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#if defined(PLATFORM_MACOS)
#include <OpenAL/al.h>
#include <OpenAL/alc.h>
#else
#include <AL/al.h>
#include <AL/alc.h>
#endif
struct AudioOpenAL : Audio {
AudioOpenAL() { initialize(); }
~AudioOpenAL() { terminate(); }
auto availableDevices() -> string_vector {
string_vector devices;
for(auto& device : queryDevices()) devices.append(device);
return devices;
}
auto availableFrequencies() -> vector<double> {
return {44100.0, 48000.0, 96000.0};
}
auto availableLatencies() -> vector<uint> {
return {20, 40, 60, 80, 100};
}
auto availableChannels() -> vector<uint> {
return {2};
}
auto ready() -> bool { return _ready; }
auto device() -> string { return _device; }
auto blocking() -> bool { return _blocking; }
auto channels() -> uint { return _channels; }
auto frequency() -> double { return (double)_frequency; }
auto latency() -> uint { return _latency; }
auto setDevice(string device) -> bool {
if(_device == device) return true;
_device = device;
return initialize();
}
auto setBlocking(bool blocking) -> bool {
if(_blocking == blocking) return true;
_blocking = blocking;
return true;
}
auto setFrequency(double frequency) -> bool {
if(_frequency == (uint)frequency) return true;
_frequency = (uint)frequency;
return initialize();
}
auto setLatency(uint latency) -> bool {
if(_latency == latency) return true;
_latency = latency;
if(_ready) updateLatency();
return true;
}
auto output(const double samples[]) -> void {
_buffer[_bufferLength] = (uint16_t)sclamp<16>(samples[0] * 32767.0) << 0;
_buffer[_bufferLength] |= (uint16_t)sclamp<16>(samples[1] * 32767.0) << 16;
if(++_bufferLength < _bufferSize) return;
ALuint alBuffer = 0;
int processed = 0;
while(true) {
alGetSourcei(_source, AL_BUFFERS_PROCESSED, &processed);
while(processed--) {
alSourceUnqueueBuffers(_source, 1, &alBuffer);
alDeleteBuffers(1, &alBuffer);
_queueLength--;
}
//wait for buffer playback to catch up to sample generation if not synchronizing
if(!_blocking || _queueLength < 3) break;
}
if(_queueLength < 3) {
alGenBuffers(1, &alBuffer);
alBufferData(alBuffer, _format, _buffer, _bufferSize * 4, _frequency);
alSourceQueueBuffers(_source, 1, &alBuffer);
_queueLength++;
}
ALint playing;
alGetSourcei(_source, AL_SOURCE_STATE, &playing);
if(playing != AL_PLAYING) alSourcePlay(_source);
_bufferLength = 0;
}
private:
auto initialize() -> bool {
terminate();
if(!queryDevices().find(_device)) _device = "";
_queueLength = 0;
updateLatency();
bool success = false;
if(_openAL = alcOpenDevice(_device)) {
if(_context = alcCreateContext(_openAL, nullptr)) {
alcMakeContextCurrent(_context);
alGenSources(1, &_source);
//alSourcef (_source, AL_PITCH, 1.0);
//alSourcef (_source, AL_GAIN, 1.0);
//alSource3f(_source, AL_POSITION, 0.0, 0.0, 0.0);
//alSource3f(_source, AL_VELOCITY, 0.0, 0.0, 0.0);
//alSource3f(_source, AL_DIRECTION, 0.0, 0.0, 0.0);
//alSourcef (_source, AL_ROLLOFF_FACTOR, 0.0);
//alSourcei (_source, AL_SOURCE_RELATIVE, AL_TRUE);
alListener3f(AL_POSITION, 0.0, 0.0, 0.0);
alListener3f(AL_VELOCITY, 0.0, 0.0, 0.0);
ALfloat listenerOrientation[] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
alListenerfv(AL_ORIENTATION, listenerOrientation);
success = true;
}
}
if(!success) return terminate(), false;
return _ready = true;
}
auto terminate() -> void {
_ready = false;
if(alIsSource(_source) == AL_TRUE) {
int playing = 0;
alGetSourcei(_source, AL_SOURCE_STATE, &playing);
if(playing == AL_PLAYING) {
alSourceStop(_source);
int queued = 0;
alGetSourcei(_source, AL_BUFFERS_QUEUED, &queued);
while(queued--) {
ALuint alBuffer = 0;
alSourceUnqueueBuffers(_source, 1, &alBuffer);
alDeleteBuffers(1, &alBuffer);
_queueLength--;
}
}
alDeleteSources(1, &_source);
_source = 0;
}
if(_context) {
alcMakeContextCurrent(nullptr);
alcDestroyContext(_context);
_context = nullptr;
}
if(_openAL) {
alcCloseDevice(_openAL);
_openAL = nullptr;
}
delete[] _buffer;
_buffer = nullptr;
}
auto queryDevices() -> string_vector {
string_vector result;
const char* list = alcGetString(nullptr, ALC_DEVICE_SPECIFIER);
if(!list) return result;
while(list && *list) {
result.append(list);
list += strlen(list) + 1;
}
return result;
}
auto updateLatency() -> void {
delete[] _buffer;
_bufferSize = _frequency * _latency / 1000.0 + 0.5;
_buffer = new uint32_t[_bufferSize]();
}
bool _ready = false;
string _device;
bool _blocking = true;
uint _channels = 2;
uint _frequency = 48000;
uint _latency = 20;
ALCdevice* _openAL = nullptr;
ALCcontext* _context = nullptr;
ALuint _source = 0;
ALenum _format = AL_FORMAT_STEREO16;
uint _queueLength = 0;
uint32_t* _buffer = nullptr;
uint _bufferLength = 0;
uint _bufferSize = 0;
};
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