tornavis/source/blender/blenkernel/intern/material.c

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 */

/** \file
 * \ingroup bke
 */

#include <string.h>
#include <math.h>
#include <stddef.h>

#include "CLG_log.h"

#include "MEM_guardedalloc.h"

#include "DNA_anim_types.h"
#include "DNA_collection_types.h"
#include "DNA_curve_types.h"
#include "DNA_material_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_customdata_types.h"
#include "DNA_gpencil_types.h"
#include "DNA_ID.h"
#include "DNA_meta_types.h"
#include "DNA_node_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"
#include "DNA_defaults.h"

#include "BLI_math.h"
#include "BLI_listbase.h"
#include "BLI_utildefines.h"
#include "BLI_array_utils.h"

#include "BKE_animsys.h"
#include "BKE_brush.h"
#include "BKE_displist.h"
#include "BKE_gpencil.h"
#include "BKE_icons.h"
#include "BKE_image.h"
#include "BKE_lib_id.h"
#include "BKE_main.h"
#include "BKE_material.h"
#include "BKE_mesh.h"
#include "BKE_scene.h"
#include "BKE_node.h"
#include "BKE_curve.h"
#include "BKE_editmesh.h"
#include "BKE_font.h"

#include "DEG_depsgraph.h"
#include "DEG_depsgraph_build.h"

#include "GPU_material.h"

#include "NOD_shader.h"

static CLG_LogRef LOG = {"bke.material"};

/** Free (or release) any data used by this material (does not free the material itself). */
void BKE_material_free(Material *ma)
{
  BKE_animdata_free((ID *)ma, false);

  /* Free gpu material before the ntree */
  GPU_material_free(&ma->gpumaterial);

  /* is no lib link block, but material extension */
  if (ma->nodetree) {
    ntreeFreeNestedTree(ma->nodetree);
    MEM_freeN(ma->nodetree);
    ma->nodetree = NULL;
  }

  MEM_SAFE_FREE(ma->texpaintslot);

  MEM_SAFE_FREE(ma->gp_style);

  BKE_icon_id_delete((ID *)ma);
  BKE_previewimg_free(&ma->preview);
}

void BKE_gpencil_material_attr_init(Material *ma)
{
  if ((ma) && (ma->gp_style == NULL)) {
    ma->gp_style = MEM_callocN(sizeof(MaterialGPencilStyle), "Grease Pencil Material Settings");

    MaterialGPencilStyle *gp_style = ma->gp_style;
    /* set basic settings */
    gp_style->stroke_rgba[3] = 1.0f;
    gp_style->fill_rgba[3] = 1.0f;
    gp_style->pattern_gridsize = 0.1f;
    gp_style->gradient_radius = 0.5f;
    ARRAY_SET_ITEMS(gp_style->mix_rgba, 1.0f, 1.0f, 1.0f, 0.2f);
    ARRAY_SET_ITEMS(gp_style->gradient_scale, 1.0f, 1.0f);
    ARRAY_SET_ITEMS(gp_style->texture_scale, 1.0f, 1.0f);
    gp_style->texture_opacity = 1.0f;
    gp_style->texture_pixsize = 100.0f;

    gp_style->flag |= GP_STYLE_STROKE_SHOW;
  }
}

void BKE_material_init(Material *ma)
{
  BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(ma, id));

  MEMCPY_STRUCT_AFTER(ma, DNA_struct_default_get(Material), id);
}

Material *BKE_material_add(Main *bmain, const char *name)
{
  Material *ma;

  ma = BKE_libblock_alloc(bmain, ID_MA, name, 0);

  BKE_material_init(ma);

  return ma;
}

Material *BKE_gpencil_material_add(Main *bmain, const char *name)
{
  Material *ma;

  ma = BKE_material_add(bmain, name);

  /* grease pencil settings */
  if (ma != NULL) {
    BKE_gpencil_material_attr_init(ma);
  }
  return ma;
}

/**
 * Only copy internal data of Material ID from source
 * to already allocated/initialized destination.
 * You probably never want to use that directly,
 * use #BKE_id_copy or #BKE_id_copy_ex for typical needs.
 *
 * WARNING! This function will not handle ID user count!
 *
 * \param flag: Copying options (see BKE_lib_id.h's LIB_ID_COPY_... flags for more).
 */
void BKE_material_copy_data(Main *bmain, Material *ma_dst, const Material *ma_src, const int flag)
{
  /* We always need allocation of our private ID data. */
  const int flag_private_id_data = flag & ~LIB_ID_CREATE_NO_ALLOCATE;

  if (ma_src->nodetree) {
    BKE_id_copy_ex(bmain, (ID *)ma_src->nodetree, (ID **)&ma_dst->nodetree, flag_private_id_data);
  }

  if ((flag & LIB_ID_COPY_NO_PREVIEW) == 0) {
    BKE_previewimg_id_copy(&ma_dst->id, &ma_src->id);
  }
  else {
    ma_dst->preview = NULL;
  }

  if (ma_src->texpaintslot != NULL) {
    ma_dst->texpaintslot = MEM_dupallocN(ma_src->texpaintslot);
  }

  if (ma_src->gp_style != NULL) {
    ma_dst->gp_style = MEM_dupallocN(ma_src->gp_style);
  }

  BLI_listbase_clear(&ma_dst->gpumaterial);

  /* TODO Duplicate Engine Settings and set runtime to NULL */
}

Material *BKE_material_copy(Main *bmain, const Material *ma)
{
  Material *ma_copy;
  BKE_id_copy(bmain, &ma->id, (ID **)&ma_copy);
  return ma_copy;
}

/* XXX (see above) material copy without adding to main dbase */
Material *BKE_material_localize(Material *ma)
{
  /* TODO(bastien): Replace with something like:
   *
   *   Material *ma_copy;
   *   BKE_id_copy_ex(bmain, &ma->id, (ID **)&ma_copy,
   *                  LIB_ID_COPY_NO_MAIN | LIB_ID_COPY_NO_PREVIEW | LIB_ID_COPY_NO_USER_REFCOUNT,
   *                  false);
   *   return ma_copy;
   *
   * NOTE: Only possible once nested node trees are fully converted to that too. */

  Material *man = BKE_libblock_copy_for_localize(&ma->id);

  man->texpaintslot = NULL;
  man->preview = NULL;

  if (ma->nodetree != NULL) {
    man->nodetree = ntreeLocalize(ma->nodetree);
  }

  if (ma->gp_style != NULL) {
    man->gp_style = MEM_dupallocN(ma->gp_style);
  }

  BLI_listbase_clear(&man->gpumaterial);

