Project 5

part1/audio_visualizer.js

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+// Based on Karl Gustavsgavan's implementation of an audio visualizer.
+// http://wemadeyoulook.at/en/blog/webgl-webaudio-api-fun/
+//
+// Audio Visualizer
+
+(function() {
+    "use strict";
+    /*global window,document,Float32Array,Uint16Array,mat4,vec3,snoise*/
+    /*global getShaderSource,createWebGLContext,createProgram*/
+
+    var NUM_WIDTH_PTS = 128;
+    var NUM_HEIGHT_PTS = 128;
+
+    var message = document.getElementById("message");
+    var canvas = document.getElementById("canvas");
+    var context = createWebGLContext(canvas, message);
+    if (!context) {
+        return;
+    }
+
+    ///////////////////////////////////////////////////////////////////////////
+
+    context.viewport(0, 0, canvas.width, canvas.height);
+    context.clearColor(1.0, 1.0, 1.0, 1.0);
+    context.enable(context.DEPTH_TEST);
+
+    var persp = mat4.create();
+    mat4.perspective(45.0, 0.5, 0.1, 100.0, persp);
+
+    var eye = [2.0, 1.0, 3.0];
+    var center = [0.0, 0.0, 0.0];
+    var up = [0.0, 0.0, 1.0];
+    var view = mat4.create();
+    mat4.lookAt(eye, center, up, view);
+
+    var positionLocation = 0;
+    var heightLocation = 1;
+    var u_modelViewPerspectiveLocation;
+    var u_timeLocation;
+    var u_time = 0;
+
+    (function initializeShader() {
+        var program;
+        var vs = getShaderSource(document.getElementById("vs"));
+        var fs = getShaderSource(document.getElementById("fs"));
+
+		var program = createProgram(context, vs, fs, message);
+		context.bindAttribLocation(program, positionLocation, "position");
+		u_modelViewPerspectiveLocation = context.getUniformLocation(program,"u_modelViewPerspective");
+                u_timeLocation = context.getUniformLocation(program, "u_time");
+
+        context.useProgram(program);
+    })();
+
+    var heights;
+    var numberOfIndices;
+
+    (function initializeGrid() {
+        function uploadMesh(positions, heights, indices) {
+            // Positions
+            var positionsName = context.createBuffer();
+            context.bindBuffer(context.ARRAY_BUFFER, positionsName);
+            context.bufferData(context.ARRAY_BUFFER, positions, context.STATIC_DRAW);
+            context.vertexAttribPointer(positionLocation, 2, context.FLOAT, false, 0, 0);
+            context.enableVertexAttribArray(positionLocation);
+
+            if (heights)
+            {
+                // Heights
+                var heightsName = context.createBuffer();
+                context.bindBuffer(context.ARRAY_BUFFER, heightsName);
+                context.bufferData(context.ARRAY_BUFFER, heights.length * heights.BYTES_PER_ELEMENT, context.STREAM_DRAW);
+                context.vertexAttribPointer(heightLocation, 1, context.FLOAT, false, 0, 0);
+                context.enableVertexAttribArray(heightLocation);
+            }
+
+            // Indices
+            var indicesName = context.createBuffer();
+            context.bindBuffer(context.ELEMENT_ARRAY_BUFFER, indicesName);
+            context.bufferData(context.ELEMENT_ARRAY_BUFFER, indices, context.STATIC_DRAW);
+        }
+
+        var WIDTH_DIVISIONS = NUM_WIDTH_PTS - 1;
+        var HEIGHT_DIVISIONS = NUM_HEIGHT_PTS - 1;
+
+        var numberOfPositions = NUM_WIDTH_PTS * NUM_HEIGHT_PTS;
+
+        var positions = new Float32Array(2 * numberOfPositions);
+        var indices = new Uint16Array(2 * ((NUM_HEIGHT_PTS * (NUM_WIDTH_PTS - 1)) + (NUM_WIDTH_PTS * (NUM_HEIGHT_PTS - 1))));
+
+        var positionsIndex = 0;
+        var indicesIndex = 0;
+        var length;
+
+        for (var j = 0; j < NUM_WIDTH_PTS; ++j)
+        {
+            positions[positionsIndex++] = j /(NUM_WIDTH_PTS - 1);
+            positions[positionsIndex++] = 0.0;
+
+            if (j>=1)
+            {
+                length = positionsIndex / 2;
+                indices[indicesIndex++] = length - 2;
+                indices[indicesIndex++] = length - 1;
