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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.

HTML

            
              <canvas id='scene'></canvas>
            
          
!

CSS

            
              body,html {
  margin:0;
  padding:0;
}
canvas {
  div { background-color: rgba(0,0,0,0); }
  -webkit-touch-callout:none;
  -webkit-user-select:none;
  user-select:none;
}
#scene {
  background-color: black;
  -webkit-touch-callout:none;
  -webkit-user-select:none;
  user-select:none;
}

            
          
!

JS

            
              //******************************************************
// Yet Another Particle Engine
var cos = Math.cos,
    sin = Math.sin,
    sqrt = Math.sqrt,
    abs = Math.abs,
    atan2 = Math.atan2,
    log = Math.log,
    random = Math.random,
    PI = Math.PI,
    sqr = function(v){return v*v;},
    particles = [],
    drawScale = 1,
    emitters = [],
    forces  = [],
    collidedMass = 0,
    maxParticles = 100,
    emissionRate = 1;

//-------------------------------------------------------
// Vectors, and not the kind you put stuff in
function Vector(x, y, z) {
  this.x = x || 0;
  this.y = y || 0;
  this.z = z || 0;
}
Vector.prototype = {
  add : function(vector) {
    this.x += vector.x;
    this.y += vector.y;
    this.z += vector.z;
    return this;
  },
  subtract : function(vector) {
    this.x -= vector.x;
    this.y -= vector.y;
    this.z -= vector.z;
    return this;
  },
  multiply : function(another) {
    this.x /= another.x;
    this.y /= another.y;
    this.z /= another.z;
    return this;
  },
  divide : function(another) {
    this.x /= another.x;
    this.y /= another.y;
    this.z /= another.z;
    return this;
  },
  scale : function(factor) {
    this.x *= factor;
    this.y *= factor;  
    this.z *= factor;  
    return this;      
  },
  magnitude : function () {
    return sqrt(sqr(this.x + this.y));
  },
  distance : function (another) {
    return abs(sqrt(sqr(this.x - another.x) + sqr(this.y - another.y)));
  },
  angle : function (angle, magnitude) {
    if(angle && magnitude)
      return Vector.fromAngle(angle, magnitude);
    return atan2(this.y, this.x);
  },
  clone : function() {
    return new Vector(this.x, this.y, this.z);
  },
  equals : function(another) {
    return this.x === another.x 
        && this.y === another.y
        && this.z === another.z;
  },
  random : function(r) {
    this.x += (random() * r * 2) - r;
    this.y += (random() * r * 2) - r;
    return this;
  }
};
Vector.fromAngle = function (angle, magnitude) {
  return new Vector(
    magnitude * cos(angle), 
    magnitude * sin(angle),
    magnitude * sin(angle));
};

//******************************************************
// A thing with mass, position, and velocity - like your mom
function Particle(pt, vc, ac, mass) {
  this.pos = pt || new Vector(0, 0);
  this.vc = vc || new Vector(0, 0);
  this.ac = ac || new Vector(0, 0);
  this.mass = mass || 1;
  this.alive = true;
}
Particle.prototype.move = function () {
  this.vc.add(this.ac);
  this.pos.add(this.vc);
};
Particle.prototype.reactToForces = function (fields) {
  var totalAccelerationX = 0;
  var totalAccelerationY = 0;
  
  for (var i = 0; i < fields.length; i++) {
    var field = fields[i];
    var vectorX = field.pos.x - this.pos.x;
    var vectorY = field.pos.y - this.pos.y;
    var distance = this.pos.distance(field.pos);
    if(distance < 1) field.grow(this);
    if(distance < 100) this.doubleSize = true;
    var force = G(this.forceBetween(field, distance));
    totalAccelerationX += vectorX * force;
    totalAccelerationY += vectorY * force;
  }
  this.ac = new Vector(totalAccelerationX, totalAccelerationY);
  
