Depsgraph: Specify whether RNA path to be resolved as entry or exit

Makes it more explicit whether RNA property is used as a source
dependency for something else, or whether some other dependency
is being hooked up to evaluate that property.

5 files changed, 78 insertions, 50 deletions

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index ec07d1e5fc0..95535355bb5 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -266,7 +266,7 @@ OperationDepsNode *DepsgraphRelationBuilder::get_node(
 
 DepsNode *DepsgraphRelationBuilder::get_node(const RNAPathKey &key) const
 {
-	return graph_->find_node_from_pointer(&key.ptr, key.prop);
+	return graph_->find_node_from_pointer(&key.ptr, key.prop, key.source);
 }
 
 OperationDepsNode *DepsgraphRelationBuilder::find_node(
@@ -1233,7 +1233,8 @@ void DepsgraphRelationBuilder::build_animdata_curves_targets(
 		{
 			continue;
 		}
-		DepsNode *node_to = graph_->find_node_from_pointer(&ptr, prop);
+		DepsNode *node_to = graph_->find_node_from_pointer(
+		        &ptr, prop, RNAPointerSource::ENTRY);
 		if (node_to == NULL) {
 			continue;
 		}
@@ -1402,7 +1403,6 @@ void DepsgraphRelationBuilder::build_driver_data(ID *id, FCurve *fcu)
 	                        fcu->rna_path ? fcu->rna_path : "",
 	                        fcu->array_index);
 	const char *rna_path = fcu->rna_path ? fcu->rna_path : "";
-	const RNAPathKey self_key(id, rna_path);
 	if (GS(id->name) == ID_AR && strstr(rna_path, "bones[")) {
 		/* Drivers on armature-level bone settings (i.e. bbone stuff),
 		 * which will affect the evaluation of corresponding pose bones.
@@ -1443,20 +1443,19 @@ void DepsgraphRelationBuilder::build_driver_data(ID *id, FCurve *fcu)
 		}
 	}
 	else if (rna_path != NULL && rna_path[0] != '\0') {
-		RNAPathKey property_key(id, rna_path);
-		if (RNA_pointer_is_null(&property_key.ptr)) {
+		RNAPathKey property_entry_key(id, rna_path, RNAPointerSource::ENTRY);
+		if (RNA_pointer_is_null(&property_entry_key.ptr)) {
 			/* TODO(sergey): This would only mean that driver is broken.
 			 * so we can't create relation anyway. However, we need to avoid
 			 * adding drivers which are known to be buggy to a dependency
-			 * graph, in order to save computational power.
-			 */
+			 * graph, in order to save computational power. */
 			return;
 		}
-		add_relation(driver_key, property_key, "Driver -> Driven Property");
+		add_relation(
+		        driver_key, property_entry_key, "Driver -> Driven Property");
 		/* Similar to the case with f-curves, driver might drive a nested
 		 * datablock, which means driver execution should wait for that
-		 * datablock to be copied.
-		 */
+		 * datablock to be copied. */
 		{
 			PointerRNA id_ptr;
 			PointerRNA ptr;
@@ -1472,13 +1471,14 @@ void DepsgraphRelationBuilder::build_driver_data(ID *id, FCurve *fcu)
 				}
 			}
 		}
-		if (property_key.prop != NULL &&
-		    RNA_property_is_idprop(property_key.prop))
+		if (property_entry_key.prop != NULL &&
+		    RNA_property_is_idprop(property_entry_key.prop))
 		{
+			RNAPathKey property_exit_key(id, rna_path, RNAPointerSource::EXIT);
 			OperationKey parameters_key(id,
 			                            DEG_NODE_TYPE_PARAMETERS,
 			                            DEG_OPCODE_PARAMETERS_EVAL);
-			add_relation(property_key,
+			add_relation(property_exit_key,
 			             parameters_key,
 			             "Driven Property -> Properties");
 		}
@@ -1494,8 +1494,7 @@ void DepsgraphRelationBuilder::build_driver_variables(ID *id, FCurve *fcu)
 	                        fcu->rna_path ? fcu->rna_path : "",
 	                        fcu->array_index);
 	const char *rna_path = fcu->rna_path ? fcu->rna_path : "";
-	const RNAPathKey self_key(id, rna_path);
-
+	const RNAPathKey self_key(id, rna_path, RNAPointerSource::ENTRY);
 	LISTBASE_FOREACH (DriverVar *, dvar, &driver->variables) {
 		/* Only used targets. */
 		DRIVER_TARGETS_USED_LOOPER_BEGIN(dvar)
@@ -1548,22 +1547,28 @@ void DepsgraphRelationBuilder::build_driver_variables(ID *id, FCurve *fcu)
 				add_relation(target_key, driver_key, "Target -> Driver");
 			}
 			else if (dtar->rna_path != NULL && dtar->rna_path[0] != '\0') {
-				RNAPathKey variable_key(dtar->id, dtar->rna_path);
-				if (RNA_pointer_is_null(&variable_key.ptr)) {
+				RNAPathKey variable_exit_key(
+				        dtar->id, dtar->rna_path, RNAPointerSource::EXIT);
+				if (RNA_pointer_is_null(&variable_exit_key.ptr)) {
 					continue;
 				}
-				if (is_same_bone_dependency(variable_key, self_key) ||
-				    is_same_nodetree_node_dependency(variable_key, self_key) ||
-				    is_same_shapekey_dependency(variable_key, self_key))
+				if (is_same_bone_dependency(variable_exit_key, self_key) ||
+				    is_same_nodetree_node_dependency(variable_exit_key, self_key) ||
+				    is_same_shapekey_dependency(variable_exit_key, self_key))
 				{
 					continue;
 				}
-				add_relation(variable_key, driver_key, "RNA Target -> Driver");
+				add_relation(variable_exit_key,
+				             driver_key,
+				             "RNA Target -> Driver");
 				if (proxy_from != NULL) {
 					RNAPathKey proxy_from_variable_key(&proxy_from->id,
-					                                   dtar->rna_path);
+					                                   dtar->rna_path,
+					                                   RNAPointerSource::EXIT);
+					RNAPathKey variable_entry_key(
+					        dtar->id, dtar->rna_path, RNAPointerSource::ENTRY);
 					add_relation(proxy_from_variable_key,
-					             variable_key,
+					             variable_entry_key,
 					             "Proxy From -> Variable");
 				}
 			}
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.h b/source/blender/depsgraph/intern/builder/deg_builder_relations.h
index 03212f6d0c8..3b1a2d00e98 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.h
@@ -164,16 +164,18 @@ struct OperationKey
 
