Pen Settings

HTML

CSS

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

JavaScript

Babel is required to process package imports. If you need a different preprocessor remove all packages first.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Behavior

Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.

HTML Settings

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.

HTML

              
                
              
            
!

CSS

              
                body
  background: #000
  margin: 0
  overflow: hidden
              
            
!

JS

              
                var canvas,
		c;
var	screenWidth = window.innerWidth;
var screenHeight = window.innerHeight;
var screenMin = (screenWidth < screenHeight) ? screenWidth : screenHeight;

let tiles, edges, crawlers, deadCrawlers;
let columns, rows;
let size, lineWidth;
let done = false;

const showGrid = false;

const setupSettings = function() {
  console.clear();

  tiles = [];
  edges = [];
  crawlers = [];
  deadCrawlers = 0;
  size = 20 + Math.random() * 20;
  lineWidth = size * (0.6 + Math.random()*0.2);
  columns = Math.ceil(screenWidth / size) - 1;
  rows = Math.ceil(screenHeight / size) - 1;
  done = false;
}


const setup = function() {
  frameRate = 30;
  setupSettings();
  setupCanvas();
  
  c.translate((screenWidth - columns*size)/2,
              (screenHeight - rows*size)/2);
  
  setupTiles(columns, rows);
  
  const start = tiles[Math.floor(Math.random() * columns)][Math.floor(Math.random() * rows)];
  huntAndKill(start);
  startCrawlers(start);
  
	draw();
}


const setupCanvas = function() {
  canvas = document.createElement('canvas');
  c = canvas.getContext('2d');
  canvas.width = screenWidth;
  canvas.height = screenHeight;
  document.body.appendChild(canvas);
  c.lineJoin = 'round';
  c.strokeStyle = hsl(200, 90, 50);
}


const setupTiles = function(columns, rows) {
  // initialise 2D array of tiles
  for (let x = 0; x < columns; x++) {
    tiles.push([]);
    for (let y = 0; y < rows; y++) {
      tiles[x].push(new Tile(x, y));
    }
  }
  // initialise 2D array of edges
  for (let x = 0; x <= columns * 2 + 1; x++) {
    edges.push([]);
    for (let y = 0; y <= rows; y++) {
      edges[x].push(new Edge(x, y));
    }
  }
  // neighbouring needs to be done after they're all initialised
  for (let x = 0; x < columns; x++) {
    for (let y = 0; y < rows; y++) {
      tiles[x][y].initialiseNeighbours(x, y);
    }
  }
}


const reset = function() {
  c.clearRect(0, 0, columns*size, rows*size);
  setupSettings();
  setupTiles(columns, rows);
  
  const start = tiles[Math.floor(Math.random() * columns)][Math.floor(Math.random() * rows)];
  huntAndKill(start);
  startCrawlers(start);
}


const huntAndKill = function(tile) {
  let startTile = tile;
  while (startTile != false) {
    kill(startTile);
    startTile = hunt();
  }
  
  // reset activity of tiles
  for (let x = 0; x < columns; x++) {
    for (let y = 0; y < rows; y++) {
      tiles[x][y].active = false;
    }
  }
}

const kill = function(tile) {
  let curTile = tile;
  curTile.activate();
  // remove an active edge
  let prev = curTile.getActiveNeighbour();
  let prevEdge = curTile.edges[prev];
  if (prevEdge) prevEdge.deactivate();
  // find a next tile
  let next = curTile.getRandomInactiveNeighbour();
  let nextTile = curTile.neighbours[next];
  while (nextTile != undefined) {
    nextTile.activate();
    curTile.edges[next].deactivate();
    curTile = nextTile;
    next = curTile.getRandomInactiveNeighbour();
    nextTile = curTile.neighbours[next];
  }
}

const hunt = function() {
  for (let x = 0; x < columns; x++) {
    for (let y = 0; y < rows; y++) {
      let tile = tiles[x][y];
      let maxNeighbours = 4;
      if (x == 0 || x == columns-1) maxNeighbours--;
      if (y == 0 || y == rows-1) maxNeighbours--;
      if (!tile.active && tile.countInactiveNeighbours() < maxNeighbours) {
        return tile;
      }
    }
  }
  return false;
}


const startCrawlers = function(start) {
  let startTile = start;
  for (let i = 0; i < 4; i++) {
    if (!startTile.edges[i].active) {
      crawlers.push(new Crawler(startTile, startTile.neighbours[i]));
    }
  }
}


const draw = function() {
  c.lineWidth = 5;
  // for (let x = 0; x < columns; x++) {
  //   for (let y = 0; y < rows; y++) {
  //     let tile = tiles[x][y];
  //     if (tile && tile.active) {
  //       tile.draw();
  //     }
  //   }
  // }
  if (showGrid) {
    for (let x = 0; x <= columns * 2 + 1; x++) {
      for (let y = 0; y <= rows; y++) {
        let edge = edges[x][y];
        if (edge && edge.active) {
          edge.draw();
        }
      }
    }
  }
  
  for (let i = 0; i < crawlers.length; i++) {
    crawlers[i].update();
    crawlers[i].draw();
  }
  
