3D View: move pre-select mesh element access into gizmo API

3 files changed, 69 insertions, 35 deletions

diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index d6f0d99b2b9..2457d78f1d4 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -27,6 +27,7 @@
 /* ********* exports for space_view3d/ module ********** */
 struct ARegion;
 struct BMEdge;
+struct BMElem;
 struct BMFace;
 struct BMVert;
 struct BPoint;
@@ -60,10 +61,12 @@ struct bPoseChannel;
 struct bScreen;
 struct rctf;
 struct rcti;
+struct wmGizmo;
 struct wmOperator;
 struct wmOperatorType;
 struct wmWindow;
 struct wmWindowManager;
+
 enum eGPUFXFlags;
 
 /* for derivedmesh drawing callbacks, for view3d_select, .... */
@@ -551,4 +554,9 @@ void ED_view3d_draw_bgpic_test(
         struct ARegion *ar, struct View3D *v3d,
         const bool do_foreground, const bool do_camera_frame);
 
+/* view3d_gizmo_preselect_type.c */
+void ED_view3d_gizmo_mesh_preselect_get_active(
+        struct bContext *C, struct wmGizmo *gz,
+        struct Base **r_base, struct BMElem **r_ele);
+
 #endif /* __ED_VIEW3D_H__ */
diff --git a/source/blender/editors/mesh/editmesh_polybuild.c b/source/blender/editors/mesh/editmesh_polybuild.c
index 7012629ec95..e7e69703237 100644
--- a/source/blender/editors/mesh/editmesh_polybuild.c
+++ b/source/blender/editors/mesh/editmesh_polybuild.c
@@ -89,48 +89,15 @@ static bool edbm_preselect_or_active(
         Base **r_base,
         BMElem **r_ele)
 {
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	ARegion *ar = CTX_wm_region(C);
 	wmGizmoMap *gzmap = ar->gizmo_map;
 	wmGizmoGroup *gzgroup = gzmap ? WM_gizmomap_group_find(gzmap, "VIEW3D_GGT_mesh_preselect_elem") : NULL;
 	if (gzgroup != NULL) {
 		wmGizmo *gz = gzgroup->gizmos.first;
-		const int object_index = RNA_int_get(gz->ptr, "object_index");
-
-		/* weak, allocate an array just to access the index. */
-		Base *base = NULL;
-		Object *obedit = NULL;
-		{
-			uint bases_len;
-			Base **bases = BKE_view_layer_array_from_bases_in_edit_mode(view_layer, CTX_wm_view3d(C), &bases_len);
-			if (object_index < bases_len) {
-				base = bases[object_index];
-				obedit = base->object;
-			}
-			MEM_freeN(bases);
-		}
-
-		*r_base = base;
-		*r_ele = NULL;
-
-		if (obedit) {
-			BMEditMesh *em = BKE_editmesh_from_object(obedit);
-			BMesh *bm = em->bm;
-			const int vert_index = RNA_int_get(gz->ptr, "vert_index");
-			const int edge_index = RNA_int_get(gz->ptr, "edge_index");
-			const int face_index = RNA_int_get(gz->ptr, "face_index");
-			if (vert_index != -1) {
-				*r_ele = (BMElem *)BM_vert_at_index_find(bm, vert_index);
-			}
-			else if (edge_index != -1) {
-				*r_ele = (BMElem *)BM_edge_at_index_find(bm, edge_index);
-			}
-			else if (face_index != -1) {
-				*r_ele = (BMElem *)BM_face_at_index_find(bm, face_index);
-			}
-		}
+		ED_view3d_gizmo_mesh_preselect_get_active(C, gz, r_base, r_ele);
 	}
 	else {
+		ViewLayer *view_layer = CTX_data_view_layer(C);
 		Base *base = view_layer->basact;
 		Object *obedit = base->object;
 		BMEditMesh *em = BKE_editmesh_from_object(obedit);
diff --git a/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.c b/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.c
index 029df078a09..418a9e76678 100644
--- a/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.c
+++ b/source/blender/editors/space_view3d/view3d_gizmo_preselect_type.c
@@ -423,3 +423,62 @@ void ED_gizmotypes_preselect_3d(void)
 }
 
 /** \} */
+
+
+/* -------------------------------------------------------------------- */
+/** \name Gizmo Accessors
+ *
+ * This avoids each user of the gizmo needing to write their own look-ups to access
+ * the information from this gizmo.
+ * \{ */
+
+void ED_view3d_gizmo_mesh_preselect_get_active(
+        bContext *C, wmGizmo *gz,
+        Base **r_base, BMElem **r_ele)
+{
+	ViewLayer *view_layer = CTX_data_view_layer(C);
+
+	const int object_index = RNA_int_get(gz->ptr, "object_index");
+
+	/* weak, allocate an array just to access the index. */
+	Base *base = NULL;
+	Object *obedit = NULL;
+	{
+		uint bases_len;
+		Base **bases = BKE_view_layer_array_from_bases_in_edit_mode(view_layer, CTX_wm_view3d(C), &bases_len);
+		if (object_index < bases_len) {
+			base = bases[object_index];
+			obedit = base->object;
+		}
+		MEM_freeN(bases);
+	}
+
+	*r_base = base;
+	*r_ele = NULL;
+
+	if (obedit) {
+		BMEditMesh *em = BKE_editmesh_from_object(obedit);
+		BMesh *bm = em->bm;
+		PropertyRNA *prop;
+
+		/* Ring select only defines edge, check properties exist first. */
+		prop = RNA_struct_find_property(gz->ptr, "vert_index");
+		const int vert_index = prop ? RNA_property_int_get(gz->ptr, prop) : -1;
+		prop = RNA_struct_find_property(gz->ptr, "edge_index");
+		const int edge_index = prop ? RNA_property_int_get(gz->ptr, prop) : -1;
+		prop = RNA_struct_find_property(gz->ptr, "face_index");
+		const int face_index = prop ? RNA_property_int_get(gz->ptr, prop) : -1;
+
+		if (vert_index != -1) {
+			*r_ele = (BMElem *)BM_vert_at_index_find(bm, vert_index);
+		}
+		else if (edge_index != -1) {
+			*r_ele = (BMElem *)BM_edge_at_index_find(bm, edge_index);
+		}
+		else if (face_index != -1) {
+			*r_ele = (BMElem *)BM_face_at_index_find(bm, face_index);
+		}
+	}
+}
+
+/** \} */