examples/webaudio_visualizer.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webaudio - visualizer</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
		<style>
			#overlay {
				position: absolute;
				z-index: 1;
				top: 0;
				left: 0;
				width: 100%;
				height:100%;
				display: flex;
				align-items: center;
				justify-content: center;
				opacity: 1;
				background-color: #000000;
				color: #ffffff;
			}

				#overlay > div {
					text-align: center;
				}

				#overlay > div > button {
					height: 20px;
					width: 100px;
					background: transparent;
					color: #ffffff;
					outline: 1px solid #ffffff;
					border: 0px;
					cursor: pointer;
				}

				#overlay > div > p {
					color: #777777;
					font-size: 12px;
				}
		</style>

		<script src="../build/three.js"></script>
		<script src="js/WebGL.js"></script>

		<script id="vertexShader" type="x-shader/x-vertex">

			varying vec2 vUv;

			void main() {

				vUv = uv;

				gl_Position = vec4( position, 1.0 );

			}

		</script>

		<script id="fragmentShader" type="x-shader/x-fragment">

			uniform sampler2D tAudioData;
			varying vec2 vUv;

			void main() {

				vec3 backgroundColor = vec3( 0.125, 0.125, 0.125 );
				vec3 color = vec3( 1.0, 1.0, 0.0 );

				float f = texture2D( tAudioData, vec2( vUv.x, 0.0 ) ).r;

				float i = step( vUv.y, f ) * step( f - 0.0125, vUv.y );

				gl_FragColor = vec4( mix( backgroundColor, color, i ), 1.0 );

			}

		</script>

	</head>
	<body>
		<div id="overlay">
			<div>
				<button id="startButton">Click to Play</button>
				<p>Audio playback requires user interaction.</p>
			</div>
		</div>
		<div id="container"></div>
		<div id="info">
			<a href="https://threejs.org" target="_blank" rel="noopener noreferrer">three.js</a> webaudio - visualizer<br/>
			music by <a href="http://www.newgrounds.com/audio/listen/376737" target="_blank" rel="noopener">skullbeatz</a>
		</div>

	<script>

	if ( WEBGL.isWebGLAvailable() === false ) {

		document.body.appendChild( WEBGL.getWebGLErrorMessage() );

	}

	var scene, camera, renderer, analyser, uniforms;

	var startButton = document.getElementById( 'startButton' );
	startButton.addEventListener( 'click', init );

	function init() {

		var fftSize = 128;

		//

		var overlay = document.getElementById( 'overlay' );
		overlay.remove();

		//

		var container = document.getElementById( 'container' );

		renderer = new THREE.WebGLRenderer( { antialias: true } );
		renderer.setSize( window.innerWidth, window.innerHeight );
		renderer.setClearColor( 0x000000 );
		renderer.setPixelRatio( window.devicePixelRatio );
		container.appendChild( renderer.domElement );

		scene = new THREE.Scene();

		camera = new THREE.Camera();

		//

		var listener = new THREE.AudioListener();

		var audio = new THREE.Audio( listener );

		var mediaElement = new Audio( 'sounds/376737_Skullbeatz___Bad_Cat_Maste.mp3' );
		mediaElement.loop = true;
		mediaElement.play();

		audio.setMediaElementSource( mediaElement );

		analyser = new THREE.AudioAnalyser( audio, fftSize );

		//

		uniforms = {

			tAudioData: { value: new THREE.DataTexture( analyser.data, fftSize / 2, 1, THREE.LuminanceFormat ) }

		};

		var material = new THREE.ShaderMaterial( {

			uniforms: uniforms,
			vertexShader: document.getElementById( 'vertexShader' ).textContent,
			fragmentShader: document.getElementById( 'fragmentShader' ).textContent

		} );

		var geometry = new THREE.PlaneBufferGeometry( 1, 1 );

		var mesh = new THREE.Mesh( geometry, material );
		scene.add( mesh );

		//

		window.addEventListener( 'resize', onResize, false );

		animate();

	}

	function onResize() {

		renderer.setSize( window.innerWidth, window.innerHeight );

	}

	function animate() {

		requestAnimationFrame( animate );

		render();

	}

	function render() {

		analyser.getFrequencyData();

		uniforms.tAudioData.value.needsUpdate = true;

		renderer.render( scene, camera );

	}

	</script>

	</body>
</html>