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Befaco
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First pass and fixing hard sync 

Also more robust FM behaviour

Fix PW sign

Few optimisations
pull/46/head
hemmer 1 year ago
parent
2034877161
commit
68726ce89e
6 changed files with 349 additions and 4 deletions
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  1. +2
    -1
      .gitignore
  2. +12
    -0
      plugin.json
  3. +331
    -0
      src/EvenVCO2.cpp
  4. +2
    -3
      src/PonyVCO.cpp
  5. +1
    -0
      src/plugin.cpp
  6. +1
    -0
      src/plugin.hpp

+ 2
- 1
.gitignore View File

@@ -3,4 +3,5 @@
/plugin.dylib
/plugin.dll
/plugin.so
.DS_Store
.DS_Store
/.vscode

+ 12
- 0
plugin.json View File

@@ -23,6 +23,18 @@
"Polyphonic"
]
},
{
"slug": "EvenVCO2",
"name": "Even VCO (beta)",
"description": "Oscillator including even-harmonic waveform",
"manualUrl": "https://www.befaco.org/even-vco/",
"modularGridUrl": "https://www.modulargrid.net/e/befaco-even-vco-",
"tags": [
"VCO",
"Hardware clone",
"Polyphonic"
]
},
{
"slug": "Rampage",
"name": "Rampage",


+ 331
- 0
src/EvenVCO2.cpp View File

@@ -0,0 +1,331 @@
#include "plugin.hpp"
#include "ChowDSP.hpp"

using simd::float_4;

struct EvenVCO2 : Module {
enum ParamIds {
OCTAVE_PARAM,
TUNE_PARAM,
PWM_PARAM,
NUM_PARAMS
};
enum InputIds {
PITCH1_INPUT,
PITCH2_INPUT,
FM_INPUT,
SYNC_INPUT,
PWM_INPUT,
NUM_INPUTS
};
enum OutputIds {
TRI_OUTPUT,
SINE_OUTPUT,
EVEN_OUTPUT,
SAW_OUTPUT,
SQUARE_OUTPUT,
NUM_OUTPUTS
};


float_4 phase[4] = {};
dsp::TSchmittTrigger<float_4> syncTrigger[4];
bool removePulseDC = true;
bool limitPW = true;

EvenVCO2() {
config(NUM_PARAMS, NUM_INPUTS, NUM_OUTPUTS);
configParam(OCTAVE_PARAM, -5.0, 4.0, 0.0, "Octave", "'", 0.5);
getParamQuantity(OCTAVE_PARAM)->snapEnabled = true;
configParam(TUNE_PARAM, -7.0, 7.0, 0.0, "Tune", " semitones");
configParam(PWM_PARAM, -1.0, 1.0, 0.0, "Pulse width");

configInput(PITCH1_INPUT, "Pitch 1");
configInput(PITCH2_INPUT, "Pitch 2");
configInput(FM_INPUT, "FM");
configInput(SYNC_INPUT, "Sync");
configInput(PWM_INPUT, "Pulse Width Modulation");

configOutput(TRI_OUTPUT, "Triangle");
configOutput(SINE_OUTPUT, "Sine");
configOutput(EVEN_OUTPUT, "Even");
configOutput(SAW_OUTPUT, "Sawtooth");
configOutput(SQUARE_OUTPUT, "Square");

// calculate up/downsampling rates
onSampleRateChange();
}

void onSampleRateChange() override {
float sampleRate = APP->engine->getSampleRate();
for (int i = 0; i < NUM_OUTPUTS; ++i) {
for (int c = 0; c < 4; c++) {
oversampler[i][c].setOversamplingIndex(oversamplingIndex);
oversampler[i][c].reset(sampleRate);
}
}

const float lowFreqRegime = oversampler[0][0].getOversamplingRatio() * 1e-3 * sampleRate;
DEBUG("Low freq regime: %g", lowFreqRegime);
}

