bsnes/higan/nall/dsp/core.hpp

168 lines
3.4 KiB
C++
Executable File

#ifdef NALL_DSP_INTERNAL_HPP
#include <math.h>
#include <nall/stdint.hpp>
namespace nall {
//precision: can be float, double or long double
#define real float
struct DSP;
struct Resampler {
DSP &dsp;
real frequency;
virtual void setFrequency() = 0;
virtual void clear() = 0;
virtual void sample() = 0;
Resampler(DSP &dsp) : dsp(dsp) {}
};
struct DSP {
enum class ResampleEngine : unsigned {
Nearest,
Linear,
Cosine,
Cubic,
Hermite,
Average,
Sinc,
};
inline void setChannels(unsigned channels);
inline void setPrecision(unsigned precision);
inline void setFrequency(real frequency); //inputFrequency
inline void setVolume(real volume);
inline void setBalance(real balance);
inline void setResampler(ResampleEngine resamplingEngine);
inline void setResamplerFrequency(real frequency); //outputFrequency
inline void sample(signed channel[]);
inline bool pending();
inline void read(signed channel[]);
inline void clear();
inline DSP();
inline ~DSP();
protected:
friend class ResampleNearest;
friend class ResampleLinear;
friend class ResampleCosine;
friend class ResampleCubic;
friend class ResampleAverage;
friend class ResampleHermite;
friend class ResampleSinc;
struct Settings {
unsigned channels;
unsigned precision;
real frequency;
real volume;
real balance;
//internal
real intensity;
real intensityInverse;
} settings;
Resampler *resampler;
inline void write(real channel[]);
#include "buffer.hpp"
Buffer buffer;
Buffer output;
inline void adjustVolume();
inline void adjustBalance();
inline signed clamp(const unsigned bits, const signed x);
};
#include "resample/nearest.hpp"
#include "resample/linear.hpp"
#include "resample/cosine.hpp"
#include "resample/cubic.hpp"
#include "resample/hermite.hpp"
#include "resample/average.hpp"
#include "resample/sinc.hpp"
#include "settings.hpp"
void DSP::sample(signed channel[]) {
for(unsigned c = 0; c < settings.channels; c++) {
buffer.write(c) = (real)channel[c] * settings.intensityInverse;
}
buffer.wroffset++;
resampler->sample();
}
bool DSP::pending() {
return output.rdoffset != output.wroffset;
}
void DSP::read(signed channel[]) {
adjustVolume();
adjustBalance();
for(unsigned c = 0; c < settings.channels; c++) {
channel[c] = clamp(settings.precision, output.read(c) * settings.intensity);
}
output.rdoffset++;
}
void DSP::write(real channel[]) {
for(unsigned c = 0; c < settings.channels; c++) {
output.write(c) = channel[c];
}
output.wroffset++;
}
void DSP::adjustVolume() {
for(unsigned c = 0; c < settings.channels; c++) {
output.read(c) *= settings.volume;
}
}
void DSP::adjustBalance() {
if(settings.channels != 2) return; //TODO: support > 2 channels
if(settings.balance < 0.0) output.read(1) *= 1.0 + settings.balance;
if(settings.balance > 0.0) output.read(0) *= 1.0 - settings.balance;
}
signed DSP::clamp(const unsigned bits, const signed x) {
const signed b = 1U << (bits - 1);
const signed m = (1U << (bits - 1)) - 1;
return (x > m) ? m : (x < -b) ? -b : x;
}
void DSP::clear() {
buffer.clear();
output.clear();
resampler->clear();
}
DSP::DSP() {
setResampler(ResampleEngine::Hermite);
setResamplerFrequency(44100.0);
setChannels(2);
setPrecision(16);
setFrequency(44100.0);
setVolume(1.0);
setBalance(0.0);
clear();
}
DSP::~DSP() {
if(resampler) delete resampler;
}
#undef real
}
#endif