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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

              var max_accel = 0.001;
var view_range = 0.01;
var flee_factor = 0.01;

// try increasing this, see if long antennae are a good idea!
var sensor_size = 4/5; 
var min_sense = 0.01; // sensors never report zero

var max_steer = 0.1;
var base_speed = 1/200;
var min_speed = base_speed/10;

// create a field of sugar concentrations
var light = new field2D(64);
var light_old = light.clone();

// create some vehicles
var agents = [];
for (var i=0; i<40; i++) {
		pos: new vec2(random(), random()),
		vel: vec2.random(min_speed),
		size: 1/(50 + random(50))

// a sugar deposit point
var source = {
  pos: new vec2(0.5, 0.5),
	vel: vec2.random(),

// mouse moves source:
function mouse(e, pt) {

function update() {
  // apply source agent to sugar:
  light.deposit(2, source.pos);
  // and then move it (random walk):
  // update field:
  var tmp = light_old;
  light_old = light;
  light = tmp;
  // diffuse it:
  light.diffuse(light_old, 0.2);
  // nervous system:
	for (var a of agents) {
    // get agent heading:
    var dir = a.vel.angle();
    // get sensor locations:
    var sensor1 = new vec2(sensor_size, sensor_size).mul(a.size).rotate(dir).add(a.pos);
    var sensor2 = new vec2(sensor_size, -sensor_size).mul(a.size).rotate(dir).add(a.pos);
    // get the sugar levels at these locations:
		var sense1 = light.sample(sensor1);
		var sense2 = light.sample(sensor2);
    // clamp:
    sense1 = Math.max(Math.min(sense1, 1), min_sense);
    sense2 = Math.max(Math.min(sense2, 1), min_sense);
    // convert to locomotion (direct wiring):
    a.wheel1 = sense2;
    a.wheel2 = sense1;
  // implement locomotion
  for (var a of agents) {
    var speed = 1. - ((a.wheel1 + a.wheel2)/2);
    var steer = (a.wheel2 - a.wheel1) / (a.wheel1 + a.wheel2);
    // add a little random walk:
    steer += srandom()*0.1;
    // limit:
    if (speed < min_speed) { speed = min_speed; }
    if (steer > max_steer) { steer = max_steer; }
    else if (steer < -max_steer) { steer = -max_steer; }
    var newvel = a.vel.clone().rotate(steer).len(base_speed * speed);
    for (var n of agents) {
      if (a == n) continue;
      var rel = n.pos.clone().sub(a.pos).relativewrap(1);
      var distance = Math.max(0, rel.len() - a.size - n.size);
      if (distance < view_range) {
        // create a repulsion:
        var factor = 1. - (distance / view_range);
        factor = -factor;
        newvel.add(rel.clone().len(factor * flee_factor))
    // locomotion
    var acc = newvel.sub(a.vel).limit(max_accel);
function draw() {
  // draw field
  light.smooth = true;  // don't want pixels
  // draw agents
  for (var a of agents) {
    // sensor (shows current state by color)
    draw2D.color(0.7, 0.7, 0.2)
  	  .circle([sensor_size, sensor_size], 0.5)
  	  .circle([sensor_size,-sensor_size], 0.5);
  	// body
  	draw2D.rect([0., 0], 1.5, 1);
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