android camera 画角度图

package com.cardroid.layer;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Camera;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.view.MotionEvent;
import android.view.View;

public class CameraDraw extends View {  
      
        private Context context ;  
        private Bitmap showBmp ;  
        private Matrix matrix ; //作用矩阵  
        private Camera camera ;   
        private int deltaX , deltaY ; //翻转角度差值  
        private int centerX , centerY ; //图片中心点  
          
        public CameraDraw(Context context) {  
            super(context);  
            this.context = context ;  
            initData();  
        }  
          
        private void initData(){  
            showBmp = BitmapFactory.decodeResource(context.getResources(), R.drawable.bg);  
            centerX = showBmp.getWidth()/2 ;  
            centerY = showBmp.getHeight()/2 ;  
            matrix = new Matrix();  
            camera = new Camera();  
        }  
      
        int lastMouseX ;  
        int lastMouseY ;  
        @Override  
        public boolean dispatchTouchEvent(MotionEvent event) {  
            int x = (int) event.getX();      
            int y = (int) event.getY();      
            switch(event.getAction()) {      
             case MotionEvent.ACTION_DOWN:   
                 lastMouseX = x ;  
                 lastMouseY = y ;  
                 break;      
             case MotionEvent.ACTION_MOVE:  
                 int dx = x - lastMouseX ;  
                 int dy = y - lastMouseY ;  
                 deltaX += dx ;  
                 deltaY += dy ;  
                 break;      
             }     
             
            invalidate();  
            return true;  
        }  
      
        @Override  
        protected void onDraw(Canvas canvas) {  
              
            camera.save();  
            //绕X轴翻转  
            camera.rotateX(-deltaY);  
            //绕Y轴翻转  
            camera.rotateY(deltaX);  
            //设置camera作用矩阵  
        

            camera.getMatrix(matrix);  
            camera.restore();  //主要是得到翻转矩阵大小
            //设置翻转中心点  
            matrix.preTranslate(-this.centerX, -this.centerY);  
            matrix.postTranslate(this.centerX, this.centerY);  
              
            canvas.drawBitmap(showBmp, matrix, null);  
        }             
      

    }

public class LayerDraw extends Activity {
    /** Called when the activity is first created. */
    private ImageView mImageView;
    private TextView tView;
    private CameraDraw carmeraCameraDraw;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        carmeraCameraDraw=new CameraDraw(this);
        //setContentView(R.layout.main);
        setContentView(carmeraCameraDraw);
//        mImageView=(ImageView)findViewById(R.id.image);
//        tView=(TextView)findViewById(R.id.tv);
       // setImage();
    }