From 39b2fdefdf54cda6ae2ccc572ab8b8a88417c5f1 Mon Sep 17 00:00:00 2001
From: Robert Kaiser <kairo@kairo.at>
Date: Sun, 14 Sep 2014 21:51:45 +0200
Subject: [PATCH] implement a sound module with a graphical display

---
 index.html          | 12 +++++++
 js/tricorder.js     | 80 +++++++++++++++++++++++++++++++++++++++------
 style/tricorder.css | 13 ++++++++
 3 files changed, 95 insertions(+), 10 deletions(-)

diff --git a/index.html b/index.html
index b426b25..265df47 100644
--- a/index.html
+++ b/index.html
@@ -34,6 +34,7 @@
 <ul id="navlist">
 <li id="navPos">Position</li>
 <li id="navGrav">Gravity</li>
+<li id="navSound">Sound</li>
 <li id="navDev">Device</li>
 <li id="navOther">Other</li>
 </ul>
@@ -99,6 +100,17 @@ a better device.
 </div>
 </section>
 
+<section id="sectSound">
+<p id="soundunavail">
+Sound sensors are unavailable on this tricorder device.
+<br/>Please talk to your superior officer or Starfleet contact to acquire
+a better device.
+</p>
+<div id="soundavail" style="display:none">
+<canvas id="soundcanvas" width="300" height="300"></canvas>
+</div>
+</section>
+
 <section id="sectDev">
 <table>
 <tr><td>Battery Level:</td><td id="devBattLevel" class="deviceVal">...</td></tr>
diff --git a/js/tricorder.js b/js/tricorder.js
index 28852a0..317fbca 100644
--- a/js/tricorder.js
+++ b/js/tricorder.js
@@ -5,6 +5,8 @@
 var gStardate, gSDBase;
 var gSounds = {};
 
+navigator.getUserMedia = (navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia);
+
 window.onload = function() {
   setTimeout(updateStardate, 0);
   gSounds.scan = new Audio("sound/scan.opus");
@@ -216,6 +218,74 @@ var gModGrav = {
   },
 }
 
+var gModSound = {
+  activate: function() {
+    //gSounds.scan.play();
+    if (navigator.getUserMedia) {
+      document.getElementById("soundunavail").style.display = "none";
+      document.getElementById("soundavail").style.display = "block";
+      navigator.getUserMedia({ audio: true },
+         function(aLocalMediaStream) {
+           gModSound.mAudio.stream = aLocalMediaStream;
+           gModSound.mAudio.context = new (window.AudioContext || window.webkitAudioContext)();
+           gModSound.mAudio.input = gModSound.mAudio.context.createMediaStreamSource(gModSound.mAudio.stream);
+           // Could put a filter in between like in http://webaudioapi.com/samples/microphone/
+           gModSound.mDisplay.canvas = document.getElementById("soundcanvas");
+           gModSound.mDisplay.context = gModSound.mDisplay.canvas.getContext("2d");
+           gModSound.mDisplay.canvas.height = document.getElementById("soundavail").clientHeight - 2;
+           gModSound.mDisplay.canvas.width = document.getElementById("soundavail").clientWidth;
+           gModSound.mAudio.frequencySlices = (gModSound.mDisplay.canvas.width > 512) ?
+                                              512 :
+                                              Math.pow(2, Math.floor(Math.log(gModSound.mDisplay.canvas.width) / Math.LN2));
+           console.log("slices: " + gModSound.mAudio.frequencySlices);
+           gModSound.mAudio.analyzer = gModSound.mAudio.context.createAnalyser();
+           // Make the FFT four times as large as needed as the upper three quarters turn out to be useless.
+           gModSound.mAudio.analyzer.fftSize = gModSound.mAudio.frequencySlices * 4;
+           console.log("FFT: " + gModSound.mAudio.analyzer.fftSize);
+           gModSound.mAudio.input.connect(gModSound.mAudio.analyzer);
+           gModSound.mDisplay.context.setTransform(1, 0, 0, -(gModSound.mDisplay.canvas.height/256), 0, gModSound.mDisplay.canvas.height);
+           gModSound.mDisplay.active = true;
+           window.requestAnimationFrame(gModSound.paintAnalyzerFrame);
+         },
+         function(err) {
+           document.getElementById("soundunavail").style.display = "block";
+           document.getElementById("soundavail").style.display = "none";
+           console.log(err);
+         }
+      );
+    }
+    else {
+      document.getElementById("soundunavail").style.display = "block";
+      document.getElementById("soundavail").style.display = "none";
+    }
+  },
+  mAudio: {
+    frequencySlices: 32, // Must be a multiple of 2 (see AnalyserNode.fftSize)
+  },
+  mDisplay: {
+    active: false,
+  },
+  paintAnalyzerFrame: function(aTimestamp) {
+    var data = new Uint8Array(gModSound.mAudio.frequencySlices);
+    gModSound.mAudio.analyzer.getByteFrequencyData(data);
+    gModSound.mDisplay.context.clearRect(0, 0, gModSound.mDisplay.canvas.width, gModSound.mDisplay.canvas.height);
+    // Out of experience, only the first half of the slices are actually useful.
+    var wid = gModSound.mDisplay.canvas.width / gModSound.mAudio.frequencySlices;
+    var fill = "#9C9CFF";
+    for (var i = 0; i < gModSound.mAudio.frequencySlices; ++i) {
+      var newFill = (data[i] > 200) ? "#FF0000" : ((data[i] > 100) ? "#FFCF00" : "#9C9CFF");
+      if (fill != newFill) { gModSound.mDisplay.context.fillStyle = newFill; fill = newFill; }
+      gModSound.mDisplay.context.fillRect(i*wid, 0, wid, data[i]);
+    }
+    if (gModSound.mDisplay.active)
+      window.requestAnimationFrame(gModSound.paintAnalyzerFrame);
+  },
+  deactivate: function() {
+    gModSound.mDisplay.active = false;
+    gModSound.mAudio.stream.stop();
+    gSounds.scan.pause();
+  },
+}
 
 var gModDev = {
   activate: function() {
@@ -254,16 +324,6 @@ var gModDev = {
   batteryTimer: null,
 }
 
-var gModSound = {
-  activate: function() {
-    //gSounds.scan.play();
-  },
-  // getUserMedia ("WebRTC") + MediaElementAudioSourceNode (WebAudio)
-  deactivate: function() {
-    gSounds.scan.pause();
-  },
-}
-
 var gModOther = {
   activate: function() {
     //gSounds.scan.play();
diff --git a/style/tricorder.css b/style/tricorder.css
index 0c73061..b6d1b76 100644
--- a/style/tricorder.css
+++ b/style/tricorder.css
@@ -141,6 +141,14 @@ a:hover, a:active { color: #FFCF00; }
   background-color: #C09070;
   color: #000000;
 }
+#navSound {
+  background-color: #E7ADE7;
+  color: #000000;
+}
+#navDev {
+  background-color: #A09090;
+  color: #000000;
+}
 #navOther {
   background-color: #6000CF;
   color: #000000;
@@ -222,6 +230,7 @@ a:hover, a:active { color: #FFCF00; }
 section {
   display: none;
   background-color: rgba(0,0,0,0.8);
+  height: 100%;
 }
 
 section.active {
@@ -244,6 +253,10 @@ section.active {
   font-size: .667em;
 }
 
+#soundavail {
+  height: 100%;
+}
+
 @media screen and (min-width: 500px) {
   body {
     font-size: 24px;
-- 
2.43.0