Animation: Add function to remove all FCurves from an Action

Add a `BKE_action_fcurves_clear(action)` function, which removes all the
Action's FCurves, and expose it as `ActionFCurves.clear()` in RNA.

This is more ergonomic than calling `remove` on f-curves until the list
is empty.

Reviewed By: sybren

Differential Revision: https://developer.blender.org/D14660

2 files changed, 18 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_action.h b/source/blender/blenkernel/BKE_action.h
index d5487b3558a..79d0fe6e20a 100644
--- a/source/blender/blenkernel/BKE_action.h
+++ b/source/blender/blenkernel/BKE_action.h
@@ -92,6 +92,11 @@ bool action_has_motion(const struct bAction *act);
  */
 bool BKE_action_is_cyclic(const struct bAction *act);
 
+/**
+ * Remove all fcurves from the action.
+ */
+void BKE_action_fcurves_clear(struct bAction *act);
+
 /* Action Groups API ----------------- */
 
 /**
diff --git a/source/blender/blenkernel/intern/action.c b/source/blender/blenkernel/intern/action.c
index 05b51e0c9fa..fee7582acb3 100644
--- a/source/blender/blenkernel/intern/action.c
+++ b/source/blender/blenkernel/intern/action.c
@@ -1983,3 +1983,16 @@ void BKE_pose_blend_read_expand(BlendExpander *expander, bPose *pose)
     BLO_expand(expander, chan->custom);
   }
 }
+
+void BKE_action_fcurves_clear(bAction *act)
+{
+  if (!act) {
+    return;
+  }
+  while (act->curves.first) {
+    FCurve *fcu = act->curves.first;
+    action_groups_remove_channel(act, fcu);
+    BKE_fcurve_free(fcu);
+  }
+  DEG_id_tag_update(&act->id, ID_RECALC_ANIMATION_NO_FLUSH);
+}