JavaScript preprocessors can help make authoring JavaScript easier and more convenient. For instance, CoffeeScript can help prevent easy-to-make mistakes and offer a cleaner syntax and Babel can bring ECMAScript 6 features to browsers that only support ECMAScript 5.

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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.

` ````
<canvas id=c></canvas>
```

` ````
canvas {
position: absolute;
top: 0;
left: 0;
}
```

` ````
// if you just don't want to read the code but still are interested in how it works, here's a guide for you: https://codepen.io/towc/blog/a-guide-to-wavy-waved-radial-waves/
var w = c.width = window.innerWidth,
h = c.height = window.innerHeight,
ctx = c.getContext('2d'),
opts = {
rays: 30,
maxRadius: Math.sqrt( w*w/4 + h*h/4 ),
circleRadiusIncrementAcceleration: 2,
radiantSpan: .4,
rayAngularVelSpan: .005,
rayAngularVelLineWidthMultiplier: 60,
rayAngularAccWaveInputBaseIncrementer: .03,
rayAngularAccWaveInputAddedIncrementer: .02,
rayAngularAccWaveMultiplier: .0003,
baseWaveInputIncrementer: .01,
addedWaveInputIncrementer: .01,
circleNumWaveIncrementerMultiplier: .1,
cx: w / 2,
cy: h / 2,
tickHueMultiplier: 1,
shadowBlur: 0,
repaintAlpha: .2,
apply: init
},
rays = [],
tick = 0,
tickHueMultiplied,
gui = new dat.GUI;
function init(){
rays.length = 0;
for( var i = 0; i < opts.rays; ++i )
rays.push( new Ray );
if( tick === 0 ){
for( opt in opts ){
if( isNaN( opts[ opt ] ) )
gui.add( opts, opt );
else
gui.add( opts, opt, 0, opts[ opt ] * 3 )
}
gui.close();
loop();
}
}
function loop(){
window.requestAnimationFrame( loop );
++tick;
ctx.globalCompositeOperation = 'source-over';
ctx.shadowBlur = 0;
ctx.fillStyle = 'rgba(0,0,0,alp)'.replace( 'alp', opts.repaintAlpha );
ctx.fillRect( 0, 0, w, h );
ctx.shadowBlur = opts.shadowBlur;
ctx.globalCompositeOperation = 'lighter';
tickHueMultiplied = opts.tickHueMultiplier * tick;
rays.map( function( ray ){ ray.step(); } );
}
function Ray(){
this.circles = [ new Circle( 0 ) ];
this.rot = Math.random() * Math.PI * 2;
this.angularVel = Math.random() * opts.rayAngularVelSpan * ( Math.random() < .5 ? 1 : -1 );
this.angularAccWaveInput = Math.random() * Math.PI * 2;
this.angularAccWaveInputIncrementer = opts.rayAngularAccWaveInputBaseIncrementer + opts.rayAngularAccWaveInputAddedIncrementer * Math.random();
var security = 100,
count = 0;
while( --security > 0 && this.circles[ count ].radius < opts.maxRadius )
this.circles.push( new Circle( ++count ) );
}
Ray.prototype.step = function(){
// this is just messy, but if you take your time to read it properly you'll understand it pretty easily
this.rot +=
this.angularVel += Math.sin(
this.angularAccWaveInput +=
this.angularAccWaveInputIncrementer ) * opts.rayAngularAccWaveMultiplier;
var rot = this.rot,
x = opts.cx,
y = opts.cy;
ctx.lineWidth = Math.min( .00001 / Math.abs( this.angularVel ), 10 / opts.rayAngularVelLineWidthMultiplier ) * opts.rayAngularVelLineWidthMultiplier;
ctx.beginPath();
ctx.moveTo( x, y );
for( var i = 0; i < this.circles.length; ++i ){
var circle = this.circles[ i ];
circle.step();
rot += circle.radiant;
var x2 = opts.cx + Math.sin( rot ) * circle.radius,
y2 = opts.cy + Math.cos( rot ) * circle.radius,
mx = ( x + x2 ) / 2,
my = ( y + y2 ) / 2;
ctx.quadraticCurveTo( x, y, mx, my );
x = x2;
y = y2;
}
ctx.strokeStyle = ctx.shadowColor = 'hsl(hue,80%,50%)'.replace( 'hue', ( ( ( rot + this.rot ) / 2 ) % ( Math.PI * 2 ) ) / Math.PI * 30 + tickHueMultiplied );
ctx.stroke();
}
function Circle( n ){
this.radius = opts.circleRadiusIncrementAcceleration * Math.pow( n, 2 );
this.waveInputIncrementer = ( opts.baseWaveInputIncrementer + opts.addedWaveInputIncrementer * Math.random() ) * ( Math.random() < .5 ? 1 : -1 ) * opts.circleNumWaveIncrementerMultiplier * n;
this.waveInput = Math.random() * Math.PI * 2;
this.radiant = Math.random() * opts.radiantSpan * ( Math.random() < .5 ? 1 : -1 );
}
Circle.prototype.step = function(){
this.waveInput += this.waveInputIncrementer;
this.radiant = Math.sin( this.waveInput ) * opts.radiantSpan;
}
init();
window.addEventListener( 'resize', function(){
w = c.width = window.innerWidth;
h = c.height = window.innerHeight;
opts.maxRadius = Math.sqrt( w*w/4 + h*h/4 );
opts.cx = w / 2;
opts.cy = h / 2;
init();
});
c.addEventListener( 'click', function(e){
opts.cx = e.clientX;
opts.cy = e.clientY;
})
```

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