scene.java

一款赛车小游戏

package demo;
import java.util.Random;

import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.LayerManager;
import javax.microedition.lcdui.game.TiledLayer;

public class Scene {
	private TiledLayer m_TLayer;						//跑道格子
	private PlayerCar	m_Player;						//玩家赛车
	private CarSprite	m_aComCar[];					//电脑赛车
	private LayerManager m_Manager;					//层管理器
	private Random 	m_Random;						//随机数
	
	public Scene( int scrWidth, int scrHeight ){
		try{
			//读取跑道格子
			Image img = Image.createImage("/demo/grid.png");
			m_TLayer = new TiledLayer( 7, 100, img, 20, 20 );
			m_TLayer.setPosition( scrWidth/2 - m_TLayer.getWidth()/2, 0);
			//读取赛车图像
			Image imgcar = Image.createImage("/demo/car.png");
			m_Player = new PlayerCar( imgcar, 17, 29 );
			m_aComCar = new CarSprite[3];
			for( int n = 0; n < m_aComCar.length; n ++ )
				m_aComCar[n] = new CarSprite( imgcar, 17, 29);

			//将所有图层添加到层管理器
			m_Manager = new LayerManager();
			for( int n = 0; n < m_aComCar.length; n ++ )
				m_Manager.append(m_aComCar[n]);
			m_Manager.append(m_Player);
			m_Manager.append(m_TLayer);
			m_Random = new Random();
		}
		catch(Exception e){}
	}
	//重新开局
	public void Reset(){
		//设置跑道
		for( int col = 0; col < m_TLayer.getColumns(); col ++ ){
			for( int row = 0; row < m_TLayer.getRows(); row ++ ){
				m_TLayer.setCell(col, row, col%2 + 1);
			}
		}
		for( int col = 0; col < m_TLayer.getColumns(); col ++ ){
			m_TLayer.setCell(col, 2, 3);
			m_TLayer.setCell(col, m_TLayer.getRows()-2, 3);
		}
		//设置各个赛车的位置
		int width = m_TLayer.getCellWidth();
		int dis = m_TLayer.getCellWidth()/2 - m_Player.getWidth()/2;
		int y = m_TLayer.getHeight() - 30;
		m_Player.setPosition(m_TLayer.getX() + 2 * width + dis, y);
		m_aComCar[0].setPosition(m_TLayer.getX() + dis, y);
		m_aComCar[0].setFrame(1);
		m_aComCar[1].setPosition(m_TLayer.getX() + 4 * width + dis, y);
		m_aComCar[1].setFrame(2);
		m_aComCar[2].setPosition(m_TLayer.getX() + 6 * width + dis, y);
		m_aComCar[2].setFrame(3);
	}
	//设置游戏画面的显示区域
	public void SetViewWindow( int scrWidth, int scrHeight ){
		if( m_Manager == null )
			return;
		//根据英雄的位置，设置游戏画面的显示区域
		int nY = m_Player.getRefPixelY() - scrHeight/2;
		if( nY < 0 )
			nY = 0;
		else if( nY > m_TLayer.getHeight() - scrHeight )
			nY = m_TLayer.getHeight() - scrHeight;
		m_Manager.setViewWindow( 0, nY, scrWidth, scrHeight );
	}
	//处理按键的输入，参数keyStates为按键状态
	public void Input(int keyStates){
		m_Player.Input(keyStates);
	}
	//逻辑操作，参数scrWidth、scrHeight分别是屏幕的宽和高
	//返回-1表示游戏失败，返回1表示游戏胜利
	public int Logic(int scrWidth, int scrHeight)
	{
		m_Player.Logic(null);
		boolean bHasCar = false;		//是否有汽车到达了终点
		for( int n = 0; n < m_aComCar.length; n ++ ){
			m_aComCar[n].Logic(m_Random);
			if( m_aComCar[n].collidesWith(m_Player, true) )
			{//如果和游戏者赛车相撞
				m_aComCar[n].MoveBack(false);
				m_Player.MoveBack(true);
			}
			//如果超出跑道范围
			if( m_aComCar[n].getX() < m_TLayer.getX() )
				m_aComCar[n].MoveBack(false);
			if( m_aComCar[n].getX() + m_aComCar[n].getWidth() > 
				m_TLayer.getX() + m_TLayer.getWidth() )
				m_aComCar[n].MoveBack(false);
			if( m_aComCar[n].getRefPixelY() < 40 )
			{//如果到达终点
				m_aComCar[n].Stop();
				bHasCar = true;
			}
		}
		//设置可视区域
		SetViewWindow(scrWidth, scrHeight);
		if( m_Player.getRefPixelY() < 40 )
		{//如果到达终点
			if( bHasCar )
				return -1;
			else
				return 1;
		}
		return 0;
	}
	//显示图像
	public void Paint(Graphics g){
		m_Manager.paint(g, 0, 0);
	}
}