alien.java

一个不错的动作类游戏

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

public class Alien
{
	Image[] imageFrames;
	Image image;
	int imageWidth;	
	int imageHeight;
	int frameWidth;	
	int frameHeight;
	int canvasWidth;	
	int canvasHeight;
	protected static final String IMAGE_NAME="alien";
	
	protected static final int RAW_FRAMES=1;
	protected int frame=0;
  
	protected static final int FRAMES=2;
	protected static final int START_FRAME=0;
	protected static final int END_FRAME=1;
	protected int xPos=0;
	protected int yPos=0;
	protected static int currentAlien=0;
	
	protected static int rows=2;
	protected static int cols=3;
	
	protected static int colOffset=3;
	protected static int rowOffset=3;
	protected static int yOffset=0;
	protected static VaderCanvas gameCanvas;
	protected static VaderManager layerManager;
	
	protected static boolean direction=true;
	protected static boolean isEnd=true;

 
	public Alien(int canvasWidth, int canvasHeight)
	{
		imageFrames=VaderManager.getFrames(IMAGE_NAME, RAW_FRAMES);
		this.canvasHeight=canvasHeight;
		this.canvasWidth=canvasWidth;		
		imageWidth=imageFrames[0].getWidth();
		imageHeight=imageFrames[0].getHeight();	
		frameWidth=imageWidth/FRAMES;
		frameHeight=imageHeight;		
		createImage();
		setSpriteImage();
		gameCanvas=layerManager.getGameCanvas();		
	}
  
    public int getHeight()				{return imageHeight;}
	public int getWidth()				{return imageWidth;}
	public int getFrameHeight()			{return frameHeight;}
	public int getFrameWidth()			{return frameWidth;}
	public int getCanvasHeight()		{return canvasHeight;}
	public int getCanvasWidth()			{return canvasWidth;}
	public Image getImage()				{return image;}
	private void setX(int x)			{xPos=x;}	
	private void setY(int y)			{yPos=y;}
	public int getX()					{return xPos;}	
	public int getY()					{return yPos;}
  
	public static void setDirection(boolean dir)				{direction=dir;} 
	public static void setEnd(boolean end)						{isEnd=end;}  
	public static int getRows()									{return rows;}
	public static int getCols()									{return cols;}
	public static void setCols(int c)								{cols=c;}
	public static void setRows(int r)								{rows=r;}
	public static void setLayerManager(VaderManager manager)		{layerManager=manager;}	
	
  	public void setPosition(int x, int y)
	{
		setX(x);
		setY(y);
	}
	private void move(int x, int y)
	{
		setX(getX()+x);
		setY(getY()+y);  	
	}
	
	public void backwards()
	{
		move(-2, 0);        
	}
	public void forwards()
	{
		move(2, 0);	
	}
	
	public void setFrame()
	{
		if(++frame>=FRAMES)
		{
			frame=0;
		}
	}

	private void setDirection()
	{  		
		if((getX()+getFrameWidth())>=canvasWidth)
		{
			setEnd(false);
		}
		else if(getX()<0)
		{
			setEnd(true);
		}  	
	}
	private void setYOffset()
	{
		yOffset+=3;
		//setPosition(getX(), getY()+yOffset);
		//move(0,yOffset);	  	
	}
	public void move()
	{  	
		if(direction)
		{
			forwards();
		}
		else
		{
			backwards();
		}  	
	
	}
	public void tick()
	{   
		currentAlien++;
		setFrame();
		move();	  
		
		int aCount=layerManager.vtrAliens.size();
		if(currentAlien>=aCount)
		{		
			currentAlien=0;
			setDirection(isEnd);
		}		
		
		int bCount=layerManager.vtrBullets.size();
		Bullet bullet; 
		        
		for (int b=0;b<bCount;b++)
		{
			bullet=(Bullet)layerManager.vtrBullets.elementAt(b);
			
			if(collidesWith(bullet))
			{	
				layerManager.removeLayer(this);
				layerManager.removeLayer(bullet);						
				layerManager.setScore(layerManager.getScore()+10);
				if(--bCount<=0)
				{
					break;
				}
			}			
		}
			
		setDirection();
		
	}
	public void draw()
	{
		Graphics g=layerManager.getGraphics();
		if(imageFrames[0]!=null)
		{
			g.setClip(xPos,yPos,frameWidth,frameHeight);
			g.drawImage(imageFrames[0],xPos-(frameWidth*frame),yPos,g.LEFT | g.TOP);
			g.setClip(0,0,getCanvasWidth(),getCanvasHeight());
		}
	}
	public boolean collidesWith(Bullet bullet)
	{
		boolean isCollision=false;
		
		if((bullet.getX()>getX() && bullet.getY()>getY()) 
			&& ((bullet.getX()+bullet.getWidth())<(getX()+getFrameWidth())
			 && (bullet.getY()+bullet.getHeight())<getY()+getFrameHeight()))
		 {
			isCollision=true;
		 } 
		 		 
		 return isCollision;
	}
	
    private void createImage()
	{
		// allocate memory to store the onscreen background image.
		// assuming all tiles are the same size, make the buffer
		// the screen size plus one row and column.	
		image=Image.createImage(getFrameWidth(), getFrameHeight());
	}
	private void setSpriteImage()
	{
		Graphics g = image.getGraphics();
		g.drawImage(imageFrames[0],0,0,g.LEFT | g.TOP);
		
	}
}