95 lines
No EOL
2.7 KiB
C++
95 lines
No EOL
2.7 KiB
C++
#pragma once
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#include "Globals.h"
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#include <cmath>
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#include <absl/types/span.h>
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template<class Type=float>
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class OnePoleFilter
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{
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public:
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OnePoleFilter() = default;
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// Normalized cutoff with respect to the sampling rate
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template<class C>
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static Type normalizedGain(Type cutoff, C sampleRate)
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{
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return std::tan( cutoff / static_cast<Type>(sampleRate) * M_PIf32 );
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}
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OnePoleFilter(Type gain)
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{
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setGain(gain);
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}
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void setGain(Type gain)
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{
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this->gain = gain;
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G = gain / ( 1 + gain);
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}
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Type getGain() const { return gain; }
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int processLowpass(absl::Span<const Type> input, absl::Span<Type> lowpass)
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{
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for (auto [in, out] = std::pair(input.begin(), lowpass.begin());
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in < input.end() && out < lowpass.end(); in++, out++)
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{
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oneLowpass(in, out);
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}
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return std::min(input.size(), lowpass.size());
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}
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int processHighpass(absl::Span<const Type> input, absl::Span<Type> highpass)
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{
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for (auto [in, out] = std::pair(input.begin(), highpass.begin());
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in < input.end() && out < highpass.end(); in++, out++)
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{
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oneHighpass(in, out);
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}
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return std::min(input.size(), highpass.size());
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}
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int processLowpassVariableGain(absl::Span<const Type> input, absl::Span<Type> lowpass, absl::Span<const Type> gain)
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{
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for (auto [in, out, g] = std::tuple(input.begin(), lowpass.begin(), gain.begin());
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in < input.end() && out < lowpass.end() && g < gain.end(); in++, out++, g++)
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{
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setGain(*g);
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oneLowpass(in, out);
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}
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return std::min({ input.size(), lowpass.size(), gain.size() });
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}
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int processHighpassVariableGain(absl::Span<const Type> input, absl::Span<Type> highpass, absl::Span<const Type> gain)
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{
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for (auto [in, out, g] = std::tuple(input.begin(), highpass.begin(), gain.begin());
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in < input.end() && out < highpass.end() && g < gain.end(); in++, out++, g++)
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{
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setGain(*g);
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oneHighpass(in, out);
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}
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return std::min({ input.size(), highpass.size(), gain.size() });
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}
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void reset() { state = 0.0; }
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private:
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Type state { 0.0 };
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Type gain { 0.25 };
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Type intermediate { 0.0 };
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Type G { gain / (1 + gain) };
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inline void oneLowpass(const Type* in, Type* out)
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{
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intermediate = G * (*in - state);
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*out = intermediate + state;
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state = *out + intermediate;
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}
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inline void oneHighpass(const Type* in, Type* out)
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{
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intermediate = G * (*in - state);
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*out = *in - intermediate - state;
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state += 2*intermediate;
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}
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}; |