OpenAL 使用基本流程

1. 初始化

        ALCcontext* p_context;        ALCdevice* p_device;        ALuint ui_source;        ALuint m_buffers[MAX_CACHE];        std::list<ALuint> m_buffer_queue;        p_device = alcOpenDevice(NULL);        p_context = alcCreate(p_device, NULL);        alcMakeContextCurrent(p_context);        alGenBuffers(MAX_SIZE, m_buffers);        alGenSource(1, &p_source);        for(auto buf : m_buffers)        {            m_buffer_queue.push_back(buf);        }

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2. 设置音效

alListenerf(AL_GAIN, 1.45f);

3. 播放

播放最简单的流程就是：
- 加载音频数据（PS：必须是Raw Data）
- 把数据写入buffer： alBufferData
- alSourcePlay

支持缓冲区的播放：
- 加载音频数据
- 回收Buffer ： alSourceUnqueueBuffers
- 把数据写入buffer： alBufferData
- 将buffer放回缓冲区：alSourceQueueBuffers
- 播放： alSourcePlay

具体流程如下：
PS：下面代码是摘出来的，不一定可以运行，看看即可

while(b_break){    //Read Data    int size= ReadData(buffer);    //recycle buffers    ALint i_num;    alGetSourcei(m_source, AL_BUFFERS_PROCESSED, &i_num);    ALuint buffers[MAX_SIZE];    alSourceUnqueueBuffers(ui_source, i_num, buffers);    for(int i = 0; i <= i_num; ++i)    {        m_bufferQueue.push_back(buffers[i]);    }    //push data to al buffers    alBuf = m_buffer_queue.front();    alBufferData(alBuf, AL_FORMAT_MONO16, buffer, size * kByte, header->samplesPerSec);    alSourceQueueBuffers(ui_source, 1, &alBuf);   //play   ALint bufferQueued;   alGetSourcei(ui_source, AL_BUFFERS_QUEUED, &bufferQueued);   if(bufferQueued != 0)       alSourcePlay(m_source);}

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3. 退出

            //stop            alSourceStop(ui_source);            //release            alcMakeContextCurrent(p_context)            alDeleteSources(1, &ui_source);            m_source = 0;            alDeleteBuffers(MAX_CACHE, m_buffer);            memset(m_buffer, 0, sizeof(m_buffer));            alcMakeContextCurrent(nullptr);            alcDestroyContext(p_context);            m_context = nullptr;            alcCloseDevice(p_device);            p_device = nullptr;            m_buffer_queue.clear();