startv

Pen Settings

CSS Base

Vendor Prefixing

Add External CSS

These stylesheets will be added in this order and before the code you write in the CSS editor. You can also add another Pen here, and it will pull the CSS from it. Try typing "font" or "ribbon" below.

Quick-add: + add another resource
via CSS Lint

Add External JavaScript

These scripts will run in this order and before the code in the JavaScript editor. You can also link to another Pen here, and it will run the JavaScript from it. Also try typing the name of any popular library.

Quick-add: + add another resource
via JS Hint

Code Indentation

     

Save Automatically?

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

Want a Run Button?

If active, the preview will update automatically when you change code.

HTML

            
              <div class="content">
  <canvas id="canvas"></canvas><br/>
  <input type="text" maxlength="7"/>
</div>
            
          
!

CSS

            
              body, html {
    background-color: #3c3c3c;
    color: #fff;
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
}
.content {
    position:absolute;
    margin-left : 50%;
    left: -380px;
}
            
          
!

JS

            
              "use strict";
(function () {
  var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
  window.requestAnimationFrame = requestAnimationFrame;
})();


var canvas = document.getElementById("canvas"),
    shapeCan = document.createElement("canvas"),
    metaCanvas = document.createElement("canvas"),
    ctx = canvas.getContext("2d"),
    sCtx = shapeCan.getContext("2d"),
    metaCtx = metaCanvas.getContext("2d"),
    input = document.getElementsByTagName("input")[0],
    width = 700,
    height = 200,
    mouseX = 0,
    mouseY = 0,
    threshold = 230,
    cycle = 0;

var demo = {
  timePassed : 0,
  lastTime : 0,
  waitTime : 0,
  nextStringWait : 1000,
  curText : "",
  textList : ["Loktars","Slime", "Text", "Yummy!"],
  curIndex : 0
};

var settings = {
  Color: {
    r: 0,
    g: 255,
    b: 0
  },
  CycleColors : false
},
    gui = new dat.GUI();

gui.addColor(settings, 'Color');
gui.add(settings, 'CycleColors');


canvas.width = metaCanvas.width = width;
canvas.height = metaCanvas.height = height;

shapeCan.width = 300;
shapeCan.height = 100;
sCtx.font = '3em Arial';

/*
		 *	Controls the emitter
		 */
function Emitter() {
  this.particles = [];
  this.shapeData = [];
  this.orphans = [];
  
  this.startTime = new Date().getTime();
  this.checkInterval = 200;
}

Emitter.prototype.update = function () {
  var partLen = this.particles.length;
  
  for (var i = 0; i < partLen; i++) {
    var particle = this.particles[i];
    if (particle) {
      particle.update();
    }
  }
  
}

Emitter.prototype.getShape = function () {
  var text = input.value;
  
  if(document.activeElement.tagName !== "INPUT"){
    inactiveDemo();
  }
  
  sCtx.clearRect(0, 0, shapeCan.width, shapeCan.height);
  sCtx.fillText(text, 10, 30);
  
  var imageData = sCtx.getImageData(0, 0, shapeCan.width, shapeCan.height).data;
  
  for(var i = 0; i < this.particles.length; i++){
    var x = this.particles[i].ox,
        y = this.particles[i].oy;
    
    if(imageData[((shapeCan.width * y + x)*4)+3] < 1){
      this.shapeData[(shapeCan.width * y + x)*4] = false;
      
      this.particles[i].ox = -100;
      this.particles[i].oy = -100;
      this.particles[i].tx += 50 - Math.random()*100;
      this.particles[i].ty += 50 - Math.random()*100;
      this.orphans.push(this.particles[i]);
    }
    
  }
  
  
  for (var i = 0; i < imageData.length; i += 8 ) {
    var x = i / 4 % shapeCan.width,
        y = (i / 4 - x) / shapeCan.width;
    
    if (imageData[i + 3] > 0) {
      if(this.shapeData[i] == false){
        if(this.orphans.length > 0){
          var part = this.orphans[0];
          
          part.ox = x;
          part.oy = y;
          part.tx = x*5;
          part.ty = y*5;
          
          this.orphans.splice(0,1);
        }else{
          var particle = new Particle({
            ox: x,
            oy: y,
            tx : x*5,
            ty : y*5
          });
          this.particles.push(particle);
        }
      }
      this.shapeData[i] = true;
    }else{
      this.startLife = new Date().getTime();
      this.shapeData[i] = false;
    }
  }
}