 struct RNAPathKey
 {
-	/* NOTE: see depsgraph_build.cpp for implementation */
-	RNAPathKey(ID *id, const char *path);
-
-	RNAPathKey(ID *id, const PointerRNA &ptr, PropertyRNA *prop);
+	RNAPathKey(ID *id, const char *path, RNAPointerSource source);
+	RNAPathKey(ID *id,
+	           const PointerRNA &ptr,
+	           PropertyRNA *prop,
+	           RNAPointerSource source);
 
 	string identifier() const;
 
 	ID *id;
 	PointerRNA ptr;
 	PropertyRNA *prop;
+	RNAPointerSource source;
 };
 
 struct DepsgraphRelationBuilder
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations_keys.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations_keys.cc
index 3aae358dda3..f86959a1693 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations_keys.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations_keys.cc
@@ -34,7 +34,7 @@
 
 namespace DEG {
 
-/////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
 // Time source.
 
 TimeSourceKey::TimeSourceKey()
@@ -52,7 +52,7 @@ string TimeSourceKey::identifier() const
 	return string("TimeSourceKey");
 }
 
-/////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
 // Component.
 
 ComponentKey::ComponentKey()
@@ -82,7 +82,7 @@ string ComponentKey::identifier() const
 	return result;
 }
 
-/////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
 // Operation.
 
 OperationKey::OperationKey()
@@ -189,30 +189,35 @@ string OperationKey::identifier() const
 	return result;
 }
 
-/////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
 // RNA path.
 
