1 files changed, 41 insertions, 0 deletions
diff --git a/source/blender/editors/armature/armature_utils.c b/source/blender/editors/armature/armature_utils.c
index 2cbfb52db91..be26ad537fc 100644
--- a/source/blender/editors/armature/armature_utils.c
+++ b/source/blender/editors/armature/armature_utils.c
@@ -156,6 +156,47 @@ bool ED_armature_ebone_is_child_recursive(EditBone *ebone_parent, EditBone *ebon
 	return false;
 }
 
+/**
+ * Finds the first parent shared by \a ebone_child
+ *
+ * \param ebone_child  Children bones to search
+ * \param ebone_child_tot  Size of the ebone_child array
+ * \return The shared parent or NULL.
+ */
+EditBone *ED_armature_bone_find_shared_parent(EditBone *ebone_child[], const unsigned int ebone_child_tot)
+{
+	unsigned int i;
+	EditBone *ebone_iter;
+
+#define EBONE_TEMP_UINT(ebone) (*((unsigned int *)(&((ebone)->temp))))
+
+	/* clear all */
+	for (i = 0; i < ebone_child_tot; i++) {
+		for (ebone_iter = ebone_child[i]; ebone_iter; ebone_iter = ebone_iter->parent) {
+			EBONE_TEMP_UINT(ebone_iter) = 0;
+		}
+	}
+
+	/* accumulate */
+	for (i = 0; i < ebone_child_tot; i++) {
+		ebone_iter = ebone_child[i];
+		for (ebone_iter = ebone_child[i]->parent; ebone_iter; ebone_iter = ebone_iter->parent) {
+			EBONE_TEMP_UINT(ebone_iter) += 1;
+		}
+	}
+
+	/* only need search the first chain */
+	for (ebone_iter = ebone_child[0]->parent; ebone_iter; ebone_iter = ebone_iter->parent) {
+		if (EBONE_TEMP_UINT(ebone_iter) == ebone_child_tot) {
+			return ebone_iter;
+		}
+	}
+
+#undef EBONE_TEMP_UINT
+
+	return NULL;
+}
+
 void ED_armature_ebone_to_mat3(EditBone *ebone, float mat[3][3])
 {
 	float delta[3];