/*
 * 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.
 *
 * The Original Code is Copyright (C) 2009 by Nicholas Bishop
 * All rights reserved.
 */

/** \file
 * \ingroup bke
 */

#include <stdlib.h>
#include <string.h>

#include "MEM_guardedalloc.h"

#include "DNA_brush_types.h"
#include "DNA_gpencil_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_modifier_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"
#include "DNA_space_types.h"
#include "DNA_view3d_types.h"
#include "DNA_workspace_types.h"

#include "BLI_bitmap.h"
#include "BLI_hash.h"
#include "BLI_listbase.h"
#include "BLI_math_vector.h"
#include "BLI_utildefines.h"

#include "BLT_translation.h"

#include "BKE_brush.h"
#include "BKE_ccg.h"
#include "BKE_colortools.h"
#include "BKE_context.h"
#include "BKE_crazyspace.h"
#include "BKE_deform.h"
#include "BKE_gpencil.h"
#include "BKE_idtype.h"
#include "BKE_image.h"
#include "BKE_key.h"
#include "BKE_lib_id.h"
#include "BKE_main.h"
#include "BKE_mesh.h"
#include "BKE_mesh_mapping.h"
#include "BKE_mesh_runtime.h"
#include "BKE_modifier.h"
#include "BKE_multires.h"
#include "BKE_object.h"
#include "BKE_paint.h"
#include "BKE_pbvh.h"
#include "BKE_subdiv_ccg.h"
#include "BKE_subsurf.h"

#include "DEG_depsgraph.h"
#include "DEG_depsgraph_query.h"

#include "RNA_enum_types.h"

#include "BLO_read_write.h"

#include "bmesh.h"

static void palette_init_data(ID *id)
{
  Palette *palette = (Palette *)id;

  BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(palette, id));

  /* Enable fake user by default. */
  id_fake_user_set(&palette->id);
}

static void palette_copy_data(Main *UNUSED(bmain),
                              ID *id_dst,
                              const ID *id_src,
                              const int UNUSED(flag))
{
  Palette *palette_dst = (Palette *)id_dst;
  const Palette *palette_src = (const Palette *)id_src;

  BLI_duplicatelist(&palette_dst->colors, &palette_src->colors);
}

static void palette_free_data(ID *id)
{
  Palette *palette = (Palette *)id;

  BLI_freelistN(&palette->colors);
}

static void palette_blend_write(BlendWriter *writer, ID *id, const void *id_address)
{
  Palette *palette = (Palette *)id;

  PaletteColor *color;
  BLO_write_id_struct(writer, Palette, id_address, &palette->id);
  BKE_id_blend_write(writer, &palette->id);

  for (color = palette->colors.first; color; color = color->next) {
    BLO_write_struct(writer, PaletteColor, color);
  }
}

static void palette_blend_read_data(BlendDataReader *reader, ID *id)
{
  Palette *palette = (Palette *)id;
  BLO_read_list(reader, &palette->colors);
}

static void palette_undo_preserve(BlendLibReader *UNUSED(reader), ID *id_new, ID *id_old)
{
  /* Whole Palette is preserved across undo-steps, and it has no extra pointer, simple. */
  /* NOTE: We do not care about potential internal references to self here, Palette has none. */
  /* NOTE: We do not swap IDProperties, as dealing with potential ID pointers in those would be
   *       fairly delicate. */
  BKE_lib_id_swap(NULL, id_new, id_old);
  SWAP(IDProperty *, id_new->properties, id_old->properties);
}

IDTypeInfo IDType_ID_PAL = {
    .id_code = ID_PAL,
    .id_filter = FILTER_ID_PAL,
    .main_listbase_index = INDEX_ID_PAL,
    .struct_size = sizeof(Palette),
    .name = "Palette",
    .name_plural = "palettes",
    .translation_context = BLT_I18NCONTEXT_ID_PALETTE,
    .flags = IDTYPE_FLAGS_NO_ANIMDATA,
    .asset_type_info = NULL,

    .init_data = palette_init_data,
    .copy_data = palette_copy_data,
    .free_data = palette_free_data,
    .make_local = NULL,
    .foreach_id = NULL,
    .foreach_cache = NULL,
    .foreach_path = NULL,
    .owner_get = NULL,

    .blend_write = palette_blend_write,
    .blend_read_data = palette_blend_read_data,
    .blend_read_lib = NULL,
    .blend_read_expand = NULL,

    .blend_read_undo_preserve = palette_undo_preserve,

    .lib_override_apply_post = NULL,
};

static void paint_curve_copy_data(Main *UNUSED(bmain),
                                  ID *id_dst,
                                  const ID *id_src,
                                  const int UNUSED(flag))
{
  PaintCurve *paint_curve_dst = (PaintCurve *)id_dst;
  const PaintCurve *paint_curve_src = (const PaintCurve *)id_src;

  if (paint_curve_src->tot_points != 0) {
    paint_curve_dst->points = MEM_dupallocN(paint_curve_src->points);
  }
}

static void paint_curve_free_data(ID *id)
{
  PaintCurve *paint_curve = (PaintCurve *)id;

  MEM_SAFE_FREE(paint_curve->points);
  paint_curve->tot_points = 0;
}

static void paint_curve_blend_write(BlendWriter *writer, ID *id, const void *id_address)
{
  PaintCurve *pc = (PaintCurve *)id;

  BLO_write_id_struct(writer, PaintCurve, id_address, &pc->id);
  BKE_id_blend_write(writer, &pc->id);

  BLO_write_struct_array(writer, PaintCurvePoint, pc->tot_points, pc->points);
}

static void paint_curve_blend_read_data(BlendDataReader *reader, ID *id)
{
  PaintCurve *pc = (PaintCurve *)id;
  BLO_read_data_address(reader, &pc->points);
}

IDTypeInfo IDType_ID_PC = {
    .id_code = ID_PC,
    .id_filter = FILTER_ID_PC,
    .main_listbase_index = INDEX_ID_PC,
    .struct_size = sizeof(PaintCurve),
    .name = "PaintCurve",
    .name_plural = "paint_curves",
    .translation_context = BLT_I18NCONTEXT_ID_PAINTCURVE,
    .flags = IDTYPE_FLAGS_NO_ANIMDATA,
    .asset_type_info = NULL,

    .init_data = NULL,
    .copy_data = paint_curve_copy_data,
    .free_data = paint_curve_free_data,
    .make_local = NULL,
    .foreach_id = NULL,
    .foreach_cache = NULL,
    .foreach_path = NULL,
    .owner_get = NULL,

    .blend_write = paint_curve_blend_write,
    .blend_read_data = paint_curve_blend_read_data,
    .blend_read_lib = NULL,
    .blend_read_expand = NULL,

    .blend_read_undo_preserve = NULL,

    .lib_override_apply_post = NULL,
};

const char PAINT_CURSOR_SCULPT[3] = {255, 100, 100};
const char PAINT_CURSOR_VERTEX_PAINT[3] = {255, 255, 255};
const char PAINT_CURSOR_WEIGHT_PAINT[3] = {200, 200, 255};
const char PAINT_CURSOR_TEXTURE_PAINT[3] = {255, 255, 255};

static ePaintOverlayControlFlags overlay_flags = 0;

void BKE_paint_invalidate_overlay_tex(Scene *scene, ViewLayer *view_layer, const Tex *tex)
{
  Paint *p = BKE_paint_get_active(scene, view_layer);
  if (!p) {
    return;
  }

  Brush *br = p->brush;
  if (!br) {
    return;
  }

  if (br->mtex.tex == tex) {
    overlay_flags |= PAINT_OVERLAY_INVALID_TEXTURE_PRIMARY;
  }
  if (br->mask_mtex.tex == tex) {
    overlay_flags |= PAINT_OVERLAY_INVALID_TEXTURE_SECONDARY;
  }
}

void BKE_paint_invalidate_cursor_overlay(Scene *scene, ViewLayer *view_layer, CurveMapping *curve)
{
  Paint *p = BKE_paint_get_active(scene, view_layer);
  if (p == NULL) {
    return;
  }

  Brush *br = p->brush;
  if (br && br->curve == curve) {
    overlay_flags |= PAINT_OVERLAY_INVALID_CURVE;
  }
}

void BKE_paint_invalidate_overlay_all(void)
{
  overlay_flags |= (PAINT_OVERLAY_INVALID_TEXTURE_SECONDARY |
                    PAINT_OVERLAY_INVALID_TEXTURE_PRIMARY | PAINT_OVERLAY_INVALID_CURVE);
}

ePaintOverlayControlFlags BKE_paint_get_overlay_flags(void)
{
  return overlay_flags;
}

void BKE_paint_set_overlay_override(eOverlayFlags flags)
{
  if (flags & BRUSH_OVERLAY_OVERRIDE_MASK) {
    if (flags & BRUSH_OVERLAY_CURSOR_OVERRIDE_ON_STROKE) {
      overlay_flags |= PAINT_OVERLAY_OVERRIDE_CURSOR;
    }
    if (flags & BRUSH_OVERLAY_PRIMARY_OVERRIDE_ON_STROKE) {
      overlay_flags |= PAINT_OVERLAY_OVERRIDE_PRIMARY;
    }
    if (flags & BRUSH_OVERLAY_SECONDARY_OVERRIDE_ON_STROKE) {
      overlay_flags |= PAINT_OVERLAY_OVERRIDE_SECONDARY;
    }
  }
  else {
    overlay_flags &= ~(PAINT_OVERRIDE_MASK);
  }
}

void BKE_paint_reset_overlay_invalid(ePaintOverlayControlFlags flag)
{
  overlay_flags &= ~(flag);
}

bool BKE_paint_ensure_from_paintmode(Scene *sce, ePaintMode mode)
{
  ToolSettings *ts = sce->toolsettings;
  Paint **paint_ptr = NULL;
  /* Some paint modes don't store paint settings as pointer, for these this can be set and
   * referenced by paint_ptr. */
  Paint *paint_tmp = NULL;

  switch (mode) {
    case PAINT_MODE_SCULPT:
      paint_ptr = (Paint **)&ts->sculpt;
      break;
    case PAINT_MODE_VERTEX:
      paint_ptr = (Paint **)&ts->vpaint;
      break;
    case PAINT_MODE_WEIGHT:
      paint_ptr = (Paint **)&ts->wpaint;
      break;
    case PAINT_MODE_TEXTURE_2D:
    case PAINT_MODE_TEXTURE_3D:
      paint_tmp = (Paint *)&ts->imapaint;
      paint_ptr = &paint_tmp;
      break;
    case PAINT_MODE_SCULPT_UV:
      paint_ptr = (Paint **)&ts->uvsculpt;
      break;
    case PAINT_MODE_GPENCIL:
      paint_ptr = (Paint **)&ts->gp_paint;
      break;
    case PAINT_MODE_VERTEX_GPENCIL:
      paint_ptr = (Paint **)&ts->gp_vertexpaint;
      break;
    case PAINT_MODE_SCULPT_GPENCIL:
      paint_ptr = (Paint **)&ts->gp_sculptpaint;
      break;
    case PAINT_MODE_WEIGHT_GPENCIL:
      paint_ptr = (Paint **)&ts->gp_weightpaint;
      break;
    case PAINT_MODE_INVALID:
      break;
  }
  if (paint_ptr) {
    BKE_paint_ensure(ts, paint_ptr);
    return true;
  }
  return false;
}

