在之前说过，像素检测是最精确的一种方式，但是一般为了性能方面的考虑，因为很少用到，但是游戏中很少会有这种纯粹的圆或矩形做检测，这个时候我们就会考虑用多矩形的方式来做检测。
多矩形的原理是：将一个物体A分解成多个矩形组成A组，将另外一个物体B分解成多个矩形组成B组，然后通过A组中的矩形和B组中的矩形是否发生了碰撞就可得知物体A与物体B是否发生了碰撞。
/** * * @param rectArray * 物体1的数组 * @param rect2Array * 物体2的数组 * @param rectX1 * @param rectY1 * @param rectX2 * @param rectY2 * @return */ public boolean CheckRectCollsion(Rect[] rectArray, Rect[] rect2Array, int rectX1, int rectY1, int rectX2, int rectY2) { 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 + rectX1; int y1 = rect.top + 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 + rectX2; int y2 = rect2.top + 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; }
下面来一个完整的例子：
public class MoreRectView extends SurfaceView implements Callback, Runnable { int sleeptime = 100; private SurfaceHolder surfaceHolder; private Paint paint; private Thread thread; private boolean flag; // 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 }; public MoreRectView(Context context) { super(context); surfaceHolder = this.getHolder(); surfaceHolder.addCallback(this); paint = new Paint(); paint.setColor(Color.WHITE); paint.setAntiAlias(true); setFocusable(true); // 设置焦点 } /** * 游戏绘图 */ public void draw(Canvas canvas) { canvas.drawColor(Color.BLACK); paint.setColor(Color.WHITE); paint.setStyle(Style.FILL); if (isCollsion) { paint.setTextSize(20); canvas.drawText("碰撞了！", 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); } } @Override public void run() { Canvas canvas = null; while (flag) { try { canvas = surfaceHolder.lockCanvas(); synchronized (canvas) { draw(canvas); } } catch (Exception e) { Log.e("collsion", e.getMessage()); } finally { if (canvas != null) surfaceHolder.unlockCanvasAndPost(canvas); } try { Thread.sleep(sleeptime); } catch (Exception e) { Log.e("collsion", e.getMessage()); } } } @Override public void surfaceCreated(SurfaceHolder holder) { flag = true; // 实例线程 thread = new Thread(this); if (!thread.isAlive()) { // 启动线程 thread.start(); } } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { } @Override public void surfaceDestroyed(SurfaceHolder holder) { flag = false; thread = null; } /** * 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 (CheckRectCollsion(arrayRect1, arrayRect2, rectX1, rectY1, rectX2, rectY2)) { isCollsion = true; } else { isCollsion = false; } return true; } /** * * @param rectArray * 物体1的数组 * @param rect2Array * 物体2的数组 * @param rectX1 * @param rectY1 * @param rectX2 * @param rectY2 * @return */ public boolean CheckRectCollsion(Rect[] rectArray, Rect[] rect2Array, int rectX1, int rectY1, int rectX2, int rectY2) { 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 + rectX1; int y1 = rect.top + 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 + rectX2; int y2 = rect2.top + 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; } }