cocos2dx 音频模块分析(5): 音效部分
我们上一篇中分析的音效部分的预加载和播放函数，这一篇来分析下其他函数：1、暂停某个播放中的音效//注意这里的nSoundId不是java端的soundID，，而是streamID//不要被参数的名字迷惑了。void SimpleAudioEngine::pauseEffect(unsigned int nSoundId){pauseEffectJNI(nSoundId);}–>> void pauseEffectJNI(unsigned int nSoundId){// void pauseEffect(int)JniMethodInfo methodInfo;if (! getStaticMethodInfo(methodInfo, "pauseEffect", "(I)V")){return ;}methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID, (int)nSoundId);methodInfo.env->DeleteLocalRef(methodInfo.classID);}—->>//java端方法：//pStreamID 这个参数，是调用unsigned int SimpleAudioEngine::playEffect()放回的StreamIDpublic void pauseEffect(final int pStreamID) {/*** Pause a playback stream. 暂停一个播放流** Pause the stream specified by the streamID. This is the* value returned by the play() function. (这个值是play函数的返回值)If the stream is* playing, it will be paused. If the stream is not playing* (e.g. is stopped or was previously paused), calling this* function will have no effect.(如果处于播放状态则暂停，如果不处于播放状态，则无效)** @param streamID a streamID returned by the play() function*/this.mSoundPool.pause(pStreamID);}2、 暂停所有音效 void pauseAllEffectsJNI(){// void pauseAllEffects()JniMethodInfo methodInfo;if (! getStaticMethodInfo(methodInfo, "pauseAllEffects", "()V")){return ;}methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID);methodInfo.env->DeleteLocalRef(methodInfo.classID);} —>>java端public void pauseAllEffects() { /*** Pause all active streams. //暂停所有正在播放的音效** Pause all streams that are currently playing. This function* iterates through all the active streams and pauses any that* are playing. It also sets a flag so that any streams that* are playing can be resumed by calling autoResume().*/this.mSoundPool.autoPause();}3、 恢复播放某个音效 void resumeEffectJNI(unsigned int nSoundId){// void resumeEffect(int)JniMethodInfo methodInfo;if (! getStaticMethodInfo(methodInfo, "resumeEffect", "(I)V")){return ;}methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID, (int)nSoundId);methodInfo.env->DeleteLocalRef(methodInfo.classID);}—>>public void resumeEffect(final int pStreamID) {/*** Resume a playback stream.* 只有处于暂停状态的stream，才可以恢复播放。* Resume the stream specified by the streamID. This* is the value returned by the play() function. If the stream* is paused, this will resume playback. If the stream was not* previously paused, calling this function will have no effect.** @param streamID a streamID returned by the play() function*/this.mSoundPool.resume(pStreamID);}4、void resumeAllEffectsJNI(){// void resumeAllEffects()JniMethodInfo methodInfo;if (! getStaticMethodInfo(methodInfo, "resumeAllEffects", "()V")){return ;}methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID);methodInfo.env->DeleteLocalRef(methodInfo.classID);}—->>>java端函数：public void resumeAllEffects() {// can not only invoke SoundPool.autoResume() here, because// it only resumes all effects paused by pauseAllEffects()// 这里注释的很清楚if (!this.mPathStreamIDsMap.isEmpty()) {final Iterator<Entry<String, ArrayList<Integer>>> iter = this.mPathStreamIDsMap.entrySet().iterator();while (iter.hasNext()) {final Entry<String, ArrayList<Integer>> entry = iter.next();for (final int pStreamID : entry.getValue()) {this.mSoundPool.resume(pStreamID);}}}}5、停止播放某个音效，这里的nSoundId同样是pStreamID，停止播放的音效是不能通过resume恢复播放的。void SimpleAudioEngine::stopEffect(unsigned int nSoundId){stopEffectJNI(nSoundId);}—>>java端：public void stopEffect(final int pStreamID) {/*** Stop a playback stream.