Android 3d翻轉動畫（實例）

    原理以後再說，主要使用android的camera實現

    實現動畫的類後面再給出來，先上使用代碼，體現一下這東西使用有多麼容易

代碼的功能：點擊這個ID爲hello的textView，它就開始3D翻轉

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".StartActivity">

    <TextView
        android:id="@+id/hello"
        android:text="@string/hello_world"
        android:background="#FFFF00FF"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />

</RelativeLayout>

StartActivity.java

public class StartActivity extends ActionBarActivity implements View.OnClickListener {


    private TextView textView = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_start);

        initView();
        initListener();
    }

    private void initListener() {
        textView.setOnClickListener(this);
    }

    private void initView() {
        textView = (TextView) findViewById(R.id.hello);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.hello :
                Rotate3dAnimation rotate3dAnimation = new Rotate3dAnimation(view.getWidth(), view.getHeight(), -90, 90);
                rotate3dAnimation.setDuration(1000);
                textView.startAnimation(rotate3dAnimation);
                break;
        }
    }
}

最後是實現動畫的類

public class Rotate3dAnimation extends Animation {

    private int centerX, centerY;
    private int width, height;
    private float startDegree, endDegree;
    {
        centerX = 0 ;
        centerY = 0 ;
    }

    public Rotate3dAnimation(int w, int h, float startDegree, float endDegree) {
        this.width = w;
        this.height = h;
        this.centerX = w>>1;
        this.centerY = h >> 1;
        this.startDegree = startDegree;
        this.endDegree = endDegree;
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        int translateX = 0 ;
        int translateZ = 0 ;
        int translateY = 0;

        double a = (endDegree - startDegree) * interpolatedTime + startDegree + 90;
//        Log.d("3d", endDegree + "");
//        Log.d("3d", startDegree + "");
//        Log.d("3d", Math.cos(a) + "");
        //Math.cos是弧度制的
        translateX = (int) (- (width >> 1) * Math.cos(a * 3.1415926 / 180));
        translateZ = (int) (- (width >> 1) * Math.sin(a * 3.1415926 / 180 ) + (width >> 1 ));

        Matrix matrix = t.getMatrix();
        Camera camera = new Camera();
        camera.save();
        camera.translate(0,0,translateZ);
        camera.rotateY(startDegree + (endDegree - startDegree) * interpolatedTime);
        camera.getMatrix(matrix);
        camera.restore();

        //設置旋轉的中心點
        matrix.preTranslate(-centerX, -centerY);
        matrix.postTranslate(centerX, centerY);
        matrix.postTranslate(translateX,translateY);
    }
}