float_4 aliasSuppressedTri(float_4* phases) {
float_4 triBuffer[3];
for (int i = 0; i < 3; ++i) {
float_4 p = 2 * phases[i] - 1.0; // range -1.0 to +1.0
float_4 s = 0.5 - simd::abs(p); // eq 30
triBuffer[i] = (s * s * s - 0.75 * s) / 3.0; // eq 29
}
return (triBuffer[0] - 2.0 * triBuffer[1] + triBuffer[2]);
}

float_4 aliasSuppressedSaw(float_4* phases) {
float_4 sawBuffer[3];
for (int i = 0; i < 3; ++i) {
float_4 p = 2 * phases[i] - 1.0; // range -1 to +1
sawBuffer[i] = (p * p * p - p) / 6.0; // eq 11
}

return (sawBuffer[0] - 2.0 * sawBuffer[1] + sawBuffer[2]);
}

float_4 aliasSuppressedDoubleSaw(float_4* phases) {
float_4 sawBuffer[3];
for (int i = 0; i < 3; ++i) {
float_4 p = 4.0 * simd::ifelse(phases[i] < 0.5, phases[i], phases[i] - 0.5) - 1.0;
sawBuffer[i] = (p * p * p - p) / 24.0; // eq 11 (modified for doubled freq)
}

return (sawBuffer[0] - 2.0 * sawBuffer[1] + sawBuffer[2]);
}

float_4 aliasSuppressedOffsetSaw(float_4* phases, float_4 pw) {
float_4 sawOffsetBuff[3];

for (int i = 0; i < 3; ++i) {
float_4 p = 2 * phases[i] - 1.0; // range -1 to +1
float_4 pwp = p + 2 * pw; // phase after pw (pw in [0, 1])
pwp += simd::ifelse(pwp > 1, -2, 0); // modulo on [-1, +1]
sawOffsetBuff[i] = (pwp * pwp * pwp - pwp) / 6.0; // eq 11
}
return (sawOffsetBuff[0] - 2.0 * sawOffsetBuff[1] + sawOffsetBuff[2]);
}

chowdsp::VariableOversampling<6, float_4> oversampler[NUM_OUTPUTS][4]; // uses a 2*6=12th order Butterworth filter
int oversamplingIndex = 1; // default is 2^oversamplingIndex == x2 oversampling

void process(const ProcessArgs& args) override {

// pitch inputs determine number of polyphony engines
const int channels = std::max({1, inputs[PITCH1_INPUT].getChannels(), inputs[PITCH2_INPUT].getChannels()});

const float pitchKnobs = 1.f + std::round(params[OCTAVE_PARAM].getValue()) + params[TUNE_PARAM].getValue() / 12.f;
const int oversamplingRatio = oversampler[0][0].getOversamplingRatio();

for (int c = 0; c < channels; c += 4) {
float_4 pw = simd::clamp(params[PWM_PARAM].getValue() + inputs[PWM_INPUT].getPolyVoltageSimd<float_4>(c) / 5.f, -1.f, 1.f);
if (limitPW) {
pw = simd::rescale(pw, -1, +1, 0.05f, 0.95f);
}
else {
pw = simd::rescale(pw, -1.f, +1.f, 0.f, 1.f);
}

const float_4 fmVoltage = inputs[FM_INPUT].getPolyVoltageSimd<float_4>(c) * 0.25f;
const float_4 pitch = inputs[PITCH1_INPUT].getPolyVoltageSimd<float_4>(c) + inputs[PITCH2_INPUT].getPolyVoltageSimd<float_4>(c);
const float_4 freq = dsp::FREQ_C4 * simd::pow(2.f, pitchKnobs + pitch + fmVoltage);
const float_4 deltaBasePhase = simd::clamp(freq * args.sampleTime / oversamplingRatio, 1e-6, 0.5f);
// floating point arithmetic doesn't work well at low frequencies, specifically because the finite difference denominator
// becomes tiny - we check for that scenario and use naive / 1st order waveforms in that frequency regime (as aliasing isn't
// a problem there). With no oversampling, at 44100Hz, the threshold frequency is 44.1Hz.
const float_4 lowFreqRegime = simd::abs(deltaBasePhase) < 1e-3;
// 1 / denominator for the second-order FD
const float_4 denominatorInv = 0.25 / (deltaBasePhase * deltaBasePhase);