  // refresh after a second
  if (deadCrawlers == crawlers.length) {
    if (!done) {
      setTimeout(reset, 3000);
      done = true;
    }
  }
  
  if (done) {
    c.fillStyle = rgba(0, 0, 0, 0.025);
    c.fillRect(0, 0, columns*size, rows*size);
  }
}


class Crawler {
  constructor(cur, next, hsl) {
    this.hsl = hsl || [210.0, 90.0, 60.0];
    this.cur = cur;
    this.next = next;
    this.active = true;
    this.draw();
  }
  
  update() {
    if (!this.active) {
      return;
    }
    if (!this.next) {
      this.kill();
      return;
    }
    
    this.cur.active = true;
    
    let edge = this.cur.getEdge(this.next);
    var changed = false;
    
    for (let i = 0; i < 4; i++) {
      // if it's not current and not the previous edge
      if (!this.next.edges[i].active && !this.next.neighbours[i].active) {
        if (changed !== false) {
          // add new crawler
          crawlers.push(new Crawler(this.next, this.next.neighbours[i], this.hsl));
        } else {
          // update current crawler
          changed = i;
        }
      }
    }
    
    // if there aren't any neighbours kill the crawler
    if (changed === false) {
      this.kill();
    } else {
      this.cur = this.next;
      this.next = this.next.neighbours[changed];
    }
    
    // update colours
    this.hsl[0] = clamp(this.hsl[0]+(Math.random()-0.5), 190, 230);
    this.hsl[1] = clamp(this.hsl[1]+(Math.random()-0.5)*3, 60, 100);
    this.hsl[2] = clamp(this.hsl[2]+(Math.random()-0.5)*4, 30, 60);
  }
  
  draw() {
    if (this.active) {
      c.lineWidth = lineWidth;
      c.strokeStyle = hsl(this.hsl[0], this.hsl[1], this.hsl[2]);
      c.beginPath();
      c.moveTo(this.cur.x*size + size*0.5, this.cur.y*size + size*0.5);
      c.lineTo(this.next.x*size + size*0.5, this.next.y*size + size*0.5);
      c.closePath();
      c.stroke();
    }
  }
  
  kill() {
    this.active = false;
    deadCrawlers++;
  }
}


class Edge {
  constructor(x, y) {
    this.vert = false;
    if (x % 2 == 0) this.vert = true;
    
    this.x = Math.floor(x / 2);
    this.y = y;
    this.active = true;
    
    // disable off the edges
    if (x == columns*2) this.active = false;
    if (y == rows && x % 2) this.active = false;
  }
  
  deactivate() {
    this.active = false;
  }
  
  draw() {
    c.strokeStyle = '#333';
    c.beginPath();
    c.moveTo(this.x*size, this.y*size);
    if (this.vert) {
      c.lineTo((this.x+1)*size, this.y*size);
    }
    else {
      c.lineTo(this.x*size, (this.y+1)*size);
    }
    c.closePath();
    c.stroke();
  }
}


class Tile {
  constructor(x, y) {
    this.x = x;
    this.y = y;
    
    // establish neighbours
    this.neighbours = [];
    this.edges = [];
    
    this.active = false;
  }
  
  initialiseNeighbours(x, y) {
    // initialise neighbours called after all hexagons are constructed
    // because otherwise the hexagons array isn't full yet
    // lots of conditionals to allow for edge hexagons
    
    // start with array of falses for neighbours
    // and empty for edges
    let e = [false, false, false, false];
    let n = [false, false, false, false];
    
    // north
    if (y > 0) {
      n[0] = tiles[x][y-1];
      e[0] = edges[x*2][y];
    }
    
    // east
    if (x < columns - 1) {
      n[1] = tiles[x+1][y];
      e[1] = edges[x*2+3][y];
    }

    // south
    if (y < rows - 1) {
      n[2] = tiles[x][y+1];
      e[2] = edges[x*2][y+1];
    }
    