Paint *BKE_paint_get_active_from_paintmode(Scene *sce, ePaintMode mode)
{
  if (sce) {
    ToolSettings *ts = sce->toolsettings;

    switch (mode) {
      case PAINT_MODE_SCULPT:
        return &ts->sculpt->paint;
      case PAINT_MODE_VERTEX:
        return &ts->vpaint->paint;
      case PAINT_MODE_WEIGHT:
        return &ts->wpaint->paint;
      case PAINT_MODE_TEXTURE_2D:
      case PAINT_MODE_TEXTURE_3D:
        return &ts->imapaint.paint;
      case PAINT_MODE_SCULPT_UV:
        return &ts->uvsculpt->paint;
      case PAINT_MODE_GPENCIL:
        return &ts->gp_paint->paint;
      case PAINT_MODE_VERTEX_GPENCIL:
        return &ts->gp_vertexpaint->paint;
      case PAINT_MODE_SCULPT_GPENCIL:
        return &ts->gp_sculptpaint->paint;
      case PAINT_MODE_WEIGHT_GPENCIL:
        return &ts->gp_weightpaint->paint;
      case PAINT_MODE_INVALID:
        return NULL;
      default:
        return &ts->imapaint.paint;
    }
  }

  return NULL;
}

const EnumPropertyItem *BKE_paint_get_tool_enum_from_paintmode(ePaintMode mode)
{
  switch (mode) {
    case PAINT_MODE_SCULPT:
      return rna_enum_brush_sculpt_tool_items;
    case PAINT_MODE_VERTEX:
      return rna_enum_brush_vertex_tool_items;
    case PAINT_MODE_WEIGHT:
      return rna_enum_brush_weight_tool_items;
    case PAINT_MODE_TEXTURE_2D:
    case PAINT_MODE_TEXTURE_3D:
      return rna_enum_brush_image_tool_items;
    case PAINT_MODE_SCULPT_UV:
      return rna_enum_brush_uv_sculpt_tool_items;
    case PAINT_MODE_GPENCIL:
      return rna_enum_brush_gpencil_types_items;
    case PAINT_MODE_VERTEX_GPENCIL:
      return rna_enum_brush_gpencil_vertex_types_items;
    case PAINT_MODE_SCULPT_GPENCIL:
      return rna_enum_brush_gpencil_sculpt_types_items;
    case PAINT_MODE_WEIGHT_GPENCIL:
      return rna_enum_brush_gpencil_weight_types_items;
    case PAINT_MODE_INVALID:
      break;
  }
  return NULL;
}

const char *BKE_paint_get_tool_prop_id_from_paintmode(ePaintMode mode)
{
  switch (mode) {
    case PAINT_MODE_SCULPT:
      return "sculpt_tool";
    case PAINT_MODE_VERTEX:
      return "vertex_tool";
    case PAINT_MODE_WEIGHT:
      return "weight_tool";
    case PAINT_MODE_TEXTURE_2D:
    case PAINT_MODE_TEXTURE_3D:
      return "image_tool";
    case PAINT_MODE_SCULPT_UV:
      return "uv_sculpt_tool";
    case PAINT_MODE_GPENCIL:
      return "gpencil_tool";
    case PAINT_MODE_VERTEX_GPENCIL:
      return "gpencil_vertex_tool";
    case PAINT_MODE_SCULPT_GPENCIL:
      return "gpencil_sculpt_tool";
    case PAINT_MODE_WEIGHT_GPENCIL:
      return "gpencil_weight_tool";
    case PAINT_MODE_INVALID:
      break;
  }

  /* Invalid paint mode. */
  return NULL;
}

Paint *BKE_paint_get_active(Scene *sce, ViewLayer *view_layer)
{
  if (sce && view_layer) {
    ToolSettings *ts = sce->toolsettings;

    if (view_layer->basact && view_layer->basact->object) {
      switch (view_layer->basact->object->mode) {
        case OB_MODE_SCULPT:
          return &ts->sculpt->paint;
        case OB_MODE_VERTEX_PAINT:
          return &ts->vpaint->paint;
        case OB_MODE_WEIGHT_PAINT:
          return &ts->wpaint->paint;
        case OB_MODE_TEXTURE_PAINT:
          return &ts->imapaint.paint;
        case OB_MODE_PAINT_GPENCIL:
          return &ts->gp_paint->paint;
        case OB_MODE_VERTEX_GPENCIL:
          return &ts->gp_vertexpaint->paint;
        case OB_MODE_SCULPT_GPENCIL:
          return &ts->gp_sculptpaint->paint;
        case OB_MODE_WEIGHT_GPENCIL:
          return &ts->gp_weightpaint->paint;
        case OB_MODE_EDIT:
          return ts->uvsculpt ? &ts->uvsculpt->paint : NULL;
        default:
          break;
      }
    }

    /* default to image paint */
    return &ts->imapaint.paint;
  }

  return NULL;
}

Paint *BKE_paint_get_active_from_context(const bContext *C)
{
  Scene *sce = CTX_data_scene(C);
  ViewLayer *view_layer = CTX_data_view_layer(C);
  SpaceImage *sima;

  if (sce && view_layer) {
    ToolSettings *ts = sce->toolsettings;
    Object *obact = NULL;

    if (view_layer->basact && view_layer->basact->object) {
      obact = view_layer->basact->object;
    }

    if ((sima = CTX_wm_space_image(C)) != NULL) {
      if (obact && obact->mode == OB_MODE_EDIT) {
        if (sima->mode == SI_MODE_PAINT) {
          return &ts->imapaint.paint;
        }
        if (sima->mode == SI_MODE_UV) {
          return &ts->uvsculpt->paint;
        }
      }
      else {
        return &ts->imapaint.paint;
      }
    }
    else {
      return BKE_paint_get_active(sce, view_layer);
    }
  }

  return NULL;
}

ePaintMode BKE_paintmode_get_active_from_context(const bContext *C)
{
  Scene *sce = CTX_data_scene(C);
  ViewLayer *view_layer = CTX_data_view_layer(C);
  SpaceImage *sima;

  if (sce && view_layer) {
    Object *obact = NULL;

    if (view_layer->basact && view_layer->basact->object) {
      obact = view_layer->basact->object;
    }

    if ((sima = CTX_wm_space_image(C)) != NULL) {
      if (obact && obact->mode == OB_MODE_EDIT) {
        if (sima->mode == SI_MODE_PAINT) {
          return PAINT_MODE_TEXTURE_2D;
        }
        if (sima->mode == SI_MODE_UV) {
          return PAINT_MODE_SCULPT_UV;
        }
      }
      else {
        return PAINT_MODE_TEXTURE_2D;
      }
    }
    else if (obact) {
      switch (obact->mode) {
        case OB_MODE_SCULPT:
          return PAINT_MODE_SCULPT;
        case OB_MODE_VERTEX_PAINT:
          return PAINT_MODE_VERTEX;
        case OB_MODE_WEIGHT_PAINT:
          return PAINT_MODE_WEIGHT;
        case OB_MODE_TEXTURE_PAINT:
          return PAINT_MODE_TEXTURE_3D;
        case OB_MODE_EDIT:
          return PAINT_MODE_SCULPT_UV;
        default:
          return PAINT_MODE_TEXTURE_2D;
      }
    }
    else {
      /* default to image paint */
      return PAINT_MODE_TEXTURE_2D;
    }
  }

  return PAINT_MODE_INVALID;
}

ePaintMode BKE_paintmode_get_from_tool(const struct bToolRef *tref)
{
  if (tref->space_type == SPACE_VIEW3D) {
    switch (tref->mode) {
      case CTX_MODE_SCULPT:
        return PAINT_MODE_SCULPT;
      case CTX_MODE_PAINT_VERTEX:
        return PAINT_MODE_VERTEX;
      case CTX_MODE_PAINT_WEIGHT:
        return PAINT_MODE_WEIGHT;
      case CTX_MODE_PAINT_GPENCIL:
        return PAINT_MODE_GPENCIL;
      case CTX_MODE_PAINT_TEXTURE:
        return PAINT_MODE_TEXTURE_3D;
      case CTX_MODE_VERTEX_GPENCIL:
        return PAINT_MODE_VERTEX_GPENCIL;
      case CTX_MODE_SCULPT_GPENCIL:
        return PAINT_MODE_SCULPT_GPENCIL;
      case CTX_MODE_WEIGHT_GPENCIL:
        return PAINT_MODE_WEIGHT_GPENCIL;
    }
  }
  else if (tref->space_type == SPACE_IMAGE) {
    switch (tref->mode) {
      case SI_MODE_PAINT:
        return PAINT_MODE_TEXTURE_2D;
      case SI_MODE_UV:
        return PAINT_MODE_SCULPT_UV;
    }
  }

  return PAINT_MODE_INVALID;
}

Brush *BKE_paint_brush(Paint *p)
{
  return p ? p->brush : NULL;
}

void BKE_paint_brush_set(Paint *p, Brush *br)
{
  if (p) {
    id_us_min((ID *)p->brush);
    id_us_plus((ID *)br);
    p->brush = br;

