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. You can use the CSS from another Pen by using it's URL and the proper URL extention.

+ 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 id="canv"></canvas>
<!-- 
[ mousemove / touchswipe ]
FYI: There's an intermittent 'flickering' when interacting that needs fixin.....
!-->
              
            
!

CSS

              
                @import url(https://fonts.googleapis.com/css?family=Economica);

body {
  width: 100%;
  margin: 0;
  overflow: hidden;
  cursor: move;
}
              
            
!

JS

              
                var c = document.getElementById('canv');
var w = c.width = window.innerWidth;
var h = c.height = window.innerHeight;

var $ = c.getContext('2d');
var _x = w / 2;
var _y = h / 2;

var sc = 150;
var num = 35;

var midX = new Array(num);
var midY = new Array(num);
var rad = new Array(num);

var msX = 0.0;
var msY = 0.0;
var _msX = 0.0;
var _msY = 0.0;

var invX = 0.0;
var invY = 0.0;
var _invX = 0.0;
var _invY = 0.0;

var spr = 0.95;
var fric = 0.95;
var flag = 1;
var arr = [];
var rint = 60;

var draw = function() {
  window.requestAnimationFrame(draw);
  inv();
  fill();
  ring();
  for(var j= 0; j < arr.length; j++) {
		arr[j].fade();
		arr[j].anim();
		arr[j]._draw();
	} 
}
var inv = function() {
  invX = msX;
  invY = msY;
  _msX += (_invX - invX) * spr;
  _msY += (_invY - invY) * spr;
  _msX *= fric;
  _msY *= fric;
  _invX = invX;
  _invY = invY;
  invX += _msX;
  invY += _msY;
}

var txt = function() {
  var t0 = "interstellar".split("").join(String.fromCharCode(0x2004));
  var t = "starlight".split("").join(String.fromCharCode(0x2004));
  $.font = "3em Economica";
  $.fillStyle = 'hsla(220, 95%, 75%, .55)';
  $.fillText(t0, (c.width - $.measureText(t0).width) * 0.5, c.height * 0.45);
  $.fillText(t, (c.width - $.measureText(t).width) * 0.5, c.height * 0.55);
  return t;
}
var fill = function() {
  $.globalCompositeOperation= 'source-over';
  var g_ = $.createLinearGradient(c.width + c.width, c.height + c.height * 1.5, c.width + c.width, 1);
  g_.addColorStop(0, ' hsla(220, 95%, 10%, .55)');
  g_.addColorStop(0.5, 'hsla(220, 95%, 30%, .55)');
  g_.addColorStop(1, 'hsla(0, 0%, 5%, 1)');
  $.fillStyle = g_;
  $.fillRect(0, 0, w, h);
  $.globalCompositeOperation= 'lighter';
  txt();
}

var ring = function() {
  for (i = 0; i < num; i++) {
    var currX = midX[i];
    var currY = midY[i];
    var currRad = rad[i];
    var dx = currX + invX;
    var dy = currY + invY;
    var s = 1 / (dx * dx + dy * dy - currRad * currRad);
    ix = dx * s + (currX * flag);
    iy = -dy * s + (currY * flag);
    var irad = currRad * s;
    var g = $.createRadialGradient(ix * sc + _x,
      iy * sc + _y,
      irad,
      ix * sc + _x,
      iy * sc + _y,
      irad * sc)
    g.addColorStop(0, 'hsla(176, 95%, 95%, 1)');
    g.addColorStop(0.5, 'hsla(201, 95%, 45%, .5)');
    g.addColorStop(1, 'hsla(0, 0%, 0%, 0)');
    $.fillStyle = g;
    $.beginPath();
    $.arc(ix * sc + _x, iy * sc + _y, irad * sc, 0, Math.PI * 2.0, true);
    $.fill();
  }
};

for(var j = 0; j < 150; j++) {
		arr[j] = new stars();
		arr[j].reset();
	}

function stars() {
	this.s = {tlap:8000, maxx:5, maxy:2, rmax:5, rt:1, dx:960, dy:540, mvx:4, mvy: 4, rnd:true, twinkle:true};
	this.reset = function() {
		this.x = (this.s.rnd ? w*Math.random() : this.s.dx);
		this.y = (this.s.rnd ? h*Math.random() : this.s.dy);
		this.r = ((this.s.rmax-1)*Math.random()) + .5;
		this.dx = (Math.random()*this.s.maxx) * (Math.random() < .5 ? -1 : 1);
		this.dy = (Math.random()*this.s.maxy) * (Math.random() < .5 ? -1 : 1);
		this.tw = (this.s.tlap/rint)*(this.r/this.s.rmax);
		this.rt = Math.random()*this.tw;
		this.s.rt = Math.random()+1;
		this.cs = Math.random()*.2+.4;
		this.s.mvx *= Math.random() * (Math.random() < .5 ? -1 : 1);
		this.s.mvy *= Math.random() * (Math.random() < .5 ? -1 : 1);
	}
	this.fade = function() {
		this.rt += this.s.rt;
	}
	this._draw = function() {
		if(this.s.twinkle && (this.rt <= 0 || this.rt >= this.tw)) this.s.rt = this.s.rt*-1;
		else if(this.rt >= this.tw) this.reset();
		var o = 1-(this.rt/this.tw);
		$.beginPath();
		$.arc(this.x,this.y,this.r,0,Math.PI*2,true);
		$.closePath();
		var rad = this.r*o;
		var g = $.createRadialGradient(this.x,this.y,0,this.x,this.y,(rad <= 0 ? 1 : rad));
		g.addColorStop(0.0, 'hsla(255,255%,255%,'+o+')');
		g.addColorStop(this.cs, 'hsla(201, 95%, 25%,'+(o*.6)+')');
		g.addColorStop(1.0, 'hsla(201, 95%, 45%,0)');
		$.fillStyle = g;
		$.fill();
	}

	this.anim = function() {
		this.x += (this.rt/this.tw)*this.dx;
		this.y += (this.rt/this.tw)*this.dy;
		if(this.x > w || this.x < 0) this.dx *= -1;
		if(this.y > h || this.y < 0) this.dy *= -1;
	}
}
var set = function() {
  var radi = Math.PI * 2.0 / num;
  for (i = 0; i < num; i++) {
    midX[i] = Math.cos(radi * i);
    midY[i] = Math.sin(radi * i);
    rad[i] = 0.1;
  }
  draw();
}
window.addEventListener('mousemove', function(e) {
  msX = (e.clientX - _x) / sc;
  msY = (e.clientY - _y) / sc;
}, false);

window.addEventListener('touchmove', function(e) {
  e.preventDefault();
  msX = (e.touches[0].clientX - _x) / sc;
  msY = (e.touches[0].clientY - _y) / sc;
}, false);

window.addEventListener('resize', function() {
  c.width = w = window.innerWidth;
  c.height = h = window.innerHeight;
  draw();
}, true);

set();
              
            
!
999px

Console