  totalAccelerationX = 0;
  totalAccelerationY = 0;
  for (var i = 0; i < particles.length; i++) {
    var field = particles[i];
    if(field === this || !field.alive) continue;
    var vectorX = field.pos.x - this.pos.x;
    var vectorY = field.pos.y - this.pos.y;
    var distance = this.pos.distance(field.pos);
    if(distance < 1) {
      if(this.mass >= field.mass) {
        var massRatio = this.mass / field.mass;
        if(particles.length <= maxParticles && this.mass>40) {
          this.alive = false;
          this.nova = true;
          collidedMass += this.mass;
        } else this.grow(field);
      } else this.alive = false;
    }
    if(this.alive) {
      var force = G(this.forceBetween(field, distance));
      totalAccelerationX += vectorX * G(force);
      totalAccelerationY += vectorY * G(force);
    }
  }

  var travelDist = this.pos.distance(this.lastPos ? this.lastPos : this.pos);
  this.velocity = travelDist - (this.lastDistance ? this.lastDistance : travelDist);
  this.lastDistance = travelDist;
  this.lastPos = this.pos.clone();

  this.ac.add(new Vector(totalAccelerationX, totalAccelerationY));
  this.lastPos = this.pos.clone();
  // if(this.mass > 20) {
  //   var chance = 1 / (this.mass - 20);
  //   if(Math.random()>chance) {
  //     this.supernova = true;
  //     this.supernovaDur = 10;
  //     this.alive = false;
  //     if(particles.length <= maxParticles) collidedMass += this.mass;
  //     delete this.size;
  //   }
  // }
};
Particle.prototype.grow = function (another) {
  this.mass += another.mass;
  this.nova = true;
  another.alive = false;
  delete this.size;
};
Particle.prototype.breakApart = function(minMass, maxParts) {
  if(!minMass) minMass = 1;
  if(!maxParts) maxParts = 2;
  var remainingMass = this.mass;
  var num = 0;
  while(remainingMass > 0) {
    var np = new Particle(this.pos.clone().random(this.mass), new Vector(0,0));
    np.mass = 1 + Math.random() * (remainingMass - 1);
    if(num>=maxParts-1) np.mass = remainingMass;
    np.mass = np.mass < minMass ? minMass : np.mass;
    remainingMass -= np.mass;
    num++;
  }
  this.nova = true;
  delete this.size;
  this.alive = false;
};
Particle.prototype.forceBetween = function(another, distance) {
  var distance = distance? distance : this.pos.distance(another.pos);
  return (this.mass * another.mass) / sqr(distance);
};

//******************************************************
//This certainly doesn't *sub*mit to particles, that's for sure
function ParticleEmitter(pos, vc, ang) {
  // to do config options for emitter - random, static, show emitter, emitter color, etc
  this.pos = pos; 
  this.vc = vc; 
  this.ang = ang || 0.09; 
  this.color = "#999"; 
}
ParticleEmitter.prototype.emit = function() {
  var angle = this.vc.angle() + 
      this.ang - (Math.random() * this.ang * 2);
  var magnitude = this.vc.magnitude();
  var position = this.pos.clone();
        position.add(
        new Vector(
          ~~((Math.random() * 100) - 50) * drawScale,       
          ~~((Math.random() * 100) - 50) * drawScale
        ));
  var velocity = Vector.fromAngle(angle, magnitude);
  return new Particle(position,velocity);
};