+            }
+        }
+
+        for (var i = 0; i < HEIGHT_DIVISIONS; ++i)
+        {
+             var v = (i + 1) / (NUM_HEIGHT_PTS - 1);
+             positions[positionsIndex++] = 0.0;
+             positions[positionsIndex++] = v;
+
+             length = (positionsIndex / 2);
+             indices[indicesIndex++] = length - 1;
+             indices[indicesIndex++] = length - 1 - NUM_WIDTH_PTS;
+
+             for (var k = 0; k < WIDTH_DIVISIONS; ++k)
+             {
+                 positions[positionsIndex++] = (k + 1) / (NUM_WIDTH_PTS - 1);
+                 positions[positionsIndex++] = v;
+
+                 length = positionsIndex / 2;
+                 var new_pt = length - 1;
+                 indices[indicesIndex++] = new_pt - 1;  // Previous side
+                 indices[indicesIndex++] = new_pt;
+
+                 indices[indicesIndex++] = new_pt - NUM_WIDTH_PTS;  // Previous bottom
+                 indices[indicesIndex++] = new_pt;
+             }
+        }
+
+        uploadMesh(positions, heights, indices);
+        numberOfIndices = indices.length;
+    })();
+
+
+    var aud_context;
+    var aud_buffer;
+    var aud_fft;
+    var aud_filter;
+    var aud_loaded;
+    var src;
+    var counter = 0;
+
+    (function initAudio(){
+        try{
+            console.log("initAudio()");
+            aud_context = new AudioContext();
+            loadAudio();
+        }catch(e){
+            alert("Browser does not support Web Audio API");
+        }
+    })();
+
+
+    function loadAudio(){
+        var req = new XMLHttpRequest();
+        req.open("GET", "13 My Favorite Things.ogg", true);
+        req.responseType = "arraybuffer";
+
+        src = aud_context.createBufferSource();    
+        src.connect(aud_context.destination);
+        req.onload = function(){
+            aud_context.decodeAudioData(req.response, function onSuccess(aud_buffer){
+                src.buffer = aud_buffer;
+                play();
+            }, function onFailure(){
+                alert("Decoding failed");
+            });
+        };
+        req.send();
+    }
+
+    function play(){
+        // Fast Fourier Transform
+        aud_fft = aud_context.createAnalyser();
+        aud_fft.fftSize = 256;
+
+        aud_filter = aud_context.createBiquadFilter();
+        aud_filter.type = 0;
+        aud_filter.frequency.value = 220;
+
+        src.connect(aud_filter);
+        aud_filter.connect(aud_fft);
+        aud_fft.connect(aud_context.destination);
+
+        src.loop = true;
+        src.start(0);
+        aud_loaded = true;
+        //document.getElementById('loading').innerHTML='';
+    }
+
+    (function animate(){
+        ///////////////////////////////////////////////////////////////////////////
+        // Update
+
+        u_time = u_time + .005;
+
+        var freqDomain = new Float32Array(aud_fft.frequencyBinCount);
+        aud_fft.getFloatFrequencyData(freqDomain);
+        for (var i = 0; i < aud_fft.frequencyBinCount; i++){
+            var value = freqDomain[i];
+            var percent = value / 256;
+        }
+
+        var model = mat4.create();
+        mat4.identity(model);
+        mat4.translate(model, [-0.5, -0.5, 0.0]);
+        var mv = mat4.create();
+        mat4.multiply(view, model, mv);
+        var mvp = mat4.create();
+        mat4.multiply(persp, mv, mvp);
+
+        ///////////////////////////////////////////////////////////////////////////
+        // Render
+        context.clear(context.COLOR_BUFFER_BIT | context.DEPTH_BUFFER_BIT);
+
+        context.uniformMatrix4fv(u_modelViewPerspectiveLocation, false, mvp);
+        context.uniform1f(u_timeLocation, u_time);
+        context.drawElements(context.LINES, numberOfIndices, context.UNSIGNED_SHORT,0);
+
+        counter = counter + 1;
+
+        function(callback){
+            window.setTimeout(callback, 1000/60);
+        }
+
+		window.requestAnimFrame(animate);
+    })();
+}());
+