    BKE_paint_toolslots_brush_update(p);
  }
}

void BKE_paint_runtime_init(const ToolSettings *ts, Paint *paint)
{
  if (paint == &ts->imapaint.paint) {
    paint->runtime.tool_offset = offsetof(Brush, imagepaint_tool);
    paint->runtime.ob_mode = OB_MODE_TEXTURE_PAINT;
  }
  else if (ts->sculpt && paint == &ts->sculpt->paint) {
    paint->runtime.tool_offset = offsetof(Brush, sculpt_tool);
    paint->runtime.ob_mode = OB_MODE_SCULPT;
  }
  else if (ts->vpaint && paint == &ts->vpaint->paint) {
    paint->runtime.tool_offset = offsetof(Brush, vertexpaint_tool);
    paint->runtime.ob_mode = OB_MODE_VERTEX_PAINT;
  }
  else if (ts->wpaint && paint == &ts->wpaint->paint) {
    paint->runtime.tool_offset = offsetof(Brush, weightpaint_tool);
    paint->runtime.ob_mode = OB_MODE_WEIGHT_PAINT;
  }
  else if (ts->uvsculpt && paint == &ts->uvsculpt->paint) {
    paint->runtime.tool_offset = offsetof(Brush, uv_sculpt_tool);
    paint->runtime.ob_mode = OB_MODE_EDIT;
  }
  else if (ts->gp_paint && paint == &ts->gp_paint->paint) {
    paint->runtime.tool_offset = offsetof(Brush, gpencil_tool);
    paint->runtime.ob_mode = OB_MODE_PAINT_GPENCIL;
  }
  else if (ts->gp_vertexpaint && paint == &ts->gp_vertexpaint->paint) {
    paint->runtime.tool_offset = offsetof(Brush, gpencil_vertex_tool);
    paint->runtime.ob_mode = OB_MODE_VERTEX_GPENCIL;
  }
  else if (ts->gp_sculptpaint && paint == &ts->gp_sculptpaint->paint) {
    paint->runtime.tool_offset = offsetof(Brush, gpencil_sculpt_tool);
    paint->runtime.ob_mode = OB_MODE_SCULPT_GPENCIL;
  }
  else if (ts->gp_weightpaint && paint == &ts->gp_weightpaint->paint) {
    paint->runtime.tool_offset = offsetof(Brush, gpencil_weight_tool);
    paint->runtime.ob_mode = OB_MODE_WEIGHT_GPENCIL;
  }
  else {
    BLI_assert_unreachable();
  }
}

uint BKE_paint_get_brush_tool_offset_from_paintmode(const ePaintMode mode)
{
  switch (mode) {
    case PAINT_MODE_TEXTURE_2D:
    case PAINT_MODE_TEXTURE_3D:
      return offsetof(Brush, imagepaint_tool);
    case PAINT_MODE_SCULPT:
      return offsetof(Brush, sculpt_tool);
    case PAINT_MODE_VERTEX:
      return offsetof(Brush, vertexpaint_tool);
    case PAINT_MODE_WEIGHT:
      return offsetof(Brush, weightpaint_tool);
    case PAINT_MODE_SCULPT_UV:
      return offsetof(Brush, uv_sculpt_tool);
    case PAINT_MODE_GPENCIL:
      return offsetof(Brush, gpencil_tool);
    case PAINT_MODE_VERTEX_GPENCIL:
      return offsetof(Brush, gpencil_vertex_tool);
    case PAINT_MODE_SCULPT_GPENCIL:
      return offsetof(Brush, gpencil_sculpt_tool);
    case PAINT_MODE_WEIGHT_GPENCIL:
      return offsetof(Brush, gpencil_weight_tool);
    case PAINT_MODE_INVALID:
      break; /* We don't use these yet. */
  }
  return 0;
}

PaintCurve *BKE_paint_curve_add(Main *bmain, const char *name)
{
  PaintCurve *pc;

  pc = BKE_id_new(bmain, ID_PC, name);

  return pc;
}

Palette *BKE_paint_palette(Paint *p)
{
  return p ? p->palette : NULL;
}

void BKE_paint_palette_set(Paint *p, Palette *palette)
{
  if (p) {
    id_us_min((ID *)p->palette);
    p->palette = palette;
    id_us_plus((ID *)p->palette);
  }
}

void BKE_paint_curve_set(Brush *br, PaintCurve *pc)
{
  if (br) {
    id_us_min((ID *)br->paint_curve);
    br->paint_curve = pc;
    id_us_plus((ID *)br->paint_curve);
  }
}

void BKE_paint_curve_clamp_endpoint_add_index(PaintCurve *pc, const int add_index)
{
  pc->add_index = (add_index || pc->tot_points == 1) ? (add_index + 1) : 0;
}

void BKE_palette_color_remove(Palette *palette, PaletteColor *color)
{
  if (BLI_listbase_count_at_most(&palette->colors, palette->active_color) ==
      palette->active_color) {
    palette->active_color--;
  }

  BLI_remlink(&palette->colors, color);

  if (palette->active_color < 0 && !BLI_listbase_is_empty(&palette->colors)) {
    palette->active_color = 0;
  }

  MEM_freeN(color);
}

void BKE_palette_clear(Palette *palette)
{
  BLI_freelistN(&palette->colors);
  palette->active_color = 0;
}

Palette *BKE_palette_add(Main *bmain, const char *name)
{
  Palette *palette = BKE_id_new(bmain, ID_PAL, name);
  return palette;
}

PaletteColor *BKE_palette_color_add(Palette *palette)
{
  PaletteColor *color = MEM_callocN(sizeof(*color), "Palette Color");
  BLI_addtail(&palette->colors, color);
  return color;
}

bool BKE_palette_is_empty(const struct Palette *palette)
{
  return BLI_listbase_is_empty(&palette->colors);
}

/* helper function to sort using qsort */
static int palettecolor_compare_hsv(const void *a1, const void *a2)
{
  const tPaletteColorHSV *ps1 = a1, *ps2 = a2;

  /* Hue */
  if (ps1->h > ps2->h) {
    return 1;
  }
  if (ps1->h < ps2->h) {
    return -1;
  }

  /* Saturation. */
  if (ps1->s > ps2->s) {
    return 1;
  }
  if (ps1->s < ps2->s) {
    return -1;
  }

  /* Value. */
  if (1.0f - ps1->v > 1.0f - ps2->v) {
    return 1;
  }
  if (1.0f - ps1->v < 1.0f - ps2->v) {
    return -1;
  }

  return 0;
}

/* helper function to sort using qsort */
static int palettecolor_compare_svh(const void *a1, const void *a2)
{
  const tPaletteColorHSV *ps1 = a1, *ps2 = a2;

  /* Saturation. */
  if (ps1->s > ps2->s) {
    return 1;
  }
  if (ps1->s < ps2->s) {
    return -1;
  }

  /* Value. */
  if (1.0f - ps1->v > 1.0f - ps2->v) {
    return 1;
  }
  if (1.0f - ps1->v < 1.0f - ps2->v) {
    return -1;
  }

  /* Hue */
  if (ps1->h > ps2->h) {
    return 1;
  }
  if (ps1->h < ps2->h) {
    return -1;
  }

  return 0;
}

static int palettecolor_compare_vhs(const void *a1, const void *a2)
{
  const tPaletteColorHSV *ps1 = a1, *ps2 = a2;

  /* Value. */
  if (1.0f - ps1->v > 1.0f - ps2->v) {
    return 1;
  }
  if (1.0f - ps1->v < 1.0f - ps2->v) {
    return -1;
  }

  /* Hue */
  if (ps1->h > ps2->h) {
    return 1;
  }
  if (ps1->h < ps2->h) {
    return -1;
  }

  /* Saturation. */
  if (ps1->s > ps2->s) {
    return 1;
  }
  if (ps1->s < ps2->s) {
    return -1;
  }

  return 0;
}

static int palettecolor_compare_luminance(const void *a1, const void *a2)
{
  const tPaletteColorHSV *ps1 = a1, *ps2 = a2;

  float lumi1 = (ps1->rgb[0] + ps1->rgb[1] + ps1->rgb[2]) / 3.0f;
  float lumi2 = (ps2->rgb[0] + ps2->rgb[1] + ps2->rgb[2]) / 3.0f;

  if (lumi1 > lumi2) {
    return -1;
  }
  if (lumi1 < lumi2) {
    return 1;
  }

  return 0;
}

void BKE_palette_sort_hsv(tPaletteColorHSV *color_array, const int totcol)
{
  /* Sort by Hue, Saturation and Value. */
  qsort(color_array, totcol, sizeof(tPaletteColorHSV), palettecolor_compare_hsv);
}

void BKE_palette_sort_svh(tPaletteColorHSV *color_array, const int totcol)
{
  /* Sort by Saturation, Value and Hue. */
  qsort(color_array, totcol, sizeof(tPaletteColorHSV), palettecolor_compare_svh);
}

void BKE_palette_sort_vhs(tPaletteColorHSV *color_array, const int totcol)
{
  /* Sort by Saturation, Value and Hue. */
  qsort(color_array, totcol, sizeof(tPaletteColorHSV), palettecolor_compare_vhs);
}

void BKE_palette_sort_luminance(tPaletteColorHSV *color_array, const int totcol)
{
  /* Sort by Luminance (calculated with the average, enough for sorting). */
  qsort(color_array, totcol, sizeof(tPaletteColorHSV), palettecolor_compare_luminance);
}

bool BKE_palette_from_hash(Main *bmain, GHash *color_table, const char *name, const bool linear)
{
  tPaletteColorHSV *color_array = NULL;
  tPaletteColorHSV *col_elm = NULL;
  bool done = false;

  const int totpal = BLI_ghash_len(color_table);

  if (totpal > 0) {
    color_array = MEM_calloc_arrayN(totpal, sizeof(tPaletteColorHSV), __func__);
    /* Put all colors in an array. */
    GHashIterator gh_iter;
    int t = 0;
    GHASH_ITER (gh_iter, color_table) {
      const uint col = POINTER_AS_INT(BLI_ghashIterator_getValue(&gh_iter));
      float r, g, b;
      float h, s, v;
      cpack_to_rgb(col, &r, &g, &b);
      rgb_to_hsv(r, g, b, &h, &s, &v);

      col_elm = &color_array[t];
      col_elm->rgb[0] = r;
      col_elm->rgb[1] = g;
      col_elm->rgb[2] = b;
      col_elm->h = h;
      col_elm->s = s;
      col_elm->v = v;
      t++;
    }
  }

