快捷導(dǎo)航

Android利用Camera實(shí)現(xiàn)中軸3D卡牌翻轉(zhuǎn)效果

更新時(shí)間：2015年12月30日 08:54:23 作者：亦楓

這篇文章主要介紹了Android利用Camera實(shí)現(xiàn)中軸3D卡牌翻轉(zhuǎn)效果,需要的朋友可以參考下

在Android系統(tǒng)API中，有兩個(gè)Camera類：

android.graphics.Camera
android.hardware.Camera

第二個(gè)應(yīng)用于手機(jī)硬件中的相機(jī)相關(guān)的操作，本文講述的是利用第一個(gè)Camera類實(shí)現(xiàn)中軸3D轉(zhuǎn)換的卡牌翻轉(zhuǎn)效果，開始之前，先看一下Android系統(tǒng)中的坐標(biāo)系：

對(duì)應(yīng)于三維坐標(biāo)系中的三個(gè)方向，Camera提供了三種旋轉(zhuǎn)方法：

rotateX()
rotateY()
rotateX()

調(diào)用這三種方法，傳入旋轉(zhuǎn)角度參數(shù)，即可實(shí)現(xiàn)視圖沿著坐標(biāo)軸旋轉(zhuǎn)的功能。本文的中軸3D旋轉(zhuǎn)效果就是讓視圖沿著Y軸旋轉(zhuǎn)的。

系統(tǒng)API Demos中已經(jīng)為我們提供了一個(gè)非常好用的3D旋轉(zhuǎn)動(dòng)畫的工具類：
Rotate3dAnimation.java：

package com.feng.androidtest;

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

/**
 * An animation that rotates the view on the Y axis between two specified angles.
 * This animation also adds a translation on the Z axis (depth) to improve the effect.
 */
public class Rotate3dAnimation extends Animation {
 private final float mFromDegrees;
 private final float mToDegrees;
 private final float mCenterX;
 private final float mCenterY;
 private final float mDepthZ;
 private final boolean mReverse;
 private Camera mCamera;

 /**
  * 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 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
  * @param reverse true if the translation should be reversed, false otherwise
  */
 public Rotate3dAnimation(float fromDegrees, float toDegrees,
   float centerX, float centerY, float depthZ, boolean reverse) {
  mFromDegrees = fromDegrees;
  mToDegrees = toDegrees;
  mCenterX = centerX;
  mCenterY = centerY;
  mDepthZ = depthZ;
  mReverse = reverse;
 }

 @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();

  Log.i("interpolatedTime", interpolatedTime+"");
  camera.save();
  if (mReverse) {
   camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);
  } else {
   camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));
  }
  camera.rotateY(degrees);
  camera.getMatrix(matrix);
  camera.restore();

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

可以看出， Rotate3dAnimation 總共做了兩件事：在構(gòu)造函數(shù)中賦值了旋轉(zhuǎn)動(dòng)畫所需要的參數(shù)，以及重寫（override）父類Animation中的applyTransformation()方法，下面分類闡述一下：

fromDegrees與toDegrees
視圖旋轉(zhuǎn)的開始角度和結(jié)束角度，當(dāng)toDegree處于90倍數(shù)時(shí)，視圖將變得不可見。
centerX與centerY
視圖旋轉(zhuǎn)的中心點(diǎn)。
depthZ
Z軸移動(dòng)基數(shù)，用于計(jì)算Camera在Z軸移動(dòng)距離
reverse
boolean類型，控制Z軸移動(dòng)方向，達(dá)到視覺遠(yuǎn)近移動(dòng)導(dǎo)致的視圖放大縮小效果。
applyTransformation()
根據(jù)動(dòng)畫播放的時(shí)間 interpolatedTime （動(dòng)畫start到end的過(guò)程，interpolatedTime從0.0變化到1.0），讓Camera在Z軸方向上進(jìn)行相應(yīng)距離的移動(dòng)，實(shí)現(xiàn)視覺上遠(yuǎn)近移動(dòng)的效果。然后調(diào)用 rotateX()方法，讓視圖圍繞Y軸進(jìn)行旋轉(zhuǎn)，產(chǎn)生3D立體旋轉(zhuǎn)效果。最后再通過(guò)Matrix來(lái)確定旋轉(zhuǎn)的中心點(diǎn)的位置。

activity_main.xml布局文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:background="@android:color/white" >

 <Button
  android:id="@+id/btn_open"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:layout_margin="16dp"
  android:onClick="onClickView"
  android:text="打開"
  android:textColor="@android:color/black"
  android:textSize="16sp" />

 <RelativeLayout
  android:id="@+id/rl_content"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:layout_below="@id/btn_open"
  android:layout_marginTop="16dp" 
  android:background="@android:color/black">

  <ImageView
   android:id="@+id/iv_logo"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:contentDescription="@null"
   android:src="@drawable/ic_qrcode" 
   android:scaleType="centerInside"/>

  <TextView
   android:id="@+id/tv_desc"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:padding="16dp"
   android:text="腳本之家。"
   android:textColor="@android:color/white"
   android:textSize="18sp" 
   android:visibility="gone"/>
 </RelativeLayout>

