Class AudioContext

include/LabSound/core/AudioContext.h:37–236

class HRTFDatabaseLoader;

class AudioContext
{
    friend class ContextGraphLock;
    friend class ContextRenderLock;

public:

    // AudioNodes should not retain the AudioContext. The majority of
    // methods that take AudioContext as a parameter do so via reference.
    // 
    // If methods from the context, such as currentTime() are
    // required in methods that do not take AudioContext as a parameter, 
    // they should instead retain a weak pointer to the 
    // AudioNodeInterface from the AudioContext they were instantiated from. 
    // 
    // Locking the AudioNodeInterface pointer is a way to check if the 
    // AudioContext is still instantiated.
    // 
    // AudioContextInterface contains data that is safe for any thread, or
    // audio processing callback to read, even if the audio context is in
    // the process of stopping or destruction.

    class AudioContextInterface
    {
        friend class AudioContext;

        int _id = 0;
        AudioContext * _ac = nullptr;
        double _currentTime = 0;

    public:
        AudioContextInterface(AudioContext * ac, int id)
            : _id(id)
            , _ac(ac)
        {
        }

        ~AudioContextInterface() { }

        // the contextId of two AudioNodeInterfaces can be compared
        // to discover if they refer to the same context.
        int contextId() const { return _id; }
        double currentTime() const { return _currentTime; }
    };

    std::weak_ptr<AudioContextInterface> audioContextInterface() { return m_audioContextInterface; }

    // ctor/dtor
    explicit AudioContext(bool isOffline);
    explicit AudioContext(bool isOffline, bool autoDispatchEvents);
    ~AudioContext();

    // External users shouldn't use this; it should be called by
    // LabSound::MakeRealtimeAudioContext(lab::Channels::Stereo)
    // It *is* harmless to call it though, it's just not necessary.
    void lazyInitialize();
    bool isInitialized() const;