//******************************************************
// Use it, Luke
// to do collapse functionality into particle
function Force(pos, m) {
  this.pos = pos;
  this.mass = m || 100;
}
Force.prototype.grow = function (another) {
  this.mass += another.mass;
  this.burp = true;
  another.alive = false;
};



function G(data) {
  return 0.00674 * data;
}

//******************************************************
var canvas = document.querySelector('#scene');
var ctx = canvas.getContext('2d');
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
var canvasWidth = canvas.width;
var canvasHeight = canvas.height;

var renderToCanvas = function (width, height, renderFunction) {
    var buffer = document.createElement('canvas');
    buffer.width = width;
    buffer.height = height;
    renderFunction(buffer.getContext('2d'));
    return buffer;
};

maxParticles = 500; 
emissionRate = 1; 
drawScale = 1.3;
minParticleSize = 2;
emitters = [
  //br
  new ParticleEmitter(
    new Vector(
      canvasWidth / 2 * drawScale + 400, 
      canvasHeight / 2 * drawScale
      ), 
    Vector.fromAngle(2, 5),
    1
  ),
  //   // bl
  //   new ParticleEmitter(
  //   new Vector(
  //     canvasWidth / 2 * drawScale - 400, 
  //     canvasHeight / 2 * drawScale + 400
  //     ), 
  //   Vector.fromAngle(1.5, 1),
  //   1
  // ),
    // tl
  new ParticleEmitter(
    new Vector(
      canvasWidth / 2 * drawScale - 400, 
      canvasHeight / 2 * drawScale
      ), 
    Vector.fromAngle(5, 5),
    1
  ),
  //   // tr
  //   new ParticleEmitter(
  //   new Vector(
  //     canvasWidth / 2 * drawScale + 400, 
  //     canvasHeight / 2 * drawScale - 400
  //     ), 
  //   Vector.fromAngle(4.5, 1),
  //   1
  // )
];
forces  = [
  new Force(
    new Vector((canvasWidth / 2 * drawScale) ,
               (canvasHeight / 2 * drawScale)), 1800)
];

function loop() {
  clear();
  update();
  draw();
  queue();
}
 
function clear() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
}
    
var ctr = 0;
var c = [
  'rgba(255,255,255,',
  'rgba(0,150,255,',
  'rgba(255,255,128,',
  'rgba(255,255,255,'
];
function rndc() {
  return c[~~(Math.random() * c.length-1)];
}
var c2 = 'rgba(255,64,32,';
function addNewParticles() {
  var _emit = function() {
    var ret = 0;
    for (var i = 0; i < emitters.length; i++) {
      for (var j = 0; j < emissionRate; j++) {
        var p = emitters[i].emit();
        p.color = ( ctr % 10 === 0 )
          ? ( Math.random() * 5 <= 1 ? c2 : rndc() ) 
          : rndc();
        p.mass = ~~(Math.random() * 5);
        particles.push(p);
        ret += p.mass;
        ctr++;
      }
    }
    return ret;
  };
  if(collidedMass !== 0) {
    while(collidedMass !== 0) {
      collidedMass -= _emit();
      collidedMass = collidedMass<0 ? 0 :collidedMass;
    }
  }
  if (particles.length > maxParticles) 
    return;
  _emit();
}

var CLIPOFFSCREEN = 1,
    BUFFEROFFSCREEN = 2,
    LOOPSCREEN = 3;

function isPositionAliveAndAdjust(particle,check) {
  return true;
  var pos = particle.pos;
  if(!check) check = BUFFEROFFSCREEN;
  if(check === CLIPOFFSCREEN) {
    return !(!particle.alive || 
             pos.x < 0 || 
             (pos.x / drawScale) > boundsX || 
             pos.y < 0 || 
             (pos.y / drawScale) > boundsY);
  } else if(check === BUFFEROFFSCREEN) {
    return !(!particle.alive || 
             pos.x < -boundsX * drawScale || 
             pos.x > 2 * boundsX * drawScale || 
             pos.y < -boundsY * drawScale || 
             pos.y > 2 * boundsY * drawScale);      
  } else if(check === LOOPSCREEN) {
    if (pos.x < 0) pos.x = boundsX * drawScale;
    if ((pos.x / drawScale) > boundsX) pos.x = 0;
    if (pos.y < 0) pos.y = boundsY * drawScale;
    if ((pos.y / drawScale) > boundsY) pos.y = 0;
    return true;
  }
}

