package man;import javax.microedition.lcdui.game.*;import javax.microedition.lcdui.*;import java.util.Random;/** * 子彈操作類 */public class ManBullets {  private ManGameCanvas manGC;  // 子彈運(yùn)動的坐標(biāo)軌跡，Locus[i][j]，j為0-5，表示：  // 子彈類型,位置x,y，速度vx,vy  private int[][] Locus;  private Sprite Bullets;        // 子彈圖象  private Random rnd;            // 隨機(jī)種子  private int SWidth, SHeight;   // 設(shè)備屏幕的寬度與高度  //--- 構(gòu)造函數(shù) ----------------------------------------------------------------  public ManBullets(ManGameCanvas manGC, Image img, int SWidth, int SHeight) {    this.manGC = manGC;    Bullets = new Sprite(img, img.getWidth(), img.getHeight());    Bullets.setFrame(0);    Locus = new int[20][5];    rnd = new Random();    this.SWidth = SWidth;    this.SHeight = SHeight;  }  //--- 初始化運(yùn)行軌跡 -----------------------------------------------------------  public void InitBulletsLocus() {    for (int i = 0; i < Locus.length; i++) {      InitBulletLocus(i);    }  }  //--- 初始化運(yùn)行軌跡隨機(jī)數(shù)組 ----------------------------------------------------  private void InitBulletLocus(int i) {    // 子彈的類型，0:上 1:下 2:左 3:右    Locus[i][0] = (rnd.nextInt() & 0x7fffffff) % 4;    switch (Locus[i][0]) {      case 0:        Locus[i][1] = -5;        Locus[i][2] = (rnd.nextInt() & 0x7fffffff) % SHeight;        Locus[i][3] = (rnd.nextInt() & 0x7fffffff) % 3 + 1; //vx        Locus[i][4] = (rnd.nextInt()) % 3; //vy        break;      case 1:        Locus[i][1] = SWidth + 5;        Locus[i][2] = (rnd.nextInt() & 0x7fffffff) % SHeight;        Locus[i][3] = ((rnd.nextInt() & 0x7fffffff) % 3 + 1) * -1; //vx        Locus[i][4] = (rnd.nextInt()) % 3; //vy        break;      case 2:        Locus[i][1] = (rnd.nextInt() & 0x7fffffff) % SWidth;        Locus[i][2] = -5;        Locus[i][3] = (rnd.nextInt()) % 3; //vx        Locus[i][4] = (rnd.nextInt() & 0x7fffffff) % 3 + 1; //vy        break;      case 3:        Locus[i][1] = (rnd.nextInt() & 0x7fffffff) % SWidth;        Locus[i][2] = SHeight + 5;        Locus[i][3] = (rnd.nextInt()) % 3; //vx        Locus[i][4] = ((rnd.nextInt() & 0x7fffffff) % 3 + 1) * -1; //vy        break;    }  }  //--- 顯示子彈 ----------------------------------------------------------------  public void paint(Graphics g, int planeX, int planeY) {    for (int i = 0; i < Locus.length; i++) {      if (isCollision(planeX, planeY, i)) {   // 碰撞判斷        if (!manGC.gameover) manGC.gameover = true;        manGC.SpExplosion.setPosition(Locus[i][1] - 16, Locus[i][2] - 16);        continue;      }      Bullets.setPosition(Locus[i][1], Locus[i][2]);      Bullets.paint(g);      UpdataBulletLocus(i); // 更新運(yùn)行軌跡數(shù)組    }  }  //--- 更新運(yùn)行軌跡數(shù)組 ---------------------------------------------------------  private void UpdataBulletLocus(int i) {    Locus[i][1] += Locus[i][3];    Locus[i][2] += Locus[i][4];    if (Locus[i][1] < -5 || Locus[i][1] > SWidth + 5) {      Locus[i][3] *= -1;    }    if (Locus[i][2] < -5 || Locus[i][2] > SHeight + 5) {      Locus[i][4] *= -1;    }  }  //--- 碰撞判斷 ----------------------------------------------------------------  private boolean isCollision(int planeX, int planeY, int i) {    boolean result = false;    // 將飛機(jī)近似的看成圓，取得其圓心坐標(biāo)    int planeXCenter  = planeX + 12;    int planeYCenter  = planeY + 12;    // 同理，取得子彈的圓心坐標(biāo)    int bulletXCenter = Locus[i][1] + 3;    int bulletYCenter = Locus[i][2] + 3;    // 理由半徑檢測，小于10即已碰撞    if (Math.abs(planeXCenter - bulletXCenter) < 10) {      if (Math.abs(planeYCenter - bulletYCenter) < 10) {        result = true;      }    }    return result;  }}