// pulsewave waveform doesn't have DC even for non 50% duty cycles, but Befaco team would like the option
// for it to be added back in for hardware compatibility reasons
const float_4 pulseDCOffset = (!removePulseDC) * 2.f * (0.5f - pw);

// hard sync
const float_4 syncMask = syncTrigger[c / 4].process(inputs[SYNC_INPUT].getPolyVoltageSimd<float_4>(c));
phase[c / 4] = simd::ifelse(syncMask, 0.5f, phase[c / 4]);

float_4* osBufferTri = oversampler[TRI_OUTPUT][c / 4].getOSBuffer();
float_4* osBufferSaw = oversampler[SAW_OUTPUT][c / 4].getOSBuffer();
float_4* osBufferSin = oversampler[SINE_OUTPUT][c / 4].getOSBuffer();
float_4* osBufferSquare = oversampler[SQUARE_OUTPUT][c / 4].getOSBuffer();
float_4* osBufferEven = oversampler[EVEN_OUTPUT][c / 4].getOSBuffer();
for (int i = 0; i < oversamplingRatio; ++i) {

phase[c / 4] += deltaBasePhase;
// ensure within [0, 1]
phase[c / 4] -= simd::floor(phase[c / 4]);

float_4 phases[3]; // phase as extrapolated to the current and two previous samples

phases[0] = phase[c / 4] - 2 * deltaBasePhase + simd::ifelse(phase[c / 4] < 2 * deltaBasePhase, 1.f, 0.f);
phases[1] = phase[c / 4] - deltaBasePhase + simd::ifelse(phase[c / 4] < deltaBasePhase, 1.f, 0.f);
phases[2] = phase[c / 4];

if (outputs[SINE_OUTPUT].isConnected() || outputs[EVEN_OUTPUT].isConnected()) {
// sin doesn't need PDW
osBufferSin[i] = -simd::cos(2.0 * M_PI * phase[c / 4]);
}

if (outputs[TRI_OUTPUT].isConnected()) {
const float_4 dpwOrder1 = 1.0 - 2.0 * simd::abs(2 * phase[c / 4] - 1.0);
const float_4 dpwOrder3 = aliasSuppressedTri(phases) * denominatorInv;

osBufferTri[i] = simd::ifelse(lowFreqRegime, dpwOrder1, dpwOrder3);
}

if (outputs[SAW_OUTPUT].isConnected()) {
const float_4 dpwOrder1 = 2 * phase[c / 4] - 1.0;
const float_4 dpwOrder3 = aliasSuppressedSaw(phases) * denominatorInv;

osBufferSaw[i] = simd::ifelse(lowFreqRegime, dpwOrder1, dpwOrder3);
}

if (outputs[SQUARE_OUTPUT].isConnected()) {

float_4 dpwOrder1 = simd::ifelse(phase[c / 4] < pw, -1.0, +1.0);
dpwOrder1 -= removePulseDC ? 2.f * (0.5f - pw) : 0.f;

float_4 saw = aliasSuppressedSaw(phases);
float_4 sawOffset = aliasSuppressedOffsetSaw(phases, pw);
float_4 dpwOrder3 = (saw - sawOffset) * denominatorInv + pulseDCOffset;

osBufferSquare[i] = simd::ifelse(lowFreqRegime, dpwOrder1, dpwOrder3);
}

if (outputs[EVEN_OUTPUT].isConnected()) {

float_4 dpwOrder1 = 4.0 * simd::ifelse(phase[c / 4] < 0.5, phase[c / 4], phase[c / 4] - 0.5) - 1.0;
float_4 dpwOrder3 = aliasSuppressedDoubleSaw(phases) * denominatorInv;
float_4 doubleSaw = simd::ifelse(lowFreqRegime, dpwOrder1, dpwOrder3);
osBufferEven[i] = 0.55 * (doubleSaw + 1.27 * osBufferSin[i]);
}


