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

3 files changed, 33 insertions, 2 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();
diff --git a/source/blender/depsgraph/intern/depsgraph_tag.cc b/source/blender/depsgraph/intern/depsgraph_tag.cc
index 21a6728c364..b00cae87311 100644
--- a/source/blender/depsgraph/intern/depsgraph_tag.cc
+++ b/source/blender/depsgraph/intern/depsgraph_tag.cc
@@ -230,6 +230,7 @@ void depsgraph_tag_to_component_opcode(const ID *id,
     case ID_RECALC_SOURCE:
       *component_type = NodeType::PARAMETERS;
       break;
+    case ID_RECALC_GEOMETRY_ALL_MODES:
     case ID_RECALC_ALL:
     case ID_RECALC_PSYS_ALL:
       BLI_assert(!"Should not happen");
@@ -705,6 +706,8 @@ const char *DEG_update_tag_as_string(IDRecalcFlag flag)
       return "TRANSFORM";
     case ID_RECALC_GEOMETRY:
       return "GEOMETRY";
+    case ID_RECALC_GEOMETRY_ALL_MODES:
+      return "GEOMETRY_ALL_MODES";
     case ID_RECALC_ANIMATION:
       return "ANIMATION";
     case ID_RECALC_PSYS_REDO:
diff --git a/source/blender/depsgraph/intern/node/deg_node_component.h b/source/blender/depsgraph/intern/node/deg_node_component.h
index 06582c88d8b..a7c69b27654 100644
--- a/source/blender/depsgraph/intern/node/deg_node_component.h
+++ b/source/blender/depsgraph/intern/node/deg_node_component.h
@@ -23,7 +23,9 @@
 
 #pragma once
 
+#include "intern/eval/deg_eval_copy_on_write.h"
 #include "intern/node/deg_node.h"
+#include "intern/node/deg_node_id.h"
 #include "intern/node/deg_node_operation.h"
 
 #include "BLI_string.h"
@@ -172,7 +174,6 @@ DEG_COMPONENT_NODE_DECLARE_GENERIC(CopyOnWrite);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(Geometry);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(ImageAnimation);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(LayerCollections);
-DEG_COMPONENT_NODE_DECLARE_GENERIC(Parameters);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(Particles);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(ParticleSettings);
 DEG_COMPONENT_NODE_DECLARE_GENERIC(Pose);
@@ -199,6 +200,21 @@ struct BoneComponentNode : public ComponentNode {
   DEG_COMPONENT_NODE_DECLARE;
 };
 
+/* Eventually we would not tag parameters in all cases.
+ * Support for this each ID needs to be added on an individual basis. */
+struct ParametersComponentNode : public ComponentNode {
+  virtual bool need_tag_cow_before_update() override
+  {
+    if (ID_TYPE_SUPPORTS_PARAMS_WITHOUT_COW(owner->id_type)) {
+      BLI_assert(deg_copy_on_write_is_expanded(owner->id_cow));
+      return false;
+    }
+    return true;
+  }
+
+  DEG_COMPONENT_NODE_DECLARE;
+};
+
 void deg_register_component_depsnodes();
 
 }  // namespace deg