+ // when dragging a box around some ducks:
+ // SHIFT selects; CTRL toggles; SHIFT+CTRL unselects; <none> clears all then selects
+ if(modifier&GDK_SHIFT_MASK)
+ select_ducks_in_box(drag_point,mouse_pos);
+
+ if(modifier&GDK_CONTROL_MASK)
+ toggle_select_ducks_in_box(drag_point,mouse_pos);
+ else if(!(modifier&GDK_SHIFT_MASK))
+ {