Refactor: move CustomData .blend I/O to blenkernel

This is part of T76372.

4 files changed, 220 insertions, 257 deletions

diff --git a/source/blender/blenkernel/BKE_customdata.h b/source/blender/blenkernel/BKE_customdata.h
index 92bfa3a9490..25360d4b3fa 100644
--- a/source/blender/blenkernel/BKE_customdata.h
+++ b/source/blender/blenkernel/BKE_customdata.h
@@ -37,6 +37,8 @@ struct BMesh;
 struct CustomData;
 struct CustomData_MeshMasks;
 struct ID;
+struct BlendWriter;
+struct BlendDataReader;
 typedef uint64_t CustomDataMask;
 
 /*a data type large enough to hold 1 element from any customdata layer type*/
@@ -571,6 +573,14 @@ typedef struct CustomDataTransferLayerMap {
 void CustomData_data_transfer(const struct MeshPairRemap *me_remap,
                               const CustomDataTransferLayerMap *laymap);
 
+/* .blend file I/O */
+void CustomData_blend_write(struct BlendWriter *writer,
+                            struct CustomData *data,
+                            int count,
+                            CustomDataMask cddata_mask,
+                            struct ID *id);
+void CustomData_blend_read(struct BlendDataReader *reader, struct CustomData *data, int count);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/blenkernel/intern/customdata.c b/source/blender/blenkernel/intern/customdata.c
index f728436a759..b75efb6cdf1 100644
--- a/source/blender/blenkernel/intern/customdata.c
+++ b/source/blender/blenkernel/intern/customdata.c
@@ -35,6 +35,8 @@
 #include "DNA_meshdata_types.h"
 #include "DNA_pointcloud_types.h"
 
+#include "BLI_bitmap.h"
+#include "BLI_endian_switch.h"
 #include "BLI_math.h"
 #include "BLI_math_color_blend.h"
 #include "BLI_mempool.h"
@@ -47,10 +49,14 @@
 
 #include "BKE_customdata.h"
 #include "BKE_customdata_file.h"
+#include "BKE_deform.h"
 #include "BKE_main.h"
 #include "BKE_mesh_mapping.h"
 #include "BKE_mesh_remap.h"
 #include "BKE_multires.h"
+#include "BKE_subsurf.h"
+
+#include "BLO_read_write.h"
 
 #include "bmesh.h"
 
@@ -5155,3 +5161,181 @@ void CustomData_data_transfer(const MeshPairRemap *me_remap,
 
