SquareWaveOscillator.h

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#ifndef __SquareWaveOscillator_h
#define __SquareWaveOscillator_h
 
#include "Oscillator.h"
 
class SquareWaveOscillator : public OscillatorTemplate<SquareWaveOscillator> {
protected:
  float pw = 0.5;
public:
  static constexpr float begin_phase = 0;
  static constexpr float end_phase = 1;
  SquareWaveOscillator(){}
  SquareWaveOscillator(float sr){
    setSampleRate(sr);
  }  
  void setPulseWidth(float value){
    pw = value;
  }
  float getSample(){
    return phase < pw ? 1 : -1;
  }
};
 
class InvertedSquareWaveOscillator : public OscillatorTemplate<InvertedSquareWaveOscillator> {
protected:
  float pw = 0.5;
public:
  static constexpr float begin_phase = 0;
  static constexpr float end_phase = 1;
  void setPulseWidth(float value){
    pw = value;
  }
  float getSample(){
    return phase < pw ? -1 : 1;
  }
};
 
class AntialiasedSquareWaveOscillator : public OscillatorTemplate<AntialiasedSquareWaveOscillator> {
protected:
  float pw = 0.5f;
public:
  static constexpr float begin_phase = 0;
  static constexpr float end_phase = 1;
  void setPulseWidth(float value){
    pw = value;
  }
  float getSample(){
    float sample = phase < pw ? 1 : -1;
    sample += polyblep(phase, incr);
    sample -= polyblep(fmod(phase + 1 - pw, 1), incr);
    return sample;
  }
  void generate(FloatArray output){
    float sample;
    if(phase < pw){
      sample = 1;
      if(phase < incr){
    float t = phase / incr;
    sample += t+t - t*t - 1;
      }
    }else{
      sample = -1;
      if(phase-pw < incr){
    float t = fmod(phase + 1 - pw, 1) / incr;
    sample -= t+t - t*t - 1;
      }
    }
    size_t len = output.getSize();
    float* dest = output.getData();
    while(len--){
      phase += incr;
      if(phase >= pw){
    if(phase >= 1){
      // wrap phase
      phase -= 1;
      // correct current sample
      float t = (phase - incr) / incr;
      sample += t*t + t+t + 1;
      *dest++ = sample;
      sample = 1;
      // correct next sample
      t = phase / incr;
      sample += t+t - t*t - 1;
    }else if(sample == 1){
      // correct current sample
      float t = (fmod(phase + 1 - pw, 1) - incr) / incr;
      sample -= t*t + t+t + 1;
      *dest++ = sample;
      sample = -1;
      // correct next sample
      t = fmod(phase + 1 - pw, 1) / incr;
      sample -= t+t - t*t - 1;
    }else{
      *dest++ = sample;
      sample = -1;
    }
      }else{
    *dest++ = sample;
    sample = 1;
      }
    }
  }
  using OscillatorTemplate<AntialiasedSquareWaveOscillator>::generate;  
};
  
#endif /* __SquareWaveOscillator_h */