bulletsprite.java

这是我在原来单位的时候写的一个坦克大战的J2ME游戏的代码,可以给其他作J2ME游戏的人作个参考

import javax.microedition.lcdui.game.*;
import javax.microedition.lcdui.*;

public class BulletSprite extends  Sprite {
  //sprite resources
  private Sprite m_babyBulletSprite;

    //gun pop image
  private  Image m_bulletPopImage;//枪花资源
  private  Sprite m_bulletPopSprite;
  private  boolean m_bDisplayGunScene;
  private  int m_gunSceneFrames;

  //constant definitions
  private int m_startPosX = 0;//子弹由坦克射出的时候的初始坐标
  private int m_startPosY = 0;

  private int m_iCurrentBulletDirection = 0;
  private int m_bulletOwer;
  private int m_currentState;

  private int m_bulletType;
  private int m_bulletSpeed ;
  private int m_bulletDamage;

  private boolean m_threadAlive = true;//run 函数是否运行
  private boolean m_bRunning = false;

  private boolean m_init ;
  private int m_tankIndex;

  //constant macro
  public final static int ANCHOR_LEFTTOP=1;
  public final static int ANCHOR_CENTER=2;
  private final static int BULLET_GUN_FRAMES=1;
  //baby tank,bullet directions
  public final static int BABY_BULLET_UP=0;
  public final static int BABY_BULLET_RIGHT=1;
  public final static int BABY_BULLET_DOWN=2;
  public final static int BABY_BULLET_LEFT=3;

  private final static int BULLETPOP_IMAGE_WIDTH = 12;
  private final static int BULLETPOP_IMAGE_HEIGHT = 12;

  //width height



  public int getTankIndex(){
    return m_tankIndex;
  }

  public BulletSprite(Image image, int frameWidth, int frameHeight,int speed,
                      int damage,int bulletOwner,int tankIndex,int bulletType) {
    super(image, frameWidth, frameHeight);
    defineReferencePixel(frameWidth / 2, frameHeight / 2);
    m_currentState = -1;

    m_bulletSpeed = speed;
    m_bulletOwer = bulletOwner;
    m_bulletDamage = damage;
    m_bulletType = bulletType;

    m_currentState = GameLogic.GAME_STATE_READY;
    m_iCurrentBulletDirection = 0;
    m_init = false; //load resource or not

    m_tankIndex = tankIndex;

	createGunpopScene();

  }

  public void pause(){
  	m_currentState = GameLogic.GAME_STATE_PAUSE;
	m_threadAlive=true;
  }

  public void stop(){
    m_currentState = GameLogic.GAME_STATE_END;
    m_threadAlive = false;
    setVisible(false);
	releaseGunpopScene();
  }
  /**
　　* 检测一个特定点是否进入一个Actor内
　　* @param px 特定点的x坐标.
　　* @param py 特定点的y坐标
　　* @return　如果特定点进入Actor范围内，那么返回true,否则为false;
   * ref point is located in the middle of the rectangele
　　*/

  public boolean isCollidingWith(int px, int py){
    try {
      int xPos=getRefPixelX();
      int yPos=getRefPixelY();
      //get the location coordinate in (left,top)corner
      //judge whether the point is inside the sprite.
      if(px>=xPos-getWidth()/2&&px<=xPos+getWidth()/2&&py>=yPos-getHeight()/2&&py<=yPos+getHeight()/2){
        return true;
      }
      return false;
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
    return true;
  }

  /**
  　　* 检测一个Actor对象是否碰上了当前的Actor对象。
  　　* @param another 另一个Actor对象
  　　* @return 如果another和当前对象发生碰撞，则返回true,否则为false.
  　　*/
  public boolean collidesWith(Sprite s,int refPoint){
      try {
        int leftTopX=0,leftTopY=0,rightTopX=0,rightTopY=0,leftBottomX=0,leftBottomY=0,rightBottomX=0,rightBottomY=0;
        //judge the four points of the rectangle
        if(refPoint==ANCHOR_CENTER){
          leftTopX=s.getRefPixelX()-s.getWidth()/2;
          leftTopY=s.getRefPixelY()+s.getHeight()/2;
          rightTopX=s.getRefPixelX()+s.getWidth()/2;
          leftBottomY=s.getRefPixelY()-s.getHeight()/2;

