Depsgraph: Fix dependency cycle when ID prop drives ID property

Introduced explicit ID property node for driers in depsgraph,
so it is clear what is the input for driver, and what is the
output.

This also solved relations builder throwing lots of errors
due to ID property not being found.

6 files changed, 69 insertions, 8 deletions

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
index 6245c514ddb..0f21c152192 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
@@ -532,15 +532,54 @@ void DepsgraphNodeBuilder::build_animdata(ID *id)
  * \param id: ID-Block that driver is attached to
  * \param fcu: Driver-FCurve
  */
-void DepsgraphNodeBuilder::build_driver(ID *id, FCurve *fcu)
+void DepsgraphNodeBuilder::build_driver(ID *id, FCurve *fcurve)
 {
 	/* Create data node for this driver */
 	ensure_operation_node(id,
 	                      DEG_NODE_TYPE_PARAMETERS,
-	                      function_bind(BKE_animsys_eval_driver, _1, id, fcu),
+	                      function_bind(BKE_animsys_eval_driver, _1, id, fcurve),
 	                      DEG_OPCODE_DRIVER,
-	                      fcu->rna_path ? fcu->rna_path : "",
-	                      fcu->array_index);
+	                      fcurve->rna_path ? fcurve->rna_path : "",
+	                      fcurve->array_index);
+	build_driver_variables(id, fcurve);
+}
+
+void DepsgraphNodeBuilder::build_driver_variables(ID * id, FCurve *fcurve)
+{
+	build_driver_id_property(id, fcurve->rna_path);
+	LISTBASE_FOREACH (DriverVar *, dvar, &fcurve->driver->variables) {
+		DRIVER_TARGETS_USED_LOOPER(dvar)
+		{
+			build_driver_id_property(dtar->id, dtar->rna_path);
+		}
+		DRIVER_TARGETS_LOOPER_END
+	}
+}
+
+void DepsgraphNodeBuilder::build_driver_id_property(ID *id,
+                                                    const char *rna_path)
+{
+	if (id == NULL || rna_path == NULL) {
+		return;
+	}
+	PointerRNA id_ptr, ptr;
+	PropertyRNA *prop;
+	RNA_id_pointer_create(id, &id_ptr);
+	if (!RNA_path_resolve_full(&id_ptr, rna_path, &ptr, &prop, NULL)) {
+		return;
+	}
+	if (prop == NULL) {
+		return;
+	}
+	if (!RNA_property_is_idprop(prop)) {
+		return;
+	}
+	const char *prop_identifier = RNA_property_identifier((PropertyRNA *)prop);
+	ensure_operation_node(id,
+	                      DEG_NODE_TYPE_PARAMETERS,
+	                      NULL,
+	                      DEG_OPCODE_ID_PROPERTY,
+	                      prop_identifier);
 }
 
 /* Recursively build graph for world */
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
index ecaece6a3ac..9d47dc6bced 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
@@ -138,6 +138,8 @@ struct DepsgraphNodeBuilder {
 	void build_cloth(Object *object);
 	void build_animdata(ID *id);
 	void build_driver(ID *id, FCurve *fcurve);
+	void build_driver_variables(ID *id, FCurve *fcurve);
+	void build_driver_id_property(ID *id, const char *rna_path);
 	void build_ik_pose(Object *object,
 	                   bPoseChannel *pchan,
 	                   bConstraint *con);
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index 914c8ef33db..40db9d1b5f1 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -1134,6 +1134,16 @@ void DepsgraphRelationBuilder::build_driver_data(ID *id, FCurve *fcu)
 			 */
 		}
 		else {
+			if (target_key.prop != NULL &&
+			    RNA_property_is_idprop(target_key.prop))
+			{
+				OperationKey parameters_key(id,
+				                            DEG_NODE_TYPE_PARAMETERS,
+				                            DEG_OPCODE_PARAMETERS_EVAL);
+				add_relation(target_key,
+				             parameters_key,
+				             "Driver Target -> Properties");
+			}
 			add_relation(driver_key, target_key, "Driver -> Target");
 		}
 	}
diff --git a/source/blender/depsgraph/intern/depsgraph.cc b/source/blender/depsgraph/intern/depsgraph.cc
index 841242b995e..2e87786639c 100644
--- a/source/blender/depsgraph/intern/depsgraph.cc
+++ b/source/blender/depsgraph/intern/depsgraph.cc
@@ -214,10 +214,18 @@ static bool pointer_to_component_node_criteria(
 	}
 	if (prop != NULL) {
 		/* All unknown data effectively falls under "parameter evaluation". */
-		*type = DEG_NODE_TYPE_PARAMETERS;
-		*operation_code = DEG_OPCODE_PARAMETERS_EVAL;
-		*operation_name = "";
-		*operation_name_tag = -1;
+		if (RNA_property_is_idprop(prop)) {
+			*type = DEG_NODE_TYPE_PARAMETERS;
+			*operation_code = DEG_OPCODE_ID_PROPERTY;
+			*operation_name = RNA_property_identifier((PropertyRNA *)prop);
+			*operation_name_tag = -1;
+		}
+		else {
+			*type = DEG_NODE_TYPE_PARAMETERS;
+			*operation_code = DEG_OPCODE_PARAMETERS_EVAL;
+			*operation_name = "";
+			*operation_name_tag = -1;
+		}
 		return true;
 	}
 	return false;
diff --git a/source/blender/depsgraph/intern/depsgraph_type_defines.cc b/source/blender/depsgraph/intern/depsgraph_type_defines.cc
index 675002d6b90..41c72d11eac 100644
--- a/source/blender/depsgraph/intern/depsgraph_type_defines.cc
+++ b/source/blender/depsgraph/intern/depsgraph_type_defines.cc
@@ -81,6 +81,7 @@ static const char *stringify_opcode(eDepsOperation_Code opcode)
 #define STRINGIFY_OPCODE(name) case DEG_OPCODE_##name: return #name
 		/* Generic Operations. */
 		STRINGIFY_OPCODE(OPERATION);
+		STRINGIFY_OPCODE(ID_PROPERTY);
 		STRINGIFY_OPCODE(PARAMETERS_EVAL);
 		STRINGIFY_OPCODE(PLACEHOLDER);
 		/* Animation, Drivers, etc. */
diff --git a/source/blender/depsgraph/intern/depsgraph_types.h b/source/blender/depsgraph/intern/depsgraph_types.h
index b2dbe5d2a62..2d0b67f7ee6 100644
--- a/source/blender/depsgraph/intern/depsgraph_types.h
+++ b/source/blender/depsgraph/intern/depsgraph_types.h
@@ -137,6 +137,7 @@ typedef enum eDepsOperation_Code {
 	DEG_OPCODE_OPERATION = 0,
 
 	/* Generic parameters evaluation. */
+	DEG_OPCODE_ID_PROPERTY,
 	DEG_OPCODE_PARAMETERS_EVAL,
 
 	// XXX: Placeholder while porting depsgraph code