face_sets(PBVH *pbvh);
void pbvh_show_face_sets_set(PBVH *pbvh, bool show_face_sets);

/* Parallelization. */

void BKE_pbvh_parallel_range_settings(struct TaskParallelSettings *settings,
                                      bool use_threading,
                                      int totnode);

struct MVert *BKE_pbvh_get_verts(const PBVH *pbvh);
const float (*BKE_pbvh_get_vert_normals(const PBVH *pbvh))[3];

PBVHColorBufferNode *BKE_pbvh_node_color_buffer_get(PBVHNode *node);
void BKE_pbvh_node_color_buffer_free(PBVH *pbvh);

#ifdef __cplusplus
}
#endif