1、安卓工程下的设置启动activity为src下面的AppActivity,启动调用的onCreate并没有做过多的事情，只是调用了父类Cocos2dxActivity的onCreate。AppActivity代码如下：
import org.cocos2dx.lib.Cocos2dxActivity;
public class AppActivity extends Cocos2dxActivity {
@Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
......
}
}
2、Cocos2dxActivity在cocos/platform/android/java/src/org/cocos2dx/lib/Cocos2dxActivity.java里，查看onCreate,代码如下：
@Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
initFMOD(); //加载声音库
try {
Class.forName("android.os.AsyncTask");
} catch (Throwable ignor) {
ignor.printStackTrace();
}
sContext = this;
PSNetwork.init(sContext); //初始化安卓网络连接服务
if (Build.VERSION.SDK_INT >= 23) {
requestUserPermissions(); //系统的部分授权
}
mMacAddress = MacAddressUtil.getMacAddress(sContext);//获取wifi的MAC地址
CocosPlayClient.init(this, false); //暂时无用
boolean isLoadOK = onLoadNativeLibraries(); //把工程中libs下面的so文件load进来，定义在AndroidManifest, meta-data标签下，android.app.lib_name. 最终在包的data/data/com.XXX.XXX/lib下面
if (false == isLoadOK) {
return;
}
this.mHandler = new Cocos2dxHandler(this);//处理安卓的弹窗等
Cocos2dxHelper.init(this);
this.mGLContextAttrs = getGLContextAttrs();//获取OpenGLEs的相关属性
this.init(); //说明如下文
if (mVideoHelper == null) {
mVideoHelper = new Cocos2dxVideoHelper(this, mFrameLayout);
}
if (mWebViewHelper == null) {
mWebViewHelper = new Cocos2dxWebViewHelper(mFrameLayout);
}
if(mEditBoxHelper == null){
mEditBoxHelper = new Cocos2dxEditBoxHelper(mFrameLayout);
}
if (null == mScreenListener) {
mScreenListener = new ScreenListener(this);
mScreenListener.begin(this);
}
}
3、Cocos2dxActivity的init函数如下：
public void init() {
// FrameLayout
ViewGroup.LayoutParams framelayout_params = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT);
mFrameLayout = new ResizeLayout(this); //继承自FrameLayout,看成是一块画布(canvas),其他控件添加在上面
mFrameLayout.setLayoutParams(framelayout_params);
// Cocos2dxEditText layout
ViewGroup.LayoutParams edittext_layout_params = new ViewGroup.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
Cocos2dxEditBox edittext = new Cocos2dxEditBox(this);
edittext.setLayoutParams(edittext_layout_params);//输入框
// ...add to FrameLayout
mFrameLayout.addView(edittext);
// Cocos2dxGLSurfaceView
this.mGLSurfaceView = this.onCreateView();//创建游戏的渲染，接受输入事件的OpenGL类
// ...add to FrameLayout
mFrameLayout.addView(this.mGLSurfaceView);//添加到画布上
// Switch to supported OpenGL (ARGB888) mode on emulator
if (isAndroidEmulator())
this.mGLSurfaceView.setEGLConfigChooser(8, 8, 8, 8, 16, 0);
this.mGLSurfaceView.setCocos2dxRenderer(new Cocos2dxRenderer());//注册自主实现的渲染器,内容如下
this.mGLSurfaceView.setCocos2dxEditText(edittext);//输入框
this.onCreateFrameLayout();
// Set framelayout as the content view
setContentView(mFrameLayout);//设置这个Activity的显示界面
}
4、Cocos2dxRenderer,cocos2dx的渲染器，继承自android.opengl.GLSurfaceView.Renderer，当3中的GLSurfaceView被创建的时候会调用render的onSurfaceCreated()方法; 当GLSurfaceView大小或者横竖屏发生变化的时候调用render的onSurfaceChanged()方法； 当系统每一次重新画GLSurfaceView的时候，调用onDrawFrame()方法。所以Cocos2dxRender对这三个方法进行了重写。
@Override
public void onSurfaceCreated(final GL10 GL10, final EGLConfig EGLConfig) {
Cocos2dxRenderer.nativeInit(this.mScreenWidth, this.mScreenHeight);//此处调用了一个定义为native的函数，设置glview等，通过jni来访问c++实现的方法，接口实现在cocos/platform/android/javaactivity-android.cpp里面，下面的5会继续讲
this.mLastTickInNanoSeconds = System.nanoTime();
mNativeInitCompleted = true;
try{
Cocos2dxActivity activity = (Cocos2dxActivity) Cocos2dxActivity.getContext();
activity.onSurfaceCreated(this, GL10, EGLConfig);
}catch( Throwable e ){
e.printStackTrace();
}
}
@Override
public void onDrawFrame(final GL10 gl) { //系统自动每秒钟调用60次这个函数
/*
* No need to use algorithm in default(60 FPS) situation, since
* onDrawFrame() was called by system 60 times per second by default.