   MEM_SAFE_FREE(tmp_data_src);
 }
+
+static void write_mdisps(BlendWriter *writer, int count, MDisps *mdlist, int external)
+{
+  if (mdlist) {
+    BLO_write_struct_array(writer, MDisps, count, mdlist);
+    for (int i = 0; i < count; i++) {
+      MDisps *md = &mdlist[i];
+      if (md->disps) {
+        if (!external) {
+          BLO_write_float3_array(writer, md->totdisp, &md->disps[0][0]);
+        }
+      }
+
+      if (md->hidden) {
+        BLO_write_raw(writer, BLI_BITMAP_SIZE(md->totdisp), md->hidden);
+      }
+    }
+  }
+}
+
+static void write_grid_paint_mask(BlendWriter *writer, int count, GridPaintMask *grid_paint_mask)
+{
+  if (grid_paint_mask) {
+    BLO_write_struct_array(writer, GridPaintMask, count, grid_paint_mask);
+    for (int i = 0; i < count; i++) {
+      GridPaintMask *gpm = &grid_paint_mask[i];
+      if (gpm->data) {
+        const int gridsize = BKE_ccg_gridsize(gpm->level);
+        BLO_write_raw(writer, sizeof(*gpm->data) * gridsize * gridsize, gpm->data);
+      }
+    }
+  }
+}
+
+void CustomData_blend_write(
+    BlendWriter *writer, CustomData *data, int count, CustomDataMask cddata_mask, ID *id)
+{
+  CustomDataLayer *layers = NULL;
+  CustomDataLayer layers_buff[CD_TEMP_CHUNK_SIZE];
+  CustomData_file_write_prepare(data, &layers, layers_buff, ARRAY_SIZE(layers_buff));
+
+  /* write external customdata (not for undo) */
+  if (data->external && !BLO_write_is_undo(writer)) {
+    CustomData_external_write(data, id, cddata_mask, count, 0);
+  }
+
+  BLO_write_struct_array_at_address(writer, CustomDataLayer, data->totlayer, data->layers, layers);
+
+  for (int i = 0; i < data->totlayer; i++) {
+    CustomDataLayer *layer = &layers[i];
+
+    if (layer->type == CD_MDEFORMVERT) {
+      /* layer types that allocate own memory need special handling */
+      BKE_defvert_blend_write(writer, count, layer->data);
+    }
+    else if (layer->type == CD_MDISPS) {
+      write_mdisps(writer, count, layer->data, layer->flag & CD_FLAG_EXTERNAL);
+    }
+    else if (layer->type == CD_PAINT_MASK) {
+      const float *layer_data = layer->data;
+      BLO_write_raw(writer, sizeof(*layer_data) * count, layer_data);
+    }
+    else if (layer->type == CD_SCULPT_FACE_SETS) {
+      const float *layer_data = layer->data;
+      BLO_write_raw(writer, sizeof(*layer_data) * count, layer_data);
+    }
+    else if (layer->type == CD_GRID_PAINT_MASK) {
+      write_grid_paint_mask(writer, count, layer->data);
+    }
+    else if (layer->type == CD_FACEMAP) {
+      const int *layer_data = layer->data;
+      BLO_write_raw(writer, sizeof(*layer_data) * count, layer_data);
+    }
+    else {
+      const char *structname;
+      int structnum;
+      CustomData_file_write_info(layer->type, &structname, &structnum);
+      if (structnum) {
+        int datasize = structnum * count;
+        BLO_write_struct_array_by_name(writer, structname, datasize, layer->data);
+      }
+      else if (!BLO_write_is_undo(writer)) { /* Do not warn on undo. */
+        printf("%s error: layer '%s':%d - can't be written to file\n",
+               __func__,
+               structname,
+               layer->type);
+      }
+    }
+  }
+
+  if (data->external) {
+    BLO_write_struct(writer, CustomDataExternal, data->external);
+  }
+
+  if (!ELEM(layers, NULL, layers_buff)) {
+    MEM_freeN(layers);
+  }
+}
+
+static void blend_read_mdisps(BlendDataReader *reader, int count, MDisps *mdisps, int external)
+{
+  if (mdisps) {
+    for (int i = 0; i < count; i++) {
+      BLO_read_data_address(reader, &mdisps[i].disps);
+      BLO_read_data_address(reader, &mdisps[i].hidden);
+
+      if (mdisps[i].totdisp && !mdisps[i].level) {
+        /* this calculation is only correct for loop mdisps;
+         * if loading pre-BMesh face mdisps this will be
+         * overwritten with the correct value in
+         * bm_corners_to_loops() */
+        float gridsize = sqrtf(mdisps[i].totdisp);
+        mdisps[i].level = (int)(logf(gridsize - 1.0f) / (float)M_LN2) + 1;
+      }
+
+      if (BLO_read_requires_endian_switch(reader) && (mdisps[i].disps)) {
+        /* DNA_struct_switch_endian doesn't do endian swap for (*disps)[] */
+        /* this does swap for data written at write_mdisps() - readfile.c */
+        BLI_endian_switch_float_array(*mdisps[i].disps, mdisps[i].totdisp * 3);
+      }
+      if (!external && !mdisps[i].disps) {
+        mdisps[i].totdisp = 0;
+      }
+    }
+  }
+}
+
+static void blend_read_paint_mask(BlendDataReader *reader,
+                                  int count,
+                                  GridPaintMask *grid_paint_mask)
+{
+  if (grid_paint_mask) {
+    for (int i = 0; i < count; i++) {
+      GridPaintMask *gpm = &grid_paint_mask[i];
+      if (gpm->data) {
+        BLO_read_data_address(reader, &gpm->data);
+      }
+    }
+  }
+}
+
+void CustomData_blend_read(BlendDataReader *reader, CustomData *data, int count)
+{
+  BLO_read_data_address(reader, &data->layers);
+
+  /* annoying workaround for bug [#31079] loading legacy files with
+   * no polygons _but_ have stale customdata */
+  if (UNLIKELY(count == 0 && data->layers == NULL && data->totlayer != 0)) {
+    CustomData_reset(data);
+    return;
+  }
+
+  BLO_read_data_address(reader, &data->external);
+
+  int i = 0;
+  while (i < data->totlayer) {
+    CustomDataLayer *layer = &data->layers[i];
+
+    if (layer->flag & CD_FLAG_EXTERNAL) {
+      layer->flag &= ~CD_FLAG_IN_MEMORY;
+    }
+
+    layer->flag &= ~CD_FLAG_NOFREE;
+
+    if (CustomData_verify_versions(data, i)) {
+      BLO_read_data_address(reader, &layer->data);
+      if (layer->type == CD_MDISPS) {
+        blend_read_mdisps(reader, count, layer->data, layer->flag & CD_FLAG_EXTERNAL);
+      }
+      else if (layer->type == CD_GRID_PAINT_MASK) {
+        blend_read_paint_mask(reader, count, layer->data);
+      }
+      i++;
+    }
+  }
+
+  CustomData_update_typemap(data);
+}
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index eed85546ab4..0e134d172c2 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -4126,88 +4126,6 @@ static void lib_link_mesh(BlendLibReader *reader, Mesh *me)
   BLO_read_id_address(reader, me->id.lib, &me->texcomesh);
 }
 