  /* TODO Duplicate Engine Settings and set runtime to NULL */

  man->id.tag |= LIB_TAG_LOCALIZED;

  return man;
}

void BKE_material_make_local(Main *bmain, Material *ma, const int flags)
{
  BKE_lib_id_make_local_generic(bmain, &ma->id, flags);
}

Material ***BKE_object_material_array(Object *ob)
{
  Mesh *me;
  Curve *cu;
  MetaBall *mb;
  bGPdata *gpd;

  if (ob->type == OB_MESH) {
    me = ob->data;
    return &(me->mat);
  }
  else if (ELEM(ob->type, OB_CURVE, OB_FONT, OB_SURF)) {
    cu = ob->data;
    return &(cu->mat);
  }
  else if (ob->type == OB_MBALL) {
    mb = ob->data;
    return &(mb->mat);
  }
  else if (ob->type == OB_GPENCIL) {
    gpd = ob->data;
    return &(gpd->mat);
  }
  return NULL;
}

short *BKE_object_material_num(Object *ob)
{
  Mesh *me;
  Curve *cu;
  MetaBall *mb;
  bGPdata *gpd;

  if (ob->type == OB_MESH) {
    me = ob->data;
    return &(me->totcol);
  }
  else if (ELEM(ob->type, OB_CURVE, OB_FONT, OB_SURF)) {
    cu = ob->data;
    return &(cu->totcol);
  }
  else if (ob->type == OB_MBALL) {
    mb = ob->data;
    return &(mb->totcol);
  }
  else if (ob->type == OB_GPENCIL) {
    gpd = ob->data;
    return &(gpd->totcol);
  }
  return NULL;
}

/* same as above but for ID's */
Material ***BKE_id_material_array(ID *id)
{
  /* ensure we don't try get materials from non-obdata */
  BLI_assert(OB_DATA_SUPPORT_ID(GS(id->name)));

  switch (GS(id->name)) {
    case ID_ME:
      return &(((Mesh *)id)->mat);
    case ID_CU:
      return &(((Curve *)id)->mat);
    case ID_MB:
      return &(((MetaBall *)id)->mat);
    case ID_GD:
      return &(((bGPdata *)id)->mat);
    default:
      break;
  }
  return NULL;
}

short *BKE_id_material_num(ID *id)
{
  /* ensure we don't try get materials from non-obdata */
  BLI_assert(OB_DATA_SUPPORT_ID(GS(id->name)));

  switch (GS(id->name)) {
    case ID_ME:
      return &(((Mesh *)id)->totcol);
    case ID_CU:
      return &(((Curve *)id)->totcol);
    case ID_MB:
      return &(((MetaBall *)id)->totcol);
    case ID_GD:
      return &(((bGPdata *)id)->totcol);
    default:
      break;
  }
  return NULL;
}

static void material_data_index_remove_id(ID *id, short index)
{
  /* ensure we don't try get materials from non-obdata */
  BLI_assert(OB_DATA_SUPPORT_ID(GS(id->name)));

  switch (GS(id->name)) {
    case ID_ME:
      BKE_mesh_material_index_remove((Mesh *)id, index);
      break;
    case ID_CU:
      BKE_curve_material_index_remove((Curve *)id, index);
      break;
    case ID_MB:
      /* meta-elems don't have materials atm */
      break;
    default:
      break;
  }
}

bool BKE_object_material_slot_used(ID *id, short actcol)
{
  /* ensure we don't try get materials from non-obdata */
  BLI_assert(OB_DATA_SUPPORT_ID(GS(id->name)));

  switch (GS(id->name)) {
    case ID_ME:
      return BKE_mesh_material_index_used((Mesh *)id, actcol - 1);
    case ID_CU:
      return BKE_curve_material_index_used((Curve *)id, actcol - 1);
    case ID_MB:
      /* meta-elems don't have materials atm */
      return false;
    case ID_GD:
      return BKE_gpencil_material_index_used((bGPdata *)id, actcol - 1);
    default:
      return false;
  }
}

static void material_data_index_clear_id(ID *id)
{
  /* ensure we don't try get materials from non-obdata */
  BLI_assert(OB_DATA_SUPPORT_ID(GS(id->name)));

  switch (GS(id->name)) {
    case ID_ME:
      BKE_mesh_material_index_clear((Mesh *)id);
      break;
    case ID_CU:
      BKE_curve_material_index_clear((Curve *)id);
      break;
    case ID_MB:
      /* meta-elems don't have materials atm */
      break;
    default:
      break;
  }
}

void BKE_material_resize_id(Main *bmain, ID *id, short totcol, bool do_id_user)
{
  Material ***matar = BKE_id_material_array(id);
  short *totcolp = BKE_id_material_num(id);

  if (matar == NULL) {
    return;
  }

  if (do_id_user && totcol < (*totcolp)) {
    short i;
    for (i = totcol; i < (*totcolp); i++) {
      id_us_min((ID *)(*matar)[i]);
    }
  }

  if (totcol == 0) {
    if (*totcolp) {
      MEM_freeN(*matar);
      *matar = NULL;
    }
  }
  else {
    *matar = MEM_recallocN(*matar, sizeof(void *) * totcol);
  }
  *totcolp = totcol;

  DEG_id_tag_update(id, ID_RECALC_COPY_ON_WRITE);
  DEG_relations_tag_update(bmain);
}

void BKE_material_append_id(Main *bmain, ID *id, Material *ma)
{
  Material ***matar;
  if ((matar = BKE_id_material_array(id))) {
    short *totcol = BKE_id_material_num(id);
    Material **mat = MEM_callocN(sizeof(void *) * ((*totcol) + 1), "newmatar");
    if (*totcol) {
      memcpy(mat, *matar, sizeof(void *) * (*totcol));
    }
    if (*matar) {
      MEM_freeN(*matar);
    }

    *matar = mat;
    (*matar)[(*totcol)++] = ma;

    id_us_plus((ID *)ma);
    BKE_objects_materials_test_all(bmain, id);

    DEG_id_tag_update(id, ID_RECALC_COPY_ON_WRITE);
    DEG_relations_tag_update(bmain);
  }
}

Material *BKE_material_pop_id(Main *bmain, ID *id, int index_i)
{
  short index = (short)index_i;
  Material *ret = NULL;
  Material ***matar;
  if ((matar = BKE_id_material_array(id))) {
    short *totcol = BKE_id_material_num(id);
    if (index >= 0 && index < (*totcol)) {
      ret = (*matar)[index];
      id_us_min((ID *)ret);

      if (*totcol <= 1) {
        *totcol = 0;
        MEM_freeN(*matar);
        *matar = NULL;
      }
      else {
        if (index + 1 != (*totcol)) {
          memmove((*matar) + index,
                  (*matar) + (index + 1),
                  sizeof(void *) * ((*totcol) - (index + 1)));
        }

