Transform: support snapping origins onto the objects geometry

Normally it wouldn't make sense for the object to snap onto it's self,
when moving origins this is a common use-case.

2 files changed, 23 insertions, 12 deletions

diff --git a/source/blender/editors/transform/transform_conversions.c b/source/blender/editors/transform/transform_conversions.c
index 4fe79dc3202..dc072d74be6 100644
--- a/source/blender/editors/transform/transform_conversions.c
+++ b/source/blender/editors/transform/transform_conversions.c
@@ -6536,11 +6536,14 @@ static void flush_trans_object_base_deps_flag(Depsgraph *depsgraph, Object *obje
       depsgraph, &object->id, DEG_OB_COMP_TRANSFORM, set_trans_object_base_deps_flag_cb, NULL);
 }
 
-static void trans_object_base_deps_flag_finish(ViewLayer *view_layer)
+static void trans_object_base_deps_flag_finish(const TransInfo *t, ViewLayer *view_layer)
 {
-  for (Base *base = view_layer->object_bases.first; base; base = base->next) {
-    if (base->object->id.tag & LIB_TAG_DOIT) {
-      base->flag_legacy |= BA_SNAP_FIX_DEPS_FIASCO;
+
+  if ((t->flag & T_OBJECT_DATA_IN_OBJECT_MODE) == 0) {
+    for (Base *base = view_layer->object_bases.first; base; base = base->next) {
+      if (base->object->id.tag & LIB_TAG_DOIT) {
+        base->flag_legacy |= BA_SNAP_FIX_DEPS_FIASCO;
+      }
     }
   }
 }
@@ -6602,7 +6605,7 @@ static void set_trans_object_base_flags(TransInfo *t)
   /* Store temporary bits in base indicating that base is being modified
    * (directly or indirectly) by transforming objects.
    */
-  trans_object_base_deps_flag_finish(view_layer);
+  trans_object_base_deps_flag_finish(t, view_layer);
 }
 
 static bool mark_children(Object *ob)
@@ -6670,7 +6673,7 @@ static int count_proportional_objects(TransInfo *t)
   /* Store temporary bits in base indicating that base is being modified
    * (directly or indirectly) by transforming objects.
    */
-  trans_object_base_deps_flag_finish(view_layer);
+  trans_object_base_deps_flag_finish(t, view_layer);
   return total;
 }
 
diff --git a/source/blender/editors/transform/transform_snap.c b/source/blender/editors/transform/transform_snap.c
index b29edcb00de..14242f6ba40 100644
--- a/source/blender/editors/transform/transform_snap.c
+++ b/source/blender/editors/transform/transform_snap.c
@@ -632,12 +632,20 @@ static void initSnappingMode(TransInfo *t)
     else if (t->tsnap.applySnap != NULL &&  // A snapping function actually exist
              (obedit_type == -1))           // Object Mode
     {
-      /* In "Edit Strokes" mode,
-       * snap tool can perform snap to selected or active objects (see T49632)
-       * TODO: perform self snap in gpencil_strokes */
-      t->tsnap.modeSelect = (((t->options & (CTX_GPENCIL_STROKES | CTX_CURSOR)) != 0) ?
-                                 SNAP_ALL :
-                                 SNAP_NOT_SELECTED);
+
+      if (t->options & (CTX_GPENCIL_STROKES | CTX_CURSOR)) {
+        /* In "Edit Strokes" mode,
+         * snap tool can perform snap to selected or active objects (see T49632)
+         * TODO: perform self snap in gpencil_strokes */
+        t->tsnap.modeSelect = SNAP_ALL;
+      }
+      else if (t->flag & T_OBJECT_DATA_IN_OBJECT_MODE) {
+        /* When we're moving the origins, allow snapping onto our own geometry (see T69132). */
+        t->tsnap.modeSelect = SNAP_ALL;
+      }
+      else {
+        t->tsnap.modeSelect = SNAP_NOT_SELECTED;
+      }
     }
     else {
       /* Grid if snap is not possible */