​

let ridx;

let row;

let cidx;

let col;

let shift;

let dir;

​

//let test = 0;

​

function preload()

{

  cp437 = loadImage( 'cp437.png' );

}

​

function next()

{

  cidx = -1;

  ridx = -1;

  shift = 0;  

​

  dir = random(1) < 0.5;

  if( random(1) < 0.5 ) {

    ridx = int( random( cp437.height ) );

    row.copy( cp437, 0, ridx, cp437.width, 1, 0, 0, cp437.width, 1 );

    row.loadPixels();

  } else {

    cidx = int( random( cp437.width ) );

    col.copy( cp437, cidx, 0, 1, cp437.height, 0, 0, 1, cp437.height );

    col.loadPixels();

  }

    /*

  cidx = test;

  ridx = -1;

   //   row.copy( cp437, 0, ridx, cp437.width, 1, 0, 0, cp437.width, 1 );

    //row.loadPixels();

 col.copy( cp437, cidx, 0, 1, cp437.height, 0, 0, 1, cp437.height );

 col.loadPixels();

  dir = false;

  ++test;

  */

}

​

function setup() {

  createCanvas(580, 256);

  cp437.filter( THRESHOLD );

  row = createImage( cp437.width, 1 );

  col = createImage( 1, cp437.height );

  next();

}

​

function draw() {

  cp437.loadPixels();

  const offs = shift * (dir?-1:1);

  if( ridx >= 0 ) {

    for( let idx = 0; idx < cp437.width; ++idx ) {

      const tq = 4*(ridx*cp437.width + (idx+offs+cp437.width)%cp437.width);

      const fq = 4*idx;

      cp437.pixels[tq] = row.pixels[fq];

      cp437.pixels[tq+1] = row.pixels[fq+1];

      cp437.pixels[tq+2] = row.pixels[fq+2];

      cp437.pixels[tq+3] = row.pixels[fq+3];

    }

  } else {

    for( let idx = 0; idx < cp437.height; ++idx ) {

      const tq = 4*(((idx+offs+cp437.height)%cp437.height)*cp437.width + cidx);

      const fq = 4*idx;

      cp437.pixels[tq] = col.pixels[fq];

      cp437.pixels[tq+1] = col.pixels[fq+1];

      cp437.pixels[tq+2] = col.pixels[fq+2];

      cp437.pixels[tq+3] = col.pixels[fq+3];

    }

  }

  cp437.updatePixels();

  image( cp437, 0, 0, 580, 256 );

  ++shift;

  if( ((ridx>=0) && (shift==9)) || ((cidx >= 0) && (shift==16)) ) {

    next();

  }

}

​

function keyPressed()

{

  if( key === "s" ) {

    save( "jan9.png" );

  }

}