*/
if( true == mIsPaused ){
return;
}
if( mDelayResumeCount <= DELAY_RESUME_COUNT ){
mDelayResumeCount = mDelayResumeCount + 1;
if( mDelayResumeCount == DELAY_RESUME_COUNT ){
Cocos2dxRenderer.nativeOnResume();
try{
Cocos2dxActivity activity = (Cocos2dxActivity) Cocos2dxActivity.getContext();
activity.nativeResume();
}catch( Throwable e ){
e.printStackTrace();
}
}
return;
}
if (sAnimationInterval <= 1.0 / 60 * Cocos2dxRenderer.NANOSECONDSPERSECOND) {
Cocos2dxRenderer.nativeRender(); //大于等于每秒60帧则不经过算法处理，直接执行nativeRender，将在6中有说明
} else {
final long now = System.nanoTime();
final long interval = now - this.mLastTickInNanoSeconds;
if (interval < Cocos2dxRenderer.sAnimationInterval) { //按照设置的帧数，如果没有到时间，则sleep到相应的时间
try {
Thread.sleep((Cocos2dxRenderer.sAnimationInterval - interval)
/ Cocos2dxRenderer.NANOSECONDSPERMICROSECOND);
} catch (final Exception e) {
}
}
/*
* Render time MUST be counted in, or the FPS will slower than
* appointed.
*/
this.mLastTickInNanoSeconds = System.nanoTime();
Cocos2dxRenderer.nativeRender();
}
try{
Cocos2dxActivity activity = (Cocos2dxActivity) Cocos2dxActivity.getContext();
activity.onDrawFrame(this, gl);
}catch( Throwable e ){
e.printStackTrace();
}
}
@Override
public void onSurfaceChanged(final GL10 GL10, final int width,
final int height) {
Cocos2dxRenderer.nativeOnSurfaceChanged(width, height);
try{
Cocos2dxActivity activity = (Cocos2dxActivity) Cocos2dxActivity.getContext();
activity.onSurfaceChanged(this, GL10, width, height);
}catch( Throwable e ){
e.printStackTrace();
}
}
5、 4里面onSurfaceCreated的nativeInit的实现放在cocos/platform/android/javaactivity-android.cpp，方法如下：
void Java_org_cocos2dx_lib_Cocos2dxRenderer_nativeInit(JNIEnv* env, jobject thiz, jint w, jint h)
{
auto director = cocos2d::Director::getInstance();
auto glview = director->getOpenGLView();
if (!glview)
{
glview = cocos2d::GLViewImpl::create("Android app");
glview->setFrameSize(w, h);
director->setOpenGLView(glview); //设置glview
//cocos_android_app_init(env, thiz);
cocos2d::Application::getInstance()->run(); //程序开始运行，android的Application实现放在CCApplication-android.cpp,run的代码如下
}
else
{
cocos2d::GL::invalidateStateCache();
cocos2d::GLProgramCache::getInstance()->reloadDefaultGLPrograms();
cocos2d::DrawPrimitives::init();
cocos2d::VolatileTextureMgr::reloadAllTextures();
cocos2d::EventCustom recreatedEvent(EVENT_RENDERER_RECREATED);
director->getEventDispatcher()->dispatchEvent(&recreatedEvent);
director->setGLDefaultValues();
}
}
int Application::run()
{
// Initialize instance and cocos2d.
if (! applicationDidFinishLaunching()) //applicationDidFinishLanunching在自己的Classes/AppDelegate进行重写,游戏已经启动
{
return 0;
}
return -1;
}
bool AppDelegate::applicationDidDinishLaunching()
{
......
director->setOpenGLView(glview);
director->setAnimationInterval(1/30.f); //设置帧数，会调用Application-android的setAnimationInterval,再通过JniHelper调用Cocos2dxRenderer中的setAnimationInterval
director->runWithScene(scene); //
return true
}
6、关于4中onDrawFrame涉及到的函数nativeRender，它也是一个native类型的函数，实现放在cocos/platform/android/jni/Java_org_cocos2dx_lib_Cocos2dxRenderer.cpp
JNIEXPORT void JNICALL Java_org_cocos2dx_lib_Cocos2dxRenderer_nativeRender(JNIEnv* env) {
cocos2d::Director::getInstance()->mainLoop(); //进入游戏的主循环，Director的mainLoop，事件的分发，渲染,内存池的管理
}