} // end of oversampling loop

// downsample (if required)
if (outputs[SINE_OUTPUT].isConnected()) {
const float_4 outSin = (oversamplingRatio > 1) ? oversampler[SINE_OUTPUT][c / 4].downsample() : osBufferSin[0];
outputs[SINE_OUTPUT].setVoltageSimd(5.f * outSin, c);
}

if (outputs[TRI_OUTPUT].isConnected()) {
const float_4 outTri = (oversamplingRatio > 1) ? oversampler[TRI_OUTPUT][c / 4].downsample() : osBufferTri[0];
outputs[TRI_OUTPUT].setVoltageSimd(5.f * outTri, c);
}

if (outputs[SAW_OUTPUT].isConnected()) {
const float_4 outSaw = (oversamplingRatio > 1) ? oversampler[SAW_OUTPUT][c / 4].downsample() : osBufferSaw[0];
outputs[SAW_OUTPUT].setVoltageSimd(5.f * outSaw, c);
}

if (outputs[SQUARE_OUTPUT].isConnected()) {
const float_4 outSquare = (oversamplingRatio > 1) ? oversampler[SQUARE_OUTPUT][c / 4].downsample() : osBufferSquare[0];
outputs[SQUARE_OUTPUT].setVoltageSimd(5.f * outSquare, c);
}

if (outputs[EVEN_OUTPUT].isConnected()) {
const float_4 outEven = (oversamplingRatio > 1) ? oversampler[EVEN_OUTPUT][c / 4].downsample() : osBufferEven[0];
outputs[EVEN_OUTPUT].setVoltageSimd(5.f * outEven, c);
}

} // end of channels loop

// Outputs
outputs[TRI_OUTPUT].setChannels(channels);
outputs[SINE_OUTPUT].setChannels(channels);
outputs[EVEN_OUTPUT].setChannels(channels);
outputs[SAW_OUTPUT].setChannels(channels);
outputs[SQUARE_OUTPUT].setChannels(channels);
}


json_t* dataToJson() override {
json_t* rootJ = json_object();
json_object_set_new(rootJ, "removePulseDC", json_boolean(removePulseDC));
json_object_set_new(rootJ, "limitPW", json_boolean(limitPW));
json_object_set_new(rootJ, "oversamplingIndex", json_integer(oversampler[0][0].getOversamplingIndex()));
return rootJ;
}

void dataFromJson(json_t* rootJ) override {
json_t* pulseDCJ = json_object_get(rootJ, "removePulseDC");
if (pulseDCJ) {
removePulseDC = json_boolean_value(pulseDCJ);
}

json_t* limitPWJ = json_object_get(rootJ, "limitPW");
if (limitPWJ) {
limitPW = json_boolean_value(limitPWJ);
}

json_t* oversamplingIndexJ = json_object_get(rootJ, "oversamplingIndex");
if (oversamplingIndexJ) {
oversamplingIndex = json_integer_value(oversamplingIndexJ);
onSampleRateChange();
}
}
};


struct EvenVCO2Widget : ModuleWidget {
EvenVCO2Widget(EvenVCO2* module) {
setModule(module);
setPanel(APP->window->loadSvg(asset::plugin(pluginInstance, "res/panels/EvenVCO.svg")));

addChild(createWidget<Knurlie>(Vec(15, 0)));
addChild(createWidget<Knurlie>(Vec(15, 365)));
addChild(createWidget<Knurlie>(Vec(15 * 6, 0)));
addChild(createWidget<Knurlie>(Vec(15 * 6, 365)));

