Refactor: Move vertex group names to object data

This commit moves the storage of `bDeformGroup` and the active index
to `Mesh`, `Lattice`, and `bGPdata` instead of `Object`. Utility
functions are added to allow easy access to the vertex groups given
an object or an ID.

As explained in T88951, the list of vertex group names is currently
stored separately per object, even though vertex group data is stored
on the geometry. This tends to complicate code and cause bugs,
especially as geometry is created procedurally and tied less closely
to an object.

The "Copy Vertex Groups to Linked" operator is removed, since they
are stored on the geometry anyway.

This patch leaves the object-level python API for vertex groups in
place. Creating a geometry-level RNA API can be a separate step;
the changes in this commit are invasive enough as it is.

Note that opening a file saved in 3.0 in an earlier version means
the vertex groups will not be available.

Differential Revision: https://developer.blender.org/D11689

3 files changed, 98 insertions, 20 deletions

diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index 7def9bdb636..ca219e83fc2 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -602,6 +602,7 @@ const EnumPropertyItem rna_enum_axis_flag_xyz_items[] = {
 
 #  include "BKE_cachefile.h"
 #  include "BKE_context.h"
+#  include "BKE_deform.h"
 #  include "BKE_mesh_runtime.h"
 #  include "BKE_modifier.h"
 #  include "BKE_object.h"
@@ -1250,12 +1251,13 @@ static const EnumPropertyItem *rna_DataTransferModifier_layers_select_src_itemf(
 #  endif
 
     if (ob_src) {
-      bDeformGroup *dg;
+      const bDeformGroup *dg;
       int i;
 
       RNA_enum_item_add_separator(&item, &totitem);
 
-      for (i = 0, dg = ob_src->defbase.first; dg; i++, dg = dg->next) {
+      const ListBase *defbase = BKE_object_defgroup_list(ob_src);
+      for (i = 0, dg = defbase->first; dg; i++, dg = dg->next) {
         tmp_item.value = i;
         tmp_item.identifier = tmp_item.name = dg->name;
         RNA_enum_item_add(&item, &totitem, &tmp_item);
@@ -1349,12 +1351,13 @@ static const EnumPropertyItem *rna_DataTransferModifier_layers_select_dst_itemf(
       Object *ob_dst = CTX_data_active_object(C); /* XXX Is this OK? */
 
       if (ob_dst) {
-        bDeformGroup *dg;
+        const bDeformGroup *dg;
         int i;
 
         RNA_enum_item_add_separator(&item, &totitem);
 
-        for (i = 0, dg = ob_dst->defbase.first; dg; i++, dg = dg->next) {
+        const ListBase *defbase = BKE_object_defgroup_list(ob_dst);
+        for (i = 0, dg = defbase->first; dg; i++, dg = dg->next) {
           tmp_item.value = i;
           tmp_item.identifier = tmp_item.name = dg->name;
           RNA_enum_item_add(&item, &totitem, &tmp_item);
diff --git a/source/blender/makesrna/intern/rna_object.c b/source/blender/makesrna/intern/rna_object.c
index 7c012922c2c..e110459eeea 100644
--- a/source/blender/makesrna/intern/rna_object.c
+++ b/source/blender/makesrna/intern/rna_object.c
@@ -790,9 +790,27 @@ static void rna_Object_dup_collection_set(PointerRNA *ptr,
   }
 }
 
+static void rna_Object_vertex_groups_begin(CollectionPropertyIterator *iter, PointerRNA *ptr)
+{
+  Object *ob = (Object *)ptr->data;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    iter->valid = 0;
+    return;
+  }
+
+  ListBase *defbase = BKE_object_defgroup_list_mutable(ob);
+  iter->valid = defbase != NULL;
+
+  rna_iterator_listbase_begin(iter, defbase, NULL);
+}
+
 static void rna_VertexGroup_name_set(PointerRNA *ptr, const char *value)
 {
   Object *ob = (Object *)ptr->owner_id;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    return;
+  }
+
   bDeformGroup *dg = (bDeformGroup *)ptr->data;
   BLI_strncpy_utf8(dg->name, value, sizeof(dg->name));
   BKE_object_defgroup_unique_name(dg, ob);
@@ -801,15 +819,25 @@ static void rna_VertexGroup_name_set(PointerRNA *ptr, const char *value)
 static int rna_VertexGroup_index_get(PointerRNA *ptr)
 {
   Object *ob = (Object *)ptr->owner_id;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    return -1;
+  }
 
