bsnes/nall/dsp/resample/cosine.hpp

45 lines
886 B
C++

#pragma once
struct ResampleCosine : Resampler {
ResampleCosine(DSP& dsp) : Resampler(dsp) {}
inline auto setFrequency() -> void;
inline auto clear() -> void;
inline auto sample() -> void;
private:
double fraction;
double step;
};
auto ResampleCosine::setFrequency() -> void {
fraction = 0.0;
step = dsp.settings.frequency / frequency;
}
auto ResampleCosine::clear() -> void {
fraction = 0.0;
}
auto ResampleCosine::sample() -> void {
while(fraction <= 1.0) {
double channel[dsp.settings.channels];
for(auto n : range(dsp.settings.channels)) {
double a = dsp.buffer.read(n, -1);
double b = dsp.buffer.read(n, -0);
double mu = fraction;
mu = (1.0 - cos(mu * 3.14159265)) / 2.0;
channel[n] = a * (1.0 - mu) + b * mu;
}
dsp.write(channel);
fraction += step;
}
dsp.buffer.rdoffset++;
fraction -= 1.0;
}