fairy.java

a java game code for java

//Source file: d:/MyProjects/Java/eatbean/eatbean/Fairy.java

package eatbean;

import java.awt.*;
//
import eatbean.util.*;
import eatbean.conf.*;
import java.util.Hashtable;

public class Fairy extends Actor {
	public static final int MAX_FRAME = 2;
	public static final int MIN_FRAME = 0;
	public static final int MAX_SIZE = 16;
	private static final Hashtable frameTable = new Hashtable();
	private static final Hashtable imgBuffTable = new Hashtable();
	private Rect bakR = null;
	private Pos[] bakP = null;
	private Image img = null;
	private boolean keepRunning = true;
	private int currFrame;
	private long lastChangeFrameTime = -1;

	public static final int DIR_WEST = 1;
	public static final int DIR_EAST = -1;
	public static final int DIR_NORTH = 2;
	public static final int DIR_SOUTH = -2;

	static {
		for(int i = MIN_FRAME; i <= MAX_FRAME; i++) {
			//分四个方向
		    frameTable.put(new Integer(parseImgIndex(i, DIR_WEST)), "fairyw"+i+".gif");
			frameTable.put(new Integer(parseImgIndex(i, DIR_EAST)), "fairye"+i+".gif");
			frameTable.put(new Integer(parseImgIndex(i, DIR_NORTH)), "fairyn"+i+".gif");
			frameTable.put(new Integer(parseImgIndex(i, DIR_SOUTH)), "fairys"+i+".gif");
		}
	}

	public Fairy(Mediator mediator) {
		super(mediator);
		init();
	}
	private void init() {
		mapPos = mediator.getFairyBornPos();
		MapElement e = mediator.getElement(mapPos);
		rect.width = MAX_SIZE;
		rect.height = MAX_SIZE;
		rect.x = adjustX(e.getLeft(), e.getWidth(), rect.width);
		rect.y = adjustY(e.getTop(), e.getHeight(), rect.height);
		currCoveredPos = mediator.getCoveredElementsMapPos(this);
		mapPos = mediator.getCurrMapPos(currCoveredPos, rect);

		currFrame = MIN_FRAME;
		img = getImage(parseImgIndex(currFrame, direction));
	}
	public void run() {
		while(keepRunning) {
			if(!mediator.getPaused()) {
				nextstep();
				//mediator.flushScreen(this);
			} else
				if(thread != null) thread.yield();
			mediator.flushScreen(this);
			nextframe();
		}
	}
	public void die() {
		keepRunning = false;
	}
	public boolean nextstep() {
		boolean result = false;
		boolean flag = true;
		backup();
		/*
		if(Debug.ON) Debug.println("mapPos: " + mapPos);
		if(Debug.ON) Debug.println("rect: " + rect);
		if(Debug.ON) Debug.println("nextDirection: " + nextDirection);
		*/
		if(nextDirection == getReverse())
			direction = nextDirection;
		else if(nextDirection != direction) {	//nextDirection 与 direction 互相垂直
			if(mediator.acceptable(getMapPos(), nextDirection)) {   //  如果此方向可行
				//则调整位置到mapPos元素的重心
				MapElement e = mediator.getElement(mapPos);
				rect.x = adjustX(e.getLeft(), e.getWidth(), rect.width);
				rect.y = adjustY(e.getTop(), e.getHeight(), rect.height);
				direction = nextDirection;
				flag = false;
			}
		}
		//if(flag) {
			switch(direction) {
				case DIR_WEST :
						rect.x = rect.x - step;
						break;
				case DIR_EAST :
						rect.x = rect.x + step;
						break;
				case DIR_NORTH :
						rect.y = rect.y - step;
						break;
				case DIR_SOUTH :
						rect.y = rect.y + step;
						break;
			}
		//}
		currCoveredPos = mediator.getCoveredElementsMapPos(this);
		//下一步是否有效
		if(!flag || mediator.acceptable(this)) {	//有效
			clear(bakP);    //  重绘被覆盖的背景
			//paint();
			Pos p = mediator.getCurrMapPos(currCoveredPos, rect);
			if(p != null)
				mapPos = p;
			//mediator.beep();
			result = true;
		} else {
			//restore data
			restore();
		}
		mediator.eatBean(this);
		mediator.checkSpriteIntersect(this);
		return result;
	}
	private void nextframe() {
		long currTime = System.currentTimeMillis();
		if(currTime - lastChangeFrameTime < SysParam.CHANGE_FRAME_TIME) return;
		currFrame++;
		if(currFrame > MAX_FRAME || currFrame < MIN_FRAME) currFrame = MIN_FRAME;
		img = getImage(parseImgIndex(currFrame, direction));
		lastChangeFrameTime = currTime;
	}
	public void clear(Pos[] p) {
		if(p == null) {
			if(Debug.ON)System.out.println("Fairy.clear(): p == null!!!!");
		} else
			mediator.repaintBg(this, p);
	}
	public void clear() {
		clear(currCoveredPos);
	}
	private void draw() {
		OffScreen offScreen = mediator.getOffScreen();
		offScreen.drawImage(img, rect.x, rect.y);
	}
	public boolean act() {
		if(thread == null) {
			thread = new Thread(this);
			thread.start();
		}
		return true;
	}
	public void paint() {
		draw();
	}
	private int adjustX(int x, int w1, int w2) {
		return x + Math.abs(w1-w2)/2;
	}
	private int adjustY(int y, int h1, int h2) {
		return y + Math.abs(h1-h2)/2;
	}
	private void backup() {
		bakR = getRect();	//backup rect
		//if(currCoveredPos == null) currCoveredPos = mediator.getCoveredElementsMapPos(this);
		if(currCoveredPos != null) {
			bakP = new Pos[currCoveredPos.length];
			for(int i = 0; i < currCoveredPos.length; i ++)
				bakP[i] = (Pos)currCoveredPos[i].clone();
		}
	}
	private void restore() {
		rect = bakR;
		currCoveredPos = bakP;
	}
	private static int parseImgIndex(int frame, int dir) {
	    return 10*frame+dir;
	}
	private Image getImage(int imgIndex) {
		Image result = null;
		synchronized(imgBuffTable) {    //  同步,保证同一Image仅被调入内存一次
		    result = super.getImage(imgBuffTable, frameTable, imgIndex);
		}
		return result;
	}
}