part1/index_audio.html

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+<html>
+    <head>
+        <title>Audio Visualizer</title>
+        <meta charset="utf-8">
+        <meta http-equiv="X-UA-Compatible" content="chrome=1">
+    </head>
+
+<div id="message" style="position:absolute;top:100px"></div> <!-- Pixel offset to avoid FPS counter -->
+<canvas id="canvas" style="border: none;" width="1024" height="768" tabindex="1"></canvas>
+
+<script id="vs" type="x-shader/x-vertex">
+    attribute vec2 position;
+    varying vec3 color;
+
+    uniform sampler2D u_freqData;
+    uniform mat4 u_modelViewPerspective;
+    uniform float u_time;
+    uniform float offset;
+
+    void main(void)
+    {
+                float y = position.y >= offset ? position.y - offset : 256.0 + (position.y - offset);
+                float height = texture2D(u_freqData, vec2(position.x, y)).r;
+                gl_Position = u_modelViewPerspective * vec4(vec3(position, height), 1.0);
+
+                vec3 green = vec3(.6117, 1.0, .8824);
+                vec3 pink = vec3(.99, .65, .65);
+                color = mix(pink, green, height);
+    }
+</script>
+
+<script id="fs" type="x-shader/x-fragment">
+    precision mediump float;
+
+    varying vec3 color;
+
+    void main(void)
+    {
+                gl_FragColor = vec4(color, 1.0);
+    }    
+</script>
+
+
+
+    <body>
+        <script src="gl-matrix.js" type="text/javascript"></script>
+        <script src="webGLUtility.js" type="text/javascript"></script>
+        <script src="audio_visualizer.js" type="text/javascript"></script>
+    </body>
+</html>

part1/index_simplex.html

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+vec3 permute(vec3 x) {
+  x = ((x*34.0)+1.0)*x;
+  return x - floor(x * (1.0 / 289.0)) * 289.0;
+}
+
+float simplexNoise(vec2 v)
+  {
+  const vec4 C = vec4(0.211324865405187, 0.366025403784439,  -0.577350269189626, 0.024390243902439); 
+
+  vec2 i  = floor(v + dot(v, C.yy) );
+  vec2 x0 = v -   i + dot(i, C.xx);
+
+  vec2 i1;
+  i1 = (x0.x > x0.y) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);
+
+  vec4 x12 = x0.xyxy + C.xxzz;
+  x12.xy -= i1;
+
+  i = i - floor(i * (1.0 / 289.0)) * 289.0;
+
+  vec3 p = permute( permute( i.y + vec3(0.0, i1.y, 1.0 ))
+        + i.x + vec3(0.0, i1.x, 1.0 ));
+
+  vec3 m = max(0.5 - vec3(dot(x0,x0), dot(x12.xy,x12.xy), dot(x12.zw,x12.zw)), 0.0);
+  m = m*m ;
+  m = m*m ;
+
+  vec3 x = 2.0 * fract(p * C.www) - 1.0;
+  vec3 h = abs(x) - 0.5;
+  vec3 ox = floor(x + 0.5);
+  vec3 a0 = x - ox;
+
+  m *= inversesqrt( a0*a0 + h*h );
+
+  vec3 g;
+  g.x  = a0.x  * x0.x  + h.x  * x0.y;
+  g.yz = a0.yz * x12.xz + h.yz * x12.yw;
+  return 130.0 * dot(m, g);
+}