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#include "../../core/configuration.h"
#if defined(jin_audio) && (jin_audio == jin_audio_sdl)
#include <iostream>
#include "../../math/math.h"
#include "../../utils/log.h"
#include "sdl_audio.h"
#include "sdl_source.h"
using namespace JinEngine::Math;
namespace JinEngine
{
namespace Audio
{
namespace SDL
{
/* עcallbackƵ̵߳ */
static void defaultCallback(void *userdata, Uint8 *stream, int size)
{
static SDLAudio* audio = static_cast<SDLAudio*>(userdata);
if (!audio->goOnProcess())
return;
audio->lock();
audio->processCommands();
audio->processSources(stream, size);
audio->processBuffer(stream, size);
audio->unlock();
}
/*call only once*/ bool SDLAudio::startSystem(const SettingBase* s)
{
jin_log_info("Initialize audio system.");
if (SDL_Init(SDL_INIT_AUDIO) < 0)
return false;
SDL_AudioSpec spec;
Setting* setting = (Setting*)s;
if (setting == nullptr)
return false;
unsigned int samplerate = setting->samplerate;
unsigned int samples = clamp<int>(setting->samples, 1, setting->samplerate);
spec.freq = samplerate; // ÿsample,õ 11025, 22050, 44100 and 48000 Hz.
spec.format = AUDIO_S16SYS; // signed 16-bit samples in native byte order
spec.channels = SDLAUDIO_CHANNELS; //
spec.samples = samples; // ÿβʱһã=setting->samplerateÿֻ1
spec.userdata = this;
spec.callback = defaultCallback;
audioDevice = SDL_OpenAudioDevice(NULL, 0, &spec, NULL, 0);
if (audioDevice == 0)
return false;
/* start audio */
SDL_PauseAudioDevice(audioDevice, 0);
return true;
}
/*call only once*/ void SDLAudio::quitSystem()
{
jin_log_info("Quit audio system.");
SDL_CloseAudio();
}
void SDLAudio::lock()
{
SDL_LockAudioDevice(audioDevice);
}
void SDLAudio::unlock()
{
SDL_UnlockAudioDevice(audioDevice);
}
bool SDLAudio::goOnProcess()
{
if (state == SDLAudio::State::STOP)
{
SDLSourceManager::get()->removeAllSource();
pause();
return false;
}
else if (state == SDLAudio::State::PAUSE)
return false;
else
return true;
}
void SDLAudio::processCommands()
{
SDLSourceManager::get()->processCommands();
}
void SDLAudio::processSources(void* buffer, size_t len)
{
SDLSourceManager::get()->processSources(buffer, len);
}
void SDLAudio::processBuffer(void* buff, size_t len)
{
short* buffer = (short*)buff;
int samples = (len / SDLAUDIO_BYTEDEPTH) >> 1; // ˫
const char L = 0, R = 1;
for (int i = 0; i < samples; ++i)
{
short* clip = buffer + (i << 1);
clip[L] *= volume;
clip[R] *= volume;
}
}
void SDLAudio::play()
{
state = State::PLAY;
}
void SDLAudio::stop()
{
state = State::STOP;
}
void SDLAudio::pause()
{
state = State::PAUSE;
}
void SDLAudio::resume()
{
state = State::PLAY;
}
void SDLAudio::setVolume(float volume)
{
this->volume = clamp(volume, 0.0f, 1.0f);
}
} // namespace SDL
} // namespace Audio
} // namespace JinEngine
#endif // (jin_audio) && (jin_audio == jin_audio_sdl)
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