gameboard.java

一个基于J2ME的pacman游戏

/**
 * PacMan for J2ME Devices
 * CS 327 - Design Project, Fall 2002
 * University of Illinois, Urbana-Champaign
 * 
 * file: GameBoard.java 
 * contact: Braden Kowitz
 * date: 11/24/02
 **/

//----------------------------------------------------------------------------//

import javax.microedition.lcdui.*;
import java.util.Vector;

/**
 * A gameborad consists of a vector of GridNodes, and actors.
 **/
public class GameBoard
{
	
	//--------------------------//
	// ENUM
	//--------------------------//

	/**
	 * Enum for a desired state
	 **/
	public static final int ALIVE = 0;
	public static final int DEAD = 1;

	//--------------------------//
	// MEMBER VARIABLES
	//--------------------------//
	
	/**
	 * A vector containing all of the GridNodes in this board.
	 **/
	private Vector nodes_;
	
	/**
	 * A vector containing all of the active GhostActors on this board.
	 **/
	private Vector ghosts_;

	/**
	 * The pacman for this board
	 **/
	private PacmanActor pacman_;

	/**
       * The state of the GameBoard
       *  - state can be : ALIVE, DEAD
       **/
      private int state_;
	
	//--------------------------//
	// FUNCTIONS
	//--------------------------//
	
	/**
	 * Simple constructor, takes no parameters.
	 **/
	public GameBoard()
	{
		nodes_ = new Vector();
		ghosts_ = new Vector();
		state_ = ALIVE;
	}

	/**
	 * Adds a GridNode to this board.
	 **/
	public void addGridNode(GridNode n)
	{
		nodes_.addElement(n);
	}

	/**
	 * Paints the board by calling paint on all GridNodes,
	 * pacman, and each ghost.
	 * @param g Graphics object where drawing should take place.
	 */
	public void paint(Graphics g)
	{
		for (int i=0; i<nodes_.size(); i++)
		{
			GridNode n = (GridNode) nodes_.elementAt(i);
			n.paint(g);
		}

		pacman_.paint(g);

		for (int i=0; i<ghosts_.size(); i++)
		{
			GhostActor ghost = (GhostActor) ghosts_.elementAt(i);
			ghost.paint(g);
			
			g.drawString(Integer.toString(pacman_.score_), 68, 65, 16|4);
			g.drawString(Integer.toString(pacman_.getLivesLeft()), 58, 65, 16|4);
		}
	}

	/**
	 * advance all actors one frame: 
	 * @return true if pacman has enough lives otherwise false
	 **/
	public boolean advanceFrame()
	{
		// and ghosts:
		for (int i=0; i<ghosts_.size(); i++)
		{
			GhostActor ghost = (GhostActor) ghosts_.elementAt(i);
			
			//March 18, 2003 
			//Moved .advanceframe functions to try to get killing correct
			//	(when pacman and ghost are in the same node, visually) codewise this is correct.
			//if we use .getNode(), pacman gets killed before we see the ghost touch him
			//if (ghost.getNode() == pacman_.getNode())

			if ((Math.abs(ghost.getX() - pacman_.getX()) < 3) && (Math.abs(ghost.getY() - pacman_.getY()) < 3))
			{
				if(pacman_.isInvincible() == false)
				{
					state_ = DEAD;
					
				}
				else
				{
					pacman_.score_+=5;
					ghost.restart();
				}

			}
	
			ghost.advanceFrame();

		}

		if (state_ == DEAD)
		{
			pacman_.restart();
			if (pacman_.getLivesLeft() < 0)
				return false;
			state_ = ALIVE;

			for (int i=0; i<ghosts_.size(); i++)
			{
				GhostActor ghost = (GhostActor) ghosts_.elementAt(i);
				ghost.restart();
			}

		}
		else	//If he's not dead, then he can still move
			pacman_.advanceFrame();
		
		return true;
	}

	/**
	 *	@param p the PacmanActor for this board
	 **/
	public void setPacman(PacmanActor p)
	{
		pacman_ = p;
	}
	
	/**
	 *	@return the PacmanActor for this board
	 **/
	public PacmanActor getPacman()
	{
		return pacman_;
	}

	/**
	 * Adds a GhostActor to this board.
	 * @param ghost the ghost to add.
	 **/
	public void addGhost(GhostActor ghost)
	{
		ghosts_.addElement(ghost);
	}
}

//----------------------------------------------------------------------------//