package com.j2medev.chapter5;
import javax.microedition.lcdui.game.*;
import javax.microedition.lcdui.*;
import java.io.*;

public class DemoCanvas
        extends GameCanvas
        implements CommandListener, Runnable {
    private Image imgA,imgB;//飛機(imgA)和敵人(imgB)的Image對象
    private Image mapImg0,mapImg1;//背景0和背景1的Image對象
    private TiledLayer tiledLayer0;//背景0
    private TiledLayer tiledLayer1;//背景1
    private LayerManager layers;//管理所有層的層管理器
    private Sprite spriteA,spriteB;//聲明精靈A和精靈B對象
    private int keyState;//按鍵狀態
    private boolean collideSta;//狀態變量，表示是否碰撞
    private Graphics g;//畫筆的引用
    private int Ypos0;//可視窗口的縱坐標

    
    public DemoCanvas() {
        //構造GameCanvas,參數true意味著CameCanvas不會自動調用KeyPressed,keyRepeated,keyReleased方法
        super(true);
        //全屏
        this.setFullScreenMode(true);
        try {//初始化兩個精靈的Image對象和兩個背景的Image對象
            imgA = Image.createImage("/img0.png");
            imgB = Image.createImage("/img1.png");
            mapImg0 = Image.createImage("/map0.png");
            mapImg1 = Image.createImage("/map1.png");
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        
        tiledLayer0 = new TiledLayer(9,20,mapImg0,28,28);//實例化背景層0,用mapImg0填充20行9列
        tiledLayer1 = new TiledLayer(12,11,mapImg1,21,40);//實例化背景層1,用mapImg1填充11行12列
        tiledLayer1.setPosition(-6,0);//初始化背景層1的位置

        int[][] map0 = {//背景層0的塊兒分布(全用1號塊兒填充)
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1},
            { 1,1,1,1,1,1,1,1,1}
            
        };
        
        
        int[][] map1 = {//背景層1的塊兒分布(左側用1號塊兒填充,右側用2號塊兒填充,其它位置不填)
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
            { 1,0,0,0,0,0,0,0,0,0,0,2},
        };
        
        //利用map0中的地圖信息填充背景層0
        for (int i = 0; i < map0.length; i++)
            for(int j = 0;j<map0[i].length;j++)
                tiledLayer0.setCell(j, i, map0[i][j]);
        

        spriteA = new Sprite(imgA,110,89);//實例化精靈A
        spriteB = new Sprite(imgB,80,80);//實例化精靈B
        
        spriteA.setPosition(50,100);//初始化精靈A的位置
        spriteB.setPosition(50,0);//初始化精靈B的位置
        
        layers= new LayerManager();//實例化一個層管理器

        layers.append(tiledLayer0);//將背景層添加到層管理器中
        
        Ypos0 = tiledLayer0.getHeight() - this.getHeight();//初始化背景層0的位置

        
        this.setFullScreenMode(true);//全屏
        setCommandListener(this);
        addCommand(new Command("Exit", Command.EXIT, 1));
        
        
        new Thread(this).start();//啟動GameCanvas線程
    }
    
    public void check(){//碰撞檢測
        if(spriteA.collidesWith(spriteB,true)) collideSta = true;
        else collideSta = false;
    }
    
    public void run() {
        while (true) {
            // repaint();
            this.g = getGraphics();//獲取畫筆
            keyState = getKeyStates();//獲取按鍵狀態
            //精靈A向左移動
            if((keyState & this.LEFT_PRESSED)!=0){
                spriteA.move(-3,0);
              }
            //精靈A向右移動
            if((keyState & this.RIGHT_PRESSED)!=0){
                spriteA.move(3,0);
            }
            //精靈A向上移動
            if((keyState & this.UP_PRESSED)!=0){
                spriteA.move(0,-3);
            }
            //精靈A向下移動
            if((keyState & this.DOWN_PRESSED)!=0){
                spriteA.move(0,3);
                
            }
            check();//碰撞檢測

            this.draw(g);//調用自定義的畫圖方法
            
            try {
                Thread.sleep(33);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    
    public void draw(Graphics g) {
        //清屏
        g.setColor(0);
        g.fillRect(0,0,this.getWidth(),this.getHeight());
        //準備畫下一幀
        spriteA.nextFrame();
        //實現背景0的循環滾動,實際上是可視窗口在循環滾動
        if(Ypos0<=0) Ypos0 = tiledLayer0.getHeight() - this.getHeight();
        
        //設置可視區域
        layers.setViewWindow(0,Ypos0,this.getWidth(),this.getHeight());
        //可視窗口向上移動
        Ypos0 = Ypos0-2;
        //畫出層管理器中的所有層
        layers.paint(g,0,0);
        //畫精靈A
        spriteA.paint(g);
        //刷新
        flushGraphics();
        
    }
    
    public void keyPressed(int keyCode) {
        //System.out.println(" ");
    }
    
    public void commandAction(Command command, Displayable displayable) {
        if (command.getCommandType() == Command.EXIT) {
            GameDemo.quitApp();
        }
    }
}