        (*totcol)--;
        *matar = MEM_reallocN(*matar, sizeof(void *) * (*totcol));
        BKE_objects_materials_test_all(bmain, id);
      }

      material_data_index_remove_id(id, index);

      DEG_id_tag_update(id, ID_RECALC_COPY_ON_WRITE);
      DEG_relations_tag_update(bmain);
    }
  }

  return ret;
}

void BKE_material_clear_id(Main *bmain, ID *id)
{
  Material ***matar;
  if ((matar = BKE_id_material_array(id))) {
    short *totcol = BKE_id_material_num(id);

    while ((*totcol)--) {
      id_us_min((ID *)((*matar)[*totcol]));
    }
    *totcol = 0;
    if (*matar) {
      MEM_freeN(*matar);
      *matar = NULL;
    }

    BKE_objects_materials_test_all(bmain, id);
    material_data_index_clear_id(id);

    DEG_id_tag_update(id, ID_RECALC_COPY_ON_WRITE);
    DEG_relations_tag_update(bmain);
  }
}

Material **BKE_object_material_get_p(Object *ob, short act)
{
  Material ***matarar, **ma_p;
  const short *totcolp;

  if (ob == NULL) {
    return NULL;
  }

  /* if object cannot have material, (totcolp == NULL) */
  totcolp = BKE_object_material_num(ob);
  if (totcolp == NULL || ob->totcol == 0) {
    return NULL;
  }

  /* return NULL for invalid 'act', can happen for mesh face indices */
  if (act > ob->totcol) {
    return NULL;
  }
  else if (act <= 0) {
    if (act < 0) {
      CLOG_ERROR(&LOG, "Negative material index!");
    }
    return NULL;
  }

  if (ob->matbits && ob->matbits[act - 1]) { /* in object */
    ma_p = &ob->mat[act - 1];
  }
  else { /* in data */

    /* check for inconsistency */
    if (*totcolp < ob->totcol) {
      ob->totcol = *totcolp;
    }
    if (act > ob->totcol) {
      act = ob->totcol;
    }

    matarar = BKE_object_material_array(ob);

    if (matarar && *matarar) {
      ma_p = &(*matarar)[act - 1];
    }
    else {
      ma_p = NULL;
    }
  }

  return ma_p;
}

Material *BKE_object_material_get(Object *ob, short act)
{
  Material **ma_p = BKE_object_material_get_p(ob, act);
  return ma_p ? *ma_p : NULL;
}

Material *BKE_gpencil_material(Object *ob, short act)
{
  Material *ma = BKE_object_material_get(ob, act);
  if (ma != NULL) {
    return ma;
  }
  else {
    return BKE_material_default_gpencil();
  }
}

MaterialGPencilStyle *BKE_gpencil_material_settings(Object *ob, short act)
{
  Material *ma = BKE_object_material_get(ob, act);
  if (ma != NULL) {
    if (ma->gp_style == NULL) {
      BKE_gpencil_material_attr_init(ma);
    }

    return ma->gp_style;
  }
  else {
    return BKE_material_default_gpencil()->gp_style;
  }
}

void BKE_material_resize_object(Main *bmain, Object *ob, const short totcol, bool do_id_user)
{
  Material **newmatar;
  char *newmatbits;

  if (do_id_user && totcol < ob->totcol) {
    short i;
    for (i = totcol; i < ob->totcol; i++) {
      id_us_min((ID *)ob->mat[i]);
    }
  }

  if (totcol == 0) {
    if (ob->totcol) {
      MEM_freeN(ob->mat);
      MEM_freeN(ob->matbits);
      ob->mat = NULL;
      ob->matbits = NULL;
    }
  }
  else if (ob->totcol < totcol) {
    newmatar = MEM_callocN(sizeof(void *) * totcol, "newmatar");
    newmatbits = MEM_callocN(sizeof(char) * totcol, "newmatbits");
    if (ob->totcol) {
      memcpy(newmatar, ob->mat, sizeof(void *) * ob->totcol);
      memcpy(newmatbits, ob->matbits, sizeof(char) * ob->totcol);
      MEM_freeN(ob->mat);
      MEM_freeN(ob->matbits);
    }
    ob->mat = newmatar;
    ob->matbits = newmatbits;
  }
  /* XXX, why not realloc on shrink? - campbell */

  ob->totcol = totcol;
  if (ob->totcol && ob->actcol == 0) {
    ob->actcol = 1;
  }
  if (ob->actcol > ob->totcol) {
    ob->actcol = ob->totcol;
  }

  DEG_id_tag_update(&ob->id, ID_RECALC_COPY_ON_WRITE | ID_RECALC_GEOMETRY);
  DEG_relations_tag_update(bmain);
}

void BKE_object_materials_test(Main *bmain, Object *ob, ID *id)
{
  /* make the ob mat-array same size as 'ob->data' mat-array */
  const short *totcol;

  if (id == NULL || (totcol = BKE_id_material_num(id)) == NULL) {
    return;
  }

  BKE_material_resize_object(bmain, ob, *totcol, false);
}

void BKE_objects_materials_test_all(Main *bmain, ID *id)
{
  /* make the ob mat-array same size as 'ob->data' mat-array */
  Object *ob;
  const short *totcol;

  if (id == NULL || (totcol = BKE_id_material_num(id)) == NULL) {
    return;
  }

  BKE_main_lock(bmain);
  for (ob = bmain->objects.first; ob; ob = ob->id.next) {
    if (ob->data == id) {
      BKE_material_resize_object(bmain, ob, *totcol, false);
    }
  }
  BKE_main_unlock(bmain);
}

void BKE_id_material_assign(Main *bmain, ID *id, Material *ma, short act)
{
  Material *mao, **matar, ***matarar;
  short *totcolp;

  if (act > MAXMAT) {
    return;
  }
  if (act < 1) {
    act = 1;
  }

  /* test arraylens */

  totcolp = BKE_id_material_num(id);
  matarar = BKE_id_material_array(id);

  if (totcolp == NULL || matarar == NULL) {
    return;
  }

  if (act > *totcolp) {
    matar = MEM_callocN(sizeof(void *) * act, "matarray1");

    if (*totcolp) {
      memcpy(matar, *matarar, sizeof(void *) * (*totcolp));
      MEM_freeN(*matarar);
    }

