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#include "muxer.h"
#include <cstdlib>
#include <sndfile.h>
#include <portaudio.h>
#include <list>
#include <cmath>
#include <vector>
#include <stdexcept>
#include <sstream>
#define SAMPLE_RATE (44100)
#define DELAY_IN_SECS (0.075)
#define GAIN (1.0)
#define FEEDBACK (0.2)
#define DRY (1.0)
#define WET (0.5)
const int delaySize = SAMPLE_RATE * DELAY_IN_SECS;
class Sound {
public:
Sound(const char* filename, float vol);
inline bool isDone() const
{
return pos >= data.size();
}
std::vector<float> data;
unsigned long pos;
float vol;
};
struct Muxer {
std::list<Sound> playing;
PaStream* stream;
float* delay;
unsigned long delayPos;
};
inline void dealWithPaError(PaError err)
{
if (err != paNoError)
{
printf("PortAudio error: %s\n", Pa_GetErrorText(err));
exit(-1);
}
}
int paMuxerCallback(const void*, void* outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo*, PaStreamCallbackFlags, void* userData)
{
Muxer* muxer = (Muxer*) userData;
float* out = (float*) outputBuffer;
for (unsigned long i = 0; i<framesPerBuffer; i++)
{
float in = 0.0;
for (auto& sound : muxer->playing)
{
if (sound.pos < sound.data.size())
{
in += sound.data[sound.pos++] * sound.vol;
}
}
if (in > 1) in = 1;
if (in < -1) in = -1;
float sample = muxer->delay[muxer->delayPos] * GAIN;
muxer->delay[muxer->delayPos] = in + (muxer->delay[muxer->delayPos] * FEEDBACK);
muxer->delayPos++;
if (muxer->delayPos > delaySize) muxer->delayPos = 0;
*out++ = (in * DRY) + (sample * WET);
}
return 0;
}
static Muxer* muxer;
void initMuxer()
{
muxer = new Muxer();
dealWithPaError(Pa_Initialize());
dealWithPaError(Pa_OpenDefaultStream(&muxer->stream, 0, 1, paFloat32, SAMPLE_RATE, paFramesPerBufferUnspecified, paMuxerCallback, muxer));
dealWithPaError(Pa_StartStream(muxer->stream));
muxer->delay = (float*) calloc(delaySize, sizeof(float));
}
void destroyMuxer()
{
dealWithPaError(Pa_AbortStream(muxer->stream));
dealWithPaError(Pa_CloseStream(muxer->stream));
dealWithPaError(Pa_Terminate());
free(muxer->delay);
delete muxer;
muxer = 0;
}
void playSound(const char* filename, float vol)
{
// First, clear out any sounds that have finished playing
muxer->playing.remove_if([] (Sound& value) { return value.isDone(); });
// Then, add the new sound
muxer->playing.emplace_back(filename, vol);
}
Sound::Sound(const char* filename, float vol)
{
SF_INFO info;
SNDFILE* file = sf_open(filename, SFM_READ, &info);
if (file == nullptr)
{
std::ostringstream errmsg;
errmsg << "LibSndFile error: ";
errmsg << sf_strerror(file);
throw std::logic_error(errmsg.str());
}
data.resize(info.frames * info.channels);
pos = 0;
this->vol = vol;
sf_readf_float(file, data.data(), info.frames);
sf_close(file);
}
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