addParam(createParam<BefacoBigKnob>(Vec(22, 32), module, EvenVCO2::OCTAVE_PARAM));
addParam(createParam<BefacoTinyKnob>(Vec(73, 131), module, EvenVCO2::TUNE_PARAM));
addParam(createParam<Davies1900hRedKnob>(Vec(16, 230), module, EvenVCO2::PWM_PARAM));

addInput(createInput<BefacoInputPort>(Vec(8, 120), module, EvenVCO2::PITCH1_INPUT));
addInput(createInput<BefacoInputPort>(Vec(19, 157), module, EvenVCO2::PITCH2_INPUT));
addInput(createInput<BefacoInputPort>(Vec(48, 183), module, EvenVCO2::FM_INPUT));
addInput(createInput<BefacoInputPort>(Vec(86, 189), module, EvenVCO2::SYNC_INPUT));

addInput(createInput<BefacoInputPort>(Vec(72, 236), module, EvenVCO2::PWM_INPUT));

addOutput(createOutput<BefacoOutputPort>(Vec(10, 283), module, EvenVCO2::TRI_OUTPUT));
addOutput(createOutput<BefacoOutputPort>(Vec(87, 283), module, EvenVCO2::SINE_OUTPUT));
addOutput(createOutput<BefacoOutputPort>(Vec(48, 306), module, EvenVCO2::EVEN_OUTPUT));
addOutput(createOutput<BefacoOutputPort>(Vec(10, 327), module, EvenVCO2::SAW_OUTPUT));
addOutput(createOutput<BefacoOutputPort>(Vec(87, 327), module, EvenVCO2::SQUARE_OUTPUT));
}

void appendContextMenu(Menu* menu) override {
EvenVCO2* module = dynamic_cast<EvenVCO2*>(this->module);
assert(module);

menu->addChild(new MenuSeparator());
menu->addChild(createSubmenuItem("Hardware compatibility", "",
[ = ](Menu * menu) {
menu->addChild(createBoolPtrMenuItem("Remove DC from pulse", "", &module->removePulseDC));
menu->addChild(createBoolPtrMenuItem("Limit pulsewidth (5\%-95\%)", "", &module->limitPW));
}
));

menu->addChild(createIndexSubmenuItem("Oversampling",
{"Off", "x2", "x4", "x8"},
[ = ]() {
return module->oversamplingIndex;
},
[ = ](int mode) {
module->oversamplingIndex = mode;
module->onSampleRateChange();
}
));
}
};


Model* modelEvenVCO2 = createModel<EvenVCO2, EvenVCO2Widget>("EvenVCO2");

+ 2
- 3
src/PonyVCO.cpp View File

@@ -251,9 +251,8 @@ struct PonyVCO : Module {
break;
}
case WAVE_PULSE: {

float_4 dpwOrder1 = simd::ifelse(phase[c / 4] < pw, -1.0, +1.0);
dpwOrder1 -= simd::ifelse(removePulseDC, 2.f * (0.5f - pw), 0.f);
float_4 dpwOrder1 = simd::ifelse(phase[c / 4] < 1. - pw, +1.0, -1.0);
dpwOrder1 -= removePulseDC ? 2.f * (0.5f - pw) : 0.f;

float_4 saw = aliasSuppressedSaw(phases);
float_4 sawOffset = aliasSuppressedOffsetSaw(phases, pw);


+ 1
- 0
src/plugin.cpp View File

@@ -7,6 +7,7 @@ void init(rack::Plugin *p) {
pluginInstance = p;

p->addModel(modelEvenVCO);
p->addModel(modelEvenVCO2);
p->addModel(modelRampage);
p->addModel(modelABC);
p->addModel(modelSpringReverb);


+ 1
- 0
src/plugin.hpp View File

@@ -8,6 +8,7 @@ using namespace rack;
extern Plugin* pluginInstance;

extern Model* modelEvenVCO;
extern Model* modelEvenVCO2;
extern Model* modelRampage;
extern Model* modelABC;
extern Model* modelSpringReverb;


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