BKE_subdiv_ccg.hh

Go to the documentation of this file.

/* SPDX-FileCopyrightText: 2018 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

 
#pragma once
 
#include <memory>
 
#include "BLI_array.hh"
#include "BLI_bit_group_vector.hh"
#include "BLI_bit_span_ops.hh"
#include "BLI_index_mask_fwd.hh"
#include "BLI_offset_indices.hh"
#include "BLI_span.hh"
#include "BLI_utility_mixins.hh"
#include "BLI_vector.hh"
 
#include "BKE_ccg.hh"
 
struct Mesh;
namespace blender::bke::subdiv {
struct Subdiv;
}
 
/* -------------------------------------------------------------------- */

struct SubdivCCGMaskEvaluator {
  float (*eval_mask)(SubdivCCGMaskEvaluator *mask_evaluator,
                     int ptex_face_index,
                     float u,
                     float v);

  void (*free)(SubdivCCGMaskEvaluator *mask_evaluator);
 
  void *user_data;
};

bool BKE_subdiv_ccg_mask_init_from_paint(SubdivCCGMaskEvaluator *mask_evaluator, const Mesh *mesh);

 
/* -------------------------------------------------------------------- */
 
struct SubdivToCCGSettings {
  int resolution;
  bool need_normal;
  bool need_mask;
};
 
struct SubdivCCGCoord {
  int grid_index;

  short x, y;

  static SubdivCCGCoord from_index(const CCGKey &key, int index)
  {
    const int grid_index = index / key.grid_area;
    const int index_in_grid = index - grid_index * key.grid_area;
 
    SubdivCCGCoord coord{};
    coord.grid_index = grid_index;
    coord.x = index_in_grid % key.grid_size;
    coord.y = index_in_grid / key.grid_size;
 
    return coord;
  }

  int to_index(const CCGKey &key) const
  {
    return key.grid_area * this->grid_index +
           CCG_grid_xy_to_index(key.grid_size, this->x, this->y);
  }
};

struct SubdivCCGAdjacentEdge {
  blender::Vector<blender::Array<SubdivCCGCoord>> boundary_coords;
};

struct SubdivCCGAdjacentVertex {
  blender::Vector<SubdivCCGCoord> corner_coords;
};

struct SubdivCCG : blender::NonCopyable {
  blender::bke::subdiv::Subdiv *subdiv = nullptr;
  int level = -1;
  int grid_size = -1;
  int grid_area = -1;
  int grids_num = -1;
  blender::Array<blender::float3> positions;
  blender::Array<blender::float3> normals;
  blender::Array<float> masks;

  blender::OffsetIndices<int> faces;
  blender::Span<int> grid_to_face_map;

  blender::Array<SubdivCCGAdjacentEdge> adjacent_edges;

  blender::Array<SubdivCCGAdjacentVertex> adjacent_verts;

  blender::BitGroupVector<> grid_hidden;
 
  /* TODO(sergey): Consider adding some accessors to a "decoded" geometry,
   * to make integration with draw manager and such easy.
   */
 
  /* TODO(sergey): Consider adding CD layers here, so we can draw final mesh
   * from grids, and have UVs and such work.
   */
 
  /* Integration with sculpting. */
  /* TODO(sergey): Is this really best way to go? Kind of annoying to have
   * such use-related flags in a more or less generic structure. */
  struct {
    bool coords = false;
    bool hidden = false;
  } dirty;
 
  ~SubdivCCG();
};

std::unique_ptr<SubdivCCG> BKE_subdiv_to_ccg(blender::bke::subdiv::Subdiv &subdiv,
                                             const SubdivToCCGSettings &settings,
                                             const Mesh &coarse_mesh,
                                             SubdivCCGMaskEvaluator *mask_evaluator = nullptr);

Mesh *BKE_subdiv_to_ccg_mesh(blender::bke::subdiv::Subdiv &subdiv,
                             const SubdivToCCGSettings &settings,
                             const Mesh &coarse_mesh);

