Function manipulator 

pub fn manipulator(
    pivot: Vec3,
    basis: &[Vec3; 3],
    mode: GizmoMode,
    size: f32,
) -> Vec<GizmoLineInstance>

The interactive handles for mode, drawn at pivot along basis.

Empty for GizmoMode::Select: the pointer tool manipulates nothing, so drawing grabbable-looking handles for it would be a lie.