fm.cpp

#include "fm.h"
#include <stdio.h>

FM::FM(WaveTable *waveTable, waveformType waveform, double freq, double *depth)
    : Oscillator(waveTable, waveform, freq) {
  this->depth = depth;
  carrierPhase = 0;
  envelopeModifier = 0;
}

double FM::getSample() {
  double in, out, freq, currentDepth;
  pthread_mutex_lock(&setFreqMutex);
  currentDepth = *depth + envelopeModifier + (getLfoPosition() * 10000);
  currentDepth = currentDepth < 0 ? 0 : currentDepth;
  freq = SAMPLE_RATE / period;
  in = ((waveTable)->*(waveform))(phase, SAMPLE_RATE / period);
  out = sin(2 * PI * (carrierPhase / period));
  carrierPhase =
      fmod((carrierPhase + 1 + (((currentDepth)*in) / freq)), period);
  advance();
  pthread_mutex_unlock(&setFreqMutex);
  return out;
}

void FM::modulate(double amount) { envelopeModifier = amount * 10000; }

void FM::setFreq(double freq) {
  double newPeriod;
  newPeriod = SAMPLE_RATE / freq;
  pthread_mutex_lock(&setFreqMutex);
  phase = phase * (newPeriod / period);
  carrierPhase = carrierPhase * (newPeriod / period);
  period = newPeriod;
  pthread_mutex_unlock(&setFreqMutex);
}