    *matarar = matar;
    *totcolp = act;
  }

  /* in data */
  mao = (*matarar)[act - 1];
  if (mao) {
    id_us_min(&mao->id);
  }
  (*matarar)[act - 1] = ma;

  if (ma) {
    id_us_plus(&ma->id);
  }

  BKE_objects_materials_test_all(bmain, id);
}

void BKE_object_material_assign(Main *bmain, Object *ob, Material *ma, short act, int assign_type)
{
  Material *mao, **matar, ***matarar;
  short *totcolp;
  char bit = 0;

  if (act > MAXMAT) {
    return;
  }
  if (act < 1) {
    act = 1;
  }

  /* prevent crashing when using accidentally */
  BLI_assert(!ID_IS_LINKED(ob));
  if (ID_IS_LINKED(ob)) {
    return;
  }

  /* test arraylens */

  totcolp = BKE_object_material_num(ob);
  matarar = BKE_object_material_array(ob);

  if (totcolp == NULL || matarar == NULL) {
    return;
  }

  if (act > *totcolp) {
    matar = MEM_callocN(sizeof(void *) * act, "matarray1");

    if (*totcolp) {
      memcpy(matar, *matarar, sizeof(void *) * (*totcolp));
      MEM_freeN(*matarar);
    }

    *matarar = matar;
    *totcolp = act;
  }

  if (act > ob->totcol) {
    /* Need more space in the material arrays */
    ob->mat = MEM_recallocN_id(ob->mat, sizeof(void *) * act, "matarray2");
    ob->matbits = MEM_recallocN_id(ob->matbits, sizeof(char) * act, "matbits1");
    ob->totcol = act;
  }

  /* Determine the object/mesh linking */
  if (assign_type == BKE_MAT_ASSIGN_EXISTING) {
    /* keep existing option (avoid confusion in scripts),
     * intentionally ignore userpref (default to obdata). */
    bit = ob->matbits[act - 1];
  }
  else if (assign_type == BKE_MAT_ASSIGN_USERPREF && ob->totcol && ob->actcol) {
    /* copy from previous material */
    bit = ob->matbits[ob->actcol - 1];
  }
  else {
    switch (assign_type) {
      case BKE_MAT_ASSIGN_OBDATA:
        bit = 0;
        break;
      case BKE_MAT_ASSIGN_OBJECT:
        bit = 1;
        break;
      case BKE_MAT_ASSIGN_USERPREF:
      default:
        bit = (U.flag & USER_MAT_ON_OB) ? 1 : 0;
        break;
    }
  }

  /* do it */

  ob->matbits[act - 1] = bit;
  if (bit == 1) { /* in object */
    mao = ob->mat[act - 1];
    if (mao) {
      id_us_min(&mao->id);
    }
    ob->mat[act - 1] = ma;
    BKE_object_materials_test(bmain, ob, ob->data);
  }
  else { /* in data */
    mao = (*matarar)[act - 1];
    if (mao) {
      id_us_min(&mao->id);
    }
    (*matarar)[act - 1] = ma;
    BKE_objects_materials_test_all(bmain, ob->data); /* Data may be used by several objects... */
  }

  if (ma) {
    id_us_plus(&ma->id);
  }
}

void BKE_material_remap_object(Object *ob, const unsigned int *remap)
{
  Material ***matar = BKE_object_material_array(ob);
  const short *totcol_p = BKE_object_material_num(ob);

  BLI_array_permute(ob->mat, ob->totcol, remap);

  if (ob->matbits) {
    BLI_array_permute(ob->matbits, ob->totcol, remap);
  }

  if (matar) {
    BLI_array_permute(*matar, *totcol_p, remap);
  }

  if (ob->type == OB_MESH) {
    BKE_mesh_material_remap(ob->data, remap, ob->totcol);
  }
  else if (ELEM(ob->type, OB_CURVE, OB_SURF, OB_FONT)) {
    BKE_curve_material_remap(ob->data, remap, ob->totcol);
  }
  else if (ob->type == OB_GPENCIL) {
    BKE_gpencil_material_remap(ob->data, remap, ob->totcol);
  }
  else {
    /* add support for this object data! */
    BLI_assert(matar == NULL);
  }
}

/**
 * Calculate a material remapping from \a ob_src to \a ob_dst.
 *
 * \param remap_src_to_dst: An array the size of `ob_src->totcol`
 * where index values are filled in which map to \a ob_dst materials.
 */
void BKE_material_remap_object_calc(Object *ob_dst, Object *ob_src, short *remap_src_to_dst)
{
  if (ob_src->totcol == 0) {
    return;
  }

  GHash *gh_mat_map = BLI_ghash_ptr_new_ex(__func__, ob_src->totcol);

  for (int i = 0; i < ob_dst->totcol; i++) {
    Material *ma_src = BKE_object_material_get(ob_dst, i + 1);
    BLI_ghash_reinsert(gh_mat_map, ma_src, POINTER_FROM_INT(i), NULL, NULL);
  }

  /* setup default mapping (when materials don't match) */
  {
    int i = 0;
    if (ob_dst->totcol >= ob_src->totcol) {
      for (; i < ob_src->totcol; i++) {
        remap_src_to_dst[i] = i;
      }
    }
    else {
      for (; i < ob_dst->totcol; i++) {
        remap_src_to_dst[i] = i;
      }
      for (; i < ob_src->totcol; i++) {
        remap_src_to_dst[i] = 0;
      }
    }
  }

  for (int i = 0; i < ob_src->totcol; i++) {
    Material *ma_src = BKE_object_material_get(ob_src, i + 1);

    if ((i < ob_dst->totcol) && (ma_src == BKE_object_material_get(ob_dst, i + 1))) {
      /* when objects have exact matching materials - keep existing index */
    }
    else {
      void **index_src_p = BLI_ghash_lookup_p(gh_mat_map, ma_src);
      if (index_src_p) {
        remap_src_to_dst[i] = POINTER_AS_INT(*index_src_p);
      }
    }
  }

  BLI_ghash_free(gh_mat_map, NULL, NULL);
}

/* XXX - this calls many more update calls per object then are needed, could be optimized */
void BKE_object_material_array_assign(Main *bmain,
                                      struct Object *ob,
                                      struct Material ***matar,
                                      short totcol)
{
  int actcol_orig = ob->actcol;
  short i;

  while ((ob->totcol > totcol) && BKE_object_material_slot_remove(bmain, ob)) {
    /* pass */
  }

