Android游戏开发之碰撞检测（矩形碰撞、圆形碰撞、像素碰撞）

摘要：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...

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:

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; } }

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