</RelativeLayout>

布局中配置了卡牌正面的圖片控件，卡牌背面的文本控件，以及他們的parent容器，也就是本文中的旋轉(zhuǎn)動(dòng)畫的執(zhí)行對(duì)象。

MainActivity.java文件：

package com.feng.androidtest;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.view.animation.DecelerateInterpolator;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.example.androidtest.R;

public class MainActivity extends Activity {

 private RelativeLayout mContentRl;
 private ImageView mLogoIv;
 private TextView mDescTv;
 private Button mOpenBtn;

 private int centerX;
 private int centerY;
 private int depthZ = 400;
 private int duration = 600;
 private Rotate3dAnimation openAnimation;
 private Rotate3dAnimation closeAnimation;

 private boolean isOpen = false;

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

  mContentRl = (RelativeLayout) findViewById(R.id.rl_content);
  mLogoIv = (ImageView) findViewById(R.id.iv_logo);
  mDescTv = (TextView) findViewById(R.id.tv_desc);
  mOpenBtn = (Button) findViewById(R.id.btn_open);

 }

 /**
  * 卡牌文本介紹打開效果：注意旋轉(zhuǎn)角度
  */
 private void initOpenAnim() {
  //從0到90度，順時(shí)針旋轉(zhuǎn)視圖，此時(shí)reverse參數(shù)為true，達(dá)到90度時(shí)動(dòng)畫結(jié)束時(shí)視圖變得不可見，
  openAnimation = new Rotate3dAnimation(0, 90, centerX, centerY, depthZ, true);
  openAnimation.setDuration(duration);
  openAnimation.setFillAfter(true);
  openAnimation.setInterpolator(new AccelerateInterpolator());
  openAnimation.setAnimationListener(new AnimationListener() {

   @Override
   public void onAnimationStart(Animation animation) {

   }

   @Override
   public void onAnimationRepeat(Animation animation) {

   }

   @Override
   public void onAnimationEnd(Animation animation) {
    mLogoIv.setVisibility(View.GONE);
    mDescTv.setVisibility(View.VISIBLE);

    //從270到360度，順時(shí)針旋轉(zhuǎn)視圖，此時(shí)reverse參數(shù)為false，達(dá)到360度動(dòng)畫結(jié)束時(shí)視圖變得可見
    Rotate3dAnimation rotateAnimation = new Rotate3dAnimation(270, 360, centerX, centerY, depthZ, false);
    rotateAnimation.setDuration(duration);
    rotateAnimation.setFillAfter(true);
    rotateAnimation.setInterpolator(new DecelerateInterpolator());
    mContentRl.startAnimation(rotateAnimation);
   }
  });
 }

 /**
  * 卡牌文本介紹關(guān)閉效果：旋轉(zhuǎn)角度與打開時(shí)逆行即可
  */
 private void initCloseAnim() {
  closeAnimation = new Rotate3dAnimation(360, 270, centerX, centerY, depthZ, true);
  closeAnimation.setDuration(duration);
  closeAnimation.setFillAfter(true);
  closeAnimation.setInterpolator(new AccelerateInterpolator());
  closeAnimation.setAnimationListener(new AnimationListener() {

   @Override
   public void onAnimationStart(Animation animation) {

   }

   @Override
   public void onAnimationRepeat(Animation animation) {

   }

   @Override
   public void onAnimationEnd(Animation animation) {
    mLogoIv.setVisibility(View.VISIBLE);
    mDescTv.setVisibility(View.GONE);

    Rotate3dAnimation rotateAnimation = new Rotate3dAnimation(90, 0, centerX, centerY, depthZ, false);
    rotateAnimation.setDuration(duration);
    rotateAnimation.setFillAfter(true);
    rotateAnimation.setInterpolator(new DecelerateInterpolator());
    mContentRl.startAnimation(rotateAnimation);
   }
  });
 }

 public void onClickView(View v) {
  //以旋轉(zhuǎn)對(duì)象的中心點(diǎn)為旋轉(zhuǎn)中心點(diǎn)，這里主要不要再onCreate方法中獲取，因?yàn)橐晥D初始繪制時(shí)，獲取的寬高為0
  centerX = mContentRl.getWidth()/2;
   centerY = mContentRl.getHeight()/2;
   if (openAnimation == null) {
   initOpenAnim();
   initCloseAnim();
  }

   //用作判斷當(dāng)前點(diǎn)擊事件發(fā)生時(shí)動(dòng)畫是否正在執(zhí)行
  if (openAnimation.hasStarted() && !openAnimation.hasEnded()) {
   return;
  }
  if (closeAnimation.hasStarted() && !closeAnimation.hasEnded()) {
   return;
  }

  //判斷動(dòng)畫執(zhí)行
  if (isOpen) {
   mContentRl.startAnimation(closeAnimation);

  }else {

   mContentRl.startAnimation(openAnimation);
  }

  isOpen = !isOpen;
  mOpenBtn.setText(isOpen ? "關(guān)閉" : "打開");
 }
}

代碼中已對(duì)核心的地方做了注釋解釋，主要弄清楚 rotate3dAnimation構(gòu)造參數(shù)中的 fromDegrees和toDegrees、depthZ、reverse參數(shù)，同時(shí)在動(dòng)畫中設(shè)置了速度插播器，如動(dòng)畫的前半程使用加速器 AccelerateInterpolator，后半程使用減速器 DecelerateInterpolator，使動(dòng)畫體驗(yàn)更加人性化。

以上就是本文的全部?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)Android軟件編程有所幫助。

您可能感興趣的文章: