Fix T76416: Armature Deform parenting option doesn't work with Grease Pencil objects

If we parent with type `PAR_ARMATURE` (where vertexgroups are already
set up and named correctly according to the corresponding bones), we
still need an armature modifier. This just wasnt added.

In contrast to meshes [which add their armature modifier early in
`ED_object_parent_set`], grease pencil used to do this (adding the
armature modifier) in `ED_gpencil_add_armature_weights`.

Now split ED_gpencil_add_armature_weights in two:
- ED_gpencil_add_armature
- ED_gpencil_add_armature_weights (which calls ED_gpencil_add_armature)
- use ED_gpencil_add_armature for the PAR_ARMATURE case

Maniphest Tasks: T76416

Differential Revision: https://developer.blender.org/D7625

1 files changed, 5 insertions, 1 deletions

diff --git a/source/blender/editors/include/ED_gpencil.h b/source/blender/editors/include/ED_gpencil.h
index d63353d3886..1403ae1f3cc 100644
--- a/source/blender/editors/include/ED_gpencil.h
+++ b/source/blender/editors/include/ED_gpencil.h
@@ -178,7 +178,11 @@ bool ED_gpencil_anim_copybuf_paste(struct bAnimContext *ac, const short copy_mod
 int ED_gpencil_session_active(void);
 int ED_undo_gpencil_step(struct bContext *C, int step, const char *name);
 
-/* ------------ Grease-Pencil Armature weights ------------------ */
+/* ------------ Grease-Pencil Armature ------------------ */
+bool ED_gpencil_add_armature(const struct bContext *C,
+                             struct ReportList *reports,
+                             struct Object *ob,
+                             struct Object *ob_arm);
 bool ED_gpencil_add_armature_weights(const struct bContext *C,
                                      struct ReportList *reports,
                                      struct Object *ob,