** Stop the stream specified by the streamID. This* is the value returned by the play() function. If the stream* is playing, it will be stopped. It also releases any native* resources associated with this stream. (会释放对应的资源)If the stream is not* playing, it will have no effect.** @param streamID a streamID returned by the play() function*/this.mSoundPool.stop(pStreamID);// remove record// 从记录列表中移除for (final String pPath : this.mPathStreamIDsMap.keySet()) {if (this.mPathStreamIDsMap.get(pPath).contains(pStreamID)) {this.mPathStreamIDsMap.get(pPath).remove(this.mPathStreamIDsMap.get(pPath).indexOf(pStreamID));break;}}}6、void stopAllEffectsJNI(){// void stopAllEffects()JniMethodInfo methodInfo;if (! getStaticMethodInfo(methodInfo, "stopAllEffects", "()V")){return ;}methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID);methodInfo.env->DeleteLocalRef(methodInfo.classID);}—>>>java端@SuppressWarnings("unchecked")public void stopAllEffects() {// stop effects，停止所有音效的播放if (!this.mPathStreamIDsMap.isEmpty()) {final Iterator<?> iter = this.mPathStreamIDsMap.entrySet().iterator();while (iter.hasNext()) {final Map.Entry<String, ArrayList<Integer>> entry = (Map.Entry<String, ArrayList<Integer>>) iter.next();for (final int pStreamID : entry.getValue()) {this.mSoundPool.stop(pStreamID);}}}// remove records，清空播放记录this.mPathStreamIDsMap.clear();}7、卸载加载的音效(重要)//pszFilePath：音效文件名void SimpleAudioEngine::unloadEffect(const char* pszFilePath){std::string fullPath = getFullPathWithoutAssetsPrefix(pszFilePath);unloadEffectJNI(fullPath.c_str());}—>> void unloadEffectJNI(const char* path){// void unloadEffect(String)JniMethodInfo methodInfo;if (! getStaticMethodInfo(methodInfo, "unloadEffect", "(Ljava/lang/String;)V")){return ;}jstring stringArg = methodInfo.env->NewStringUTF(path);methodInfo.env->CallStaticVoidMethod(methodInfo.classID, methodInfo.methodID, stringArg);methodInfo.env->DeleteLocalRef(stringArg);methodInfo.env->DeleteLocalRef(methodInfo.classID);}—>>>public void unloadEffect(final String pPath) {// stop effects// 先停止final ArrayList<Integer> streamIDs = this.mPathStreamIDsMap.get(pPath);if (streamIDs != null) {for (final Integer pStreamID : streamIDs) {this.mSoundPool.stop(pStreamID);}}this.mPathStreamIDsMap.remove(pPath);// unload effectfinal Integer soundID = this.mPathSoundIDMap.get(pPath);if(soundID != null){/*** Unload a sound from a sound ID.** Unloads the sound specified by the soundID. This is the value* returned by the load() function. Returns true if the sound is* successfully unloaded, false if the sound was already unloaded.** @param soundID a soundID returned by the load() function* @return true if just unloaded, false if previously unloaded*/// 卸载音效this.mSoundPool.unload(soundID);// 从mPathSoundIDMap中移除this.mPathSoundIDMap.remove(pPath);}}/************************************************总结:音效部分最重要的函数是preloadEffect，unloadEffect，playEffect，stopAllEffects其他的感觉不是很常用，java有两个比较重要的map，一个是：private final HashMap<String, Integer> mPathSoundIDMap = new HashMap<String, Integer>();这个是用来存放所有加载的音效文件路径和SoundID的map。一个是：// sound path and stream ids map cocos2dx原本注释// a file may be played many times at the same time// so there is an array map to a file pathprivate final HashMap<String, ArrayList<Integer>> mPathStreamIDsMap = new HashMap<String, ArrayList<Integer>>();用来存放所有播放的音效文件路径和StreamIDs的map。注意：这里的SoundID和StreamID不是一个概念，一个音效文件只对应一个SoundID，而却可以对应多个StreamID，因为一个音效文件可以播放多次(StreamID)，但是只需要加载一次(SoundID).************************************************/
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