  /* now we have the right number of slots */
  for (i = 0; i < totcol; i++) {
    BKE_object_material_assign(bmain, ob, (*matar)[i], i + 1, BKE_MAT_ASSIGN_USERPREF);
  }

  if (actcol_orig > ob->totcol) {
    actcol_orig = ob->totcol;
  }

  ob->actcol = actcol_orig;
}

short BKE_object_material_slot_find_index(Object *ob, Material *ma)
{
  Material ***matarar;
  short a, *totcolp;

  if (ma == NULL) {
    return 0;
  }

  totcolp = BKE_object_material_num(ob);
  matarar = BKE_object_material_array(ob);

  if (totcolp == NULL || matarar == NULL) {
    return 0;
  }

  for (a = 0; a < *totcolp; a++) {
    if ((*matarar)[a] == ma) {
      break;
    }
  }
  if (a < *totcolp) {
    return a + 1;
  }
  return 0;
}

bool BKE_object_material_slot_add(Main *bmain, Object *ob)
{
  if (ob == NULL) {
    return false;
  }
  if (ob->totcol >= MAXMAT) {
    return false;
  }

  BKE_object_material_assign(bmain, ob, NULL, ob->totcol + 1, BKE_MAT_ASSIGN_USERPREF);
  ob->actcol = ob->totcol;
  return true;
}

/* ****************** */

bool BKE_object_material_slot_remove(Main *bmain, Object *ob)
{
  Material *mao, ***matarar;
  short *totcolp;
  short a, actcol;

  if (ob == NULL || ob->totcol == 0) {
    return false;
  }

  /* this should never happen and used to crash */
  if (ob->actcol <= 0) {
    CLOG_ERROR(&LOG, "invalid material index %d, report a bug!", ob->actcol);
    BLI_assert(0);
    return false;
  }

  /* take a mesh/curve/mball as starting point, remove 1 index,
   * AND with all objects that share the ob->data
   *
   * after that check indices in mesh/curve/mball!!!
   */

  totcolp = BKE_object_material_num(ob);
  matarar = BKE_object_material_array(ob);

  if (ELEM(NULL, matarar, *matarar)) {
    return false;
  }

  /* can happen on face selection in editmode */
  if (ob->actcol > ob->totcol) {
    ob->actcol = ob->totcol;
  }

  /* we delete the actcol */
  mao = (*matarar)[ob->actcol - 1];
  if (mao) {
    id_us_min(&mao->id);
  }

  for (a = ob->actcol; a < ob->totcol; a++) {
    (*matarar)[a - 1] = (*matarar)[a];
  }
  (*totcolp)--;

  if (*totcolp == 0) {
    MEM_freeN(*matarar);
    *matarar = NULL;
  }

  actcol = ob->actcol;

  for (Object *obt = bmain->objects.first; obt; obt = obt->id.next) {
    if (obt->data == ob->data) {
      /* Can happen when object material lists are used, see: T52953 */
      if (actcol > obt->totcol) {
        continue;
      }
      /* WATCH IT: do not use actcol from ob or from obt (can become zero) */
      mao = obt->mat[actcol - 1];
      if (mao) {
        id_us_min(&mao->id);
      }

      for (a = actcol; a < obt->totcol; a++) {
        obt->mat[a - 1] = obt->mat[a];
        obt->matbits[a - 1] = obt->matbits[a];
      }
      obt->totcol--;
      if (obt->actcol > obt->totcol) {
        obt->actcol = obt->totcol;
      }

      if (obt->totcol == 0) {
        MEM_freeN(obt->mat);
        MEM_freeN(obt->matbits);
        obt->mat = NULL;
        obt->matbits = NULL;
      }
    }
  }

  /* check indices from mesh */
  if (ELEM(ob->type, OB_MESH, OB_CURVE, OB_SURF, OB_FONT)) {
    material_data_index_remove_id((ID *)ob->data, actcol - 1);
    if (ob->runtime.curve_cache) {
      BKE_displist_free(&ob->runtime.curve_cache->disp);
    }
  }
  /* check indices from gpencil */
  else if (ob->type == OB_GPENCIL) {
    BKE_gpencil_material_index_reassign((bGPdata *)ob->data, ob->totcol, actcol - 1);
  }

  return true;
}

static bNode *nodetree_uv_node_recursive(bNode *node)
{
  bNode *inode;
  bNodeSocket *sock;

  for (sock = node->inputs.first; sock; sock = sock->next) {
    if (sock->link) {
      inode = sock->link->fromnode;
      if (inode->typeinfo->nclass == NODE_CLASS_INPUT && inode->typeinfo->type == SH_NODE_UVMAP) {
        return inode;
      }
      else {
        return nodetree_uv_node_recursive(inode);
      }
    }
  }

  return NULL;
}

typedef bool (*ForEachTexNodeCallback)(bNode *node, void *userdata);
static bool ntree_foreach_texnode_recursive(bNodeTree *nodetree,
                                            ForEachTexNodeCallback callback,
                                            void *userdata)
{
  for (bNode *node = nodetree->nodes.first; node; node = node->next) {
    if (node->typeinfo->nclass == NODE_CLASS_TEXTURE &&
        node->typeinfo->type == SH_NODE_TEX_IMAGE && node->id) {
      if (!callback(node, userdata)) {
        return false;
      }
    }
    else if (ELEM(node->type, NODE_GROUP, NODE_CUSTOM_GROUP) && node->id) {
      /* recurse into the node group and see if it contains any textures */
      if (!ntree_foreach_texnode_recursive((bNodeTree *)node->id, callback, userdata)) {
        return false;
      }
    }
  }
  return true;
}

static bool count_texture_nodes_cb(bNode *UNUSED(node), void *userdata)
{
  (*((int *)userdata))++;
  return true;
}

static int count_texture_nodes_recursive(bNodeTree *nodetree)
{
  int tex_nodes = 0;
  ntree_foreach_texnode_recursive(nodetree, count_texture_nodes_cb, &tex_nodes);

  return tex_nodes;
}

struct FillTexPaintSlotsData {
  bNode *active_node;
  Material *ma;
  int index;
  int slot_len;
};

static bool fill_texpaint_slots_cb(bNode *node, void *userdata)
{
  struct FillTexPaintSlotsData *fill_data = userdata;

  Material *ma = fill_data->ma;
  int index = fill_data->index;
  fill_data->index++;

  if (fill_data->active_node == node) {
    ma->paint_active_slot = index;
  }

  ma->texpaintslot[index].ima = (Image *)node->id;
  ma->texpaintslot[index].interp = ((NodeTexImage *)node->storage)->interpolation;