-static void direct_link_mdisps(BlendDataReader *reader, int count, MDisps *mdisps, int external)
-{
-  if (mdisps) {
-    for (int i = 0; i < count; i++) {
-      BLO_read_data_address(reader, &mdisps[i].disps);
-      BLO_read_data_address(reader, &mdisps[i].hidden);
-
-      if (mdisps[i].totdisp && !mdisps[i].level) {
-        /* this calculation is only correct for loop mdisps;
-         * if loading pre-BMesh face mdisps this will be
-         * overwritten with the correct value in
-         * bm_corners_to_loops() */
-        float gridsize = sqrtf(mdisps[i].totdisp);
-        mdisps[i].level = (int)(logf(gridsize - 1.0f) / (float)M_LN2) + 1;
-      }
-
-      if (BLO_read_requires_endian_switch(reader) && (mdisps[i].disps)) {
-        /* DNA_struct_switch_endian doesn't do endian swap for (*disps)[] */
-        /* this does swap for data written at write_mdisps() - readfile.c */
-        BLI_endian_switch_float_array(*mdisps[i].disps, mdisps[i].totdisp * 3);
-      }
-      if (!external && !mdisps[i].disps) {
-        mdisps[i].totdisp = 0;
-      }
-    }
-  }
-}
-
-static void direct_link_grid_paint_mask(BlendDataReader *reader,
-                                        int count,
-                                        GridPaintMask *grid_paint_mask)
-{
-  if (grid_paint_mask) {
-    for (int i = 0; i < count; i++) {
-      GridPaintMask *gpm = &grid_paint_mask[i];
-      if (gpm->data) {
-        BLO_read_data_address(reader, &gpm->data);
-      }
-    }
-  }
-}
-
-/*this isn't really a public api function, so prototyped here*/
-static void direct_link_customdata(BlendDataReader *reader, CustomData *data, int count)
-{
-
-  BLO_read_data_address(reader, &data->layers);
-
-  /* annoying workaround for bug [#31079] loading legacy files with
-   * no polygons _but_ have stale customdata */
-  if (UNLIKELY(count == 0 && data->layers == NULL && data->totlayer != 0)) {
-    CustomData_reset(data);
-    return;
-  }
-
-  BLO_read_data_address(reader, &data->external);
-
-  int i = 0;
-  while (i < data->totlayer) {
-    CustomDataLayer *layer = &data->layers[i];
-
-    if (layer->flag & CD_FLAG_EXTERNAL) {
-      layer->flag &= ~CD_FLAG_IN_MEMORY;
-    }
-
-    layer->flag &= ~CD_FLAG_NOFREE;
-
-    if (CustomData_verify_versions(data, i)) {
-      BLO_read_data_address(reader, &layer->data);
-      if (layer->type == CD_MDISPS) {
-        direct_link_mdisps(reader, count, layer->data, layer->flag & CD_FLAG_EXTERNAL);
-      }
-      else if (layer->type == CD_GRID_PAINT_MASK) {
-        direct_link_grid_paint_mask(reader, count, layer->data);
-      }
-      i++;
-    }
-  }
-
-  CustomData_update_typemap(data);
-}
-
 static void direct_link_mesh(BlendDataReader *reader, Mesh *mesh)
 {
   BLO_read_pointer_array(reader, (void **)&mesh->mat);
@@ -4229,15 +4147,15 @@ static void direct_link_mesh(BlendDataReader *reader, Mesh *mesh)
   BLO_read_data_address(reader, &mesh->adt);
   BKE_animdata_blend_read_data(reader, mesh->adt);
 
