Android游戏开发之碰撞检测(矩形碰撞、圆形碰撞、像素碰撞)

本文为大家分享了Android游戏开发之碰撞检测,供大家参考,具体内容如下

矩形碰撞 原理: 两个矩形位置 的四种情况 不是这四中情况 则碰撞

圆形碰撞 原理: 利用两个圆心之间的距离进行判定.当两个圆心的距离小于半径之和则碰撞.

像素碰撞 原理:不适用 遍历所有像素 检测 太多了

多矩形碰撞 原理:设置多个矩形碰撞检测区域 检测碰撞矩形数组 与另一碰撞矩形数组之间的位置关系.

矩形碰撞 代码:

public class MySurfaceView extends SurfaceView implements Callback, Runnable {
 private SurfaceHolder sfh;
 private Paint paint;
 private Thread th;
 private boolean flag;
 private Canvas canvas;
 private int screenW, screenH;
 //定义两个矩形的宽高坐标
 private int x1 = 10, y1 = 110, w1 = 40, h1 = 40;
 private int x2 = 100, y2 = 110, w2 = 40, h2 = 40;
 //便于观察是否发生了碰撞设置一个标识位
 private boolean isCollsion;

 /**
  * SurfaceView初始化函数
  */
 public MySurfaceView(Context context) {
  super(context);
  sfh = this.getHolder();
  sfh.addCallback(this);
  paint = new Paint();
  paint.setColor(Color.WHITE);
  paint.setAntiAlias(true);
  setFocusable(true);
 }

 /**
  * SurfaceView视图创建,响应此函数
  */
 @Override
 public void surfaceCreated(SurfaceHolder holder) {
  screenW = this.getWidth();
  screenH = this.getHeight();
  flag = true;
  //实例线程
  th = new Thread(this);
  //启动线程
  th.start();
 }

 /**
  * 游戏绘图
  */
 public void myDraw() {
  try {
   canvas = sfh.lockCanvas();
   if (canvas != null) {
    canvas.drawColor(Color.BLACK);
    if (isCollsion) {
     paint.setColor(Color.RED);
     paint.setTextSize(20);
     canvas.drawText("Collision!", 0, 30, paint);
    } else {
     paint.setColor(Color.WHITE);
    }
    //绘制两个矩形
    canvas.drawRect(x1, y1, x1 + w1, y1 + h1, paint);
    canvas.drawRect(x2, y2, x2 + w2, y2 + h2, paint);
   }
  } catch (Exception e) {
   // TODO: handle exception
  } finally {
   if (canvas != null)
    sfh.unlockCanvasAndPost(canvas);
  }
 }

 /**
  * 触屏事件监听
  */
 @Override
 public boolean onTouchEvent(MotionEvent event) {
  //让矩形1随着触屏位置移动
  x1 = (int) event.getX() - w1 / 2;
  y1 = (int) event.getY() - h1 / 2;
  if (isCollsionWithRect(x1, y1, w1, h1, x2, y2, w2, h2)) {
   isCollsion = true;
  } else {
   isCollsion = false;
  }
  return true;
 }

 /**
  * 按键事件监听
  */
 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
  return super.onKeyDown(keyCode, event);
 }

 /**
  * 游戏逻辑
  */
 private void logic() {

 }

 public boolean isCollsionWithRect(int x1, int y1, int w1, int h1, int x2, int y2, int w2, int h2) {
  if (x1 >= x2 && x1 >= x2 + w2) {
   return false;
  } else if (x1 <= x2 && x1 + w1 <= x2) {
   return false;
  } else if (y1 >= y2 && y1 >= y2 + h2) {
   return false;
  } else if (y1 <= y2 && y1 + h1 <= y2) {
   return false;
  }
  return true;
 }

 @Override
 public void run() {
  while (flag) {
   long start = System.currentTimeMillis();
   myDraw();
   logic();
   long end = System.currentTimeMillis();
   try {
    if (end - start < 50) {
     Thread.sleep(50 - (end - start));
    }
   } catch (InterruptedException e) {
    e.printStackTrace();
   }
  }
 }

 /**
  * SurfaceView视图状态发生改变,响应此函数
  */
 @Override
 public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
 }

 /**
  * SurfaceView视图消亡时,响应此函数
  */
 @Override
 public void surfaceDestroyed(SurfaceHolder holder) {
  flag = false;
 }
}

圆形碰撞 代码:

public class MySurfaceView extends SurfaceView implements Callback, Runnable {
 private SurfaceHolder sfh;
 private Paint paint;
 private Thread th;
 private boolean flag;
 private Canvas canvas;
 private int screenW, screenH;
 //定义两个圆形的半径与坐标
 private int r1 = 20, r2 = 20;
 private int x1 = 50, y1 = 100, x2 = 150, y2 = 100;
 //定义一个碰撞标识位
 private boolean isCollision;