    // west
    if (x > 0) {
      n[3] = tiles[x-1][y];
      e[3] = edges[x*2+1][y];
    }

    this.neighbours = n;
    this.edges = e;
  }
  
  update() {
  }
  
  draw() {
    c.fillRect(this.x*size, this.y*size, size, size);
  }
  
  activate() {
    this.active = true;
  }
  
  countInactiveNeighbours() {
    // returns number of inactive neighbours
    let inactiveNeighbours = 0;
    for (let i = 0; i < 4; i++) {
      if (this.neighbours[i] && !this.neighbours[i].active) {
        inactiveNeighbours++;
      }
    }
    return inactiveNeighbours;
  }
  
  getInactiveNeighbours() {
    // returns array of booleans for inactive neighbours
    let inactiveNeighbours = [];
    for (let i = 0; i < 4; i++) {
      // if neighbour exists and is inactive
      if (this.neighbours[i] && !this.neighbours[i].active) {
        inactiveNeighbours.push(true);
      } else {
        inactiveNeighbours.push(false);
      }
    }
    return inactiveNeighbours;
  }
  
  getRandomInactiveNeighbour() {
    let count = this.countInactiveNeighbours();
    if (count == 0) return false;
    let choice = Math.floor(Math.random() * count);
    let inactives = this.getInactiveNeighbours();
    let through = 0;
    for (let i = 0; i < 4; i++) {
      if (inactives[i]) {
        if (through == choice) {
          return i;
        }
        through++;
      }
    }
  }
  
  getActiveNeighbour() {
    for (let i = 0; i < 4; i++) {
      if (this.neighbours[i].active) {
        return i;
      }
    }
  }
  
  getEdge(neighbour) {
    if (!neighbour) return false;
    let diffX = this.x - neighbour.x;
    let diffY = this.y - neighbour.y;
    if (diffX == 1) {
      return this.edges[3];
    }
    else if (diffX == -1) {
      return this.edges[1];
    }
    else if (diffY == 1) {
      return this.edges[2];
    }
    else if (diffY == -1) {
      return this.edges[0];
    }
    return false;
  }
}









function rgba(r, g, b, a) { return 'rgba('+clamp(r,0,255)+', '+clamp(g,0,255)+', '+clamp(b,0,255)+', '+clamp(a,0,1)+')';};
function hsl(h, s, l) { return 'hsl('+h+', '+clamp(s,0,100)+'%, '+clamp(l,0,100)+'%)';};
function hsla(h, s, l, a) { return 'hsla('+h+', '+clamp(s,0,100)+'%, '+clamp(l,0,100)+'%, '+clamp(a,0,1)+')';};

function clamp(value, min, max) { 
	if (max < min) {
		var temp = min;
		min = max;
		max = temp;
	}
	return Math.max(min, Math.min(value, max)); 
};




// IGNORE FROM HERE
//=====================================


var mouseX = 0,
	mouseY = 0,
	lastMouseX = 0,
	lastMouseY = 0,
	frameRate = 60,
	lastUpdate = Date.now(),
	mouseDown = false;

function cjsloop() {

	var now = Date.now();
	var elapsedMils = now - lastUpdate;


	if (elapsedMils>=(1000/window.frameRate)) {
		draw();

		lastUpdate = now - elapsedMils % (1000/window.frameRate );
		lastMouseX = mouseX;
		lastMouseY = mouseY;
	}

	requestAnimationFrame(cjsloop);

};


// requestAnimationFrame
// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating

// requestAnimationFrame polyfill by Erik Möller
// fixes from Paul Irish and Tino Zijdel

(function() {
    var lastTime = 0;
    var vendors = ['ms', 'moz', 'webkit', 'o'];
    for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
        window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
        window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame']
                                   || window[vendors[x]+'CancelRequestAnimationFrame'];
    }

    if (!window.requestAnimationFrame)
        window.requestAnimationFrame = function(callback, element) {
            var currTime = new Date().getTime();
            var timeToCall = Math.max(0, 16 - (currTime - lastTime));
            var id = window.setTimeout(function() { callback(currTime + timeToCall); },
              timeToCall);
            lastTime = currTime + timeToCall;
            return id;
        };

    if (!window.cancelAnimationFrame)
        window.cancelAnimationFrame = function(id) {
            clearTimeout(id);
        };
}());


window.addEventListener('load',init);

function init() {

  setup();
	cjsloop();

}

              
            
!
999px

Console