JavaScript Waves

index.html

<div id="wave-wrap">

	<canvas id="wave_1" ></canvas>
	<canvas id="wave_2" ></canvas>

</div>

<footer id="footer">

</footer>

javascript-waves.markdown

JavaScript Waves

Some JavaScript waves from habitify.co

A Pen by Jordan Halvorsen on CodePen.

License.

script.js

function wave_1( background, canvas_id, max_height, wave_compression ){
	var WIDTH = $( window ).width();
	var height = 100;
	var background = background;

	function sketchProc(processing) {  
	  processing.draw = function () {
	    processing.background(0, 0, 0 ,0);
	    var now = + new Date;
	    var dt = now - lastUpdate;
	    lastUpdate = now;
	    update(dt);
	    draw();
	  };
	  processing.setup = function () {
	     processing.size(WIDTH, height);
	     processing.frameRate(60);
	  };
	}
	var canvas = document.getElementById( canvas_id );
	// attaching the sketchProc function to the canvas
	var lastUpdate =+ new Date;
	var pjs = new Processing(canvas, sketchProc);

	// Resolution of simulation
	var NUM_POINTS = 200;
	// Width of simulation
	var Y_OFFSET = 55;
	var ITERATIONS = 12;
	// Make points to go on the wave
	function makeWavePoints(numPoints) {
	    var t = [];
	    for (var n = 0; n < numPoints + 3; n++) {
	        // This represents a point on the wave
	        var newPoint = {
	            x: n / numPoints * WIDTH,
	            y: Y_OFFSET,
	        }
	        t.push(newPoint);
	    }
	    return t
	}

	// A phase difference to apply to each sine
	var offset = 0;

	var NUM_BACKGROUND_WAVES = 7;
	var BACKGROUND_WAVE_MAX_HEIGHT = max_height;
	var BACKGROUND_WAVE_COMPRESSION = wave_compression;
	// Amounts by which a particular sine is offset
	var sineOffsets = [];
	// Amounts by which a particular sine is amplified
	var sineAmplitudes = [];
	// Amounts by which a particular sine is stretched
	var sineStretches = [];
	// Amounts by which a particular sine's offset is multiplied
	var offsetStretches = [];
	// Set each sine's values to a reasonable random value
	for (var i = -0; i < NUM_BACKGROUND_WAVES; i++) {
	    var sineOffset = -Math.PI + 2 * Math.PI * Math.random();
	    sineOffsets.push(sineOffset);
	    var sineAmplitude = Math.random() * BACKGROUND_WAVE_MAX_HEIGHT;
	    sineAmplitudes.push(sineAmplitude);
	    var sineStretch = Math.random() * BACKGROUND_WAVE_COMPRESSION;
	    sineStretches.push(sineStretch)
	    var offsetStretch = Math.random() * BACKGROUND_WAVE_COMPRESSION;
	    offsetStretches.push(offsetStretch);
	}

	// This function sums together the sines generated above,
	// given an input value x
	function overlapSines(x) {
	    var result = 0;
	    for (var i = 0;i < NUM_BACKGROUND_WAVES; i++) {
	        result = result
	            + sineOffsets[i]
	            + sineAmplitudes[i] 
	            * Math.sin(x * sineStretches[i] + offset * offsetStretches[i]);
	    }
	    return result;
	}

	var wavePoints = makeWavePoints(NUM_POINTS);

	// Callback when updating
	function update(dt) {
	    offset = offset + 1;
	}

	// Callback for drawing
	function draw() {

		var canvas = document.getElementById( canvas_id );
		var context = canvas.getContext('2d');

		var firstPoint = wavePoints[0];
		var lastPoint = wavePoints[wavePoints.length - 1];


		context.beginPath();
		context.moveTo(firstPoint.x, firstPoint.y + overlapSines(firstPoint.x));
		for (var n = 0; n < wavePoints.length;n++) {
	   		var p = wavePoints[n];
		   if (n > 0) {
				var leftPoint = wavePoints[n-1];
				context.lineTo(p.x, p.y + overlapSines(p.x));
		   }
	    }

	  	var canvasHeight = $( "#" + canvas_id ).height();
	  	context.lineTo(lastPoint.x, canvasHeight);
	  	context.lineTo(0, canvasHeight);
	  	context.lineTo(0, firstPoint.y + overlapSines(firstPoint.x));

		context.closePath();

		context.lineWidth = 0;
		context.strokeStyle = background;
		context.fillStyle = background;
	    context.fill();
	    context.stroke();
	}
}

wave_1( '#2A5DFF', 'wave_1', 10, 1/22 );
wave_1( '#339DFF', 'wave_2', 10, 1/20 );

scripts

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
<script src="https://d3vv6lp55qjaqc.cloudfront.net/items/283W302a0p2a2W2d1C2f/processing.js"></script>

style.css

*{box-sizing: border-box}article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}audio,canvas,video{display:inline-block}audio:not([controls]){display:none;height:0}[hidden],template{display:none}html{font-family:sans-serif;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%}body{margin:0}a{background:0 0}a:focus{outline:thin dotted}a:active,a:hover{outline:0}h1{font-size:2em;margin:.67em 0}abbr[title]{border-bottom:1px dotted}b,strong{font-weight:700}dfn{font-style:italic}hr{-moz-box-sizing:content-box;box-sizing:content-box;height:0}mark{background:#ff0;color:#000}code,kbd,pre,samp{font-family:monospace,serif;font-size:1em}pre{white-space:pre-wrap}q{quotes:"\201C" "\201D" "\2018" "\2019"}small{font-size:80%}sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}sup{top:-.5em}sub{bottom:-.25em}img{border:0;vertical-align: middle}svg:not(:root){overflow:hidden}figure{margin:0}fieldset{border:1px solid silver;margin:0 2px;padding:.35em .625em .75em}legend{border:0;padding:0}button,input,select,textarea{font-family:inherit;font-size:100%;margin:0}button,input{line-height:normal}button,select{text-transform:none}button,html input[type=button],input[type=reset],input[type=submit]{-webkit-appearance:button;cursor:pointer}button[disabled],html input[disabled]{cursor:default}input[type=checkbox],input[type=radio]{box-sizing:border-box;padding:0}input[type=search]{-webkit-appearance:textfield;-moz-box-sizing:content-box;-webkit-box-sizing:content-box;box-sizing:content-box}input[type=search]::-webkit-search-cancel-button,input[type=search]::-webkit-search-decoration{-webkit-appearance:none}button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}textarea{overflow:auto;vertical-align:top}table{border-collapse:collapse;border-spacing:0}

body {
  font-family: sans-serif;
  background: #ffffff;
	position: absolute;
	bottom: 0;
}

#footer {
  background: #339dff;
  color: #fff;
  padding: 50px 0;
  text-align: center;
}

#wave-wrap {
  position: relative;
}

#wave_1 {
  width: 100%;
}

#wave_2 {
  position: absolute;
  bottom: 0;
  left: 0;
  z-index: 2;
  outline: none;
  width: 100%;
}