mirror of https://github.com/bsnes-emu/bsnes.git
65 lines
1.5 KiB
C++
65 lines
1.5 KiB
C++
#ifdef NALL_DSP_INTERNAL_HPP
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struct ResampleHermite : Resampler {
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ResampleHermite(DSP& dsp) : Resampler(dsp) {}
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inline auto setFrequency() -> void;
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inline auto clear() -> void;
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inline auto sample() -> void;
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private:
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double fraction;
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double step;
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};
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auto ResampleHermite::setFrequency() -> void {
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fraction = 0.0;
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step = dsp.settings.frequency / frequency;
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}
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auto ResampleHermite::clear() -> void {
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fraction = 0.0;
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}
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auto ResampleHermite::sample() -> void {
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while(fraction <= 1.0) {
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double channel[dsp.settings.channels];
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for(auto n : range(dsp.settings.channels)) {
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double a = dsp.buffer.read(n, -3);
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double b = dsp.buffer.read(n, -2);
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double c = dsp.buffer.read(n, -1);
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double d = dsp.buffer.read(n, -0);
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const double tension = 0.0; //-1 = low, 0 = normal, +1 = high
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const double bias = 0.0; //-1 = left, 0 = even, +1 = right
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double mu1, mu2, mu3, m0, m1, a0, a1, a2, a3;
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mu1 = fraction;
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mu2 = mu1 * mu1;
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mu3 = mu2 * mu1;
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m0 = (b - a) * (1.0 + bias) * (1.0 - tension) / 2.0;
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m0 += (c - b) * (1.0 - bias) * (1.0 - tension) / 2.0;
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m1 = (c - b) * (1.0 + bias) * (1.0 - tension) / 2.0;
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m1 += (d - c) * (1.0 - bias) * (1.0 - tension) / 2.0;
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a0 = +2 * mu3 - 3 * mu2 + 1;
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a1 = mu3 - 2 * mu2 + mu1;
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a2 = mu3 - mu2;
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a3 = -2 * mu3 + 3 * mu2;
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channel[n] = (a0 * b) + (a1 * m0) + (a2 * m1) + (a3 * c);
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}
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dsp.write(channel);
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fraction += step;
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}
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dsp.buffer.rdoffset++;
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fraction -= 1.0;
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}
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#endif
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