-  /* Normally BKE_defvert_blend_read should be called in direct_link_customdata,
+  /* Normally BKE_defvert_blend_read should be called in CustomData_blend_read,
    * but for backwards compatibility in do_versions to work we do it here. */
   BKE_defvert_blend_read(reader, mesh->totvert, mesh->dvert);
 
-  direct_link_customdata(reader, &mesh->vdata, mesh->totvert);
-  direct_link_customdata(reader, &mesh->edata, mesh->totedge);
-  direct_link_customdata(reader, &mesh->fdata, mesh->totface);
-  direct_link_customdata(reader, &mesh->ldata, mesh->totloop);
-  direct_link_customdata(reader, &mesh->pdata, mesh->totpoly);
+  CustomData_blend_read(reader, &mesh->vdata, mesh->totvert);
+  CustomData_blend_read(reader, &mesh->edata, mesh->totedge);
+  CustomData_blend_read(reader, &mesh->fdata, mesh->totface);
+  CustomData_blend_read(reader, &mesh->ldata, mesh->totloop);
+  CustomData_blend_read(reader, &mesh->pdata, mesh->totpoly);
 
   mesh->texflag &= ~ME_AUTOSPACE_EVALUATED;
   mesh->edit_mesh = NULL;
@@ -4254,10 +4172,10 @@ static void direct_link_mesh(BlendDataReader *reader, Mesh *mesh)
     BLO_read_list(reader, &mesh->mr->levels);
     MultiresLevel *lvl = mesh->mr->levels.first;
 
-    direct_link_customdata(reader, &mesh->mr->vdata, lvl->totvert);
+    CustomData_blend_read(reader, &mesh->mr->vdata, lvl->totvert);
     BKE_defvert_blend_read(
         reader, lvl->totvert, CustomData_get(&mesh->mr->vdata, 0, CD_MDEFORMVERT));
-    direct_link_customdata(reader, &mesh->mr->fdata, lvl->totface);
+    CustomData_blend_read(reader, &mesh->mr->fdata, lvl->totface);
 
     BLO_read_data_address(reader, &mesh->mr->edge_flags);
     BLO_read_data_address(reader, &mesh->mr->edge_creases);
@@ -7984,8 +7902,8 @@ static void direct_link_hair(BlendDataReader *reader, Hair *hair)
   BKE_animdata_blend_read_data(reader, hair->adt);
 
   /* Geometry */
-  direct_link_customdata(reader, &hair->pdata, hair->totpoint);
-  direct_link_customdata(reader, &hair->cdata, hair->totcurve);
+  CustomData_blend_read(reader, &hair->pdata, hair->totpoint);
+  CustomData_blend_read(reader, &hair->cdata, hair->totcurve);
   BKE_hair_update_customdata_pointers(hair);
 
   /* Materials */
@@ -8011,7 +7929,7 @@ static void direct_link_pointcloud(BlendDataReader *reader, PointCloud *pointclo
   BKE_animdata_blend_read_data(reader, pointcloud->adt);
 
