Header Waves

by Faisal Khan Janjua

HTML

<div class="header">
  <h1>Animated waves...</h1>
  
</div>
<div class="canvas-wrap">
  <canvas id="canvas"></canvas>
</div>
<div class="content">
  <h1>Animated waves...</h1>
</div>


<script id="rendered-js">
(function () {
	"use strict";
	var cvs, ctx;
	var nodes = 6;
	var waves = [];
	var waveHeight = 60;
	var colours = ["#f80000", "#00f800", "#0000f8"];

	// Initiator function
	function init() {
		cvs = document.getElementById("canvas");
		ctx = cvs.getContext("2d");
		resizeCanvas(cvs);
		for (var i = 0; i < 3; i++) {
			waves.push(new wave(colours[i], 1, nodes));
		}
		update();
	}

	function update() {
		var fill = window.getComputedStyle(document.querySelector(".header"), null).getPropertyValue("background-color");
		ctx.fillStyle = fill;
		ctx.globalCompositeOperation = "source-over";
		ctx.fillRect(0, 0, cvs.width, cvs.height);
		ctx.globalCompositeOperation = "screen";
		for (var i = 0; i < waves.length; i++) {
			for (var j = 0; j < waves[i].nodes.length; j++) {
				bounce(waves[i].nodes[j]);
			}
			drawWave(waves[i]);
		}
		ctx.fillStyle = fill;

		requestAnimationFrame(update);
	}

	function wave(colour, lambda, nodes) {

		this.colour = colour;
		this.lambda = lambda;
		this.nodes = [];
		var tick = 1;

		for (var i = 0; i <= nodes + 2; i++) {
			var temp = [(i - 1) * cvs.width / nodes, 0, Math.random() * 200, .3];
			this.nodes.push(temp);
			console.log(temp);
		}
		console.log(this.nodes);
	}

	function bounce(nodeArr) {
		nodeArr[1] = waveHeight / 2 * Math.sin(nodeArr[2] / 20) + cvs.height / 2;
		nodeArr[2] = nodeArr[2] + nodeArr[3];

	}

	function drawWave(obj) {

		var diff = function (a, b) {
			return (b - a) / 2 + a;
		};

		ctx.fillStyle = obj.colour;
		ctx.beginPath();
		ctx.moveTo(0, cvs.height);
		ctx.lineTo(obj.nodes[0][0], obj.nodes[0][1]);

		for (var i = 0; i < obj.nodes.length; i++) {

			if (obj.nodes[i + 1]) {
				ctx.quadraticCurveTo(
					obj.nodes[i][0], obj.nodes[i][1],
					diff(obj.nodes[i][0], obj.nodes[i + 1][0]),...

SCSS

$primary: #22184c;

*,*::before,*::after {
  box-sizing: border-box;
}

html {
  font-family: "Work Sans", sans-serif;
  color: #333;
  font-size: 18px;
  line-height: 1.5;
  font-weight: 300;
}

body {
  margin: 0;
  padding: 0;
  background: #f8f8f8;
}

.header,
.content {
  min-height: 100px;
  height: 50vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.header {
  background-color: $primary;
  background-image: linear-gradient(to bottom, rgba(#715, 0.5), transparent);
  color: #ddf;
}

.content {
  color: $primary;
}

h1 {
  font-size: 3rem;
  letter-spacing: 0.1ch;
  font-weight: 300;
  margin: 0;
  opacity: 0.5;
}

.canvas-wrap {
  max-width: 100%;
  overflow: hidden;
  position: absolute;
  transform: translateY(-50%);
}

canvas {
  display: block;
}