Android游戏开发之碰撞检测（矩形碰撞、圆形碰撞、像素碰撞）

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; }}

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; }}

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; }}