FollowPath.java

package vooga.towerdefense.action.movement;

import vooga.towerdefense.action.Action;
import vooga.towerdefense.attributes.AttributeConstantsEnum;
import vooga.towerdefense.gameelements.GameElement;
import vooga.towerdefense.model.Path;
import util.Location;
import util.Vector;

/**
 * Makes the action initiator follow a path.
 * 
 * @author Mattew Roy
 * @author Zhen Gou
 * 
 * 
 */

public class FollowPath extends Action {

	private static final double DISTANCE_OFFSET = 5;
	private Path myPath;
	private Location myCurrentPathNode;
	private GameElement myInitiator;

	public FollowPath(GameElement initiator, Path path) {
		super();
		myInitiator = initiator;
		myPath = path;
		changeNode();
	}

	public void executeAction(double elapsedTime) {
		if (myInitiator.getCenter().distance(myCurrentPathNode) < DISTANCE_OFFSET) {
			changeNode();
		}
	}

	/**
	 * Movement logic, if path has next, change movement direction towards next
	 * node, if not, stop moving.
	 */
	private void changeNode() {
		if (myPath.hasNext()) {
			myCurrentPathNode = myPath.next();
			Vector newDirection = myInitiator.getCenter().difference(
					myCurrentPathNode);
			newDirection = new Vector(-1 * newDirection.getDirection(),
					newDirection.getMagnitude());

			myInitiator.getAttributeManager()
					.getAttribute(AttributeConstantsEnum.DIRECTION.toString())
					.setValue(newDirection.getDirection());
		}

		else {
			myInitiator.getAttributeManager()
					.getAttribute(AttributeConstantsEnum.MOVE_SPEED.toString())
					.setValue(0);
		}
	}

	public void setPath(Path path) {
		myPath = path;
	}

}