  /* Create the Palette. */
  if (totpal > 0) {
    /* Sort by Hue and saturation. */
    BKE_palette_sort_hsv(color_array, totpal);

    Palette *palette = BKE_palette_add(bmain, name);
    if (palette) {
      for (int i = 0; i < totpal; i++) {
        col_elm = &color_array[i];
        PaletteColor *palcol = BKE_palette_color_add(palette);
        if (palcol) {
          copy_v3_v3(palcol->rgb, col_elm->rgb);
          if (linear) {
            linearrgb_to_srgb_v3_v3(palcol->rgb, palcol->rgb);
          }
        }
      }
      done = true;
    }
  }
  else {
    done = false;
  }

  if (totpal > 0) {
    MEM_SAFE_FREE(color_array);
  }

  return done;
}

bool BKE_paint_select_face_test(Object *ob)
{
  return ((ob != NULL) && (ob->type == OB_MESH) && (ob->data != NULL) &&
          (((Mesh *)ob->data)->editflag & ME_EDIT_PAINT_FACE_SEL) &&
          (ob->mode & (OB_MODE_VERTEX_PAINT | OB_MODE_WEIGHT_PAINT | OB_MODE_TEXTURE_PAINT)));
}

bool BKE_paint_select_vert_test(Object *ob)
{
  return ((ob != NULL) && (ob->type == OB_MESH) && (ob->data != NULL) &&
          (((Mesh *)ob->data)->editflag & ME_EDIT_PAINT_VERT_SEL) &&
          (ob->mode & OB_MODE_WEIGHT_PAINT || ob->mode & OB_MODE_VERTEX_PAINT));
}

bool BKE_paint_select_elem_test(Object *ob)
{
  return (BKE_paint_select_vert_test(ob) || BKE_paint_select_face_test(ob));
}

void BKE_paint_cavity_curve_preset(Paint *p, int preset)
{
  CurveMapping *cumap = NULL;
  CurveMap *cuma = NULL;

  if (!p->cavity_curve) {
    p->cavity_curve = BKE_curvemapping_add(1, 0, 0, 1, 1);
  }
  cumap = p->cavity_curve;
  cumap->flag &= ~CUMA_EXTEND_EXTRAPOLATE;
  cumap->preset = preset;

  cuma = cumap->cm;
  BKE_curvemap_reset(cuma, &cumap->clipr, cumap->preset, CURVEMAP_SLOPE_POSITIVE);
  BKE_curvemapping_changed(cumap, false);
}

eObjectMode BKE_paint_object_mode_from_paintmode(ePaintMode mode)
{
  switch (mode) {
    case PAINT_MODE_SCULPT:
      return OB_MODE_SCULPT;
    case PAINT_MODE_VERTEX:
      return OB_MODE_VERTEX_PAINT;
    case PAINT_MODE_WEIGHT:
      return OB_MODE_WEIGHT_PAINT;
    case PAINT_MODE_TEXTURE_2D:
    case PAINT_MODE_TEXTURE_3D:
      return OB_MODE_TEXTURE_PAINT;
    case PAINT_MODE_SCULPT_UV:
      return OB_MODE_EDIT;
    case PAINT_MODE_INVALID:
    default:
      return 0;
  }
}

bool BKE_paint_ensure(ToolSettings *ts, struct Paint **r_paint)
{
  Paint *paint = NULL;
  if (*r_paint) {
    /* Tool offset should never be 0 for initialized paint settings, so it's a reliable way to
     * check if already initialized. */
    if ((*r_paint)->runtime.tool_offset == 0) {
      /* Currently only image painting is initialized this way, others have to be allocated. */
      BLI_assert(ELEM(*r_paint, (Paint *)&ts->imapaint));

      BKE_paint_runtime_init(ts, *r_paint);
    }
    else {
      BLI_assert(ELEM(*r_paint,
                      /* Cast is annoying, but prevent NULL-pointer access. */
                      (Paint *)ts->gp_paint,
                      (Paint *)ts->gp_vertexpaint,
                      (Paint *)ts->gp_sculptpaint,
                      (Paint *)ts->gp_weightpaint,
                      (Paint *)ts->sculpt,
                      (Paint *)ts->vpaint,
                      (Paint *)ts->wpaint,
                      (Paint *)ts->uvsculpt,
                      (Paint *)&ts->imapaint));
#ifdef DEBUG
      struct Paint paint_test = **r_paint;
      BKE_paint_runtime_init(ts, *r_paint);
      /* Swap so debug doesn't hide errors when release fails. */
      SWAP(Paint, **r_paint, paint_test);
      BLI_assert(paint_test.runtime.ob_mode == (*r_paint)->runtime.ob_mode);
      BLI_assert(paint_test.runtime.tool_offset == (*r_paint)->runtime.tool_offset);
#endif
    }
    return true;
  }

  if (((VPaint **)r_paint == &ts->vpaint) || ((VPaint **)r_paint == &ts->wpaint)) {
    VPaint *data = MEM_callocN(sizeof(*data), __func__);
    paint = &data->paint;
  }
  else if ((Sculpt **)r_paint == &ts->sculpt) {
    Sculpt *data = MEM_callocN(sizeof(*data), __func__);
    paint = &data->paint;

    /* Turn on X plane mirror symmetry by default */
    paint->symmetry_flags |= PAINT_SYMM_X;

    /* Make sure at least dyntopo subdivision is enabled */
    data->flags |= SCULPT_DYNTOPO_SUBDIVIDE | SCULPT_DYNTOPO_COLLAPSE;
  }
  else if ((GpPaint **)r_paint == &ts->gp_paint) {
    GpPaint *data = MEM_callocN(sizeof(*data), __func__);
    paint = &data->paint;
  }
  else if ((GpVertexPaint **)r_paint == &ts->gp_vertexpaint) {
    GpVertexPaint *data = MEM_callocN(sizeof(*data), __func__);
    paint = &data->paint;
  }
  else if ((GpSculptPaint **)r_paint == &ts->gp_sculptpaint) {
    GpSculptPaint *data = MEM_callocN(sizeof(*data), __func__);
    paint = &data->paint;
  }
  else if ((GpWeightPaint **)r_paint == &ts->gp_weightpaint) {
    GpWeightPaint *data = MEM_callocN(sizeof(*data), __func__);
    paint = &data->paint;
  }
  else if ((UvSculpt **)r_paint == &ts->uvsculpt) {
    UvSculpt *data = MEM_callocN(sizeof(*data), __func__);
    paint = &data->paint;
  }
  else if (*r_paint == &ts->imapaint.paint) {
    paint = &ts->imapaint.paint;
  }

  paint->flags |= PAINT_SHOW_BRUSH;

  *r_paint = paint;

  BKE_paint_runtime_init(ts, paint);

  return false;
}

void BKE_paint_init(Main *bmain, Scene *sce, ePaintMode mode, const char col[3])
{
  UnifiedPaintSettings *ups = &sce->toolsettings->unified_paint_settings;
  Paint *paint = BKE_paint_get_active_from_paintmode(sce, mode);

  BKE_paint_ensure_from_paintmode(sce, mode);

  /* If there's no brush, create one */
  if (PAINT_MODE_HAS_BRUSH(mode)) {
    Brush *brush = BKE_paint_brush(paint);
    if (brush == NULL) {
      eObjectMode ob_mode = BKE_paint_object_mode_from_paintmode(mode);
      brush = BKE_brush_first_search(bmain, ob_mode);
      if (!brush) {
        brush = BKE_brush_add(bmain, "Brush", ob_mode);
        id_us_min(&brush->id); /* fake user only */
      }
      BKE_paint_brush_set(paint, brush);
    }
  }

  memcpy(paint->paint_cursor_col, col, 3);
  paint->paint_cursor_col[3] = 128;
  ups->last_stroke_valid = false;
  zero_v3(ups->average_stroke_accum);
  ups->average_stroke_counter = 0;
  if (!paint->cavity_curve) {
    BKE_paint_cavity_curve_preset(paint, CURVE_PRESET_LINE);
  }
}

void BKE_paint_free(Paint *paint)
{
  BKE_curvemapping_free(paint->cavity_curve);
  MEM_SAFE_FREE(paint->tool_slots);
}

void BKE_paint_copy(Paint *src, Paint *tar, const int flag)
{
  tar->brush = src->brush;
  tar->cavity_curve = BKE_curvemapping_copy(src->cavity_curve);
  tar->tool_slots = MEM_dupallocN(src->tool_slots);

  if ((flag & LIB_ID_CREATE_NO_USER_REFCOUNT) == 0) {
    id_us_plus((ID *)tar->brush);
    id_us_plus((ID *)tar->palette);
    if (src->tool_slots != NULL) {
      for (int i = 0; i < tar->tool_slots_len; i++) {
        id_us_plus((ID *)tar->tool_slots[i].brush);
      }
    }
  }
}

void BKE_paint_stroke_get_average(Scene *scene, Object *ob, float stroke[3])
{
  UnifiedPaintSettings *ups = &scene->toolsettings->unified_paint_settings;
  if (ups->last_stroke_valid && ups->average_stroke_counter > 0) {
    float fac = 1.0f / ups->average_stroke_counter;
    mul_v3_v3fl(stroke, ups->average_stroke_accum, fac);
  }
  else {
    copy_v3_v3(stroke, ob->obmat[3]);
  }
}

void BKE_paint_blend_write(BlendWriter *writer, Paint *p)
{
  if (p->cavity_curve) {
    BKE_curvemapping_blend_write(writer, p->cavity_curve);
  }
  BLO_write_struct_array(writer, PaintToolSlot, p->tool_slots_len, p->tool_slots);
}

void BKE_paint_blend_read_data(BlendDataReader *reader, const Scene *scene, Paint *p)
{
  if (p->num_input_samples < 1) {
    p->num_input_samples = 1;
  }

