View 3D: refactor edit-mode meta-element selection

Meta-element selection now follows conventions for other picking
functions (e.g. EDBM_select_pick).

- Split meta-element find-nearest into a separate function.

- Cycle the meta-element starting from the active & selected
  instead of comparing & setting a static variable.

- Order elements using depth (from front-to-back)
  when cycling multiple elements.

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/editors/include/ED_mball.h b/source/blender/editors/include/ED_mball.h
index 74071765716..7f2c4dff311 100644
--- a/source/blender/editors/include/ED_mball.h
+++ b/source/blender/editors/include/ED_mball.h
@@ -12,6 +12,7 @@ extern "C" {
 #endif
 
 struct Base;
+struct MetaElem;
 struct Object;
 struct SelectPick_Params;
 struct UndoType;
@@ -32,6 +33,11 @@ struct MetaElem *ED_mball_add_primitive(struct bContext *C,
                                         float dia,
                                         int type);
 
+struct Base *ED_mball_base_and_elem_from_select_buffer(struct Base **bases,
+                                                       uint bases_len,
+                                                       const uint select_id,
+                                                       struct MetaElem **r_ml);
+
 /**
  * Select meta-element with mouse click (user can select radius circle or stiffness circle).
  *