 /**
  * SurfaceView初始化函数
  */
 public MySurfaceView(Context context) {
  super(context);
  sfh = this.getHolder();
  sfh.addCallback(this);
  paint = new Paint();
  paint.setColor(Color.WHITE);
  paint.setAntiAlias(true);
  setFocusable(true);
 }

 /**
  * SurfaceView视图创建,响应此函数
  */
 @Override
 public void surfaceCreated(SurfaceHolder holder) {
  screenW = this.getWidth();
  screenH = this.getHeight();
  flag = true;
  //实例线程
  th = new Thread(this);
  //启动线程
  th.start();
 }

 /**
  * 游戏绘图
  */
 public void myDraw() {
  try {
   canvas = sfh.lockCanvas();
   if (canvas != null) {
    canvas.drawColor(Color.BLACK);
    if (isCollision) {
     paint.setColor(Color.RED);
     paint.setTextSize(20);
     canvas.drawText("Collision!", 0, 30, paint);
    } else {
     paint.setColor(Color.WHITE);
    }
    canvas.drawCircle(x1, y1, r1, paint);
    canvas.drawCircle(x2, y2, r2, paint);
   }
  } catch (Exception e) {
   // TODO: handle exception
  } finally {
   if (canvas != null)
    sfh.unlockCanvasAndPost(canvas);
  }
 }

 /**
  * 触屏事件监听
  */
 @Override
 public boolean onTouchEvent(MotionEvent event) {
  x1 = (int) event.getX();
  y1 = (int) event.getY();
  if (isCollisionWithCircle(x1, y1, x2, y2, r1, r2)) {
   isCollision = true;
  } else {
   isCollision = false;
  }
  return true;
 }
 /**
  * 圆形碰撞
  * @param x1 圆形1的圆心X坐标
  * @param y1 圆形2的圆心X坐标
  * @param x2 圆形1的圆心Y坐标
  * @param y2 圆形2的圆心Y坐标
  * @param r1 圆形1的半径
  * @param r2 圆形2的半径
  * @return
  */
 private boolean isCollisionWithCircle(int x1, int y1, int x2, int y2, int r1, int r2) {
  //Math.sqrt:开平方
  //Math.pow(double x, double y): X的Y次方
  if (Math.sqrt(Math.pow(x1 - x2, 2) + Math.pow(y1 - y2, 2)) <= r1 + r2) {
   //如果两圆的圆心距小于或等于两圆半径则认为发生碰撞
   return true;
  }
  return false;
 }

 /**
  * 按键事件监听
  */
 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
  return super.onKeyDown(keyCode, event);
 }

 /**
  * 游戏逻辑
  */
 private void logic() {
 }

 @Override
 public void run() {
  while (flag) {
   long start = System.currentTimeMillis();
   myDraw();
   logic();
   long end = System.currentTimeMillis();
   try {
    if (end - start < 50) {
     Thread.sleep(50 - (end - start));
    }
   } catch (InterruptedException e) {
    e.printStackTrace();
   }
  }
 }

 /**
  * SurfaceView视图状态发生改变,响应此函数
  */
 @Override
 public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
 }

 /**
  * SurfaceView视图消亡时,响应此函数
  */
 @Override
 public void surfaceDestroyed(SurfaceHolder holder) {
  flag = false;
 }
}

多矩形碰撞 代码

public class MySurfaceView extends SurfaceView implements Callback, Runnable {
 private SurfaceHolder sfh;
 private Paint paint;
 private Thread th;
 private boolean flag;
 private Canvas canvas;
 private int screenW, screenH;
 //定义两个矩形图形的宽高坐标
 private int rectX1 = 10, rectY1 = 10, rectW1 = 40, rectH1 = 40;
 private int rectX2 = 100, rectY2 = 110, rectW2 = 40, rectH2 = 40;
 //便于观察是否发生了碰撞设置一个标识位
 private boolean isCollsion;
 //定义第一个矩形的矩形碰撞数组
 private Rect clipRect1 = new Rect(0, 0, 15, 15);
 private Rect clipRect2 = new Rect(rectW1 - 15, rectH1 - 15, rectW1, rectH1);
 private Rect[] arrayRect1 = new Rect[] { clipRect1, clipRect2 };
 //定义第二个矩形的矩形碰撞数组
 private Rect clipRect3 = new Rect(0, 0, 15, 15);
 private Rect clipRect4 = new Rect(rectW2 - 15, rectH2 - 15, rectW2, rectH2);
 private Rect[] arrayRect2 = new Rect[] { clipRect3, clipRect4 };

 /**
  * SurfaceView初始化函数
  */
 public MySurfaceView(Context context) {
  super(context);
  sfh = this.getHolder();
  sfh.addCallback(this);
  paint = new Paint();
  paint.setColor(Color.WHITE);
  paint.setAntiAlias(true);
  setFocusable(true);
 }