  BLO_read_data_address(reader, &p->cavity_curve);
  if (p->cavity_curve) {
    BKE_curvemapping_blend_read(reader, p->cavity_curve);
  }
  else {
    BKE_paint_cavity_curve_preset(p, CURVE_PRESET_LINE);
  }

  BLO_read_data_address(reader, &p->tool_slots);

  /* Workaround for invalid data written in older versions. */
  const size_t expected_size = sizeof(PaintToolSlot) * p->tool_slots_len;
  if (p->tool_slots && MEM_allocN_len(p->tool_slots) < expected_size) {
    MEM_freeN(p->tool_slots);
    p->tool_slots = MEM_callocN(expected_size, "PaintToolSlot");
  }

  BKE_paint_runtime_init(scene->toolsettings, p);
}

void BKE_paint_blend_read_lib(BlendLibReader *reader, Scene *sce, Paint *p)
{
  if (p) {
    BLO_read_id_address(reader, sce->id.lib, &p->brush);
    for (int i = 0; i < p->tool_slots_len; i++) {
      if (p->tool_slots[i].brush != NULL) {
        BLO_read_id_address(reader, sce->id.lib, &p->tool_slots[i].brush);
      }
    }
    BLO_read_id_address(reader, sce->id.lib, &p->palette);
    p->paint_cursor = NULL;

    BKE_paint_runtime_init(sce->toolsettings, p);
  }
}

bool paint_is_face_hidden(const MLoopTri *lt, const MVert *mvert, const MLoop *mloop)
{
  return ((mvert[mloop[lt->tri[0]].v].flag & ME_HIDE) ||
          (mvert[mloop[lt->tri[1]].v].flag & ME_HIDE) ||
          (mvert[mloop[lt->tri[2]].v].flag & ME_HIDE));
}

bool paint_is_grid_face_hidden(const uint *grid_hidden, int gridsize, int x, int y)
{
  /* skip face if any of its corners are hidden */
  return (BLI_BITMAP_TEST(grid_hidden, y * gridsize + x) ||
          BLI_BITMAP_TEST(grid_hidden, y * gridsize + x + 1) ||
          BLI_BITMAP_TEST(grid_hidden, (y + 1) * gridsize + x + 1) ||
          BLI_BITMAP_TEST(grid_hidden, (y + 1) * gridsize + x));
}

bool paint_is_bmesh_face_hidden(BMFace *f)
{
  BMLoop *l_iter;
  BMLoop *l_first;

  l_iter = l_first = BM_FACE_FIRST_LOOP(f);
  do {
    if (BM_elem_flag_test(l_iter->v, BM_ELEM_HIDDEN)) {
      return true;
    }
  } while ((l_iter = l_iter->next) != l_first);

  return false;
}

float paint_grid_paint_mask(const GridPaintMask *gpm, uint level, uint x, uint y)
{
  int factor = BKE_ccg_factor(level, gpm->level);
  int gridsize = BKE_ccg_gridsize(gpm->level);

  return gpm->data[(y * factor) * gridsize + (x * factor)];
}

/* threshold to move before updating the brush rotation */
#define RAKE_THRESHHOLD 20

void paint_update_brush_rake_rotation(UnifiedPaintSettings *ups, Brush *brush, float rotation)
{
  if (brush->mtex.brush_angle_mode & MTEX_ANGLE_RAKE) {
    ups->brush_rotation = rotation;
  }
  else {
    ups->brush_rotation = 0.0f;
  }

  if (brush->mask_mtex.brush_angle_mode & MTEX_ANGLE_RAKE) {
    ups->brush_rotation_sec = rotation;
  }
  else {
    ups->brush_rotation_sec = 0.0f;
  }
}

bool paint_calculate_rake_rotation(UnifiedPaintSettings *ups,
                                   Brush *brush,
                                   const float mouse_pos[2])
{
  bool ok = false;
  if ((brush->mtex.brush_angle_mode & MTEX_ANGLE_RAKE) ||
      (brush->mask_mtex.brush_angle_mode & MTEX_ANGLE_RAKE)) {
    const float r = RAKE_THRESHHOLD;
    float rotation;

    float dpos[2];
    sub_v2_v2v2(dpos, ups->last_rake, mouse_pos);

    if (len_squared_v2(dpos) >= r * r) {
      rotation = atan2f(dpos[0], dpos[1]);

      copy_v2_v2(ups->last_rake, mouse_pos);

      ups->last_rake_angle = rotation;

      paint_update_brush_rake_rotation(ups, brush, rotation);
      ok = true;
    }
    /* make sure we reset here to the last rotation to avoid accumulating
     * values in case a random rotation is also added */
    else {
      paint_update_brush_rake_rotation(ups, brush, ups->last_rake_angle);
      ok = false;
    }
  }
  else {
    ups->brush_rotation = ups->brush_rotation_sec = 0.0f;
    ok = true;
  }
  return ok;
}

void BKE_sculptsession_free_deformMats(SculptSession *ss)
{
  MEM_SAFE_FREE(ss->orig_cos);
  MEM_SAFE_FREE(ss->deform_cos);
  MEM_SAFE_FREE(ss->deform_imats);
}

void BKE_sculptsession_free_vwpaint_data(struct SculptSession *ss)
{
  struct SculptVertexPaintGeomMap *gmap = NULL;
  if (ss->mode_type == OB_MODE_VERTEX_PAINT) {
    gmap = &ss->mode.vpaint.gmap;

    MEM_SAFE_FREE(ss->mode.vpaint.previous_color);
  }
  else if (ss->mode_type == OB_MODE_WEIGHT_PAINT) {
    gmap = &ss->mode.wpaint.gmap;

    MEM_SAFE_FREE(ss->mode.wpaint.alpha_weight);
    if (ss->mode.wpaint.dvert_prev) {
      BKE_defvert_array_free_elems(ss->mode.wpaint.dvert_prev, ss->totvert);
      MEM_freeN(ss->mode.wpaint.dvert_prev);
      ss->mode.wpaint.dvert_prev = NULL;
    }
  }
  else {
    return;
  }
  MEM_SAFE_FREE(gmap->vert_to_loop);
  MEM_SAFE_FREE(gmap->vert_map_mem);
  MEM_SAFE_FREE(gmap->vert_to_poly);
  MEM_SAFE_FREE(gmap->poly_map_mem);
}

/**
 * Write out the sculpt dynamic-topology #BMesh to the #Mesh.
 */
static void sculptsession_bm_to_me_update_data_only(Object *ob, bool reorder)
{
  SculptSession *ss = ob->sculpt;

  if (ss->bm) {
    if (ob->data) {
      BMIter iter;
      BMFace *efa;
      BM_ITER_MESH (efa, &iter, ss->bm, BM_FACES_OF_MESH) {
        BM_elem_flag_set(efa, BM_ELEM_SMOOTH, ss->bm_smooth_shading);
      }
      if (reorder) {
        BM_log_mesh_elems_reorder(ss->bm, ss->bm_log);
      }
      BM_mesh_bm_to_me(NULL,
                       ss->bm,
                       ob->data,
                       (&(struct BMeshToMeshParams){
                           .calc_object_remap = false,
                       }));
    }
  }
}

void BKE_sculptsession_bm_to_me(Object *ob, bool reorder)
{
  if (ob && ob->sculpt) {
    sculptsession_bm_to_me_update_data_only(ob, reorder);

    /* Ensure the objects evaluated mesh doesn't hold onto arrays
     * now realloc'd in the mesh T34473. */
    DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
  }
}

static void sculptsession_free_pbvh(Object *object)
{
  SculptSession *ss = object->sculpt;

  if (!ss) {
    return;
  }

  if (ss->pbvh) {
    BKE_pbvh_free(ss->pbvh);
    ss->pbvh = NULL;
  }

  MEM_SAFE_FREE(ss->pmap);
  MEM_SAFE_FREE(ss->pmap_mem);

  MEM_SAFE_FREE(ss->epmap);
  MEM_SAFE_FREE(ss->epmap_mem);

  MEM_SAFE_FREE(ss->vemap);
  MEM_SAFE_FREE(ss->vemap_mem);

  MEM_SAFE_FREE(ss->persistent_base);

  MEM_SAFE_FREE(ss->preview_vert_index_list);
  ss->preview_vert_index_count = 0;

  MEM_SAFE_FREE(ss->preview_vert_index_list);

  MEM_SAFE_FREE(ss->vertex_info.connected_component);
  MEM_SAFE_FREE(ss->vertex_info.boundary);

  MEM_SAFE_FREE(ss->fake_neighbors.fake_neighbor_index);
}

void BKE_sculptsession_bm_to_me_for_render(Object *object)
{
  if (object && object->sculpt) {
    if (object->sculpt->bm) {
      /* Ensure no points to old arrays are stored in DM
       *
       * Apparently, we could not use DEG_id_tag_update
       * here because this will lead to the while object
       * surface to disappear, so we'll release DM in place.
       */
      BKE_object_free_derived_caches(object);

      sculptsession_bm_to_me_update_data_only(object, false);

      /* In contrast with sculptsession_bm_to_me no need in
       * DAG tag update here - derived mesh was freed and
       * old pointers are nowhere stored.
       */
    }
  }
}

void BKE_sculptsession_free(Object *ob)
{
  if (ob && ob->sculpt) {
    SculptSession *ss = ob->sculpt;

    if (ss->bm) {
      BKE_sculptsession_bm_to_me(ob, true);
      BM_mesh_free(ss->bm);
    }

    sculptsession_free_pbvh(ob);

    MEM_SAFE_FREE(ss->pmap);
    MEM_SAFE_FREE(ss->pmap_mem);

    MEM_SAFE_FREE(ss->epmap);
    MEM_SAFE_FREE(ss->epmap_mem);