function plotParticles(boundsX, boundsY) {
  var currentParticles = [];
  for (var i = 0; i < particles.length; i++) {
    var particle = particles[i];
    particle.reactToForces(forces);
    if(!isPositionAliveAndAdjust(particle))
      continue;
    particle.move();
    currentParticles.push(particle);
  }
}

var offscreenCache = {};
function renderParticle(p) {
    var position = p.pos;
    if(!p.size) p.size = Math.floor(p.mass / 100);

    
    if(!p.opacity) p.opacity = 0.05;
    if(p.velocity > 0) {
      if(p.opacity<=0.18)
        p.opacity += 0.04;
    }
      if(p.opacity>0.08)
        p.opacity -= 0.02;

    var actualSize = p.size / drawScale;
    actualSize = actualSize < minParticleSize ? minParticleSize : actualSize;
    if(p.mass>8) actualSize *= 2;
    if(p.nova) {
      actualSize *= 4;
      p.nova = false;
    }
    if(p.doubleSize) {
      p.doubleSize = false;
      actualSize *= 2;
    }
    // if(p.supernova) {
    //   actualSize *= 6;
    //   opacity = 0.15;
    //   p.supernovaDur = p.supernovaDur - 1;
    //   if(p.supernovaDur === 0)
    //     p.supernova = false;
    // }
    var cacheKey = actualSize + '_' + p.opacity + '_' + p.color;
    var cacheValue = offscreenCache[cacheKey];
    if(!cacheValue) {
      cacheValue = renderToCanvas(actualSize * 32, actualSize * 32, function(ofsContext) {
        var opacity = p.opacity;
        var fills = [
          {size:actualSize/2,  opacity:1},
          {size:actualSize,  opacity:opacity},
          {size:actualSize * 2, opacity:opacity / 2},
          {size:actualSize * 4, opacity:opacity / 3},
          {size:actualSize * 8, opacity:opacity / 5},
          {size:actualSize * 16, opacity:opacity / 16}
        ];
        ofsContext.beginPath();
        for(var f in fills) {
          f = fills[f];
          ofsContext.fillStyle = p.color + f.opacity + ')';
          ofsContext.arc(
            actualSize * 16, 
            actualSize * 16, 
            f.size , 0, Math.PI*2, true); 
          ofsContext.fill();
        }
        ofsContext.closePath();
      });
      offscreenCache[cacheKey] = cacheValue;    
    } 
      var posX = p.pos.x / drawScale;
    var posY = p.pos.y / drawScale;
    ctx.drawImage(cacheValue, posX, posY);
}

var fills = [
  {size:15,opacity:1  },
  {size:25,opacity:0.3},
  {size:50,opacity:0.1} ];

function renderScene(ofsContext) {
  for (var i = 0; i < forces.length; i++) {
    var p = forces[i];
    var position = p.pos;
    var opacity = 1;
    
    ofsContext.beginPath();
    for(var f in fills) {
      f = fills[f];
      var o = p.burp === true ? 1 : f.opacity;
      p.burp = false;
      // ofsContext.fillStyle = 'rgba(255,255,255,' + o + ')';
      // ofsContext.arc(position.x / drawScale, 
      //   position.y / drawScale, 
      //   f.size / drawScale, 0, Math.PI*2, true); 
      // ofsContext.fill();
    }
    ofsContext.closePath();
  }
  
  for (var i = 0; i < particles.length; i++) {
    var p = particles[i];
    renderParticle(p);
  }
}

function draw() { 
  renderScene(ctx);
}

function update() {
  addNewParticles();
  plotParticles(canvas.width, canvas.height);
}
 
function queue() {
  window.requestAnimationFrame(loop);
}

$('canvas').mousedown(function(e){

});

$('canvas').mouseup(function(e){

});

loop();

            
          
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