// This effect Copyright (C) 2004 and later Cockos Incorporated
// License: GPL - http://www.gnu.org/licenses/gpl.html

desc: tonifier

slider1:0<-100,6,1>wet mix (dB)
slider2:-100<-100,6,1>dry mix (dB)
slider3:10<1,1000,10>block size (ms)
slider4:0<-48,48,1>freq shift (semitones)

slider5:0<0,6,1>max auto shift (octaves)
slider6:100<0,20000>auto shift min frequency (Hz)
slider7:1000<0,20000>auto shift max frequency (Hz)
slider8:0,Output frequency (Hz)

@slider
  lbsize=bsize;
  bsize=(slider3*srate*0.001)|0; 
  ibsize=1/bsize;
  sscal=2 ^ (slider4/12)*ibsize*2;
  wet=2 ^ (slider1/6)*ibsize*1.7;  // 1.7 seems about right for volume scaling
  dry=2 ^ (slider2/6);

  lbsize != bsize ? (
  bpos= 
  zccnt0=zccnt1=
  lzccnt0=lzccnt1=
  ampcnt0=ampcnt1=
  lampcnt0=lampcnt1=
  ls0=ls1=0;
  );

  maxf=slider7/srate*2; minf=slider6/srate*2;

@block
  updcnt=updcnt+samplesblock; 
  updcnt > srate*0.2 ? ( updcnt=0; slider8=(freq0+freq1)*0.25*srate; sliderchange(128); );

@sample

// count zero crossings
ts0=spl0>0;

ts0 && ls0 ? zccnt0+=1;
ls0=!ts0;

ts1=spl1>0;
ts1 && ls1 ? zccnt1+=1;
ls1=!ts1;

// count amplitude (square maybe?)
ampcnt0+=abs(spl0);
ampcnt1+=abs(spl1);

// find local amplitude and update buffer
fbpos=bsize+bsize+bpos+bpos;
acnt0=lampcnt0+ampcnt0-fbpos[0];
fbpos[0]=ampcnt0;
fbpos+=1;
acnt1=lampcnt1+ampcnt1-fbpos[0];
fbpos[0]=ampcnt1;

// find local zero crossing count and update buffer
fbpos=bpos+bpos;
lcnt0=lzccnt0+zccnt0-fbpos[0];
fbpos[0]=zccnt0;
fbpos+=1;
lcnt1=lzccnt1+zccnt1-fbpos[0];
fbpos[0]=zccnt1;

// advance buffer
bpos+=1;
bpos >= bsize ? (
    bpos=0;
    // keep ampcnt* and zccnt* in a reasonable range
    lampcnt0=ampcnt0;
    lampcnt1=ampcnt1;
    lzccnt0=zccnt0;
    lzccnt1=zccnt1;
    ampcnt0=ampcnt1=zccnt0=zccnt1=0;
);

freq0=lcnt0*sscal;
freq1=lcnt1*sscal;

loop(slider5,
  freq0 > maxf ? freq0*=0.5 : (freq0 < minf ? freq0 *= 2);
  freq1 > maxf ? freq1*=0.5 : (freq1 < minf ? freq1 *= 2);
);

tpos0=tpos0+$pi*freq0;
tpos1=tpos1+$pi*freq1;

spl0=sin(tpos0)*acnt0*wet + spl0*dry;
spl1=sin(tpos1)*acnt1*wet + spl1*dry;
