// remix of perlin noise flow field

// by purzbeats

// https://editor.p5js.org/purzbeats/sketches/_zSaBDiBS

​

var inc = 0.06;

var scl = 20;

var cols, rows;

var zoff = 0;

​

var n = 0;

​

var fr;

​

var particles = [];

var flowfield = [];

​

function mod(a, b) {

  return a - b * floor(a / b);

}

​

function setup() {

  col1 = color(235, 212, 203);

  col2 = color(218, 159, 147);

  col3 = color(182, 70, 95);

  col4 = color(137, 6, 32);

  col5 = color(44, 7, 3);

​

  colors = [col1, col2, col3, col4, col5];

  // createCanvas(windowWidth, windowHeight);

  createCanvas(600, 600);

  cols = floor(width / scl);

  rows = floor(height / scl);

  frameRate(144);

  fr = createP('');

  background(245);

  flowfield = new Array(cols * rows);

  for (var i = 0; i < 25; i++) {

    particles[i] = new Particle(); 

    particles[i].i = i;

  }

}

​

function draw() {

  var yoff = 0;

  if (frameCount % 3 == 0)

    background(200, 1);

  if (frameCount % 3 == 0) {

  for (var y = 0; y < rows; y++) {

    var xoff = 0;

    for (var x = 0; x < cols; x++) {

      var index = x + y * cols;

      var angle = noise(xoff, yoff, zoff) * TWO_PI * 4;

      var r = noise(xoff, yoff) * 2;

      var v = p5.Vector.fromAngle(angle);

      v.setMag(0.05);

      flowfield[index] = v;

      xoff += inc;

      push();

      translate(x * scl, y * scl);

      rotate(v.heading());

      // stroke(127);

      // line(0, 0, scl, 0);

      pop();

      // noFill();

      // rect (x * scl, y * scl, scl, scl);

    }

    yoff += inc;

    zoff += 0.0006;

  }

  }

  for (var i = 0; i < particles.length; i++) {  

    particles[i].follow(flowfield);

    particles[i].update();

    particles[i].color();

    particles[i].show();

    particles[i].edges();

  }

  // fr.html(floor(frameRate()));

}