228 lines
6.8 KiB
C++
228 lines
6.8 KiB
C++
// 2 Operator FM Synth firmware for Sitka Instruments WS-1.0
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// by Oleksiy Hrachov
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//
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// Code is partly based on Knob_LightLevel_x2_FMSynth example from Mozzi Library
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//
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// Although the code designed to work on Sitka Instruments WS-1.0 synth, it should
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// be pretty easy to adapt to run on other arduino/mozzi-based setups.
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// Edit config.h to match your setup.
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//
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// This code is licenced under GPL v3 or later
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//ToDo:
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//optimize MIDI input (maybe neohwserial and this parser might help https://github.com/eclab/grains/tree/main/midi)
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//add ramp LFO
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//add uneven rations (like 3:2, 3:5)
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//rework LFO/Intensity so when LFO rate is 0, intensity doesn't depend on its phase
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#include <Mozzi.h>
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#include <MIDI.h>
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#include <Oscil.h>
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#include <tables/sin2048_int8.h>
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#include <tables/square_no_alias_2048_int8.h>
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#include <tables/saw2048_int8.h>
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#include <tables/whitenoise8192_int8.h>
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#include <Smooth.h>
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#include <ADSR.h>
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#include <mozzi_midi.h>
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#include <IntMap.h>
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#include <OverSample.h>
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#include "config.h"
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IntMap kMapCarrierNote( 0, 4095, 24 * pitchSubSteps, 84 * pitchSubSteps );
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IntMap kMapIntensity( 0, 1023, 10, 350 );
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IntMap kMapHarmonics( 0, 1023, 1, 40 );
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IntMap kMapLFOSpeed( 0, 1023, 1, 10000 );
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IntMap kMapAttack( 0, 1023, 0, 80 );
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IntMap kMapDecayRelease( 0, 1023, 8, 160 );
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IntMap kMapSustain( 0, 1023, 0, 255 );
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Oscil<SIN2048_NUM_CELLS, MOZZI_AUDIO_RATE> aCarrier(SIN2048_DATA);
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Oscil<SIN2048_NUM_CELLS, MOZZI_AUDIO_RATE> aModulator(SIN2048_DATA);
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Oscil<SIN2048_NUM_CELLS, MOZZI_CONTROL_RATE> kSineLFO(SIN2048_DATA);
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Oscil<SQUARE_NO_ALIAS_2048_NUM_CELLS, MOZZI_CONTROL_RATE> kSquareLFO(SQUARE_NO_ALIAS_2048_DATA);
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Oscil<SAW2048_NUM_CELLS, MOZZI_CONTROL_RATE> kSawLFO(SAW2048_DATA);
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Oscil<WHITENOISE8192_NUM_CELLS, MOZZI_CONTROL_RATE> kNoiseLFO(WHITENOISE8192_DATA);
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ADSR <MOZZI_CONTROL_RATE, MOZZI_CONTROL_RATE> envelope;
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Smooth <long> aSmoothIntensity(0.95f);
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OverSample <unsigned int, 2> kOverSamplePitch;
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//Global variables
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byte gain;
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bool MIDINotePlaying;
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bool gateIsHigh = false;
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float carrierFreq;
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long FMIntensity; // carries control info from updateControl to updateAudio
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void MIDINoteOn(byte channel, byte note, byte velocity) {
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carrierFreq = mtof((int) note);
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envelope.noteOn();
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MIDINotePlaying = true;
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digitalWrite(LED, LOW);
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}
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void MIDINoteOff(byte channel, byte note, byte velocity) {
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envelope.noteOff();
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digitalWrite(LED, HIGH);
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}
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long softClip(long input) {
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int threshold = 2048;
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if (input < -threshold) {
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return -threshold + (input + threshold) / 4;
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} else if (input > threshold) {
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return threshold + (input - threshold) / 4;
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} else {
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return input;
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}
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}
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void setup(){
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pinMode(LED, OUTPUT);
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pinMode(GateIn, INPUT_PULLUP);
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pinMode(EnvSwitch, INPUT_PULLUP);
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pinMode(DroneSwitch, INPUT_PULLUP);
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MIDI.setHandleNoteOn(MIDINoteOn);
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MIDI.setHandleNoteOff(MIDINoteOff);
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MIDI.setHandleClock(nullptr);
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MIDI.setHandleStart(nullptr);
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MIDI.setHandleStop(nullptr);
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MIDI.setHandleContinue(nullptr);
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MIDI.setHandleControlChange(nullptr);
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MIDI.begin(MIDI_CHANNEL);
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MIDI.turnThruOff();
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startMozzi();
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envelope.setAttackLevel(255);
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digitalWrite(LED, HIGH);
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}
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void updateControl(){
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for(int i=0; i<10; i++) { // Hacky way to drain the buffer faster
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MIDI.read();
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}
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//Get Control Values
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int CVInVal = mozziAnalogRead(CVIn);
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int knob1Val = mozziAnalogRead(Knob1);
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int knob2Val = mozziAnalogRead(Knob2);