  /* for new renderer, we need to traverse the treeback in search of a UV node */
  bNode *uvnode = nodetree_uv_node_recursive(node);

  if (uvnode) {
    NodeShaderUVMap *storage = (NodeShaderUVMap *)uvnode->storage;
    ma->texpaintslot[index].uvname = storage->uv_map;
    /* set a value to index so UI knows that we have a valid pointer for the mesh */
    ma->texpaintslot[index].valid = true;
  }
  else {
    /* just invalidate the index here so UV map does not get displayed on the UI */
    ma->texpaintslot[index].valid = false;
  }

  return fill_data->index != fill_data->slot_len;
}

static void fill_texpaint_slots_recursive(bNodeTree *nodetree,
                                          bNode *active_node,
                                          Material *ma,
                                          int slot_len)
{
  struct FillTexPaintSlotsData fill_data = {active_node, ma, 0, slot_len};
  ntree_foreach_texnode_recursive(nodetree, fill_texpaint_slots_cb, &fill_data);
}

void BKE_texpaint_slot_refresh_cache(Scene *scene, Material *ma)
{
  int count = 0;

  if (!ma) {
    return;
  }

  /* COW needed when adding texture slot on an object with no materials. */
  DEG_id_tag_update(&ma->id, ID_RECALC_SHADING | ID_RECALC_COPY_ON_WRITE);

  if (ma->texpaintslot) {
    MEM_freeN(ma->texpaintslot);
    ma->tot_slots = 0;
    ma->texpaintslot = NULL;
  }

  if (scene->toolsettings->imapaint.mode == IMAGEPAINT_MODE_IMAGE) {
    ma->paint_active_slot = 0;
    ma->paint_clone_slot = 0;
    return;
  }

  if (!(ma->nodetree)) {
    ma->paint_active_slot = 0;
    ma->paint_clone_slot = 0;
    return;
  }

  count = count_texture_nodes_recursive(ma->nodetree);

  if (count == 0) {
    ma->paint_active_slot = 0;
    ma->paint_clone_slot = 0;
    return;
  }

  ma->texpaintslot = MEM_callocN(sizeof(*ma->texpaintslot) * count, "texpaint_slots");

  bNode *active_node = nodeGetActiveTexture(ma->nodetree);

  fill_texpaint_slots_recursive(ma->nodetree, active_node, ma, count);

  ma->tot_slots = count;

  if (ma->paint_active_slot >= count) {
    ma->paint_active_slot = count - 1;
  }

  if (ma->paint_clone_slot >= count) {
    ma->paint_clone_slot = count - 1;
  }

  return;
}

void BKE_texpaint_slots_refresh_object(Scene *scene, struct Object *ob)
{
  int i;

  for (i = 1; i < ob->totcol + 1; i++) {
    Material *ma = BKE_object_material_get(ob, i);
    BKE_texpaint_slot_refresh_cache(scene, ma);
  }
}

struct FindTexPaintNodeData {
  bNode *node;
  short iter_index;
  short index;
};

static bool texpaint_slot_node_find_cb(bNode *node, void *userdata)
{
  struct FindTexPaintNodeData *find_data = userdata;
  if (find_data->iter_index++ == find_data->index) {
    find_data->node = node;
    return false;
  }

  return true;
}

bNode *BKE_texpaint_slot_material_find_node(Material *ma, short texpaint_slot)
{
  struct FindTexPaintNodeData find_data = {NULL, 0, texpaint_slot};
  ntree_foreach_texnode_recursive(ma->nodetree, texpaint_slot_node_find_cb, &find_data);

  return find_data.node;
}

/* r_col = current value, col = new value, (fac == 0) is no change */
void ramp_blend(int type, float r_col[3], const float fac, const float col[3])
{
  float tmp, facm = 1.0f - fac;

  switch (type) {
    case MA_RAMP_BLEND:
      r_col[0] = facm * (r_col[0]) + fac * col[0];
      r_col[1] = facm * (r_col[1]) + fac * col[1];
      r_col[2] = facm * (r_col[2]) + fac * col[2];
      break;
    case MA_RAMP_ADD:
      r_col[0] += fac * col[0];
      r_col[1] += fac * col[1];
      r_col[2] += fac * col[2];
      break;
    case MA_RAMP_MULT:
      r_col[0] *= (facm + fac * col[0]);
      r_col[1] *= (facm + fac * col[1]);
      r_col[2] *= (facm + fac * col[2]);
      break;
    case MA_RAMP_SCREEN:
      r_col[0] = 1.0f - (facm + fac * (1.0f - col[0])) * (1.0f - r_col[0]);
      r_col[1] = 1.0f - (facm + fac * (1.0f - col[1])) * (1.0f - r_col[1]);
      r_col[2] = 1.0f - (facm + fac * (1.0f - col[2])) * (1.0f - r_col[2]);
      break;
    case MA_RAMP_OVERLAY:
      if (r_col[0] < 0.5f) {
        r_col[0] *= (facm + 2.0f * fac * col[0]);
      }
      else {
        r_col[0] = 1.0f - (facm + 2.0f * fac * (1.0f - col[0])) * (1.0f - r_col[0]);
      }
      if (r_col[1] < 0.5f) {
        r_col[1] *= (facm + 2.0f * fac * col[1]);
      }
      else {
        r_col[1] = 1.0f - (facm + 2.0f * fac * (1.0f - col[1])) * (1.0f - r_col[1]);
      }
      if (r_col[2] < 0.5f) {
        r_col[2] *= (facm + 2.0f * fac * col[2]);
      }
      else {
        r_col[2] = 1.0f - (facm + 2.0f * fac * (1.0f - col[2])) * (1.0f - r_col[2]);
      }
      break;
    case MA_RAMP_SUB:
      r_col[0] -= fac * col[0];
      r_col[1] -= fac * col[1];
      r_col[2] -= fac * col[2];
      break;
    case MA_RAMP_DIV:
      if (col[0] != 0.0f) {
        r_col[0] = facm * (r_col[0]) + fac * (r_col[0]) / col[0];
      }
      if (col[1] != 0.0f) {
        r_col[1] = facm * (r_col[1]) + fac * (r_col[1]) / col[1];
      }
      if (col[2] != 0.0f) {
        r_col[2] = facm * (r_col[2]) + fac * (r_col[2]) / col[2];
      }
      break;
    case MA_RAMP_DIFF:
      r_col[0] = facm * (r_col[0]) + fac * fabsf(r_col[0] - col[0]);
      r_col[1] = facm * (r_col[1]) + fac * fabsf(r_col[1] - col[1]);
      r_col[2] = facm * (r_col[2]) + fac * fabsf(r_col[2] - col[2]);
      break;
    case MA_RAMP_DARK:
      r_col[0] = min_ff(r_col[0], col[0]) * fac + r_col[0] * facm;
      r_col[1] = min_ff(r_col[1], col[1]) * fac + r_col[1] * facm;
      r_col[2] = min_ff(r_col[2], col[2]) * fac + r_col[2] * facm;
      break;
    case MA_RAMP_LIGHT:
      tmp = fac * col[0];
      if (tmp > r_col[0]) {
        r_col[0] = tmp;
      }
      tmp = fac * col[1];
      if (tmp > r_col[1]) {
        r_col[1] = tmp;
      }
      tmp = fac * col[2];
      if (tmp > r_col[2]) {
        r_col[2] = tmp;
      }
      break;
    case MA_RAMP_DODGE:
      if (r_col[0] != 0.0f) {
        tmp = 1.0f - fac * col[0];
        if (tmp <= 0.0f) {
          r_col[0] = 1.0f;
        }
        else if ((tmp = (r_col[0]) / tmp) > 1.0f) {
          r_col[0] = 1.0f;
        }
        else {
          r_col[0] = tmp;
        }
      }
      if (r_col[1] != 0.0f) {
        tmp = 1.0f - fac * col[1];
        if (tmp <= 0.0f) {
          r_col[1] = 1.0f;
        }
        else if ((tmp = (r_col[1]) / tmp) > 1.0f) {
          r_col[1] = 1.0f;
        }
        else {
          r_col[1] = tmp;
        }
      }
      if (r_col[2] != 0.0f) {
        tmp = 1.0f - fac * col[2];
        if (tmp <= 0.0f) {
          r_col[2] = 1.0f;
        }
        else if ((tmp = (r_col[2]) / tmp) > 1.0f) {
          r_col[2] = 1.0f;
        }
        else {
          r_col[2] = tmp;
        }
      }
      break;
    case MA_RAMP_BURN:
      tmp = facm + fac * col[0];

