Cleanup/refactor binding code for MeshDeform modifier.

We had two different ways of doing it, SurfaceDeform and LaplacianDeform
would do it through a special modifier stack evaluation triggered from
binding operator, while MeshDeform would do it through a regular
depsgraph update/eval (also triggered from its binding op).

This enforces the later to search back for orig modifier data inside
modifier code (to apply binding on that one, and not on useless CoW
one).

Besides the question of safety about modifying orig data from threaded
despgraph (that was *probably* OK, but think it's bad idea in general),
it's much better to have a common way of doing that kind of things.

For now it remains rather dodgy, but at least it's reasonably consistent
and safe now.

This commit also fixes a potential memleak from binding process of
MeshDeform, and does some general cleanup a bit.

1 files changed, 19 insertions, 30 deletions

diff --git a/source/blender/editors/object/object_modifier.c b/source/blender/editors/object/object_modifier.c
index 7b4fba23551..200ff1ab0d6 100644
--- a/source/blender/editors/object/object_modifier.c
+++ b/source/blender/editors/object/object_modifier.c
@@ -1944,52 +1944,41 @@ static bool meshdeform_poll(bContext *C)
 
 static int meshdeform_bind_exec(bContext *C, wmOperator *op)
 {
-	Main *bmain = CTX_data_main(C);
 	Depsgraph *depsgraph = CTX_data_depsgraph(C);
+	Scene *scene = CTX_data_scene(C);
 	Object *ob = ED_object_active_context(C);
 	MeshDeformModifierData *mmd = (MeshDeformModifierData *)edit_modifier_property_get(op, ob, eModifierType_MeshDeform);
 
-	if (!mmd)
+	if (mmd == NULL) {
 		return OPERATOR_CANCELLED;
+	}
 
-	if (mmd->bindcagecos) {
-		MEM_freeN(mmd->bindcagecos);
-		if (mmd->dyngrid) MEM_freeN(mmd->dyngrid);
-		if (mmd->dyninfluences) MEM_freeN(mmd->dyninfluences);
-		if (mmd->bindinfluences) MEM_freeN(mmd->bindinfluences);
-		if (mmd->bindoffsets) MEM_freeN(mmd->bindoffsets);
-		if (mmd->dynverts) MEM_freeN(mmd->dynverts);
-		if (mmd->bindweights) MEM_freeN(mmd->bindweights);  /* deprecated */
-		if (mmd->bindcos) MEM_freeN(mmd->bindcos);  /* deprecated */
-
-		mmd->bindcagecos = NULL;
-		mmd->dyngrid = NULL;
-		mmd->dyninfluences = NULL;
-		mmd->bindinfluences = NULL;
-		mmd->bindoffsets = NULL;
-		mmd->dynverts = NULL;
-		mmd->bindweights = NULL; /* deprecated */
-		mmd->bindcos = NULL; /* deprecated */
+	if (mmd->bindcagecos != NULL) {
+		MEM_SAFE_FREE(mmd->bindcagecos);
+		MEM_SAFE_FREE(mmd->dyngrid);
+		MEM_SAFE_FREE(mmd->dyninfluences);
+		MEM_SAFE_FREE(mmd->bindinfluences);
+		MEM_SAFE_FREE(mmd->bindoffsets);
+		MEM_SAFE_FREE(mmd->dynverts);
+		MEM_SAFE_FREE(mmd->bindweights);  /* Deprecated */
+		MEM_SAFE_FREE(mmd->bindcos);  /* Deprecated */
 		mmd->totvert = 0;
 		mmd->totcagevert = 0;
 		mmd->totinfluence = 0;
 	}
 	else {
-		int mode = mmd->modifier.mode;
-		mmd->bindfunc = ED_mesh_deform_bind_callback;
+		/* Force modifier to run, it will call binding routine (this has to happen outside of depsgraph evaluation). */
+		const int mode = mmd->modifier.mode;
 		mmd->modifier.mode |= eModifierMode_Realtime;
-
-		/* Force depsgraph update, this will do binding. */
-		DEG_id_tag_update(&ob->id, OB_RECALC_DATA);
-		BKE_scene_graph_update_tagged(depsgraph, bmain);
-
-		mmd->bindfunc = NULL;
+		mmd->bindfunc = ED_mesh_deform_bind_callback;
+		object_force_modifier_update_for_bind(depsgraph, scene, ob);
 		mmd->modifier.mode = mode;
+		mmd->bindfunc = NULL;
 	}
 
-	DEG_id_tag_update(&ob->id, OB_RECALC_DATA);
+	/* We need DEG_TAG_COPY_ON_WRITE to ensure (un)binding is flushed to CoW copies of the object... */
+	DEG_id_tag_update(&ob->id, DEG_TAG_GEOMETRY | DEG_TAG_COPY_ON_WRITE);
 	WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
-
 	return OPERATOR_FINISHED;
 }