   /* Geometry */
-  direct_link_customdata(reader, &pointcloud->pdata, pointcloud->totpoint);
+  CustomData_blend_read(reader, &pointcloud->pdata, pointcloud->totpoint);
   BKE_pointcloud_update_customdata_pointers(pointcloud);
 
   /* Materials */
@@ -8072,7 +7990,7 @@ static void direct_link_simulation(BlendDataReader *reader, Simulation *simulati
     BLO_read_data_address(reader, &state->type);
     if (STREQ(state->type, SIM_TYPE_NAME_PARTICLE_SIMULATION)) {
       ParticleSimulationState *particle_state = (ParticleSimulationState *)state;
-      direct_link_customdata(reader, &particle_state->attributes, particle_state->tot_particles);
+      CustomData_blend_read(reader, &particle_state->attributes, particle_state->tot_particles);
     }
   }
 
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index e69f46735d4..c764f2d9e05 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -1785,100 +1785,6 @@ static void write_curve(BlendWriter *writer, Curve *cu, const void *id_address)
   }
 }
 
-static void write_mdisps(BlendWriter *writer, int count, MDisps *mdlist, int external)
-{
-  if (mdlist) {
-    BLO_write_struct_array(writer, MDisps, count, mdlist);
-    for (int i = 0; i < count; i++) {
-      MDisps *md = &mdlist[i];
-      if (md->disps) {
-        if (!external) {
-          BLO_write_float3_array(writer, md->totdisp, &md->disps[0][0]);
-        }
-      }
-
-      if (md->hidden) {
-        BLO_write_raw(writer, BLI_BITMAP_SIZE(md->totdisp), md->hidden);
-      }
-    }
-  }
-}
-
-static void write_grid_paint_mask(BlendWriter *writer, int count, GridPaintMask *grid_paint_mask)
-{
-  if (grid_paint_mask) {
-    BLO_write_struct_array(writer, GridPaintMask, count, grid_paint_mask);
-    for (int i = 0; i < count; i++) {
-      GridPaintMask *gpm = &grid_paint_mask[i];
-      if (gpm->data) {
-        const int gridsize = BKE_ccg_gridsize(gpm->level);
-        BLO_write_raw(writer, sizeof(*gpm->data) * gridsize * gridsize, gpm->data);
-      }
-    }
-  }
-}
-
-static void write_customdata(BlendWriter *writer,
-                             ID *id,
-                             int count,
-                             CustomData *data,
-                             CustomDataLayer *layers,
-                             CustomDataMask cddata_mask)
-{
-  /* write external customdata (not for undo) */
-  if (data->external && !BLO_write_is_undo(writer)) {
-    CustomData_external_write(data, id, cddata_mask, count, 0);
-  }
-
-  BLO_write_struct_array_at_address(writer, CustomDataLayer, data->totlayer, data->layers, layers);
-
-  for (int i = 0; i < data->totlayer; i++) {
-    CustomDataLayer *layer = &layers[i];
-    const char *structname;
-    int structnum, datasize;
-
-    if (layer->type == CD_MDEFORMVERT) {
-      /* layer types that allocate own memory need special handling */
-      BKE_defvert_blend_write(writer, count, layer->data);
-    }
-    else if (layer->type == CD_MDISPS) {
-      write_mdisps(writer, count, layer->data, layer->flag & CD_FLAG_EXTERNAL);
-    }
-    else if (layer->type == CD_PAINT_MASK) {
-      const float *layer_data = layer->data;
-      BLO_write_raw(writer, sizeof(*layer_data) * count, layer_data);
-    }
-    else if (layer->type == CD_SCULPT_FACE_SETS) {
-      const float *layer_data = layer->data;
-      BLO_write_raw(writer, sizeof(*layer_data) * count, layer_data);
-    }
-    else if (layer->type == CD_GRID_PAINT_MASK) {
-      write_grid_paint_mask(writer, count, layer->data);
-    }
-    else if (layer->type == CD_FACEMAP) {
-      const int *layer_data = layer->data;
-      BLO_write_raw(writer, sizeof(*layer_data) * count, layer_data);
-    }
-    else {
-      CustomData_file_write_info(layer->type, &structname, &structnum);
-      if (structnum) {
-        datasize = structnum * count;
-        BLO_write_struct_array_by_name(writer, structname, datasize, layer->data);
-      }
-      else if (!BLO_write_is_undo(writer)) { /* Do not warn on undo. */
-        printf("%s error: layer '%s':%d - can't be written to file\n",
-               __func__,
-               structname,
-               layer->type);
-      }
-    }
-  }
-
-  if (data->external) {
-    BLO_write_struct(writer, CustomDataExternal, data->external);
-  }
-}
-
 static void write_mesh(BlendWriter *writer, Mesh *mesh, const void *id_address)
 {
   if (mesh->id.us > 0 || BLO_write_is_undo(writer)) {
@@ -1888,21 +1794,6 @@ static void write_mesh(BlendWriter *writer, Mesh *mesh, const void *id_address)
     memset(&mesh->fdata, 0, sizeof(mesh->fdata));
     memset(&mesh->runtime, 0, sizeof(mesh->runtime));
 
