Depsgraph: Fix missing point cache reset when physics changes

Among all the lines moved around, the general idea is quite simple.
Actually, there are two ideas implemented there.

First one, is when object itself is tagged for update, we tag its
point cache component for evaluation, which makes it so point cache
is properly reset. We do it implicitly because otherwise we'll need
to go everywhere and add explicit tag in almost all the properties.

Second thing is, we link all collider and force fields to a point
cache component using special type of link. This type of link only
allows flush if change is caused by a user update. This way reset
does not happen when change is caused due to animation, but will
properly happen when user causes indirect change to the objects
which are part of physics simulation.

4 files changed, 73 insertions, 65 deletions

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
index e8e3e241ebf..637fd5887a0 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
@@ -399,7 +399,10 @@ void DepsgraphNodeBuilder::end_build()
 		if (op_node == NULL) {
 			continue;
 		}
-		op_node->tag_update(graph_);
+		/* Since the tag is coming from a saved copy of entry tags, this means
+		 * that originally node was explicitly tagged for user update.
+		 */
+		op_node->tag_update(graph_, DEG_UPDATE_SOURCE_USER_EDIT);
 	}
 }
 
@@ -818,6 +821,22 @@ void DepsgraphNodeBuilder::build_object_constraints(Object *object)
 	                   DEG_OPCODE_TRANSFORM_CONSTRAINTS);
 }
 
+void DepsgraphNodeBuilder::build_object_pointcache(Object *object)
+{
+	if (!BKE_ptcache_object_has(scene_, object, 0)) {
+		return;
+	}
+	Scene *scene_cow = get_cow_datablock(scene_);
+	Object *object_cow = get_cow_datablock(object);
+	add_operation_node(&object->id,
+	                   DEG_NODE_TYPE_POINT_CACHE,
+	                   function_bind(BKE_object_eval_ptcache_reset,
+	                                 _1,
+	                                 scene_cow,
+	                                 object_cow),
+	                   DEG_OPCODE_POINT_CACHE_RESET);
+}
+
 /**
  * Build graph nodes for AnimData block
  * \param id: ID-Block which hosts the AnimData
@@ -1123,15 +1142,6 @@ void DepsgraphNodeBuilder::build_particles(Object *object,
 				break;
 		}
 	}
-
-	/* TODO(sergey): Do we need a point cache operations here? */
-	add_operation_node(&object->id,
-	                   DEG_NODE_TYPE_CACHE,
-	                   function_bind(BKE_ptcache_object_reset,
-	                                 scene_cow,
-	                                 ob_cow,
-	                                 PTCACHE_RESET_DEPSGRAPH),
-	                   DEG_OPCODE_POINT_CACHE_RESET);
 }
 
 void DepsgraphNodeBuilder::build_particle_settings(ParticleSettings *part) {
@@ -1147,19 +1157,6 @@ void DepsgraphNodeBuilder::build_particle_settings(ParticleSettings *part) {
 	                   DEG_OPCODE_PARTICLE_SETTINGS_EVAL);
 }
 
-void DepsgraphNodeBuilder::build_cloth(Object *object)
-{
-	Scene *scene_cow = get_cow_datablock(scene_);
-	Object *object_cow = get_cow_datablock(object);
-	add_operation_node(&object->id,
-	                   DEG_NODE_TYPE_CACHE,
-	                   function_bind(BKE_object_eval_cloth,
-	                                 _1,
-	                                 scene_cow,
-	                                 object_cow),
-	                   DEG_OPCODE_GEOMETRY_CLOTH_MODIFIER);
-}
-
 /* Shapekeys */
 void DepsgraphNodeBuilder::build_shapekeys(Key *key)
 {
@@ -1204,13 +1201,6 @@ void DepsgraphNodeBuilder::build_object_data_geometry(
 	                             DEG_OPCODE_PLACEHOLDER,
 	                             "Eval Init");
 	op_node->set_as_entry();
-	// TODO: "Done" operation
-	/* Cloth modifier. */
-	LISTBASE_FOREACH (ModifierData *, md, &object->modifiers) {
-		if (md->type == eModifierType_Cloth) {
-			build_cloth(object);
-		}
-	}
 	/* Materials. */
 	if (object->totcol != 0) {
 		if (object->type == OB_MESH) {
@@ -1221,7 +1211,6 @@ void DepsgraphNodeBuilder::build_object_data_geometry(
 			                                 object_cow),
 			                   DEG_OPCODE_SHADING);
 		}
-
 		for (int a = 1; a <= object->totcol; a++) {
 			Material *ma = give_current_material(object, a);
 			if (ma != NULL) {
@@ -1229,10 +1218,9 @@ void DepsgraphNodeBuilder::build_object_data_geometry(
 			}
 		}
 	}
-	/* Geometry collision. */
-	if (ELEM(object->type, OB_MESH, OB_CURVE, OB_LATTICE)) {
-		// add geometry collider relations
-	}
+	/* Point caches. */
+	build_object_pointcache(object);
+	/* Geometry. */
 	build_object_data_geometry_datablock((ID *)object->data, is_object_visible);
 }
 