-  return BLI_findindex(&ob->defbase, ptr->data);
+  const ListBase *defbase = BKE_object_defgroup_list(ob);
+  return BLI_findindex(defbase, ptr->data);
 }
 
 static PointerRNA rna_Object_active_vertex_group_get(PointerRNA *ptr)
 {
   Object *ob = (Object *)ptr->owner_id;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    return PointerRNA_NULL;
+  }
+
+  const ListBase *defbase = BKE_object_defgroup_list(ob);
+
   return rna_pointer_inherit_refine(
-      ptr, &RNA_VertexGroup, BLI_findlink(&ob->defbase, ob->actdef - 1));
+      ptr, &RNA_VertexGroup, BLI_findlink(defbase, BKE_object_defgroup_active_index_get(ob) - 1));
 }
 
 static void rna_Object_active_vertex_group_set(PointerRNA *ptr,
@@ -817,7 +845,13 @@ static void rna_Object_active_vertex_group_set(PointerRNA *ptr,
                                                struct ReportList *reports)
 {
   Object *ob = (Object *)ptr->owner_id;
-  int index = BLI_findindex(&ob->defbase, value.data);
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    return;
+  }
+
+  const ListBase *defbase = BKE_object_defgroup_list(ob);
+
+  int index = BLI_findindex(defbase, value.data);
   if (index == -1) {
     BKE_reportf(reports,
                 RPT_ERROR,
@@ -827,19 +861,27 @@ static void rna_Object_active_vertex_group_set(PointerRNA *ptr,
     return;
   }
 
-  ob->actdef = index + 1;
+  BKE_object_defgroup_active_index_set(ob, index + 1);
 }
 
 static int rna_Object_active_vertex_group_index_get(PointerRNA *ptr)
 {
   Object *ob = (Object *)ptr->owner_id;
-  return ob->actdef - 1;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    return -1;
+  }
+
+  return BKE_object_defgroup_active_index_get(ob) - 1;
 }
 
 static void rna_Object_active_vertex_group_index_set(PointerRNA *ptr, int value)
 {
   Object *ob = (Object *)ptr->owner_id;
-  ob->actdef = value + 1;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    return;
+  }
+
+  BKE_object_defgroup_active_index_set(ob, value + 1);
 }
 
 static void rna_Object_active_vertex_group_index_range(
@@ -848,15 +890,24 @@ static void rna_Object_active_vertex_group_index_range(
   Object *ob = (Object *)ptr->owner_id;
 
   *min = 0;
-  *max = max_ii(0, BLI_listbase_count(&ob->defbase) - 1);
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    *max = 0;
+    return;
+  }
+  const ListBase *defbase = BKE_object_defgroup_list(ob);
+  *max = max_ii(0, BLI_listbase_count(defbase) - 1);
 }
 
 void rna_object_vgroup_name_index_get(PointerRNA *ptr, char *value, int index)
 {
   Object *ob = (Object *)ptr->owner_id;
-  bDeformGroup *dg;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    value[0] = '\0';
+    return;
+  }
 
-  dg = BLI_findlink(&ob->defbase, index - 1);
+  const ListBase *defbase = BKE_object_defgroup_list(ob);
+  const bDeformGroup *dg = BLI_findlink(defbase, index - 1);
 
   if (dg) {
     BLI_strncpy(value, dg->name, sizeof(dg->name));
@@ -869,21 +920,34 @@ void rna_object_vgroup_name_index_get(PointerRNA *ptr, char *value, int index)
 int rna_object_vgroup_name_index_length(PointerRNA *ptr, int index)
 {
   Object *ob = (Object *)ptr->owner_id;
-  bDeformGroup *dg;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    return 0;
+  }
 
