// WahWah v0.2
// by Benito

class WahWah extends UGen {

  protected Envelope ff;
  float lowFreq = 400, highFreq = 8000;
  float attackTime = 100, attackExp = 1, decayTime = 100, decayExp = 1;
  double two_pi_over_sf;
  float res, n2res;
  float y1 = 0, y2 = 0, y0 = 0;
  float a1 = 0, a2 = 0, b0 = 0;
  
  WahWah(AudioContext context) {
    super(context, 1, 1);
    ff = new Envelope(context, lowFreq);
    two_pi_over_sf = TWO_PI / context.getSampleRate();
    
    setRes(.99);

  }
  
  public void setRes(float res) {
    if(res < 0) {
      this.res = 0;
    }
    else if(res > .999999f) {
      this.res = .999999f;
    }
    else {
      this.res = res;
    }
    
    a2 = res * res;
    n2res = -2 * res;
  }
  
  void wah(float amt) {
    ff.clear();
    ff.addSegment(highFreq, attackTime, attackExp, null);
    ff.addSegment(lowFreq, decayTime, decayExp, null);
    println("wah " + amt);
  }
  
  void calculateBuffer() {
    float[] bi = bufIn[0];
    float[] bo = bufOut[0];
    
    for(int i = 0; i < bi.length; i++) {
      
      /*
      // BUTTERWORTH shelf
      double pif = 2 * PI * env[i];
      double k = pif / tan((float)(pif * sr2i));
      
      a0 = (float)(pif / (k + pif));
      b1 = (float)((pif - k) / (k + pif));
      */
      
      //b0 = env[i] * TWO_PI / 44100;
      //a1 = (b0 - 1) * q;
      //a2 = (b0 - 1) * (1 - q);
      
      
      float cosw = (float)Math.cos(ff.getValue(0, i) *  two_pi_over_sf);
      a1 = n2res * cosw;
      b0 = 1 + a1 + a2;
      
      y2 = y1;
      y1 = y0;
      bo[i] = y0 = b0 * bi[i] - a1 * y1 - a2 * y2;
    }
  }
}


// WahEffect v0.1
// by Benito

class WahEffect extends Effect {
  BiquadFilter filt;
  Envelope ff;
  float filtq = 1;
  float lowFreq = 1000, highFreq = 12000;
  float attackTime = 400, attackExp = 1, decayTime = 100, decayExp = .5;
  
  WahEffect(AudioContext context) {
    ff = new Envelope(context, lowFreq);
    filt = new BiquadFilter(context, BiquadFilter.LP, ff, filtq);
    
    in = filt;
    out = filt;
  }
  
  void hit(float amt) {
    ff.clear();
    ff.addSegment(highFreq, attackTime, attackExp, null);
    ff.addSegment(lowFreq, decayTime, decayExp, null);
    //println("wah!");
  }
}

class Effect extends Bead {
  UGen in, out;
  
  void addInput(UGen inp) {
    in.addInput(inp);
  }
}