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 includes JSX processing.

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

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

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.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

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

Visit your global Editor Settings.

HTML

              
                <canvas></canvas>

<div class="hud">
  FPS: <span id="framerate">0</span><br>
  Particles: <span id="particles">0</span>
</div>
              
            
!

CSS

              
                html, body {
  height: 100%;  
}

body {
  background: #000;
  overflow: hidden;
}

canvas {
  background: #000;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 0;
}

.hud {  
  position: absolute;
  top: 0;
  left: 0;  
  font-family: "Lucida Console", Monaco, monospace;
  letter-spacing: 1px;
  line-height: 1.6;
  color: #eee;
  font-size: 10px;
  padding: 4px 8px;
  background: rgba(0,0,0,0.3);
  pointer-events: none;
  user-select: none;
}
              
            
!

JS

              
                // Inspired by Pixi particles
// https://github.com/pixijs/pixi-particles


var total = 2000;
var spawnWave = 3;
var spawnFreq = 0.0013;
var colorStep = 0.15;
var fade = "rgba(0,0,0,0.4)";

var canvas  = document.querySelector("canvas");
var context = canvas.getContext("2d");
var ticker  = TweenLite.ticker;

var vw = canvas.width  = window.innerWidth;
var vh = canvas.height = window.innerHeight;

var xPos  = vw / 2;
var yPos  = vh / 2;
var prevX = xPos;
var prevY = yPos;
var emitX = 0;
var emitY = 0;

var hue = 0;
var lastTime = 0;
var spawnTimer = 0;

var particles = new LinkedList();
var pool = new LinkedList();

// Stat usage
var $framerate = document.querySelector("#framerate");
var $particles = document.querySelector("#particles");
var prevTime = 0;
var frames = 0;

function init() {
  
  var i = total;
  while (i--) {    
    pool.add(new Particle());
  }
    
  lastTime = ticker.time;
  
  document.addEventListener("mouseenter", enterAction);
  window.addEventListener("resize", resizeAction);
  window.addEventListener("mousemove", mouseAction);
  window.addEventListener("touchmove", touchAction);
  ticker.addEventListener("tick", update);  
}

//
// PARTICLE
// ===========================================================================
class Particle {
  
  constructor() {
       
    this.prev = null;
    this.next = null;
        
    this.alpha = random(0.8, 1);     
    this.brightness = random(70, 80);
    this.friction = random(0.98, 1);
    this.gravity = random(0.03, 0.07);    
    this.hue = 0;   
    this.size = 2;
    this.time = random(0.7, 1.1);     
    this.vx = this._vx = random(-1.75, 1.75);
    this.vy = this._vy = random(-1.5, 1.5);
    this.x = 0;
    this.y = 0;
    
    this.animation = new TimelineLite({
      paused: true,
      onComplete: () => {
        pool.add(particles.remove(this));
      }
    });
      
    this.animation.to(this, this.time, {      
      alpha: 0.5,      
      brightness: 50,
      x: random(-5, 5),   
      y: random(-50, 50),     
      ease: Linear.easeNone,      
      modifiers: {
        x: x => {
          this.spawnX += this.vx;
          return this.spawnX + x;          
        },
        y: y => {
          this.vy += this.gravity;            
          this.spawnY += this.vy;
          return this.spawnY + y;
        }
      }
    });    
  }
  
  spawn(x, y, hue, startTime) {
    
    var norm = 1 - startTime / this.time;
    
    this.vx = this._vx;
    this.vy = this._vy;
    this.vy += this.gravity * norm;
    
    this.spawnX = x + this.vx;
    this.spawnY = y + this.vy;  
    
    this.hue = hue;
    this.animation.play(startTime);
  }  
}

//
// UPDATE
// ===========================================================================
function update() {
   
  context.fillStyle = fade;
  context.fillRect(0, 0, vw, vh);
  
  var p = particles.first;
  while (p) {
    context.fillStyle = `hsla(${p.hue}, 100%, ${p.brightness}%, ${p.alpha})`;
    context.fillRect(p.x, p.y, p.size, p.size);
    p = p.next;
  }
  
  var current = ticker.time;
  var delta = current - lastTime;
  spawnTimer -= delta;
    
  // Spawn particles based on frequency and amount of time
  // that has passed since the last update
  while (spawnTimer <= 0) {
    
    spawnTimer += spawnFreq;        
    hue += colorStep;
    
    // Interpolate position
    var norm = 1 + spawnTimer / delta;
    emitX = prevX + (xPos - prevX) * norm;
    emitY = prevY + (yPos - prevY) * norm; 
            
    var i = spawnWave;    
    while (i--) {
      
      if (!pool.size) continue;
      
      var color = random(hue, hue + 30) % 360;    
      
      var particle = particles.add(pool.remove(pool.first));
      particle.spawn(emitX, emitY, color >> 0, -spawnTimer);      
    }
  }
    
  frames++;
  
  // Update stats every second
  if (current > prevTime + 1) {
    $framerate.textContent = frames / (current - prevTime) + 0.5 >> 0;
    $particles.textContent = particles.size;
    prevTime = current;
    frames = 0;
  }
    
  lastTime = current;
  prevX = xPos;
  prevY = yPos;
}

function touchAction(event) {
  event.preventDefault();
  xPos = event.targetTouches[0].clientX;
  yPos = event.targetTouches[0].clientY;
}

function mouseAction(event) {
  xPos = event.clientX;
  yPos = event.clientY;
}

function resizeAction() {
  vw = canvas.width  = window.innerWidth;
  vh = canvas.height = window.innerHeight;
}

function enterAction(event) {
  prevX = event.clientX;
  prevY = event.clientY;
}

function random(min, max) {
  if (max == null) { max = min; min = 0; }
  return Math.random() * (max - min) + min;
}

init();



              
            
!
999px

Console