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
index b826a2979cc..3c0c5f749ca 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
@@ -183,6 +183,7 @@ struct DepsgraphNodeBuilder {
 	void build_object_data_speaker(Object *object);
 	void build_object_transform(Object *object);
 	void build_object_constraints(Object *object);
+	void build_object_pointcache(Object *object);
 	void build_pose_constraints(Object *object,
 	                            bPoseChannel *pchan,
 	                            int pchan_index,
@@ -190,7 +191,6 @@ struct DepsgraphNodeBuilder {
 	void build_rigidbody(Scene *scene);
 	void build_particles(Object *object, bool is_object_visible);
 	void build_particle_settings(ParticleSettings *part);
-	void build_cloth(Object *object);
 	void build_animdata(ID *id);
 	void build_animdata_nlastrip_targets(ListBase *strips);
 	void build_action(bAction *action);
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index d336bfb6188..e66c3a25e33 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -87,6 +87,7 @@ extern "C" {
 #include "BKE_node.h"
 #include "BKE_object.h"
 #include "BKE_particle.h"
+#include "BKE_pointcache.h"
 #include "BKE_rigidbody.h"
 #include "BKE_shader_fx.h"
 #include "BKE_shrinkwrap.h"
@@ -184,9 +185,13 @@ static bool check_id_has_anim_component(ID *id)
 	       (!BLI_listbase_is_empty(&adt->nla_tracks));
 }
 
-static eDepsOperation_Code bone_target_opcode(ID *target, const char *subtarget, ID *id, const char *component_subdata, RootPChanMap *root_map)
+static eDepsOperation_Code bone_target_opcode(ID *target,
+                                              const char *subtarget,
+                                              ID *id,
+                                              const char *component_subdata,
+                                              RootPChanMap *root_map)
 {
-	/* same armature  */
+	/* Same armature.  */
 	if (target == id) {
 		/* Using "done" here breaks in-chain deps, while using
 		 * "ready" here breaks most production rigs instead.
@@ -197,7 +202,6 @@ static eDepsOperation_Code bone_target_opcode(ID *target, const char *subtarget,
 			return DEG_OPCODE_BONE_READY;
 		}
 	}
-
 	return DEG_OPCODE_BONE_DONE;
 }
 
@@ -642,6 +646,8 @@ void DepsgraphRelationBuilder::build_object(Base *base, Object *object)
 	if (object->dup_group != NULL) {
 		build_collection(object, object->dup_group);
 	}
+	/* Point caches. */
+	build_object_pointcache(object);
 }
 
 void DepsgraphRelationBuilder::build_object_flags(Base *base, Object *object)
@@ -846,11 +852,47 @@ void DepsgraphRelationBuilder::build_object_parent(Object *object)
 			break;
 		}
 	}
+}
 
