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

1 files changed, 7 insertions, 8 deletions

diff --git a/source/blender/modifiers/intern/MOD_mask.cc b/source/blender/modifiers/intern/MOD_mask.cc
index a77f6cfe8ba..9aa8e3dd7c8 100644
--- a/source/blender/modifiers/intern/MOD_mask.cc
+++ b/source/blender/modifiers/intern/MOD_mask.cc
@@ -119,7 +119,7 @@ static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphConte
 
 /* A vertex will be in the mask if a selected bone influences it more than a certain threshold. */
 static void compute_vertex_mask__armature_mode(MDeformVert *dvert,
-                                               Object *ob,
+                                               Mesh *mesh,
                                                Object *armature_ob,
                                                float threshold,
                                                MutableSpan<bool> r_vertex_mask)
@@ -127,7 +127,7 @@ static void compute_vertex_mask__armature_mode(MDeformVert *dvert,
   /* Element i is true if there is a selected bone that uses vertex group i. */
   Vector<bool> selected_bone_uses_group;
 
-  for (bDeformGroup *def : ListBaseWrapper<bDeformGroup>(ob->defbase)) {
+  LISTBASE_FOREACH (bDeformGroup *, def, &mesh->vertex_group_names) {
     bPoseChannel *pchan = BKE_pose_channel_find_name(armature_ob->pose, def->name);
     bool bone_for_group_exists = pchan && pchan->bone && (pchan->bone->flag & BONE_SELECTED);
     selected_bone_uses_group.append(bone_for_group_exists);
@@ -325,10 +325,9 @@ void copy_masked_polys_to_new_mesh(const Mesh &src_mesh,
  * 2. Find edges and polygons only using those vertices.
  * 3. Create a new mesh that only uses the found vertices, edges and polygons.
  */
-static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *mesh)
+static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *UNUSED(ctx), Mesh *mesh)
 {
   MaskModifierData *mmd = reinterpret_cast<MaskModifierData *>(md);
-  Object *ob = ctx->object;
   const bool invert_mask = mmd->flag & MOD_MASK_INV;
 
   /* Return empty or input mesh when there are no vertex groups. */
@@ -339,7 +338,7 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 
   /* Quick test to see if we can return early. */
   if (!(ELEM(mmd->mode, MOD_MASK_MODE_ARM, MOD_MASK_MODE_VGROUP)) || (mesh->totvert == 0) ||
-      BLI_listbase_is_empty(&ob->defbase)) {
+      BLI_listbase_is_empty(&mesh->vertex_group_names)) {
     return mesh;
   }
 
@@ -348,15 +347,15 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
     Object *armature_ob = mmd->ob_arm;
 
     /* Return input mesh if there is no armature with bones. */
-    if (ELEM(NULL, armature_ob, armature_ob->pose, ob->defbase.first)) {
+    if (ELEM(NULL, armature_ob, armature_ob->pose)) {
       return mesh;
     }
 
     vertex_mask = Array<bool>(mesh->totvert);
-    compute_vertex_mask__armature_mode(dvert, ob, armature_ob, mmd->threshold, vertex_mask);
+    compute_vertex_mask__armature_mode(dvert, mesh, armature_ob, mmd->threshold, vertex_mask);
   }
   else {
-    int defgrp_index = BKE_object_defgroup_name_index(ob, mmd->vgroup);
+    int defgrp_index = BKE_id_defgroup_name_index(&mesh->id, mmd->vgroup);
 
     /* Return input mesh if the vertex group does not exist. */
     if (defgrp_index == -1) {