    MEM_SAFE_FREE(ss->vemap);
    MEM_SAFE_FREE(ss->vemap_mem);

    if (ss->bm_log) {
      BM_log_free(ss->bm_log);
    }

    MEM_SAFE_FREE(ss->texcache);

    if (ss->tex_pool) {
      BKE_image_pool_free(ss->tex_pool);
    }

    MEM_SAFE_FREE(ss->orig_cos);
    MEM_SAFE_FREE(ss->deform_cos);
    MEM_SAFE_FREE(ss->deform_imats);

    if (ss->pose_ik_chain_preview) {
      for (int i = 0; i < ss->pose_ik_chain_preview->tot_segments; i++) {
        MEM_SAFE_FREE(ss->pose_ik_chain_preview->segments[i].weights);
      }
      MEM_SAFE_FREE(ss->pose_ik_chain_preview->segments);
      MEM_SAFE_FREE(ss->pose_ik_chain_preview);
    }

    if (ss->boundary_preview) {
      MEM_SAFE_FREE(ss->boundary_preview->vertices);
      MEM_SAFE_FREE(ss->boundary_preview->edges);
      MEM_SAFE_FREE(ss->boundary_preview->distance);
      MEM_SAFE_FREE(ss->boundary_preview->edit_info);
      MEM_SAFE_FREE(ss->boundary_preview);
    }

    BKE_sculptsession_free_vwpaint_data(ob->sculpt);

    MEM_freeN(ss);

    ob->sculpt = NULL;
  }
}

MultiresModifierData *BKE_sculpt_multires_active(Scene *scene, Object *ob)
{
  Mesh *me = (Mesh *)ob->data;
  ModifierData *md;
  VirtualModifierData virtualModifierData;

  if (ob->sculpt && ob->sculpt->bm) {
    /* can't combine multires and dynamic topology */
    return NULL;
  }

  if (!CustomData_get_layer(&me->ldata, CD_MDISPS)) {
    /* multires can't work without displacement layer */
    return NULL;
  }

  /* Weight paint operates on original vertices, and needs to treat multires as regular modifier
   * to make it so that PBVH vertices are at the multires surface. */
  if ((ob->mode & OB_MODE_SCULPT) == 0) {
    return NULL;
  }

  for (md = BKE_modifiers_get_virtual_modifierlist(ob, &virtualModifierData); md; md = md->next) {
    if (md->type == eModifierType_Multires) {
      MultiresModifierData *mmd = (MultiresModifierData *)md;

      if (!BKE_modifier_is_enabled(scene, md, eModifierMode_Realtime)) {
        continue;
      }

      if (mmd->sculptlvl > 0 && !(mmd->flags & eMultiresModifierFlag_UseSculptBaseMesh)) {
        return mmd;
      }

      return NULL;
    }
  }

  return NULL;
}

/* Checks if there are any supported deformation modifiers active */
static bool sculpt_modifiers_active(Scene *scene, Sculpt *sd, Object *ob)
{
  ModifierData *md;
  Mesh *me = (Mesh *)ob->data;
  VirtualModifierData virtualModifierData;

  if (ob->sculpt->bm || BKE_sculpt_multires_active(scene, ob)) {
    return false;
  }

  /* non-locked shape keys could be handled in the same way as deformed mesh */
  if ((ob->shapeflag & OB_SHAPE_LOCK) == 0 && me->key && ob->shapenr) {
    return true;
  }

  md = BKE_modifiers_get_virtual_modifierlist(ob, &virtualModifierData);

  /* exception for shape keys because we can edit those */
  for (; md; md = md->next) {
    const ModifierTypeInfo *mti = BKE_modifier_get_info(md->type);
    if (!BKE_modifier_is_enabled(scene, md, eModifierMode_Realtime)) {
      continue;
    }
    if (md->type == eModifierType_Multires && (ob->mode & OB_MODE_SCULPT)) {
      MultiresModifierData *mmd = (MultiresModifierData *)md;
      if (!(mmd->flags & eMultiresModifierFlag_UseSculptBaseMesh)) {
        continue;
      }
    }
    if (md->type == eModifierType_ShapeKey) {
      continue;
    }

    if (mti->type == eModifierTypeType_OnlyDeform) {
      return true;
    }
    if ((sd->flags & SCULPT_ONLY_DEFORM) == 0) {
      return true;
    }
  }

  return false;
}

/**
 * \param need_mask: So that the evaluated mesh that is returned has mask data.
 */
static void sculpt_update_object(Depsgraph *depsgraph,
                                 Object *ob,
                                 Mesh *me_eval,
                                 bool need_pmap,
                                 bool need_mask,
                                 bool UNUSED(need_colors))
{
  Scene *scene = DEG_get_input_scene(depsgraph);
  Sculpt *sd = scene->toolsettings->sculpt;
  SculptSession *ss = ob->sculpt;
  const Mesh *me = BKE_object_get_original_mesh(ob);
  MultiresModifierData *mmd = BKE_sculpt_multires_active(scene, ob);
  const bool use_face_sets = (ob->mode & OB_MODE_SCULPT) != 0;

  ss->depsgraph = depsgraph;

  ss->deform_modifiers_active = sculpt_modifiers_active(scene, sd, ob);
  ss->show_mask = (sd->flags & SCULPT_HIDE_MASK) == 0;
  ss->show_face_sets = (sd->flags & SCULPT_HIDE_FACE_SETS) == 0;

  ss->building_vp_handle = false;

  ss->scene = scene;

  if (need_mask) {
    if (mmd == NULL) {
      BLI_assert(CustomData_has_layer(&me->vdata, CD_PAINT_MASK));
    }
    else {
      BLI_assert(CustomData_has_layer(&me->ldata, CD_GRID_PAINT_MASK));
    }
  }

  ss->shapekey_active = (mmd == NULL) ? BKE_keyblock_from_object(ob) : NULL;

  /* NOTE: Weight pPaint require mesh info for loop lookup, but it never uses multires code path,
   * so no extra checks is needed here. */
  if (mmd) {
    ss->multires.active = true;
    ss->multires.modifier = mmd;
    ss->multires.level = mmd->sculptlvl;
    ss->totvert = me_eval->totvert;
    ss->totpoly = me_eval->totpoly;
    ss->totfaces = me->totpoly;

    /* These are assigned to the base mesh in Multires. This is needed because Face Sets operators
     * and tools use the Face Sets data from the base mesh when Multires is active. */
    ss->mvert = me->mvert;
    ss->mpoly = me->mpoly;
    ss->mloop = me->mloop;
  }
  else {
    ss->totvert = me->totvert;
    ss->totpoly = me->totpoly;
    ss->totfaces = me->totpoly;
    ss->mvert = me->mvert;
    ss->mpoly = me->mpoly;
    ss->mloop = me->mloop;
    ss->multires.active = false;
    ss->multires.modifier = NULL;
    ss->multires.level = 0;
    ss->vmask = CustomData_get_layer(&me->vdata, CD_PAINT_MASK);
    ss->vcol = CustomData_get_layer(&me->vdata, CD_PROP_COLOR);
  }

  /* Sculpt Face Sets. */
  if (use_face_sets) {
    BLI_assert(CustomData_has_layer(&me->pdata, CD_SCULPT_FACE_SETS));
    ss->face_sets = CustomData_get_layer(&me->pdata, CD_SCULPT_FACE_SETS);
  }
  else {
    ss->face_sets = NULL;
  }

  ss->subdiv_ccg = me_eval->runtime.subdiv_ccg;

  PBVH *pbvh = BKE_sculpt_object_pbvh_ensure(depsgraph, ob);
  BLI_assert(pbvh == ss->pbvh);
  UNUSED_VARS_NDEBUG(pbvh);

  BKE_pbvh_subdiv_cgg_set(ss->pbvh, ss->subdiv_ccg);
  BKE_pbvh_face_sets_set(ss->pbvh, ss->face_sets);

  BKE_pbvh_face_sets_color_set(ss->pbvh, me->face_sets_color_seed, me->face_sets_color_default);

  if (need_pmap && ob->type == OB_MESH && !ss->pmap) {
    BKE_mesh_vert_poly_map_create(
        &ss->pmap, &ss->pmap_mem, me->mpoly, me->mloop, me->totvert, me->totpoly, me->totloop);
  }

  pbvh_show_mask_set(ss->pbvh, ss->show_mask);
  pbvh_show_face_sets_set(ss->pbvh, ss->show_face_sets);

  if (ss->deform_modifiers_active) {
    if (!ss->orig_cos) {
      int a;

      BKE_sculptsession_free_deformMats(ss);

      ss->orig_cos = (ss->shapekey_active) ?
                         BKE_keyblock_convert_to_vertcos(ob, ss->shapekey_active) :
                         BKE_mesh_vert_coords_alloc(me, NULL);

      BKE_crazyspace_build_sculpt(depsgraph, scene, ob, &ss->deform_imats, &ss->deform_cos);
      BKE_pbvh_vert_coords_apply(ss->pbvh, ss->deform_cos, me->totvert);

      for (a = 0; a < me->totvert; a++) {
        invert_m3(ss->deform_imats[a]);
      }
    }
  }
  else {
    BKE_sculptsession_free_deformMats(ss);
  }

  if (ss->shapekey_active != NULL && ss->deform_cos == NULL) {
    ss->deform_cos = BKE_keyblock_convert_to_vertcos(ob, ss->shapekey_active);
  }

  /* if pbvh is deformed, key block is already applied to it */
  if (ss->shapekey_active) {
    bool pbvh_deformed = BKE_pbvh_is_deformed(ss->pbvh);
    if (!pbvh_deformed || ss->deform_cos == NULL) {
      float(*vertCos)[3] = BKE_keyblock_convert_to_vertcos(ob, ss->shapekey_active);

      if (vertCos) {
        if (!pbvh_deformed) {
          /* apply shape keys coordinates to PBVH */
          BKE_pbvh_vert_coords_apply(ss->pbvh, vertCos, me->totvert);
        }
        if (ss->deform_cos == NULL) {
          ss->deform_cos = vertCos;
        }
        if (vertCos != ss->deform_cos) {
          MEM_freeN(vertCos);
        }
      }
    }
  }
}

void BKE_sculpt_update_object_before_eval(Object *ob)
{
  /* Update before mesh evaluation in the dependency graph. */
  SculptSession *ss = ob->sculpt;

  if (ss && ss->building_vp_handle == false) {
    if (!ss->cache && !ss->filter_cache && !ss->expand_cache) {
      /* We free pbvh on changes, except in the middle of drawing a stroke
       * since it can't deal with changing PVBH node organization, we hope
       * topology does not change in the meantime .. weak. */
      sculptsession_free_pbvh(ob);