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int knob3Val = mozziAnalogRead(Knob3);
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int knob4Val = mozziAnalogRead(Knob4);
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int knobAVal = mozziAnalogRead(KnobA);
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int knobDRVal = mozziAnalogRead(KnobDR);
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int knobSVal = mozziAnalogRead(KnobS);
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bool droneSwitchVal = digitalRead(DroneSwitch);
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bool envSwitchVal = digitalRead(EnvSwitch);
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bool gateInVal = !digitalRead(GateIn);
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//Remap the values and assign to parameter
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int intensity = kMapIntensity(knob1Val);
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int harmonics = kMapHarmonics(knob2Val);
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int LFOSpeed = kMapLFOSpeed(knob3Val);
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float expLFOSpeed = (float) LFOSpeed * LFOSpeed / 400000;
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float modSpeed = expLFOSpeed;
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//Set pitch and play notes on trigger
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if (!MIDINotePlaying) {
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if (oversamplingEnabled) {
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int oversampledCVInVal = kOverSamplePitch.next(CVInVal);
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carrierFreq = mtof((float) kMapCarrierNote(oversampledCVInVal) / pitchSubSteps);
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} else {
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carrierFreq = mtof((float) kMapCarrierNote(CVInVal << 2) / pitchSubSteps);
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}
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digitalWrite(LED, !gateInVal);
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if (gateInVal && !gateIsHigh) {
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gateIsHigh = true;
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envelope.noteOn();
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} else if (!gateInVal && gateIsHigh) {
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gateIsHigh = false;
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envelope.noteOff();
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}
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} else if (MIDINotePlaying && !envelope.playing()) {
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MIDINotePlaying = false;
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}
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//Update Envelope Settings
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int attackTime = kMapAttack(knobAVal);
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int decayReleaseTime = kMapDecayRelease(knobDRVal);
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int sustainLevel = kMapSustain(knobSVal);
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envelope.setDecayLevel(sustainLevel);
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envelope.setTimes(attackTime, decayReleaseTime, 30000, decayReleaseTime); //30000 is so the note will sustain 30 seconds unless a noteOff comes
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//Calculate the modulation frequency
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int FMmodFreq = carrierFreq * harmonics;
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//Set oscillator frequencies
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aCarrier.setFreq(carrierFreq);
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aModulator.setFreq(FMmodFreq);
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kSineLFO.setFreq(modSpeed);
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kSquareLFO.setFreq(modSpeed);
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kSawLFO.setFreq(modSpeed);
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kNoiseLFO.setFreq(modSpeed/4096);
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envelope.update();
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int sineLFOLevel;
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int squareLFOLevel;
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int sawLFOLevel;
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int noiseLFOLevel;
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if (knob4Val < 255) {
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sineLFOLevel = 255 - knob4Val;
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squareLFOLevel = knob4Val;
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sawLFOLevel = 0;
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noiseLFOLevel = 0;
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} else if (knob4Val < 511) {
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sineLFOLevel = 0;
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squareLFOLevel = 511 - knob4Val;
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sawLFOLevel = knob4Val - 255;
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noiseLFOLevel = 0;
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} else if (knob4Val < 767) {
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sineLFOLevel = 0;
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squareLFOLevel = 0;
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sawLFOLevel = 767 - knob4Val;
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noiseLFOLevel = knob4Val - 511;
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} else {
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sineLFOLevel = 0;
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squareLFOLevel = 0;
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sawLFOLevel = 0;
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noiseLFOLevel = 255;
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}
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int shapedLFO = (kSineLFO.next() * sineLFOLevel +
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kSquareLFO.next() * squareLFOLevel +
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kSawLFO.next() * sawLFOLevel +
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kNoiseLFO.next() * noiseLFOLevel)>>8;
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int env = envelope.next();
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int intensityEnv;
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if(envSwitchVal) {
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intensityEnv = env*3;
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} else {
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intensityEnv = 1;
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}
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FMIntensity = ((long)(intensity + intensityEnv) * (shapedLFO+128))>>8; //(shapedLFO+128))>>16; //(kSineLFO.next()+128))>>8;
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if(!droneSwitchVal) {
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gain = env;
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} else {
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gain = 255;
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}
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}
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AudioOutput updateAudio(){
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long modulation = aSmoothIntensity.next(FMIntensity) * aModulator.next();
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long signal = (aCarrier.phMod(modulation) * gain) >> 8; //envelope
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signal = softClip((signal * (127 + driveAmount)) >> 8); //overdrive
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return MonoOutput::from8Bit(signal);
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}
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void loop(){
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audioHook();
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} |