-    /* Reduce xdata layers, fill xlayers with layers to be written.
-     * This makes xdata invalid for Blender, which is why we made a
-     * temporary local copy. */
-    CustomDataLayer *vlayers = NULL, vlayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *elayers = NULL, elayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *flayers = NULL, flayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *llayers = NULL, llayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *players = NULL, players_buff[CD_TEMP_CHUNK_SIZE];
-
-    CustomData_file_write_prepare(&mesh->vdata, &vlayers, vlayers_buff, ARRAY_SIZE(vlayers_buff));
-    CustomData_file_write_prepare(&mesh->edata, &elayers, elayers_buff, ARRAY_SIZE(elayers_buff));
-    flayers = flayers_buff;
-    CustomData_file_write_prepare(&mesh->ldata, &llayers, llayers_buff, ARRAY_SIZE(llayers_buff));
-    CustomData_file_write_prepare(&mesh->pdata, &players, players_buff, ARRAY_SIZE(players_buff));
-
     BLO_write_id_struct(writer, Mesh, id_address, &mesh->id);
     write_iddata(writer, &mesh->id);
 
@@ -1914,29 +1805,12 @@ static void write_mesh(BlendWriter *writer, Mesh *mesh, const void *id_address)
     BLO_write_pointer_array(writer, mesh->totcol, mesh->mat);
     BLO_write_raw(writer, sizeof(MSelect) * mesh->totselect, mesh->mselect);
 
-    write_customdata(writer, &mesh->id, mesh->totvert, &mesh->vdata, vlayers, CD_MASK_MESH.vmask);
-    write_customdata(writer, &mesh->id, mesh->totedge, &mesh->edata, elayers, CD_MASK_MESH.emask);
+    CustomData_blend_write(writer, &mesh->vdata, mesh->totvert, CD_MASK_MESH.vmask, &mesh->id);
+    CustomData_blend_write(writer, &mesh->edata, mesh->totedge, CD_MASK_MESH.emask, &mesh->id);
     /* fdata is really a dummy - written so slots align */
-    write_customdata(writer, &mesh->id, mesh->totface, &mesh->fdata, flayers, CD_MASK_MESH.fmask);
-    write_customdata(writer, &mesh->id, mesh->totloop, &mesh->ldata, llayers, CD_MASK_MESH.lmask);
-    write_customdata(writer, &mesh->id, mesh->totpoly, &mesh->pdata, players, CD_MASK_MESH.pmask);
-
-    /* free temporary data */
-    if (vlayers && vlayers != vlayers_buff) {
-      MEM_freeN(vlayers);
-    }
-    if (elayers && elayers != elayers_buff) {
-      MEM_freeN(elayers);
-    }
-    if (flayers && flayers != flayers_buff) {
-      MEM_freeN(flayers);
-    }
-    if (llayers && llayers != llayers_buff) {
-      MEM_freeN(llayers);
-    }
-    if (players && players != players_buff) {
-      MEM_freeN(players);
-    }
+    CustomData_blend_write(writer, &mesh->fdata, mesh->totface, CD_MASK_MESH.fmask, &mesh->id);
+    CustomData_blend_write(writer, &mesh->ldata, mesh->totloop, CD_MASK_MESH.lmask, &mesh->id);
+    CustomData_blend_write(writer, &mesh->pdata, mesh->totpoly, CD_MASK_MESH.pmask, &mesh->id);
   }
 }
 
