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, 16 insertions, 56 deletions

diff --git a/source/blender/blenkernel/intern/geometry_component_mesh.cc b/source/blender/blenkernel/intern/geometry_component_mesh.cc
index 28e46aab732..af500ab3427 100644
--- a/source/blender/blenkernel/intern/geometry_component_mesh.cc
+++ b/source/blender/blenkernel/intern/geometry_component_mesh.cc
@@ -53,7 +53,6 @@ GeometryComponent *MeshComponent::copy() const
   if (mesh_ != nullptr) {
     new_component->mesh_ = BKE_mesh_copy_for_eval(mesh_, false);
     new_component->ownership_ = GeometryOwnershipType::Owned;
-    new_component->vertex_group_names_ = blender::Map(vertex_group_names_);
   }
   return new_component;
 }
@@ -67,7 +66,6 @@ void MeshComponent::clear()
     }
     mesh_ = nullptr;
   }
-  vertex_group_names_.clear();
 }
 
 bool MeshComponent::has_mesh() const
@@ -84,23 +82,6 @@ void MeshComponent::replace(Mesh *mesh, GeometryOwnershipType ownership)
   ownership_ = ownership;
 }
 
-/* This function exists for the same reason as #vertex_group_names_. Non-nodes modifiers need to
- * be able to replace the mesh data without losing the vertex group names, which may have come
- * from another object. */
-void MeshComponent::replace_mesh_but_keep_vertex_group_names(Mesh *mesh,
-                                                             GeometryOwnershipType ownership)
-{
-  BLI_assert(this->is_mutable());
-  if (mesh_ != nullptr) {
-    if (ownership_ == GeometryOwnershipType::Owned) {
-      BKE_id_free(nullptr, mesh_);
-    }
-    mesh_ = nullptr;
-  }
-  mesh_ = mesh;
-  ownership_ = ownership;
-}
-
 /* Return the mesh and clear the component. The caller takes over responsibility for freeing the
  * mesh (if the component was responsible before). */
 Mesh *MeshComponent::release()
@@ -111,28 +92,6 @@ Mesh *MeshComponent::release()
   return mesh;
 }
 
-void MeshComponent::copy_vertex_group_names_from_object(const Object &object)
-{
-  BLI_assert(this->is_mutable());
-  vertex_group_names_.clear();
-  int index = 0;
-  LISTBASE_FOREACH (const bDeformGroup *, group, &object.defbase) {
-    vertex_group_names_.add(group->name, index);
-    index++;
-  }
-}
-
-const blender::Map<std::string, int> &MeshComponent::vertex_group_names() const
-{
-  return vertex_group_names_;
-}
-
-/* This is only exposed for the internal attribute API. */
-blender::Map<std::string, int> &MeshComponent::vertex_group_names()
-{
-  return vertex_group_names_;
-}
-
 /* Get the mesh from this component. This method can be used by multiple threads at the same
  * time. Therefore, the returned mesh should not be modified. No ownership is transferred. */
 const Mesh *MeshComponent::get_for_read() const
@@ -864,8 +823,8 @@ class VertexGroupsAttributeProvider final : public DynamicAttributesProvider {
     BLI_assert(component.type() == GEO_COMPONENT_TYPE_MESH);
     const MeshComponent &mesh_component = static_cast<const MeshComponent &>(component);
     const Mesh *mesh = mesh_component.get_for_read();
-    const int vertex_group_index = mesh_component.vertex_group_names().lookup_default_as(
-        attribute_name, -1);
+    const int vertex_group_index = BLI_findstringindex(
+        &mesh->vertex_group_names, attribute_name.data(), offsetof(bDeformGroup, name));
     if (vertex_group_index < 0) {
       return {};
     }
@@ -889,8 +848,9 @@ class VertexGroupsAttributeProvider final : public DynamicAttributesProvider {
     if (mesh == nullptr) {
       return {};
     }
-    const int vertex_group_index = mesh_component.vertex_group_names().lookup_default_as(
-        attribute_name, -1);
+
+    const int vertex_group_index = BLI_findstringindex(
+        &mesh->vertex_group_names, attribute_name.data(), offsetof(bDeformGroup, name));
     if (vertex_group_index < 0) {
       return {};
     }
@@ -913,13 +873,13 @@ class VertexGroupsAttributeProvider final : public DynamicAttributesProvider {
   {
     BLI_assert(component.type() == GEO_COMPONENT_TYPE_MESH);
     MeshComponent &mesh_component = static_cast<MeshComponent &>(component);
+    Mesh *mesh = mesh_component.get_for_write();
 
-    const int vertex_group_index = mesh_component.vertex_group_names().pop_default_as(
-        attribute_name, -1);
+    const int vertex_group_index = BLI_findstringindex(
+        &mesh->vertex_group_names, attribute_name.data(), offsetof(bDeformGroup, name));
     if (vertex_group_index < 0) {
       return false;
     }
-    Mesh *mesh = mesh_component.get_for_write();
     if (mesh == nullptr) {
       return true;
     }
@@ -938,14 +898,14 @@ class VertexGroupsAttributeProvider final : public DynamicAttributesProvider {
   {
     BLI_assert(component.type() == GEO_COMPONENT_TYPE_MESH);
     const MeshComponent &mesh_component = static_cast<const MeshComponent &>(component);
-    for (const auto item : mesh_component.vertex_group_names().items()) {
-      const StringRefNull name = item.key;
-      const int vertex_group_index = item.value;
-      if (vertex_group_index >= 0) {
-        AttributeMetaData meta_data{ATTR_DOMAIN_POINT, CD_PROP_FLOAT};
-        if (!callback(name, meta_data)) {
-          return false;
-        }
+    const Mesh *mesh = mesh_component.get_for_read();
+    if (mesh == nullptr) {
+      return true;
+    }
+
+    LISTBASE_FOREACH (const bDeformGroup *, group, &mesh->vertex_group_names) {
+      if (!callback(group->name, {ATTR_DOMAIN_POINT, CD_PROP_FLOAT})) {
+        return false;
       }
     }
     return true;