Add parallel offset grip editing for polylines

src/scene/model/object.rs

@@ -178,6 +178,7 @@ pub enum GripMenuAction {
     RectangleWidth,
     RectangleHeight,
     RectangleResize,
+    MoveParallel,
     AddVertex,
     RemoveVertex,
     ConvertToArc,

src/scene/pick/grip.rs

@@ -61,6 +61,7 @@ pub enum GripEditMode {
     RectangleWidth,
     RectangleHeight,
     RectangleResize,
+    MoveParallel,
 }
 
 #[derive(Clone, Debug)]
@@ -125,6 +126,12 @@ impl GripEdit {
         edit
     }
 
+    pub fn move_parallel(handle: Handle, grip_id: usize, world: DVec3) -> Self {
+        let mut edit = Self::single(handle, grip_id, false, world);
+        edit.mode = GripEditMode::MoveParallel;
+        edit
+    }
+
     pub fn rectangle_resize(
         handle: Handle,
         grip_id: usize,