-RNAPathKey::RNAPathKey(ID *id, const PointerRNA &ptr, PropertyRNA *prop)
+RNAPathKey::RNAPathKey(ID *id, const char *path, RNAPointerSource source)
         : id(id),
-          ptr(ptr),
-          prop(prop)
-{
-}
-
-RNAPathKey::RNAPathKey(ID *id, const char *path)
-        : id(id)
+          source(source)
 {
-	/* create ID pointer for root of path lookup */
+	/* Create ID pointer for root of path lookup. */
 	PointerRNA id_ptr;
 	RNA_id_pointer_create(id, &id_ptr);
-	/* try to resolve path... */
+	/* Try to resolve path. */
 	int index;
-	if (!RNA_path_resolve_full(&id_ptr, path, &this->ptr, &this->prop, &index)) {
-		this->ptr = PointerRNA_NULL;
-		this->prop = NULL;
+	if (!RNA_path_resolve_full(&id_ptr, path, &ptr, &prop, &index)) {
+		ptr = PointerRNA_NULL;
+		prop = NULL;
 	}
 }
 
+RNAPathKey::RNAPathKey(ID *id,
+                       const PointerRNA &ptr,
+                       PropertyRNA *prop,
+                       RNAPointerSource source)
+        : id(id),
+          ptr(ptr),
+          prop(prop),
+          source(source)
+{
+}
+
 string RNAPathKey::identifier() const
 {
 	const char *id_name   = (id) ?  id->name : "<No ID>";
diff --git a/source/blender/depsgraph/intern/depsgraph.cc b/source/blender/depsgraph/intern/depsgraph.cc
index dabab482eff..d7da6658e3e 100644
--- a/source/blender/depsgraph/intern/depsgraph.cc
+++ b/source/blender/depsgraph/intern/depsgraph.cc
@@ -121,6 +121,7 @@ Depsgraph::~Depsgraph()
 static bool pointer_to_component_node_criteria(
         const PointerRNA *ptr,
         const PropertyRNA *prop,
+        RNAPointerSource /*source*/,
         ID **id,
         eDepsNode_Type *type,
         const char **subdata,
@@ -287,16 +288,16 @@ static bool pointer_to_component_node_criteria(
 
 /* Convenience wrapper to find node given just pointer + property. */
 DepsNode *Depsgraph::find_node_from_pointer(const PointerRNA *ptr,
-                                            const PropertyRNA *prop) const
+                                            const PropertyRNA *prop,
+                                            RNAPointerSource source) const
 {
 	ID *id;
 	eDepsNode_Type node_type;
 	const char *component_name, *operation_name;
 	eDepsOperation_Code operation_code;
 	int operation_name_tag;
-
 	if (pointer_to_component_node_criteria(
-	                 ptr, prop,
+	                 ptr, prop, source,
 	                 &id, &node_type, &component_name,
 	                 &operation_code, &operation_name, &operation_name_tag))
 	{
diff --git a/source/blender/depsgraph/intern/depsgraph.h b/source/blender/depsgraph/intern/depsgraph.h
index 27dd27c923b..a816fcc32df 100644
--- a/source/blender/depsgraph/intern/depsgraph.h
+++ b/source/blender/depsgraph/intern/depsgraph.h
@@ -103,6 +103,20 @@ struct DepsRelation {
 	void unlink();
 };
 
+/* For queries which gives operation node or key defines whether we are
+ * interested in a result of the given property or whether we are linking some
+ * dependency to that property. */
+enum class RNAPointerSource {
+	/* Query will return pointer to an entry operation of component which is
+	 * responsible for evaluation of the given property. */
+	ENTRY,
+	/* Query will return pointer to an exit operation of component which is
+	 * responsible for evaluation of the given property.
+	 * More precisely, it will return operation at which the property is known
+	 * to be evaluated. */
+	EXIT,
+};
+
 /* ********* */
 /* Depsgraph */
 
@@ -125,9 +139,10 @@ struct Depsgraph {
 	 *              results in inner nodes being returned
 	 *
 	 * \return A node matching the required characteristics if it exists
-	 * or NULL if no such node exists in the graph
-	 */
-	DepsNode *find_node_from_pointer(const PointerRNA *ptr, const PropertyRNA *prop) const;
+	 * or NULL if no such node exists in the graph */
+	DepsNode *find_node_from_pointer(const PointerRNA *ptr,
+	                                 const PropertyRNA *prop,
+	                                 RNAPointerSource source) const;
 
 	TimeSourceDepsNode *add_time_source();
 	TimeSourceDepsNode *find_time_source() const;