      BKE_sculptsession_free_deformMats(ob->sculpt);

      /* In vertex/weight paint, force maps to be rebuilt. */
      BKE_sculptsession_free_vwpaint_data(ob->sculpt);
    }
    else {
      PBVHNode **nodes;
      int n, totnode;

      BKE_pbvh_search_gather(ss->pbvh, NULL, NULL, &nodes, &totnode);

      for (n = 0; n < totnode; n++) {
        BKE_pbvh_node_mark_update(nodes[n]);
      }

      MEM_freeN(nodes);
    }
  }
}

void BKE_sculpt_update_object_after_eval(Depsgraph *depsgraph, Object *ob_eval)
{
  /* Update after mesh evaluation in the dependency graph, to rebuild PBVH or
   * other data when modifiers change the mesh. */
  Object *ob_orig = DEG_get_original_object(ob_eval);
  Mesh *me_eval = BKE_object_get_evaluated_mesh(ob_eval);

  BLI_assert(me_eval != NULL);
  sculpt_update_object(depsgraph, ob_orig, me_eval, false, false, false);
}

void BKE_sculpt_color_layer_create_if_needed(struct Object *object)
{
  Mesh *orig_me = BKE_object_get_original_mesh(object);
  if (!U.experimental.use_sculpt_vertex_colors) {
    return;
  }

  if (CustomData_has_layer(&orig_me->vdata, CD_PROP_COLOR)) {
    return;
  }

  CustomData_add_layer(&orig_me->vdata, CD_PROP_COLOR, CD_DEFAULT, NULL, orig_me->totvert);
  BKE_mesh_update_customdata_pointers(orig_me, true);
  DEG_id_tag_update(&orig_me->id, ID_RECALC_GEOMETRY_ALL_MODES);
}

void BKE_sculpt_update_object_for_edit(
    Depsgraph *depsgraph, Object *ob_orig, bool need_pmap, bool need_mask, bool need_colors)
{
  BLI_assert(ob_orig == DEG_get_original_object(ob_orig));

  Object *ob_eval = DEG_get_evaluated_object(depsgraph, ob_orig);
  Mesh *me_eval = BKE_object_get_evaluated_mesh(ob_eval);
  BLI_assert(me_eval != NULL);

  sculpt_update_object(depsgraph, ob_orig, me_eval, need_pmap, need_mask, need_colors);
}

int BKE_sculpt_mask_layers_ensure(Object *ob, MultiresModifierData *mmd)
{
  const float *paint_mask;
  Mesh *me = ob->data;
  int ret = 0;

  paint_mask = CustomData_get_layer(&me->vdata, CD_PAINT_MASK);

  /* if multires is active, create a grid paint mask layer if there
   * isn't one already */
  if (mmd && !CustomData_has_layer(&me->ldata, CD_GRID_PAINT_MASK)) {
    GridPaintMask *gmask;
    int level = max_ii(1, mmd->sculptlvl);
    int gridsize = BKE_ccg_gridsize(level);
    int gridarea = gridsize * gridsize;
    int i, j;

    gmask = CustomData_add_layer(&me->ldata, CD_GRID_PAINT_MASK, CD_CALLOC, NULL, me->totloop);

    for (i = 0; i < me->totloop; i++) {
      GridPaintMask *gpm = &gmask[i];

      gpm->level = level;
      gpm->data = MEM_callocN(sizeof(float) * gridarea, "GridPaintMask.data");
    }

    /* if vertices already have mask, copy into multires data */
    if (paint_mask) {
      for (i = 0; i < me->totpoly; i++) {
        const MPoly *p = &me->mpoly[i];
        float avg = 0;

        /* mask center */
        for (j = 0; j < p->totloop; j++) {
          const MLoop *l = &me->mloop[p->loopstart + j];
          avg += paint_mask[l->v];
        }
        avg /= (float)p->totloop;

        /* fill in multires mask corner */
        for (j = 0; j < p->totloop; j++) {
          GridPaintMask *gpm = &gmask[p->loopstart + j];
          const MLoop *l = &me->mloop[p->loopstart + j];
          const MLoop *prev = ME_POLY_LOOP_PREV(me->mloop, p, j);
          const MLoop *next = ME_POLY_LOOP_NEXT(me->mloop, p, j);

          gpm->data[0] = avg;
          gpm->data[1] = (paint_mask[l->v] + paint_mask[next->v]) * 0.5f;
          gpm->data[2] = (paint_mask[l->v] + paint_mask[prev->v]) * 0.5f;
          gpm->data[3] = paint_mask[l->v];
        }
      }
    }

    ret |= SCULPT_MASK_LAYER_CALC_LOOP;
  }

  /* create vertex paint mask layer if there isn't one already */
  if (!paint_mask) {
    CustomData_add_layer(&me->vdata, CD_PAINT_MASK, CD_CALLOC, NULL, me->totvert);
    ret |= SCULPT_MASK_LAYER_CALC_VERT;
  }

  return ret;
}

void BKE_sculpt_toolsettings_data_ensure(struct Scene *scene)
{
  BKE_paint_ensure(scene->toolsettings, (Paint **)&scene->toolsettings->sculpt);

  Sculpt *sd = scene->toolsettings->sculpt;
  if (!sd->detail_size) {
    sd->detail_size = 12;
  }
  if (!sd->detail_percent) {
    sd->detail_percent = 25;
  }
  if (sd->constant_detail == 0.0f) {
    sd->constant_detail = 3.0f;
  }

  /* Set sane default tiling offsets */
  if (!sd->paint.tile_offset[0]) {
    sd->paint.tile_offset[0] = 1.0f;
  }
  if (!sd->paint.tile_offset[1]) {
    sd->paint.tile_offset[1] = 1.0f;
  }
  if (!sd->paint.tile_offset[2]) {
    sd->paint.tile_offset[2] = 1.0f;
  }
}

static bool check_sculpt_object_deformed(Object *object, const bool for_construction)
{
  bool deformed = false;

  /* Active modifiers means extra deformation, which can't be handled correct
   * on birth of PBVH and sculpt "layer" levels, so use PBVH only for internal brush
   * stuff and show final evaluated mesh so user would see actual object shape.
   */
  deformed |= object->sculpt->deform_modifiers_active;

  if (for_construction) {
    deformed |= object->sculpt->shapekey_active != NULL;
  }
  else {
    /* As in case with modifiers, we can't synchronize deformation made against
     * PBVH and non-locked keyblock, so also use PBVH only for brushes and
     * final DM to give final result to user.
     */
    deformed |= object->sculpt->shapekey_active && (object->shapeflag & OB_SHAPE_LOCK) == 0;
  }

  return deformed;
}

void BKE_sculpt_face_sets_ensure_from_base_mesh_visibility(Mesh *mesh)
{
  const int face_sets_default_visible_id = 1;
  const int face_sets_default_hidden_id = -(face_sets_default_visible_id + 1);

  bool initialize_new_face_sets = false;

  if (CustomData_has_layer(&mesh->pdata, CD_SCULPT_FACE_SETS)) {
    /* Make everything visible. */
    int *current_face_sets = CustomData_get_layer(&mesh->pdata, CD_SCULPT_FACE_SETS);
    for (int i = 0; i < mesh->totpoly; i++) {
      current_face_sets[i] = abs(current_face_sets[i]);
    }
  }
  else {
    initialize_new_face_sets = true;
    int *new_face_sets = CustomData_add_layer(
        &mesh->pdata, CD_SCULPT_FACE_SETS, CD_CALLOC, NULL, mesh->totpoly);

    /* Initialize the new Face Set data-layer with a default valid visible ID and set the default
     * color to render it white. */
    for (int i = 0; i < mesh->totpoly; i++) {
      new_face_sets[i] = face_sets_default_visible_id;
    }
    mesh->face_sets_color_default = face_sets_default_visible_id;
  }

  int *face_sets = CustomData_get_layer(&mesh->pdata, CD_SCULPT_FACE_SETS);

  for (int i = 0; i < mesh->totpoly; i++) {
    if (!(mesh->mpoly[i].flag & ME_HIDE)) {
      continue;
    }

    if (initialize_new_face_sets) {
      /* When initializing a new Face Set data-layer, assign a new hidden Face Set ID to hidden
       * vertices. This way, we get at initial split in two Face Sets between hidden and
       * visible vertices based on the previous mesh visibly from other mode that can be
       * useful in some cases. */
      face_sets[i] = face_sets_default_hidden_id;
    }
    else {
      /* Otherwise, set the already existing Face Set ID to hidden. */
      face_sets[i] = -abs(face_sets[i]);
    }
  }
}

void BKE_sculpt_sync_face_sets_visibility_to_base_mesh(Mesh *mesh)
{
  int *face_sets = CustomData_get_layer(&mesh->pdata, CD_SCULPT_FACE_SETS);
  if (!face_sets) {
    return;
  }

  for (int i = 0; i < mesh->totpoly; i++) {
    const bool is_face_set_visible = face_sets[i] >= 0;
    SET_FLAG_FROM_TEST(mesh->mpoly[i].flag, !is_face_set_visible, ME_HIDE);
  }

  BKE_mesh_flush_hidden_from_polys(mesh);
}

void BKE_sculpt_sync_face_sets_visibility_to_grids(Mesh *mesh, SubdivCCG *subdiv_ccg)
{
  int *face_sets = CustomData_get_layer(&mesh->pdata, CD_SCULPT_FACE_SETS);
  if (!face_sets) {
    return;
  }

  if (!subdiv_ccg) {
    return;
  }

  CCGKey key;
  BKE_subdiv_ccg_key_top_level(&key, subdiv_ccg);
  for (int i = 0; i < mesh->totloop; i++) {
    const int face_index = BKE_subdiv_ccg_grid_to_face_index(subdiv_ccg, i);
    const bool is_hidden = (face_sets[face_index] < 0);