      if (tmp <= 0.0f) {
        r_col[0] = 0.0f;
      }
      else if ((tmp = (1.0f - (1.0f - (r_col[0])) / tmp)) < 0.0f) {
        r_col[0] = 0.0f;
      }
      else if (tmp > 1.0f) {
        r_col[0] = 1.0f;
      }
      else {
        r_col[0] = tmp;
      }

      tmp = facm + fac * col[1];
      if (tmp <= 0.0f) {
        r_col[1] = 0.0f;
      }
      else if ((tmp = (1.0f - (1.0f - (r_col[1])) / tmp)) < 0.0f) {
        r_col[1] = 0.0f;
      }
      else if (tmp > 1.0f) {
        r_col[1] = 1.0f;
      }
      else {
        r_col[1] = tmp;
      }

      tmp = facm + fac * col[2];
      if (tmp <= 0.0f) {
        r_col[2] = 0.0f;
      }
      else if ((tmp = (1.0f - (1.0f - (r_col[2])) / tmp)) < 0.0f) {
        r_col[2] = 0.0f;
      }
      else if (tmp > 1.0f) {
        r_col[2] = 1.0f;
      }
      else {
        r_col[2] = tmp;
      }
      break;
    case MA_RAMP_HUE: {
      float rH, rS, rV;
      float colH, colS, colV;
      float tmpr, tmpg, tmpb;
      rgb_to_hsv(col[0], col[1], col[2], &colH, &colS, &colV);
      if (colS != 0) {
        rgb_to_hsv(r_col[0], r_col[1], r_col[2], &rH, &rS, &rV);
        hsv_to_rgb(colH, rS, rV, &tmpr, &tmpg, &tmpb);
        r_col[0] = facm * (r_col[0]) + fac * tmpr;
        r_col[1] = facm * (r_col[1]) + fac * tmpg;
        r_col[2] = facm * (r_col[2]) + fac * tmpb;
      }
      break;
    }
    case MA_RAMP_SAT: {
      float rH, rS, rV;
      float colH, colS, colV;
      rgb_to_hsv(r_col[0], r_col[1], r_col[2], &rH, &rS, &rV);
      if (rS != 0) {
        rgb_to_hsv(col[0], col[1], col[2], &colH, &colS, &colV);
        hsv_to_rgb(rH, (facm * rS + fac * colS), rV, r_col + 0, r_col + 1, r_col + 2);
      }
      break;
    }
    case MA_RAMP_VAL: {
      float rH, rS, rV;
      float colH, colS, colV;
      rgb_to_hsv(r_col[0], r_col[1], r_col[2], &rH, &rS, &rV);
      rgb_to_hsv(col[0], col[1], col[2], &colH, &colS, &colV);
      hsv_to_rgb(rH, rS, (facm * rV + fac * colV), r_col + 0, r_col + 1, r_col + 2);
      break;
    }
    case MA_RAMP_COLOR: {
      float rH, rS, rV;
      float colH, colS, colV;
      float tmpr, tmpg, tmpb;
      rgb_to_hsv(col[0], col[1], col[2], &colH, &colS, &colV);
      if (colS != 0) {
        rgb_to_hsv(r_col[0], r_col[1], r_col[2], &rH, &rS, &rV);
        hsv_to_rgb(colH, colS, rV, &tmpr, &tmpg, &tmpb);
        r_col[0] = facm * (r_col[0]) + fac * tmpr;
        r_col[1] = facm * (r_col[1]) + fac * tmpg;
        r_col[2] = facm * (r_col[2]) + fac * tmpb;
      }
      break;
    }
    case MA_RAMP_SOFT: {
      float scr, scg, scb;

      /* first calculate non-fac based Screen mix */
      scr = 1.0f - (1.0f - col[0]) * (1.0f - r_col[0]);
      scg = 1.0f - (1.0f - col[1]) * (1.0f - r_col[1]);
      scb = 1.0f - (1.0f - col[2]) * (1.0f - r_col[2]);

      r_col[0] = facm * (r_col[0]) +
                 fac * (((1.0f - r_col[0]) * col[0] * (r_col[0])) + (r_col[0] * scr));
      r_col[1] = facm * (r_col[1]) +
                 fac * (((1.0f - r_col[1]) * col[1] * (r_col[1])) + (r_col[1] * scg));
      r_col[2] = facm * (r_col[2]) +
                 fac * (((1.0f - r_col[2]) * col[2] * (r_col[2])) + (r_col[2] * scb));
      break;
    }
    case MA_RAMP_LINEAR:
      if (col[0] > 0.5f) {
        r_col[0] = r_col[0] + fac * (2.0f * (col[0] - 0.5f));
      }
      else {
        r_col[0] = r_col[0] + fac * (2.0f * (col[0]) - 1.0f);
      }
      if (col[1] > 0.5f) {
        r_col[1] = r_col[1] + fac * (2.0f * (col[1] - 0.5f));
      }
      else {
        r_col[1] = r_col[1] + fac * (2.0f * (col[1]) - 1.0f);
      }
      if (col[2] > 0.5f) {
        r_col[2] = r_col[2] + fac * (2.0f * (col[2] - 0.5f));
      }
      else {
        r_col[2] = r_col[2] + fac * (2.0f * (col[2]) - 1.0f);
      }
      break;
  }
}