Emitter.prototype.render = function () {
  if (new Date().getTime() > this.startTime + this.checkInterval) {
    this.startTime = new Date().getTime();
    this.getShape();
  }
  
  metaCtx.clearRect(0,0,metaCanvas.width, metaCanvas.height);
  
  var partLen = this.particles.length,
      r = ~~settings.Color.r,
      g = ~~settings.Color.g,
      b = ~~settings.Color.b;
  
  while(partLen--){
    var particle = this.particles[partLen];
    metaCtx.beginPath();
    
    var grad = metaCtx.createRadialGradient(particle.x, particle.y, 1, particle.x, particle.y, particle.size);
    grad.addColorStop(0, "rgba(" + r + "," + g + "," + b + ",1)");
    grad.addColorStop(1, "rgba(" + r + "," + g + "," + b + ",0)");
    metaCtx.fillStyle = grad;
    
    metaCtx.arc(particle.x, particle.y, particle.size, 0, Math.PI*2);
    metaCtx.fill();
  }
  
  
  for(var i = 0; i < this.orphans.length; i++){
    var orphan = this.orphans[i];
    
    if(orphan.y < canvas.height){
      orphan.ty += orphan.speed;
    }
  }		    
  
  if(settings.CycleColors){
    colorCycle();
  }
  metabalize();
  
  for (var i in gui.__controllers) {
    gui.__controllers[i].updateDisplay();
  }
}


/*
		 *	Controls the individual particles
		 */
    function Particle(options) {
      options = options || {};
      this.ox = options.ox;
      this.oy = options.oy;
      
      this.x = this.ox*5;
      this.y = 0;
      
      this.tx = options.tx;
      this.ty = options.ty;
      
      this.size = (Math.random()*10)+8;
      this.speed = Math.random()*1 + 0.5;
      
      this.startLife = new Date().getTime();
      this.lifeTime = new Date().getTime() - this.startLife;
      
      this.vx = 0;
      this.vy = 0;
      
      this.render = true;
    }

Particle.prototype.update = function () {
  var tx = this.tx - this.x,
      ty = this.ty - this.y,
      dist = Math.sqrt(tx*tx+ty*ty),
      rad = Math.atan2(ty,tx);
  
  this.vx += (Math.cos(rad))*(this.speed*10);
  this.vy += (Math.sin(rad))*(this.speed*10);
  
  if(dist < 5){
    this.vx*=0.2;
    this.vy*=0.2;
  }else{
    this.vx*=0.4;
    this.vy*=0.4;
  }
  
  this.x += this.vx;
  this.y += this.vy;
}

function metabalize(){
  var imageData = metaCtx.getImageData(0,0,width,height),
      pix = imageData.data;
  
  for (var i = 0, n = pix.length; i <n; i += 4) {
    if(pix[i+3]<threshold){
      pix[i+3]/=6;
      if(pix[i+3]>threshold/4){
        pix[i+3]=0;
      }
    }
  }
  ctx.putImageData(imageData, 0, 0);    
}

function colorCycle(){
  cycle+=0.1;
  
  if(cycle>100){
    cycle = 0;   
  }
  settings.Color.r = ~~(Math.sin(.3*cycle + 0) * 127+ 128);
  settings.Color.g =  ~~(Math.sin(.3*cycle + 2) * 127+ 128);
  settings.Color.b = ~~( Math.sin(.3*cycle + 4) * 127+ 128);
}

function inactiveDemo(){
  // this whole func is a hack.. just added to do something w/o needing interaction
  demo.timePassed = new Date().getTime() - demo.lastTime;
  
  if(demo.timePassed > demo.nextStringWait){
    var lastTime = demo.lastTime;
    
    demo.lastTime = new Date().getTime();
    
    if(lastTime == 0){
      demo.waitTime = 0;
      demo.nextStringWait = 2000;
    }else{
      demo.nextStringWait = 8000;
      demo.waitTime = demo.lastTime + 3000;
    }
    
    demo.curText = demo.textList[demo.curIndex];
    demo.curIndex++;
    
    if(demo.curIndex >= demo.textList.length){
      demo.curIndex = 0;
    }
  }
  
  if(new Date().getTime() > demo.waitTime){
    input.value = demo.curText;
  }else{
    var str = input.value.split('');
    str.pop();
    input.value = str.join('');
  }
  
}

function render() {
  emitter.update();
  emitter.render();
  requestAnimationFrame(render);
}

var emitter = new Emitter();
render();


            
          
!
999px
Loading ..................

Console