 /**
  * SurfaceView视图创建,响应此函数
  */
 @Override
 public void surfaceCreated(SurfaceHolder holder) {
  screenW = this.getWidth();
  screenH = this.getHeight();
  flag = true;
  //实例线程
  th = new Thread(this);
  //启动线程
  th.start();
 }

 /**
  * 游戏绘图
  */
 public void myDraw() {
  try {
   canvas = sfh.lockCanvas();
   if (canvas != null) {
    canvas.drawColor(Color.BLACK);
    paint.setColor(Color.WHITE);
    paint.setStyle(Style.FILL);
    if (isCollsion) {
     paint.setTextSize(20);
     canvas.drawText("Collision!", 0, 30, paint);
    }
    //绘制两个矩形
    canvas.drawRect(rectX1, rectY1, rectX1 + rectW1, rectY1 + rectH1, paint);
    canvas.drawRect(rectX2, rectY2, rectX2 + rectW2, rectY2 + rectH2, paint);
    //---绘制碰撞区域使用非填充,并设置画笔颜色白色
    paint.setStyle(Style.STROKE);
    paint.setColor(Color.RED);
    //绘制第一个矩形的所有矩形碰撞区域
    for (int i = 0; i < arrayRect1.length; i++) {
     canvas.drawRect(arrayRect1[i].left + this.rectX1, arrayRect1[i].top + this.rectY1, arrayRect1[i].right + this.rectX1, arrayRect1[i].bottom
       + this.rectY1, paint);
    }
    //绘制第二个矩形的所有矩形碰撞区域
    for (int i = 0; i < arrayRect2.length; i++) {
     canvas.drawRect(arrayRect2[i].left + this.rectX2, arrayRect2[i].top + this.rectY2, arrayRect2[i].right + this.rectX2, arrayRect2[i].bottom
       + rectY2, paint);
    }
   }
  } catch (Exception e) {
   // TODO: handle exception
  } finally {
   if (canvas != null)
    sfh.unlockCanvasAndPost(canvas);
  }
 }

 /**
  * 触屏事件监听
  */
 @Override
 public boolean onTouchEvent(MotionEvent event) {
  //让矩形1随着触屏位置移动
  rectX1 = (int) event.getX() - rectW1 / 2;
  rectY1 = (int) event.getY() - rectH1 / 2;
  if (isCollsionWithRect(arrayRect1, arrayRect2)) {
   isCollsion = true;
  } else {
   isCollsion = false;
  }
  return true;
 }

 /**
  * 按键事件监听
  */
 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
  return super.onKeyDown(keyCode, event);
 }

 /**
  * 游戏逻辑
  */
 private void logic() {

 }

 //Rect 类中的四个属性 top bottom left right
 //分别表示这个矩形的   上  下   左   右
 public boolean isCollsionWithRect(Rect[] rectArray, Rect[] rect2Array) {
  Rect rect = null;
  Rect rect2 = null;
  for (int i = 0; i < rectArray.length; i++) {
   //依次取出第一个矩形数组的每个矩形实例
   rect = rectArray[i];
   //获取到第一个矩形数组中每个矩形元素的属性值
   int x1 = rect.left + this.rectX1;
   int y1 = rect.top + this.rectY1;
   int w1 = rect.right - rect.left;
   int h1 = rect.bottom - rect.top;
   for (int j = 0; j < rect2Array.length; j++) {
    //依次取出第二个矩形数组的每个矩形实例
    rect2 = rect2Array[j];
    //获取到第二个矩形数组中每个矩形元素的属性值
    int x2 = rect2.left + this.rectX2;
    int y2 = rect2.top + this.rectY2;
    int w2 = rect2.right - rect2.left;
    int h2 = rect2.bottom - rect2.top;
    //进行循环遍历两个矩形碰撞数组所有元素之间的位置关系
    if (x1 >= x2 && x1 >= x2 + w2) {
    } else if (x1 <= x2 && x1 + w1 <= x2) {
    } else if (y1 >= y2 && y1 >= y2 + h2) {
    } else if (y1 <= y2 && y1 + h1 <= y2) {
    } else {
     //只要有一个碰撞矩形数组与另一碰撞矩形数组发生碰撞则认为碰撞
     return true;
    }
   }
  }
  return false;
 }

 @Override
 public void run() {
  while (flag) {
   long start = System.currentTimeMillis();
   myDraw();
   logic();
   long end = System.currentTimeMillis();
   try {
    if (end - start < 50) {
     Thread.sleep(50 - (end - start));
    }
   } catch (InterruptedException e) {
    e.printStackTrace();
   }
  }
 }

 /**
  * SurfaceView视图状态发生改变,响应此函数
  */
 @Override
 public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
 }

 /**
  * SurfaceView视图消亡时,响应此函数
  */
 @Override
 public void surfaceDestroyed(SurfaceHolder holder) {
  flag = false;
 }
}

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持呐喊教程。

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