Android 3D旋转动画之Camera 和 Matrix

前面两篇博文讲解的都是Android 的2D动画效果，要想做出非常炫酷的3D动画效果怎么办？android 并没有提供3D动画接口给用户，所以我们得自己重写这样一个3D接口动画。效果图：接口如下：

/*
* @Title: My3dAnimation.java
* @Description: TODO<请描述此文件是做什么的>
* @author: xjp
* @data: 2014年9月15日 上午8:54:10
* @version: V1.0
*/
package com.xjp.animator;

import android.graphics.Camera;
import android.graphics.Matrix;
import android.view.animation.Animation;
import android.view.animation.Transformation;

/**
* TODO<请描述这个类是干什么的>
*
* @author xjp
* @data: 2014年9月15日 上午8:54:10
* @version: V1.0
*/
public class My3dAnimation extends Animation {

private final float mFromDegrees;
private final float mToDegrees;
private final float mCenterX;
private final float mCenterY;
private final float mDepthZ;
private Camera mCamera;
private int mDirection;
private final static int ROTATE_X = 0;//沿着x轴旋转
private final static int ROTATE_Y = 1;//沿着y轴旋转

/**
* Creates a new 3D rotation on the Y axis. The rotation is defined by its
* start angle and its end angle. Both angles are in degrees. The rotation
* is performed around a center point on the 2D space, definied by a pair of
* X and Y coordinates, called centerX and centerY. When the animation
* starts, a translation on the Z axis (depth) is performed. The length of
* the translation can be specified, as well as whether the translation
* should be reversed in time.
*
* @param direction
*            the direction of the 3D rotation
* @param fromDegrees
*            the start angle of the 3D rotation
* @param toDegrees
*            the end angle of the 3D rotation
* @param centerX
*            the X center of the 3D rotation
* @param centerY
*            the Y center of the 3D rotation
*/
public My3dAnimation(int direction, float fromDegrees, float toDegrees,
float centerX, float centerY, float depthZ) {
mDirection = direction;
mFromDegrees = fromDegrees;
mToDegrees = toDegrees;
mCenterX = centerX;
mCenterY = centerY;
mDepthZ = depthZ;
}

@Override
public void initialize(int width, int height, int parentWidth,
int parentHeight) {
super.initialize(width, height, parentWidth, parentHeight);
mCamera = new Camera();
}

@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
final float fromDegrees = mFromDegrees;
float degrees = fromDegrees
+ ((mToDegrees - fromDegrees) * interpolatedTime);

final float centerX = mCenterX;
final float centerY = mCenterY;
final Camera camera = mCamera;

final Matrix matrix = t.getMatrix();

camera.save();

if (centerX!=0){
if (interpolatedTime < 0.5) {
camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);
} else {
camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));
}
}

switch (mDirection) {
case ROTATE_X:
camera.rotateX(degrees);
break;
case ROTATE_Y:
camera.rotateY(degrees);
break;
}

camera.getMatrix(matrix);
camera.restore();
matrix.preTranslate(-centerX, -centerY);
matrix.postTranslate(centerX, centerY);
}
}

示例代码如下:

package com.xjp.animator;

import com.xjp.animator.R;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.LinearInterpolator;
import android.widget.ImageView;
import android.app.Activity;

public class MainActivity extends Activity implements
android.view.View.OnClickListener {

private ImageView img1;
private ImageView img2;
private ImageView img3;
private ViewGroup mContainer;
private final static int ROTATE_X = 0;
private final static int ROTATE_Y = 1;
private My3dAnimation my3dAnimation;

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

findViews();
}

/**
* TODO<请描述这个方法是干什么的>
*
* @throw
* @return void
* @param
*/
private void findViews() {
// TODO Auto-generated method stub
mContainer = (ViewGroup) findViewById(R.id.container);
mContainer
.setPersistentDrawingCache(ViewGroup.PERSISTENT_ANIMATION_CACHE);

img1 = (ImageView) findViewById(R.id.img_left);
img1.setOnClickListener(this);
img2 = (ImageView) findViewById(R.id.img_right);
img2.setOnClickListener(this);

img3 = (ImageView) findViewById(R.id.img_3);
img3.setOnClickListener(this);
}

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
float centerX = v.getWidth() / 2.0f;
float centerY = v.getHeight() / 2.0f;
if (v.getId() == R.id.img_left) {
my3dAnimation = new My3dAnimation(ROTATE_X, 0, 180, centerX,
centerY, 310f);
}
if (v.getId() == R.id.img_right) {
my3dAnimation = new My3dAnimation(ROTATE_Y, 0, 180, centerX,
centerY, 310f);
}
if (v.getId() == R.id.img_3) {
centerX = 0;
my3dAnimation = new My3dAnimation(ROTATE_Y, 0, 20, centerX,
centerY, 310f);
}
my3dAnimation.setDuration(1000);
my3dAnimation.setInterpolator(new LinearInterpolator());
my3dAnimation.setFillAfter(true);
v.startAnimation(my3dAnimation);
}
}

<a target=_blank href="https://github.com/xujinping/D3AnimaDemo">源码地址</a>

完结。