【转】 Camera模仿3D效果的小例子（图片无限旋转）

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.util.Log;
import android.view.MotionEvent;
import android.view.View;

public class FlipImgEffectView 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 FlipImgEffectView(Context context) {
        super(context);
        this.context = context ;
        initData();
    }  

    private void initData(){
        showBmp = BitmapFactory.decodeResource(context.getResources(), R.drawable.pp);
        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);  

        Log.d("TAG", "-deltaY" + -deltaY) ;
        Log.d("TAG", "deltaX" + -deltaX) ;
        Log.d("TAG", "--------------------------------------") ;
        //设置camera作用矩阵
        camera.getMatrix(matrix);
        camera.restore();
        //设置翻转中心点
        matrix.preTranslate(-this.centerX, -this.centerY);
        matrix.postTranslate(this.centerX, this.centerY);  

        canvas.drawBitmap(showBmp, matrix, null);
    }             

}  

原文链接：http://www.devdiv.com/thread-104482-1-1.html