-  dg = BLI_findlink(&ob->defbase, index - 1);
+  const ListBase *defbase = BKE_object_defgroup_list(ob);
+  bDeformGroup *dg = BLI_findlink(defbase, index - 1);
   return (dg) ? strlen(dg->name) : 0;
 }
 
 void rna_object_vgroup_name_index_set(PointerRNA *ptr, const char *value, short *index)
 {
   Object *ob = (Object *)ptr->owner_id;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    *index = -1;
+    return;
+  }
+
   *index = BKE_object_defgroup_name_index(ob, value) + 1;
 }
 
 void rna_object_vgroup_name_set(PointerRNA *ptr, const char *value, char *result, int maxlen)
 {
   Object *ob = (Object *)ptr->owner_id;
+  if (!BKE_object_supports_vertex_groups(ob)) {
+    result[0] = '\0';
+    return;
+  }
+
   bDeformGroup *dg = BKE_object_defgroup_find_name(ob, value);
   if (dg) {
     /* No need for BLI_strncpy_utf8, since this matches an existing group. */
@@ -1960,7 +2024,9 @@ static void rna_Object_vgroup_remove(Object *ob,
                                      PointerRNA *defgroup_ptr)
 {
   bDeformGroup *defgroup = defgroup_ptr->data;
-  if (BLI_findindex(&ob->defbase, defgroup) == -1) {
+  ListBase *defbase = BKE_object_defgroup_list_mutable(ob);
+
+  if (BLI_findindex(defbase, defgroup) == -1) {
     BKE_reportf(reports,
                 RPT_ERROR,
                 "DeformGroup '%s' not in object '%s'",
@@ -2687,7 +2753,6 @@ static void rna_def_object_vertex_groups(BlenderRNA *brna, PropertyRNA *cprop)
 
   prop = RNA_def_property(srna, "active_index", PROP_INT, PROP_UNSIGNED);
   RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
-  RNA_def_property_int_sdna(prop, NULL, "actdef");
   RNA_def_property_int_funcs(prop,
                              "rna_Object_active_vertex_group_index_get",
                              "rna_Object_active_vertex_group_index_set",
@@ -3274,7 +3339,15 @@ static void rna_def_object(BlenderRNA *brna)
 
   /* vertex groups */
   prop = RNA_def_property(srna, "vertex_groups", PROP_COLLECTION, PROP_NONE);
-  RNA_def_property_collection_sdna(prop, NULL, "defbase", NULL);
+  RNA_def_property_collection_funcs(prop,
+                                    "rna_Object_vertex_groups_begin",
+                                    "rna_iterator_listbase_next",
+                                    "rna_iterator_listbase_end",
+                                    "rna_iterator_listbase_get",
+                                    NULL,
+                                    NULL,
+                                    NULL,
+                                    NULL);
   RNA_def_property_struct_type(prop, "VertexGroup");
   RNA_def_property_override_clear_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);
   RNA_def_property_ui_text(prop, "Vertex Groups", "Vertex groups of the object");
diff --git a/source/blender/makesrna/intern/rna_particle.c b/source/blender/makesrna/intern/rna_particle.c
index 8edb80f68c5..de4cfb2b61a 100644
--- a/source/blender/makesrna/intern/rna_particle.c
+++ b/source/blender/makesrna/intern/rna_particle.c
@@ -1430,9 +1430,10 @@ static void psys_vg_name_get__internal(PointerRNA *ptr, char *value, int index)
 {
   Object *ob = (Object *)ptr->owner_id;
   ParticleSystem *psys = (ParticleSystem *)ptr->data;
+  const ListBase *defbase = BKE_object_defgroup_list(ob);
 
   if (psys->vgroup[index] > 0) {
-    bDeformGroup *defGroup = BLI_findlink(&ob->defbase, psys->vgroup[index] - 1);
+    bDeformGroup *defGroup = BLI_findlink(defbase, psys->vgroup[index] - 1);
 
     if (defGroup) {
       strcpy(value, defGroup->name);
@@ -1448,7 +1449,8 @@ static int psys_vg_name_len__internal(PointerRNA *ptr, int index)
   ParticleSystem *psys = (ParticleSystem *)ptr->data;
 
   if (psys->vgroup[index] > 0) {
-    bDeformGroup *defGroup = BLI_findlink(&ob->defbase, psys->vgroup[index] - 1);
+    const ListBase *defbase = BKE_object_defgroup_list(ob);
+    bDeformGroup *defGroup = BLI_findlink(defbase, psys->vgroup[index] - 1);
 
     if (defGroup) {
       return strlen(defGroup->name);