@Override
public void explainPrimarySelection(Actor player, LocalSession session, Vector pos) {
player.print("Starting a new polygon at " + pos + ".");
session.dispatchCUIEvent(player, new SelectionShapeEvent(getTypeID()));
session.dispatchCUIEvent(player, new SelectionPoint2DEvent(0, pos, getArea()));
session.dispatchCUIEvent(player, new SelectionMinMaxEvent(region.getMinimumY(), region.getMaximumY()));
}