-	/* exception case: parent is duplivert */
-	if ((object->type == OB_MBALL) && (object->parent->transflag & OB_DUPLIVERTS)) {
-		//dag_add_relation(dag, node2, node, DAG_RL_DATA_DATA | DAG_RL_OB_OB, "Duplivert");
+void DepsgraphRelationBuilder::build_object_pointcache(Object *object)
+{
+	ComponentKey point_cache_key(&object->id, DEG_NODE_TYPE_POINT_CACHE);
+	/* Different point caches are affecting different aspects of life of the
+	 * object. We keep track of those aspects and avoid duplicate relations. */
+	enum {
+		FLAG_TRANSFORM = (1 << 0),
+		FLAG_GEOMETRY = (1 << 1),
+		FLAG_ALL = (FLAG_TRANSFORM | FLAG_GEOMETRY),
+	};
+	ListBase ptcache_id_list;
+	BKE_ptcache_ids_from_object(&ptcache_id_list, object, scene_, 0);
+	int handled_components = 0;
+	LISTBASE_FOREACH (PTCacheID *, ptcache_id, &ptcache_id_list) {
+		/* Check which components needs the point cache. */
+		int flag;
+		if (ptcache_id->type == PTCACHE_TYPE_RIGIDBODY) {
+			flag = FLAG_TRANSFORM;
+			ComponentKey transform_key(&object->id,
+			                           DEG_NODE_TYPE_TRANSFORM);
+			add_relation(point_cache_key,
+			             transform_key,
+			             "Point Cache -> Rigid Body");
+		}
+		else {
+			flag = FLAG_GEOMETRY;
+			ComponentKey geometry_key(&object->id,
+			                           DEG_NODE_TYPE_GEOMETRY);
+			add_relation(point_cache_key,
+			             geometry_key,
+			             "Point Cache -> Geometry");
+		}
+		/* Tag that we did handle that component. */
+		handled_components |= flag;
+		if (handled_components == FLAG_ALL) {
+			break;
+		}
 	}
+	BLI_freelistN(&ptcache_id_list);
 }
 
 void DepsgraphRelationBuilder::build_constraints(ID *id,
@@ -1744,12 +1786,6 @@ void DepsgraphRelationBuilder::build_particles(Object *object)
 	 */
 	ComponentKey transform_key(&object->id, DEG_NODE_TYPE_TRANSFORM);
 	add_relation(transform_key, obdata_ubereval_key, "Partcile Eval");
-
-	OperationKey point_cache_reset_key(&object->id,
-	                                   DEG_NODE_TYPE_CACHE,
-	                                   DEG_OPCODE_POINT_CACHE_RESET);
-	add_relation(transform_key, point_cache_reset_key, "Object Transform -> Point Cache Reset");
-	add_relation(point_cache_reset_key, obdata_ubereval_key, "Point Cache Reset -> UberEval");
 }
 
 void DepsgraphRelationBuilder::build_particle_settings(ParticleSettings *part)
@@ -1783,19 +1819,6 @@ void DepsgraphRelationBuilder::build_particles_visualization_object(
 	}
 }
 
-void DepsgraphRelationBuilder::build_cloth(Object *object,
-                                           ModifierData * /*md*/)
-{
-	OperationKey cache_key(&object->id,
-	                       DEG_NODE_TYPE_CACHE,
-	                       DEG_OPCODE_GEOMETRY_CLOTH_MODIFIER);
-	/* Cache component affects on modifier. */
-	OperationKey modifier_key(&object->id,
-	                          DEG_NODE_TYPE_GEOMETRY,
-	                          DEG_OPCODE_GEOMETRY_UBEREVAL);
-	add_relation(cache_key, modifier_key, "Cloth Cache -> Cloth");
-}
-
 /* Shapekeys */
 void DepsgraphRelationBuilder::build_shapekeys(Key *key)
 {
@@ -1869,9 +1892,6 @@ void DepsgraphRelationBuilder::build_object_data_geometry(Object *object)
 				TimeSourceKey time_src_key;
 				add_relation(time_src_key, obdata_ubereval_key, "Time Source");
 			}
-			if (md->type == eModifierType_Cloth) {
-				build_cloth(object, md);
-			}
 		}
 	}
 	/* Grease Pencil Modifiers */
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.h b/source/blender/depsgraph/intern/builder/deg_builder_relations.h
index e5854fa8d20..e86c6504693 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.h
@@ -217,6 +217,7 @@ struct DepsgraphRelationBuilder
 	void build_object_data_lightprobe(Object *object);
 	void build_object_data_speaker(Object *object);
 	void build_object_parent(Object *object);
+	void build_object_pointcache(Object *object);
 	void build_constraints(ID *id,
 	                       eDepsNode_Type component_type,
 	                       const char *component_subdata,
@@ -244,7 +245,6 @@ struct DepsgraphRelationBuilder
 	void build_particles_visualization_object(Object *object,
 	                                          ParticleSystem *psys,
 	                                          Object *draw_object);
-	void build_cloth(Object *object, ModifierData *md);
 	void build_ik_pose(Object *object,
 	                   bPoseChannel *pchan,
 	                   bConstraint *con,