    /* Avoid creating and modifying the grid_hidden bitmap if the base mesh face is visible and
     * there is not bitmap for the grid. This is because missing grid_hidden implies grid is fully
     * visible. */
    if (is_hidden) {
      BKE_subdiv_ccg_grid_hidden_ensure(subdiv_ccg, i);
    }

    BLI_bitmap *gh = subdiv_ccg->grid_hidden[i];
    if (gh) {
      BLI_bitmap_set_all(gh, is_hidden, key.grid_area);
    }
  }
}

void BKE_sculpt_sync_face_set_visibility(struct Mesh *mesh, struct SubdivCCG *subdiv_ccg)
{
  BKE_sculpt_face_sets_ensure_from_base_mesh_visibility(mesh);
  BKE_sculpt_sync_face_sets_visibility_to_base_mesh(mesh);
  BKE_sculpt_sync_face_sets_visibility_to_grids(mesh, subdiv_ccg);
}

void BKE_sculpt_ensure_orig_mesh_data(Scene *scene, Object *object)
{
  Mesh *mesh = BKE_mesh_from_object(object);
  MultiresModifierData *mmd = BKE_sculpt_multires_active(scene, object);

  BLI_assert(object->mode == OB_MODE_SCULPT);

  /* Copy the current mesh visibility to the Face Sets. */
  BKE_sculpt_face_sets_ensure_from_base_mesh_visibility(mesh);
  if (object->sculpt != NULL) {
    /* If a sculpt session is active, ensure we have its faceset data porperly up-to-date. */
    object->sculpt->face_sets = CustomData_get_layer(&mesh->pdata, CD_SCULPT_FACE_SETS);

    /* NOTE: In theory we could add that on the fly when required by sculpt code.
     * But this then requires proper update of depsgraph etc. For now we play safe, optimization is
     * always possible later if it's worth it. */
    BKE_sculpt_mask_layers_ensure(object, mmd);
  }

  /* Tessfaces aren't used and will become invalid. */
  BKE_mesh_tessface_clear(mesh);

  /* We always need to flush updates from depsgraph here, since at the very least
   * `BKE_sculpt_face_sets_ensure_from_base_mesh_visibility()` will have updated some data layer of
   * the mesh.
   *
   * All known potential sources of updates:
   *   - Addition of, or changes to, the `CD_SCULPT_FACE_SETS` data layer
   *     (`BKE_sculpt_face_sets_ensure_from_base_mesh_visibility`).
   *   - Addition of a `CD_PAINT_MASK` data layer (`BKE_sculpt_mask_layers_ensure`).
   *   - Object has any active modifier (modifier stack can be different in Sculpt mode).
   *   - Multires:
   *     + Differences of subdiv levels between sculpt and object modes
   *       (`mmd->sculptlvl != mmd->lvl`).
   *     + Addition of a `CD_GRID_PAINT_MASK` data layer (`BKE_sculpt_mask_layers_ensure`).
   */
  DEG_id_tag_update(&object->id, ID_RECALC_GEOMETRY);
}

static PBVH *build_pbvh_for_dynamic_topology(Object *ob)
{
  PBVH *pbvh = BKE_pbvh_new();
  BKE_pbvh_build_bmesh(pbvh,
                       ob->sculpt->bm,
                       ob->sculpt->bm_smooth_shading,
                       ob->sculpt->bm_log,
                       ob->sculpt->cd_vert_node_offset,
                       ob->sculpt->cd_face_node_offset);
  pbvh_show_mask_set(pbvh, ob->sculpt->show_mask);
  pbvh_show_face_sets_set(pbvh, false);
  return pbvh;
}

static PBVH *build_pbvh_from_regular_mesh(Object *ob, Mesh *me_eval_deform, bool respect_hide)
{
  Mesh *me = BKE_object_get_original_mesh(ob);
  const int looptris_num = poly_to_tri_count(me->totpoly, me->totloop);
  PBVH *pbvh = BKE_pbvh_new();
  BKE_pbvh_respect_hide_set(pbvh, respect_hide);

  MLoopTri *looptri = MEM_malloc_arrayN(looptris_num, sizeof(*looptri), __func__);

  BKE_mesh_recalc_looptri(me->mloop, me->mpoly, me->mvert, me->totloop, me->totpoly, looptri);

  BKE_sculpt_sync_face_set_visibility(me, NULL);

  BKE_pbvh_build_mesh(pbvh,
                      me,
                      me->mpoly,
                      me->mloop,
                      me->mvert,
                      me->totvert,
                      &me->vdata,
                      &me->ldata,
                      &me->pdata,
                      looptri,
                      looptris_num);

  pbvh_show_mask_set(pbvh, ob->sculpt->show_mask);
  pbvh_show_face_sets_set(pbvh, ob->sculpt->show_face_sets);

  const bool is_deformed = check_sculpt_object_deformed(ob, true);
  if (is_deformed && me_eval_deform != NULL) {
    int totvert;
    float(*v_cos)[3] = BKE_mesh_vert_coords_alloc(me_eval_deform, &totvert);
    BKE_pbvh_vert_coords_apply(pbvh, v_cos, totvert);
    MEM_freeN(v_cos);
  }

  return pbvh;
}

static PBVH *build_pbvh_from_ccg(Object *ob, SubdivCCG *subdiv_ccg, bool respect_hide)
{
  CCGKey key;
  BKE_subdiv_ccg_key_top_level(&key, subdiv_ccg);
  PBVH *pbvh = BKE_pbvh_new();
  BKE_pbvh_respect_hide_set(pbvh, respect_hide);

  Mesh *base_mesh = BKE_mesh_from_object(ob);
  BKE_sculpt_sync_face_set_visibility(base_mesh, subdiv_ccg);

  BKE_pbvh_build_grids(pbvh,
                       subdiv_ccg->grids,
                       subdiv_ccg->num_grids,
                       &key,
                       (void **)subdiv_ccg->grid_faces,
                       subdiv_ccg->grid_flag_mats,
                       subdiv_ccg->grid_hidden);
  pbvh_show_mask_set(pbvh, ob->sculpt->show_mask);
  pbvh_show_face_sets_set(pbvh, ob->sculpt->show_face_sets);
  return pbvh;
}

PBVH *BKE_sculpt_object_pbvh_ensure(Depsgraph *depsgraph, Object *ob)
{
  if (ob == NULL || ob->sculpt == NULL) {
    return NULL;
  }

  bool respect_hide = true;
  if (ob->mode & (OB_MODE_VERTEX_PAINT | OB_MODE_WEIGHT_PAINT)) {
    if (!(BKE_paint_select_vert_test(ob) || BKE_paint_select_face_test(ob))) {
      respect_hide = false;
    }
  }

  PBVH *pbvh = ob->sculpt->pbvh;
  if (pbvh != NULL) {
    /* NOTE: It is possible that grids were re-allocated due to modifier
     * stack. Need to update those pointers. */
    if (BKE_pbvh_type(pbvh) == PBVH_GRIDS) {
      Object *object_eval = DEG_get_evaluated_object(depsgraph, ob);
      Mesh *mesh_eval = object_eval->data;
      SubdivCCG *subdiv_ccg = mesh_eval->runtime.subdiv_ccg;
      if (subdiv_ccg != NULL) {
        BKE_sculpt_bvh_update_from_ccg(pbvh, subdiv_ccg);
      }
    }
    return pbvh;
  }

  if (ob->sculpt->bm != NULL) {
    /* Sculpting on a BMesh (dynamic-topology) gets a special PBVH. */
    pbvh = build_pbvh_for_dynamic_topology(ob);
  }
  else {
    Object *object_eval = DEG_get_evaluated_object(depsgraph, ob);
    Mesh *mesh_eval = object_eval->data;
    if (mesh_eval->runtime.subdiv_ccg != NULL) {
      pbvh = build_pbvh_from_ccg(ob, mesh_eval->runtime.subdiv_ccg, respect_hide);
    }
    else if (ob->type == OB_MESH) {
      Mesh *me_eval_deform = object_eval->runtime.mesh_deform_eval;
      pbvh = build_pbvh_from_regular_mesh(ob, me_eval_deform, respect_hide);
    }
  }

  ob->sculpt->pbvh = pbvh;
  return pbvh;
}

void BKE_sculpt_bvh_update_from_ccg(PBVH *pbvh, SubdivCCG *subdiv_ccg)
{
  BKE_pbvh_grids_update(pbvh,
                        subdiv_ccg->grids,
                        (void **)subdiv_ccg->grid_faces,
                        subdiv_ccg->grid_flag_mats,
                        subdiv_ccg->grid_hidden);
}

bool BKE_sculptsession_use_pbvh_draw(const Object *ob, const View3D *v3d)
{
  SculptSession *ss = ob->sculpt;
  if (ss == NULL || ss->pbvh == NULL || ss->mode_type != OB_MODE_SCULPT) {
    return false;
  }

  if (BKE_pbvh_type(ss->pbvh) == PBVH_FACES) {
    /* Regular mesh only draws from PBVH without modifiers and shape keys. */
    const bool full_shading = (v3d && (v3d->shading.type > OB_SOLID));
    return !(ss->shapekey_active || ss->deform_modifiers_active || full_shading);
  }

  /* Multires and dyntopo always draw directly from the PBVH. */
  return true;
}

/* Returns the Face Set random color for rendering in the overlay given its ID and a color seed. */
#define GOLDEN_RATIO_CONJUGATE 0.618033988749895f
void BKE_paint_face_set_overlay_color_get(const int face_set, const int seed, uchar r_color[4])
{
  float rgba[4];
  float random_mod_hue = GOLDEN_RATIO_CONJUGATE * (abs(face_set) + (seed % 10));
  random_mod_hue = random_mod_hue - floorf(random_mod_hue);
  const float random_mod_sat = BLI_hash_int_01(abs(face_set) + seed + 1);
  const float random_mod_val = BLI_hash_int_01(abs(face_set) + seed + 2);
  hsv_to_rgb(random_mod_hue,
             0.6f + (random_mod_sat * 0.25f),
             1.0f - (random_mod_val * 0.35f),
             &rgba[0],
             &rgba[1],
             &rgba[2]);
  rgba_float_to_uchar(r_color, rgba);
}