Constraints: introduce wrapper functions to access target lists.

Instead of directly accessing constraint-specific callbacks
in code all over blender, introduce two wrappers to retrieve
and free the target list.

This incidentally revealed a place within the Collada exporter
in BCAnimationSampler.cpp that didn't clean up after retrieving
the targets, resulting in a small memory leak. Fixing this should
be the only functional change in this commit.

This was split off from D9732.

Differential Revision: https://developer.blender.org/D13844

1 files changed, 3 insertions, 6 deletions

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index ae159373efd..c16325b7299 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -1137,6 +1137,7 @@ void DepsgraphRelationBuilder::build_constraints(ID *id,
   /* Add dependencies for each constraint in turn. */
   for (bConstraint *con = (bConstraint *)constraints->first; con; con = con->next) {
     const bConstraintTypeInfo *cti = BKE_constraint_typeinfo_get(con);
+    ListBase targets = {nullptr, nullptr};
     /* Invalid constraint type. */
     if (cti == nullptr) {
       continue;
@@ -1188,9 +1189,7 @@ void DepsgraphRelationBuilder::build_constraints(ID *id,
         add_relation(cache_key, constraint_op_key, cti->name);
       }
     }
-    else if (cti->get_constraint_targets) {
-      ListBase targets = {nullptr, nullptr};
-      cti->get_constraint_targets(con, &targets);
+    else if (BKE_constraint_targets_get(con, &targets)) {
       LISTBASE_FOREACH (bConstraintTarget *, ct, &targets) {
         if (ct->tar == nullptr) {
           continue;
@@ -1300,9 +1299,7 @@ void DepsgraphRelationBuilder::build_constraints(ID *id,
           add_relation(target_transform_key, constraint_op_key, cti->name);
         }
       }
-      if (cti->flush_constraint_targets) {
-        cti->flush_constraint_targets(con, &targets, true);
-      }
+      BKE_constraint_targets_flush(con, &targets, true);
     }
   }
 }