@@ -3468,30 +3342,17 @@ static void write_workspace(BlendWriter *writer, WorkSpace *workspace, const voi
 static void write_hair(BlendWriter *writer, Hair *hair, const void *id_address)
 {
   if (hair->id.us > 0 || BLO_write_is_undo(writer)) {
-    CustomDataLayer *players = NULL, players_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *clayers = NULL, clayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomData_file_write_prepare(&hair->pdata, &players, players_buff, ARRAY_SIZE(players_buff));
-    CustomData_file_write_prepare(&hair->cdata, &clayers, clayers_buff, ARRAY_SIZE(clayers_buff));
-
     /* Write LibData */
     BLO_write_id_struct(writer, Hair, id_address, &hair->id);
     write_iddata(writer, &hair->id);
 
     /* Direct data */
-    write_customdata(writer, &hair->id, hair->totpoint, &hair->pdata, players, CD_MASK_ALL);
-    write_customdata(writer, &hair->id, hair->totcurve, &hair->cdata, clayers, CD_MASK_ALL);
+    CustomData_blend_write(writer, &hair->pdata, hair->totpoint, CD_MASK_ALL, &hair->id);
+    CustomData_blend_write(writer, &hair->cdata, hair->totcurve, CD_MASK_ALL, &hair->id);
     BLO_write_pointer_array(writer, hair->totcol, hair->mat);
     if (hair->adt) {
       BKE_animdata_blend_write(writer, hair->adt);
     }
-
-    /* Remove temporary data. */
-    if (players && players != players_buff) {
-      MEM_freeN(players);
-    }
-    if (clayers && clayers != clayers_buff) {
-      MEM_freeN(clayers);
-    }
   }
 }
 
@@ -3507,8 +3368,8 @@ static void write_pointcloud(BlendWriter *writer, PointCloud *pointcloud, const
     write_iddata(writer, &pointcloud->id);
 
     /* Direct data */
-    write_customdata(
-        writer, &pointcloud->id, pointcloud->totpoint, &pointcloud->pdata, players, CD_MASK_ALL);
+    CustomData_blend_write(
+        writer, &pointcloud->pdata, pointcloud->totpoint, CD_MASK_ALL, &pointcloud->id);
     BLO_write_pointer_array(writer, pointcloud->totcol, pointcloud->mat);
     if (pointcloud->adt) {
       BKE_animdata_blend_write(writer, pointcloud->adt);
@@ -3569,21 +3430,11 @@ static void write_simulation(BlendWriter *writer, Simulation *simulation, const
         ParticleSimulationState *particle_state = (ParticleSimulationState *)state;
         BLO_write_struct(writer, ParticleSimulationState, particle_state);
 
-        CustomDataLayer *layers = NULL;
-        CustomDataLayer layers_buff[CD_TEMP_CHUNK_SIZE];
-        CustomData_file_write_prepare(
-            &particle_state->attributes, &layers, layers_buff, ARRAY_SIZE(layers_buff));
-
-        write_customdata(writer,
-                         &simulation->id,
-                         particle_state->tot_particles,
-                         &particle_state->attributes,
-                         layers,
-                         CD_MASK_ALL);
-
-        if (layers != NULL && layers != layers_buff) {
-          MEM_freeN(layers);
-        }
+        CustomData_blend_write(writer,
+                               &particle_state->attributes,
+                               particle_state->tot_particles,
+                               CD_MASK_ALL,
+                               &simulation->id);
       }
       else if (STREQ(state->type, SIM_TYPE_NAME_PARTICLE_MESH_EMITTER)) {
         ParticleMeshEmitterSimulationState *emitter_state = (ParticleMeshEmitterSimulationState *)