CCGKey BKE_subdiv_ccg_key(const SubdivCCG &subdiv_ccg, int level);
CCGKey BKE_subdiv_ccg_key_top_level(const SubdivCCG &subdiv_ccg);

void BKE_subdiv_ccg_recalc_normals(SubdivCCG &subdiv_ccg);

void BKE_subdiv_ccg_update_normals(SubdivCCG &subdiv_ccg, const blender::IndexMask &face_mask);

void BKE_subdiv_ccg_average_grids(SubdivCCG &subdiv_ccg);

void BKE_subdiv_ccg_average_stitch_faces(SubdivCCG &subdiv_ccg,
                                         const blender::IndexMask &face_mask);

void BKE_subdiv_ccg_topology_counters(const SubdivCCG &subdiv_ccg,
                                      int &r_num_vertices,
                                      int &r_num_edges,
                                      int &r_num_faces,
                                      int &r_num_loops);
 
using SubdivCCGNeighborCoords = blender::Vector<SubdivCCGCoord, 256>;
struct SubdivCCGNeighbors {
  SubdivCCGNeighborCoords coords;
  int num_duplicates;
 
  blender::Span<SubdivCCGCoord> unique() const
  {
    return this->coords.as_span().drop_back(num_duplicates);
  }
 
  blender::Span<SubdivCCGCoord> duplicates() const
  {
    return this->coords.as_span().take_back(num_duplicates);
  }
};
 
void BKE_subdiv_ccg_print_coord(const char *message, const SubdivCCGCoord &coord);
bool BKE_subdiv_ccg_check_coord_valid(const SubdivCCG &subdiv_ccg, const SubdivCCGCoord &coord);
 
/* CCG element neighbors.
 *
 * Neighbors are considered:
 *
 * - For an inner elements of a grid other elements which are sharing same row or column (4
 *   neighbor elements in total).
 *
 * - For the corner element a single neighboring element on every adjacent edge, single from
 *   every grid.
 *
 * - For the boundary element two neighbor elements on the boundary (from same grid) and one
 *   element inside of every neighboring grid. */

void BKE_subdiv_ccg_neighbor_coords_get(const SubdivCCG &subdiv_ccg,
                                        const SubdivCCGCoord &coord,
                                        bool include_duplicates,
                                        SubdivCCGNeighbors &r_neighbors);
 
inline int BKE_subdiv_ccg_grid_to_face_index(const SubdivCCG &subdiv_ccg, const int grid_index)
{
  return subdiv_ccg.grid_to_face_map[grid_index];
}
 
void BKE_subdiv_ccg_eval_limit_positions(const SubdivCCG &subdiv_ccg,
                                         const CCGKey &key,
                                         int grid_index,
                                         blender::MutableSpan<blender::float3> r_limit_positions);
 
enum class SubdivCCGAdjacencyType : int8_t {
  None,
  Vertex,
  Edge,
};

SubdivCCGAdjacencyType BKE_subdiv_ccg_coarse_mesh_adjacency_info_get(
    const SubdivCCG &subdiv_ccg,
    const SubdivCCGCoord &coord,
    blender::Span<int> corner_verts,
    blender::OffsetIndices<int> faces,
    int &r_v1,
    int &r_v2);

bool BKE_subdiv_ccg_coord_is_mesh_boundary(blender::OffsetIndices<int> faces,
                                           blender::Span<int> corner_verts,
                                           blender::BitSpan boundary_verts,
                                           const SubdivCCG &subdiv_ccg,
                                           SubdivCCGCoord coord);
 
blender::BitGroupVector<> &BKE_subdiv_ccg_grid_hidden_ensure(SubdivCCG &subdiv_ccg);
void BKE_subdiv_ccg_grid_hidden_free(SubdivCCG &subdiv_ccg);
 
template<typename Fn>
inline void BKE_subdiv_ccg_foreach_visible_grid_vert(const CCGKey &key,
                                                     const blender::BitGroupVector<> &grid_hidden,
                                                     const int grid,
                                                     const Fn &fn)
{
  if (grid_hidden.is_empty()) {
    for (const int i : blender::IndexRange(key.grid_area)) {
      fn(i);
    }
  }
  else {
    blender::bits::foreach_0_index(grid_hidden[grid], fn);
  }
}
 
namespace blender::bke::ccg {

inline IndexRange grid_range(const int grid_area, const int grid)
{
  return IndexRange(grid * grid_area, grid_area);
}
inline IndexRange grid_range(const CCGKey &key, const int grid)
{
  return grid_range(key.grid_area, grid);
}

inline IndexRange face_range(const OffsetIndices<int> faces, const int grid_area, const int face)
{
  const IndexRange corners = faces[face];
  return IndexRange(corners.start() * grid_area, corners.size() * grid_area);
}
inline IndexRange face_range(const OffsetIndices<int> faces, const CCGKey &key, const int face)
{
  return face_range(faces, key.grid_area, face);
}

inline int grid_xy_to_vert(const CCGKey &key, const int grid, const int x, const int y)
{
  return key.grid_area * grid + CCG_grid_xy_to_index(key.grid_size, x, y);
}
 
}  // namespace blender::bke::ccg