/*
JSFX Name: AB Comparison
Author: RCJacH
Release Date: Jan 2017
Link: https://github.com/RCJacH/ReaScripts
Version: 1.1
Reference: 
  Jonas Eriksson BeatFinder JSFX
  Audio Vitamin Contra
About:
  This JSFX alternates between signals from different channels for objective
  comparison purposes.
  
  Instruction:
    1. Set different comparing items to sequential stereo channels.
    2. Set **# of Inputs** to number of stereo channels to compare.
    3. Set desired switching beat length using **Switch Beat length**.
      Alternatively, set **Millisecond Mode** to > 0 for switching based on time
    4. Set switching mode using **Mode**:
      Manual = Switch by pressing channel trigger;
      Sequential = Switch to the next channel;
      Random = Switch to a random different channel;
      Guess = Switch to a random channel, press trigger to show answer.
    **Output Channel Display**s the current output channel.
Changelog:
 * v1.1 (2017-01-19)
  + Millisecond Mode.
  + Beat Mode works while not playing.
  + Guess Mode added Answer Display Time.
  + Limitation for user input.
  + Default channel initialization.
  # Triggers in Sequential/Random Mode changes to Manual Mode.
  # Clicking on time-line do not reset to output 1-2.
  # Guess Mode switches by triggering, rather than time.
 * v1.0 (2017-01-19)
  + Initial Release
*/

// Licensed under the GNU GPL - http://www.gnu.org/licenses/gpl.html

desc: AB Comparison

slider1: 2<1,8,1> # of Inputs
slider2: 8<1,16,1> Switch Beat Length
slider3: 0<0,5000,10> Millisecond Mode (when > 0)

slider6: 0<0,2,1{Manual,Sequential,Random,Guessing}> Mode
slider7: 2<0.5,5,0.1> Answer Displaying Time (s)

slider11: 0<0,8,1{1-2,3-4,5-6,7-8,9-10,11-12,13-14,15-16,Guess}> Output Channel Display
slider12: 0<0,8,1> -_OutCh

in_pin:input 1 L
in_pin:input 1 R
in_pin:input 2 L
in_pin:input 2 R
in_pin:input 3 L
in_pin:input 3 R
in_pin:input 4 L
in_pin:input 4 R
in_pin:input 5 L
in_pin:input 5 R
in_pin:input 6 L
in_pin:input 6 R
in_pin:input 7 L
in_pin:input 7 R
in_pin:input 8 L
in_pin:input 8 R
out_pin:output L
out_pin:output R

@init
i_diff = 0;
i_result = 0;
i_answerTime = 0;
msCnt = 0;

@slider
i_maxchs = max(1, min(8, slider1));
i_beats = max(1, min(16, slider2));
i_ms =  max(0, slider3 * srate * 0.001);
mode = slider6;
msCnt = 0;

//Disable User Selection of *OutChannel*
slider11 = i_result = mode == 3 ? 8 : slider12;

@block

beats_per_sample = ( tempo / 60 ) / srate;
offset = 0;

// Switch automatically only in sequential/random mode
mode > 0 && mode < 3 ? (
  // Check whether in millisecond mode or beat mode
  i_ms ? ( // ms Mode
    // Calculate the samplesblock approaching next switch
    msCnt += samplesblock;
    i_diff = msCnt + samplesblock >= i_ms ? i_ms - msCnt : 0;
    msCnt > i_ms ? msCnt = 0;
    // i_diff = how many samples left until next beat
  ) : ( // Beat Mode
    //WhyAddThis is Jonas's magic number.
    WhyAddThis = 0.97902 / (srate * ( 60 / tempo ) );
    // Transport Playing
    play_state & 1 ? (
      // Calculate the samplesblock approaching next switch
      curBeat = beat_position;
      nextBeat = ceil(curBeat);
      bp = (curBeat + beats_per_sample * samplesblock);
      i_diff = curBeat % i_beats == i_beats - 1 &&
        bp >= nextBeat ? nextBeat - curBeat : 0;
    ) : (
      msCnt += samplesblock * beats_per_sample;
      i_diff = msCnt + samplesblock * beats_per_sample >= i_beats ?
        i_beats - msCnt : 0;
      msCnt > i_beats ? msCnt = 0;
    );
    // i_diff = how many beats left until next beat.
  );  
);

// When a trigger button is pressed
trigger ? (
  // In Sequential/Random Mode, change to Manual Mode
  // In Manual Mode, switch output directly.
  mode < 3 ? (
    mode ? slider6 = mode = 0;
    // Get button number
    i_trig = log10(trigger)/ log10(2);
    slider11 = slider12 = i_trig;
  );
  // In Guess Mode, press any trigger to reveal answer.
  mode == 3 ? (
    slider12 = floor(rand(i_maxchs - 1) + 0.5);
    slider11 = i_result = slider12;
    i_answerTime = slider7 * srate;
  );
  trigger = 0;
);

// When an answer is shown in Guess Mode
i_answerTime ? (
  // Check to see when to conceal *Output* to "Guess".
  i_answerTime = i_answerTime > 0 ? i_answerTime - samplesblock : 0;
  !i_answerTime ? slider11 = i_result = 8;
);

@sample
// Only calculate samples when beat changes within a samplesblock.
i_diff ? (
  (i_ms && i_diff - offset == 0) ||
  (!i_ms && i_diff - WhyAddThis - offset * beats_per_sample <= 0) ? (
    mode == 1 ? (
      // Sequential Mode adds one to output.
      slider12 = (slider12 + 1) % i_maxchs;
    ):(
      // Random Mode generate a random and different output.
      while (i = floor(rand(i_maxchs - 1) + 0.5); i == slider12; );
      slider12 = i;
    );
    slider11 = i_result = slider12;
    i_diff = 0;
  );
  offset += 1;
);

spl0 = spl(slider12 * 2);
spl1 = spl(slider12 * 2 + 1);