#眉標=Java
#副標=如何簡化遊戲的設計
#大標=Game API進階（中）
＃引言＝

===========<box>=============
[程式１]
MyGameWithSpriteRotateCanvas.java
import javax.microedition.lcdui.* ;
import javax.microedition.lcdui.game.* ;

public class MyGameWithSpriteRotateCanvas extends GameCanvas
implements Runnable
{
        private LayerManager lm;
        private Sprite c1 ;
        public MyGameWithSpriteRotateCanvas()
        {
                super(true) ;
                lm = new LayerManager();
                c1 = createTank("/pic/tank.png") ;
                lm.append(c1);
        }
        private Sprite createTank(String pic)
        {
                Image img = null ;
                try
                {
                        img = Image.createImage(pic);
                }catch(Exception exp)
                {
                        System.out.println(exp);
                }
                return new Sprite(img,32,32)  ;
        }
        boolean conti = true ;
        int rate = 100 ;
        public void run()
        {
                long st = 0 ;
                long et = 0 ;
                Graphics g = getGraphics() ;
                while(conti)
                {
                        st = System.currentTimeMillis() ;
                        input() ;
                        render(g) ;
                        et = System.currentTimeMillis() ;
                        if((et-st)<rate)
                        {
                                try
                                {
                                        Thread.sleep(rate-(et-st));
                                }catch(Exception exp){}
                        }
                }
        }
        int x = 10 ;
        int y = 10 ;
        public void input()
        {
                int keystate = getKeyStates() ;
                if((keystate & UP_PRESSED)!=0)
                {
                        y = y - 2 ;
                        //判斷上邊界
                        if( y <= 0 )
                                y = 0 ;
                }if((keystate & DOWN_PRESSED)!=0)
                {
                        y = y + 2 ;
                        //判斷下邊界
                        if( y >= 96 )
                                y = 90 ;
                }if((keystate & LEFT_PRESSED)!=0)
                {
                        x = x - 2 ;
                        //判斷左邊界
                        if( x <= 0 )
                                x = 0 ;

                }if((keystate & RIGHT_PRESSED)!=0)
                {
                        x = x + 2 ;
                        //判斷右邊界
                        if( x >= 96 )
                                x = 90 ;

                }
        }
        public void render(Graphics g)
        {
                g.setColor(255,255,255);
                g.fillRect(0,0,getWidth(),getHeight());

                c1.setPosition(x,y);
                lm.paint(g,10,10);

                g.setColor(0,0,0);
                g.drawRect(10,10,128,128);
                flushGraphics() ;
        }
        public void start()
        {
                Thread t = new Thread(this) ;
                t.start();
        }
        public void exit()
        {
                conti = false ;
        }
}

	==========<end>======================

============<box>===============
[程式2]
TankSprite.java
import javax.microedition.lcdui.* ;
import javax.microedition.lcdui.game.* ;
public class TankSprite extends Sprite
{
        int bx = 0 ;
        int by = 0 ;
        public TankSprite(Image img,int w,int h,int bx,int by)
        {
                super(img,w,h);
                this.bx = bx ;
                this.by = by ;
        }
        public void moveUp()
        {
                move(0,-2) ;
                //判斷上邊界
                if( getY() <= 0 )
                {
                        setPosition(getX(),0) ;
                }
        }
        public void moveDown()
        {
                move(0,2) ;
                //判斷下邊界
                if( getY() > (by - getHeight()) )
                {
                        setPosition(getX(),(by - getHeight())) ;
                }
        }
        public void moveLeft()
        {
                move(-2,0) ;
                //判斷左邊界
                if( getX() <= 0 )
                {
                        setPosition(0,getY()) ;
                }
        }
        public void moveRight()
        {
                move(2,0) ;
                //判斷右邊界
                if( getX() > (bx - getWidth()) )
                {
                        setPosition((bx - getWidth()),getY()) ;
                }
        }
}
=============<end>========================

　　==========<box>============
　　[程式３]
MyGameWithSpriteRotateCanvas2.java
import javax.microedition.lcdui.* ;
import javax.microedition.lcdui.game.* ;
public class MyGameWithSpriteRotateCanvas2 extends GameCanvas
implements Runnable
{
        private LayerManager lm;
        private TankSprite c1 ;
        public MyGameWithSpriteRotateCanvas2()
        {
                super(true) ;
                lm = new LayerManager();
                c1 = createTank("/pic/tank.png") ;
                c1.setPosition(10,10);
                lm.append(c1);
        }
        private TankSprite createTank(String pic)
        {
                Image img = null ;
                try
                {
                        img = Image.createImage(pic);
                }catch(Exception exp)
                {
                        System.out.println(exp);
                }
                return new TankSprite(img,32,32,128,128)  ;
        }
        boolean conti = true ;
        int rate = 100 ;
        public void run()
        {
                long st = 0 ;
                long et = 0 ;
                Graphics g = getGraphics() ;
                while(conti)
                {
                        st = System.currentTimeMillis() ;
                        input() ;
                        render(g) ;
                        et = System.currentTimeMillis() ;
                        if((et-st)<rate)
                        {
                                try
                                {
                                        Thread.sleep(rate-(et-st));
                                }catch(Exception exp){}
                        }
                }
        }

        public void input()
        {
                int keystate = getKeyStates() ;
                if((keystate & UP_PRESSED)!=0)
                {
                        c1.moveUp() ;
                }if((keystate & DOWN_PRESSED)!=0)
                {
                        c1.moveDown();
                }if((keystate & LEFT_PRESSED)!=0)
                {
                        c1.moveLeft();

                }if((keystate & RIGHT_PRESSED)!=0)
                {
                       c1.moveRight();
                }
        }
        public void render(Graphics g)
        {
                g.setColor(255,255,255);
                g.fillRect(0,0,getWidth(),getHeight());

                lm.paint(g,10,10);

                g.setColor(0,0,0);
                g.drawRect(10,10,128,128);
                flushGraphics() ;
        }
        public void start()
        {
                Thread t = new Thread(this) ;
                t.start();
        }
        public void exit()
        {
                conti = false ;
        }
}
　　==========<end>============================
　　如此一來，整個系統看起來有調理多了。



＝＝＝＝＝＝＝＝＝＝＝<box>=============
[程式4]
c1 = createTank("/pic/tank.png") ;
c1.setPosition(20,20);
System.out.println("Pixel X:"+ c1.getX());
System.out.println("Pixel Y:"+ c1.getY());
System.out.println("Pixel X ref :"+ c1.getRefPixelX());
System.out.println("Pixel Y ref :"+ c1.getRefPixelY());
===========<end>=======================



========<box>============
?程式５?
c1.defineReferencePixel(5,5);
c1.setPosition(20,20);
System.out.println("Pixel X:"+ c1.getX());
System.out.println("Pixel Y:"+ c1.getY());
System.out.println("Pixel X ref :"+ c1.getRefPixelX());
System.out.println("Pixel Y ref :"+ c1.getRefPixelY());
=========<end>=============



==========<box>========
[程式6]
c1.defineReferencePixel(5,5);
c1.setRefPixelPosition(40,40);
System.out.println("Pixel X:"+ c1.getX());
System.out.println("Pixel Y:"+ c1.getY());
System.out.println("Pixel X ref :"+ c1.getRefPixelX());
System.out.println("Pixel Y ref :"+ c1.getRefPixelY());
==========<end>==================