/**
 * \brief copy/paste buffer, if we had a proper py api that would be better
 * \note matcopybuf.nodetree does _NOT_ use ID's
 * \todo matcopybuf.nodetree's  node->id's are NOT validated, this will crash!
 */
static Material matcopybuf;
static short matcopied = 0;

void BKE_material_copybuf_clear(void)
{
  memset(&matcopybuf, 0, sizeof(Material));
  matcopied = 0;
}

void BKE_material_copybuf_free(void)
{
  if (matcopybuf.nodetree) {
    ntreeFreeLocalTree(matcopybuf.nodetree);
    MEM_freeN(matcopybuf.nodetree);
    matcopybuf.nodetree = NULL;
  }

  matcopied = 0;
}

void BKE_material_copybuf_copy(Main *bmain, Material *ma)
{
  if (matcopied) {
    BKE_material_copybuf_free();
  }

  memcpy(&matcopybuf, ma, sizeof(Material));

  if (ma->nodetree != NULL) {
    matcopybuf.nodetree = ntreeCopyTree_ex(ma->nodetree, bmain, false);
  }

  matcopybuf.preview = NULL;
  BLI_listbase_clear(&matcopybuf.gpumaterial);
  /* TODO Duplicate Engine Settings and set runtime to NULL */
  matcopied = 1;
}

void BKE_material_copybuf_paste(Main *bmain, Material *ma)
{
  ID id;

  if (matcopied == 0) {
    return;
  }

  /* Free gpu material before the ntree */
  GPU_material_free(&ma->gpumaterial);

  if (ma->nodetree) {
    ntreeFreeNestedTree(ma->nodetree);
    MEM_freeN(ma->nodetree);
  }

  id = (ma->id);
  memcpy(ma, &matcopybuf, sizeof(Material));
  (ma->id) = id;

  if (matcopybuf.nodetree != NULL) {
    ma->nodetree = ntreeCopyTree_ex(matcopybuf.nodetree, bmain, false);
  }
}

void BKE_material_eval(struct Depsgraph *depsgraph, Material *material)
{
  DEG_debug_print_eval(depsgraph, __func__, material->id.name, material);
  GPU_material_free(&material->gpumaterial);
}

/* Default Materials
 *
 * Used for rendering when objects have no materials assigned, and initializing
 * default shader nodes. */

static Material default_material_empty;
static Material default_material_surface;
static Material default_material_volume;
static Material default_material_gpencil;

static Material *default_materials[] = {&default_material_empty,
                                        &default_material_surface,
                                        &default_material_volume,
                                        &default_material_gpencil,
                                        NULL};

static void material_default_gpencil_init(Material *ma)
{
  strcpy(ma->id.name, "MADefault GPencil");
  BKE_gpencil_material_attr_init(ma);
  add_v3_fl(&ma->gp_style->stroke_rgba[0], 0.6f);
}

static void material_default_surface_init(Material *ma)
{
  bNodeTree *ntree = ntreeAddTree(NULL, "Shader Nodetree", ntreeType_Shader->idname);
  ma->nodetree = ntree;
  ma->use_nodes = true;

  bNode *principled = nodeAddStaticNode(NULL, ntree, SH_NODE_BSDF_PRINCIPLED);
  bNodeSocket *base_color = nodeFindSocket(principled, SOCK_IN, "Base Color");
  copy_v3_v3(((bNodeSocketValueRGBA *)base_color->default_value)->value, &ma->r);

  bNode *output = nodeAddStaticNode(NULL, ntree, SH_NODE_OUTPUT_MATERIAL);

  nodeAddLink(ntree,
              principled,
              nodeFindSocket(principled, SOCK_OUT, "BSDF"),
              output,
              nodeFindSocket(output, SOCK_IN, "Surface"));

  principled->locx = 10.0f;
  principled->locy = 300.0f;
  output->locx = 300.0f;
  output->locy = 300.0f;

  nodeSetActive(ntree, output);
}

static void material_default_volume_init(Material *ma)
{
  bNodeTree *ntree = ntreeAddTree(NULL, "Shader Nodetree", ntreeType_Shader->idname);
  ma->nodetree = ntree;
  ma->use_nodes = true;

  bNode *principled = nodeAddStaticNode(NULL, ntree, SH_NODE_VOLUME_PRINCIPLED);
  bNode *output = nodeAddStaticNode(NULL, ntree, SH_NODE_OUTPUT_MATERIAL);

  nodeAddLink(ntree,
              principled,
              nodeFindSocket(principled, SOCK_OUT, "Volume"),
              output,
              nodeFindSocket(output, SOCK_IN, "Volume"));

  principled->locx = 10.0f;
  principled->locy = 300.0f;
  output->locx = 300.0f;
  output->locy = 300.0f;

  nodeSetActive(ntree, output);
}

Material *BKE_material_default_empty(void)
{
  return &default_material_empty;
}

Material *BKE_material_default_surface(void)
{
  return &default_material_surface;
}

Material *BKE_material_default_volume(void)
{
  return &default_material_volume;
}

Material *BKE_material_default_gpencil(void)
{
  return &default_material_gpencil;
}

void BKE_material_defaults_free_gpu(void)
{
  for (int i = 0; default_materials[i]; i++) {
    Material *ma = default_materials[i];
    if (ma->gpumaterial.first) {
      GPU_material_free(&ma->gpumaterial);
    }
  }
}

/* Module functions called on startup and exit. */

void BKE_materials_init(void)
{
  for (int i = 0; default_materials[i]; i++) {
    BKE_material_init(default_materials[i]);
  }

  material_default_surface_init(&default_material_surface);
  material_default_volume_init(&default_material_volume);
  material_default_gpencil_init(&default_material_gpencil);
}

void BKE_materials_exit(void)
{
  for (int i = 0; default_materials[i]; i++) {
    BKE_material_free(default_materials[i]);
  }
}