a587a43ff9
Dual-stage compressor (optical + VCA) with output transformer saturation. - Port-Hamiltonian T4B opto-cell model with implicit trapezoidal integration - Feed-forward VCA with 7 ratios, 6 attack/release presets, Dual release mode - 3 transformer types (Nickel/Iron/Steel) with 4x oversampled waveshaping - Analog-style needle VU meters, horizontal GR meters - Sidechain HPF, stereo link, independent section bypass - Full state save/restore, CI/CD for Windows/macOS/Linux
109 sor
3.6 KiB
C++
109 sor
3.6 KiB
C++
#include "TransformerSaturation.h"
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TransformerSaturation::TransformerSaturation() {}
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void TransformerSaturation::prepare (double sampleRate, int samplesPerBlock)
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{
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sr = sampleRate;
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oversampler.initProcessing ((size_t) samplesPerBlock);
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// Iron tonestack: very subtle low shelf +0.2dB at 110Hz
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auto ironCoeffs = juce::dsp::IIR::Coefficients<float>::makeLowShelf (
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sampleRate, 110.0f, 0.707f, juce::Decibels::decibelsToGain (0.2f));
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ironBoostL.coefficients = ironCoeffs;
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ironBoostR.coefficients = ironCoeffs;
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// Steel tonestack: subtle low shelf +0.4dB at 40Hz
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auto steelCoeffs = juce::dsp::IIR::Coefficients<float>::makeLowShelf (
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sampleRate, 40.0f, 0.707f, juce::Decibels::decibelsToGain (0.4f));
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steelBoostL.coefficients = steelCoeffs;
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steelBoostR.coefficients = steelCoeffs;
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}
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void TransformerSaturation::reset()
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{
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oversampler.reset();
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ironBoostL.reset(); ironBoostR.reset();
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steelBoostL.reset(); steelBoostR.reset();
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}
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void TransformerSaturation::processBlock (juce::AudioBuffer<float>& buffer, Type type)
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{
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if (type == Off) return;
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const int numChannels = std::min (buffer.getNumChannels(), 2);
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const int numSamples = buffer.getNumSamples();
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// Select parameters per type:
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// drive: how hard the tanh clips (1.0 = no effect)
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// even: 2nd harmonic amount (asymmetric warmth)
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// odd: 3rd harmonic amount (edge/presence)
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// mix: wet/dry blend (keeps effect very subtle)
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float drive, even, odd, mix;
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switch (type)
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{
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case Nickel:
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drive = 1.05f; even = 0.002f; odd = 0.0005f; mix = 0.3f;
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break;
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case Iron:
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drive = 1.15f; even = 0.008f; odd = 0.002f; mix = 0.5f;
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break;
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case Steel:
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drive = 1.3f; even = 0.012f; odd = 0.008f; mix = 0.6f;
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break;
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default:
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return;
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}
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// 4x upsample
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juce::dsp::AudioBlock<float> block (buffer);
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auto oversampledBlock = oversampler.processSamplesUp (block);
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const int osNumSamples = (int) oversampledBlock.getNumSamples();
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const int osNumChannels = std::min ((int) oversampledBlock.getNumChannels(), 2);
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// Apply waveshaping at oversampled rate
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for (int ch = 0; ch < osNumChannels; ++ch)
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{
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float* data = oversampledBlock.getChannelPointer ((size_t) ch);
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for (int i = 0; i < osNumSamples; ++i)
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{
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float x = data[i];
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float dry = x;
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// Soft-clip: tanh(drive*x)/drive — unity gain at DC
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float shaped = std::tanh (drive * x) / drive;
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// Add subtle harmonic content
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shaped += even * x * std::abs (x); // 2nd harmonic (even-order)
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shaped -= odd * x * x * x; // 3rd harmonic (odd-order)
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// Blend dry/wet to keep the effect subtle
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data[i] = dry + (shaped - dry) * mix;
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}
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}
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// 4x downsample
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oversampler.processSamplesDown (block);
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// Post-saturation tonestack (very subtle EQ coloration)
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if (type == Iron)
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{
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for (int i = 0; i < numSamples; ++i)
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{
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if (numChannels > 0) buffer.setSample (0, i, ironBoostL.processSample (buffer.getSample (0, i)));
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if (numChannels > 1) buffer.setSample (1, i, ironBoostR.processSample (buffer.getSample (1, i)));
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}
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}
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else if (type == Steel)
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{
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for (int i = 0; i < numSamples; ++i)
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{
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if (numChannels > 0) buffer.setSample (0, i, steelBoostL.processSample (buffer.getSample (0, i)));
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if (numChannels > 1) buffer.setSample (1, i, steelBoostR.processSample (buffer.getSample (1, i)));
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}
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}
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}
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