        }else if(refPoint==ANCHOR_LEFTTOP){
          leftTopX=s.getRefPixelX();
          leftTopY=s.getRefPixelY();
          rightTopX=s.getRefPixelX()+getWidth();
          leftBottomY=s.getRefPixelY()+getHeight();
        }
        rightTopY=leftTopY;
        leftBottomX=leftTopX;
        rightBottomX=rightTopX;
        rightBottomY=leftBottomY;

        if(isCollidingWith(leftTopX,leftTopY)||
           isCollidingWith(rightTopX,rightTopY)||
           isCollidingWith(leftBottomX,leftBottomY)||
           isCollidingWith(rightBottomX,rightBottomY)){
          return true;
        }
      }
      catch (Exception ex) {
        ex.printStackTrace();
      }

      return false;
    }



  public int getGameState(){
    return m_currentState;
  }

  public void start(){
    m_bRunning = false;
    m_threadAlive = true;
    m_currentState = GameLogic.GAME_STATE_LOOP;
    setVisible(true);
  }

  public void setRefPixelPosition(int x,
                                int y){
  if (!m_bRunning) {
    m_startPosX = x;
    m_startPosY = y;
  }
  super.setRefPixelPosition(x, y);
}
  public void setDirection(int angel){
    m_iCurrentBulletDirection = angel;
  }

  public void changeBulletDamage(int damage){
  	m_bulletDamage=damage;
  }

  /**
   *
   * 1. 　根据相应角度进行移动.(目前只考虑前后左右90度的情况)。
　　　　if(bullet is alive)
           move fixed pixels in direction;　　
　　
2.碰到障碍物的处理。
　　　if(子弹碰到障碍物　or
　　　子弹碰到地图边界 or
　　　坦克被击毁　or
　　　子弹击中敌方或者本方坦克)
　　　　子弹消失;
　　　
　　　if(击中敌方坦克)
　　　　　爆炸效果.
          敌方生命值减小。

   */
  public void run(){
    m_bRunning = true;

    if(!m_threadAlive){
      return;
    }

    switch (m_currentState) {
      case GameLogic.GAME_STATE_READY:
        if(!m_init){

        }
        break;
      case GameLogic.GAME_STATE_END:
        reset();
        break;
      case GameLogic.GAME_STATE_LOOP:
        if (Sprite.TRANS_NONE == m_iCurrentBulletDirection) {
          m_startPosY -= m_bulletSpeed;
        }
        if (Sprite.TRANS_ROT180 == m_iCurrentBulletDirection) {
          m_startPosY += m_bulletSpeed;
        }
        if (Sprite.TRANS_ROT90 == m_iCurrentBulletDirection) {
          m_startPosX += m_bulletSpeed;
        }
        if (Sprite.TRANS_ROT270 == m_iCurrentBulletDirection) {
          m_startPosX -= m_bulletSpeed;
        }
        setRefPixelPosition(m_startPosX, m_startPosY);
        setTransform(m_iCurrentBulletDirection); //调整子弹头方向。

        displayBabyBullet();
        GameLogic.collidesWith(this, m_bulletOwer,
                               m_bulletDamage);
        break;
      case GameLogic.GAME_STATE_PAUSE:
        if (m_bDisplayGunScene == true) {
          displayGunPopScene();
        }
        break;
      default:
        break;
    }
  }

  private  void releaseGunpopScene() {
    try {
      m_bulletPopImage = null;
      if (null != m_bulletPopSprite) {
        GameLogic.m_layerManager.remove(m_bulletPopSprite);
        m_bulletPopSprite = null;
      }

    }
    catch (Exception ex) {
      ex.printStackTrace();
    }

  }

   private void createGunpopScene() {
    try {
      m_bulletPopImage=null;
      m_bulletPopImage = Image.createImage("/tank/bullet_res/gunpop.png");
      m_bulletPopSprite = new Sprite(m_bulletPopImage, BULLETPOP_IMAGE_WIDTH,
                                     BULLETPOP_IMAGE_HEIGHT);
      m_bulletPopSprite.defineReferencePixel(BULLETPOP_IMAGE_WIDTH / 2,
                                             BULLETPOP_IMAGE_HEIGHT / 2);
      m_bulletPopSprite.setVisible(false);
      GameLogic.m_layerManager.insert(m_bulletPopSprite, 0);
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
  }


  public void startGupPopScene() {
    m_bDisplayGunScene = true;
    pause();
  }

  private void displayGunPopScene() {

    try {
      if (false == m_bulletPopSprite.isVisible()) {
        m_bulletPopSprite.setVisible(true);
      }
      m_bulletPopSprite.setRefPixelPosition(getRefPixelX(), getRefPixelY());
      m_gunSceneFrames++;
      if (m_gunSceneFrames <= BULLET_GUN_FRAMES) {
        m_bulletPopSprite.nextFrame();
      }
      else {
        reset();
      }

    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
  }


  private void displayBabyBullet() {
    try {
      if (m_bulletType != GameLogic.BULLET_TYPE_BABY) {
        return;
      }
      /**
       * 1.display one frame per circle;
       * 2.set it invisible the time it collides with other things;
       */
      nextFrame();
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
  }

  public void reset(){
    m_bRunning = false;
    m_threadAlive = true;
    m_startPosX = m_startPosY = 0;
    m_iCurrentBulletDirection = 0;
    m_currentState = GameLogic.GAME_STATE_READY;
//gun pop scenes
    m_gunSceneFrames=0;
    m_bDisplayGunScene=false;

    try {
      //bullet消失
      setVisible(false);
      if(null!=m_bulletPopSprite){
        m_bulletPopSprite.setVisible(false);
      }
    }
    catch (Exception ex) {
      ex.printStackTrace();
    }
  }
}