#defaults=no
#patchname=no
<?

// Delta Thing - Version 3.4

int DELTA_FROM_RANGE = 1;
int DELTA_FROM_VALUE = 2;

// delta() - returns the changed parameter value
//   v - the parameter's current value
//   vmin - the minimum of the range of v
//   vmax - the maximum of the range of v
//   dt - type of delta, either from a value chosen from the range,
//        or a value which is a percentage of the current value
//   cp - probability of there being a change, from 0.0 to 1.0
//   cb - change bias is from -1.0 to 1.0
//   sc - scaling applied to the random value/percentage
//   cm - multiple to round the change to.  Use 0.0 for no rounding
//   fm - multiple to round the final result to.  Use 0.0 for no rounding

float delta( float v, float vmin, float vmax, int dt, float cp, float cb, float sc, float cm, float fm)
{
  float r;
  float lo;
  float hi;
  float x;
  float h;
  int yi;
  float yf;

  // Assume no change to the current value
  x = v;

  // Generate a random to determine if a change will occur or not
  r = rand(0.0, 1.0);

  // If cp exists (i.e. not 0) AND random r is less than the change probability then we do the change
  if (cp > 0.0)
  {
  if (r <= cp)
  {

    // If delta is to be taken from value's min/max range...
    if (dt == DELTA_FROM_RANGE)
    {

      // Calculate the lo/hi values using the change bias
      if (cb > 0.0)
      {
        // Positive bias
        lo = (vmin - v) - ((vmin - v) * cb);
        hi = vmax - v;
      }
      else
      {
        // Negative bias
        lo = vmin - v;
        hi = (vmax - v) + ((vmax - v) * cb);
      }

    // Else the delta is based on lo/hi percentages
    }
    else
    {
      // Calculate the lo/hi values using the change bias
      if (cb > 0.0)
      {
        // Positive bias
        lo = -1.0 + cb;
        hi = 1.0;
      }
      else
      {
        // Negative bias
        lo = -1.0;
        hi = 1.0 + cb;
      }
    }

    // Generate a random scaled change amount
    r = rand(lo, hi) * sc;

    // If the change amount should be rounded to a multiple 
    if (cm > 0.0)
    {
      if (r < 0.0)
      {
        h = -0.5;
      }
      else
      {
        h = 0.5;
      }

      // Scale by cm, round, and type cast to int
      yi = ((r / cm) + h);

      // Type cast back to float
      yf = yi;

      // Unscale back by cm
      r = yf * cm;
    }

    // If delta is from value's min/max range
    if (dt == DELTA_FROM_RANGE)
    {
      // Add change amount to v
      x = v + r;

    // Else delta is a percentage of current value 
    }
    else
    {
      // Add change amount percentage of current value
      x = v + (v * r);
    }

    // If the final result should be rounded to a multiple
    if (fm > 0.0)
    {
      if (x < 0.0)
      {
        h = -0.5;
      }
      else
      {
        h = 0.5;
      }

      // Scale by fm, round, and type cast to int
      yi = ((x / fm) + h);

      // Type cast back to float
      yf = yi;

      // Unscale back by fm
      x = yf * fm;
    }

    // Although Zebra will attempt to do limits, sometimes it gets wonky, so do it here too
    if (x < vmin)
    {
      x = vmin;
    }

    if (x > vmax)
    {
      x = vmax;
    }
  }
  }

  return x;
}

// Default scaling
float s = 0.1;

// General purpose counting
int i;

for ( i = 1; i <= 4; i++ )
{
  if (Env[i].active)
  {
    Env[i].Attack = delta(Env[i].Attack, Env[i].Attack.min, Env[i].Attack.max, DELTA_FROM_RANGE, 1.0, 0.85, s, 0.0, 0.0);
    Env[i].Decay = delta(Env[i].Decay, Env[i].Decay.min, Env[i].Decay.max, DELTA_FROM_RANGE, 0.5, 0.75, s, 0.0, 0.0);
    Env[i].Release = delta(Env[i].Release, Env[i].Release.min, Env[i].Release.max, DELTA_FROM_RANGE, 0.5, 0.5, s, 0.0, 0.0);
  }
}

for ( i = 1; i <= 4; i++ )
{
  if (MSEG[i].active)
  {
    MSEG[i].Attack = delta(MSEG[i].Attack, MSEG[i].Attack.min, MSEG[i].Attack.max, DELTA_FROM_RANGE, 0.5, -0.75, s, 0.0, 0.0);
    MSEG[i].Release = delta(MSEG[i].Release, MSEG[i].Release.min, MSEG[i].Release.max, DELTA_FROM_RANGE, 0.5, -0.75, s, 0.0, 0.0);
  }
}

?>