Depsgraph: support flushing parameters without a full COW update

Avoid computationally expensive copying operations
when only some settings have been modified.

This is done by adding support for updating parameters
without tagging for copy-on-write.

Currently only mesh data blocks are supported,
other data-blocks can be added individually.

This prepares for changing values such as edit-mesh auto-smooth angle
in edit-mode without duplicating all mesh-data.
The benefit will only be seen when the user interface no longer tags
all ID's for copy on write updates.

ID_RECALC_GEOMETRY_ALL_MODES has been added to support situations
where non edit-mode geometry is modified in edit-mode.
While this isn't something user are likely to do,
Python scripts may change the underlying mesh.

Reviewed By: sergey

Ref D11377

1 files changed, 13 insertions, 1 deletions

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
index 20169f0a961..56168739fae 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
@@ -1215,7 +1215,19 @@ void DepsgraphNodeBuilder::build_parameters(ID *id)
   op_node = add_operation_node(id, NodeType::PARAMETERS, OperationCode::PARAMETERS_ENTRY);
   op_node->set_as_entry();
   /* Generic evaluation node. */
-  add_operation_node(id, NodeType::PARAMETERS, OperationCode::PARAMETERS_EVAL);
+
+  if (ID_TYPE_SUPPORTS_PARAMS_WITHOUT_COW(GS(id->name))) {
+    ID *id_cow = get_cow_id(id);
+    add_operation_node(
+        id,
+        NodeType::PARAMETERS,
+        OperationCode::PARAMETERS_EVAL,
+        [id_cow, id](::Depsgraph * /*depsgraph*/) { BKE_id_eval_properties_copy(id_cow, id); });
+  }
+  else {
+    add_operation_node(id, NodeType::PARAMETERS, OperationCode::PARAMETERS_EVAL);
+  }
+
   /* Explicit exit operation. */
   op_node = add_operation_node(id, NodeType::PARAMETERS, OperationCode::PARAMETERS_EXIT);
   op_node->set_as_exit();