bsnes/higan/audio/resample/cubic.hpp

51 lines
1.0 KiB
C++

#pragma once
struct ResampleCubic : Resampler {
ResampleCubic(DSP& dsp) : Resampler(dsp) {}
inline auto setFrequency() -> void;
inline auto clear() -> void;
inline auto sample() -> void;
private:
double fraction;
double step;
};
auto ResampleCubic::setFrequency() -> void {
fraction = 0.0;
step = dsp.settings.frequency / frequency;
}
auto ResampleCubic::clear() -> void {
fraction = 0.0;
}
auto ResampleCubic::sample() -> void {
while(fraction <= 1.0) {
double channel[dsp.settings.channels];
for(auto n : range(dsp.settings.channels)) {
double a = dsp.buffer.read(n, -3);
double b = dsp.buffer.read(n, -2);
double c = dsp.buffer.read(n, -1);
double d = dsp.buffer.read(n, -0);
double mu = fraction;
double A = d - c - a + b;
double B = a - b - A;
double C = c - a;
double D = b;
channel[n] = A * (mu * 3) + B * (mu * 2) + C * mu + D;
}
dsp.write(channel);
fraction += step;
}
dsp.buffer.rdoffset++;
fraction -= 1.0;
}