From ede4449de87bcc220301d288e64d507f51ad4c77 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Benjamin=20B=C3=A4dorf?= <hello@benjaminbaedorf.eu>
Date: Fri, 7 Jun 2019 18:31:53 +0200
Subject: [PATCH] Tryna get pitch

---
 src/index.js | 81 ++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 56 insertions(+), 25 deletions(-)

diff --git a/src/index.js b/src/index.js
index 37bf08e..3dbd84d 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,12 +1,24 @@
 import p5 from 'p5';
-import 'p5/lib/addons/p5.sound'; 
 import './index.scss';
 
-const VOLUME_NORMALIZATION = 1000;
-const THRESHOLD = 5 / VOLUME_NORMALIZATION;
+const VOLUME_THRESHOLD = 0;
+const FFT_SIZE = 1024;
 
 function getColorValue(volume) {
-  return Math.floor(volume * VOLUME_NORMALIZATION * 256);
+  const normalizedVolume = volume * VOLUME_NORMALIZATION;
+  const color = Math.floor(normalizedVolume);
+  const opacity = (normalizedVolume > VOLUME_MAX ? normalizedVolume : VOLUME_MAX) / 100;
+  return `rgba(${color}, ${color}, ${color}, ${opacity})`;
+}
+
+function getRMS(spectrum) {
+  let rms = 0;
+  for (let i = 0; i < spectrum.length; i++) {
+    rms += spectrum[i] * spectrum[i];
+  }
+  rms /= spectrum.length;
+  rms = Math.sqrt(rms);
+  return rms;
 }
 
 function getWidth(volume) {
@@ -23,8 +35,38 @@ function getRandomY() {
 
 
 async function main() {
-  const mic = new p5.AudioIn();
-  mic.start();
+  const audioCtx = new AudioContext();
+  const microphone = await navigator.mediaDevices.getUserMedia({ audio: true });
+  const analyser = new AnalyserNode(audioCtx);
+
+  let fresh = false;
+  let spectrum = [];
+  let volume = 0;
+  analyser.smoothingTimeConstant = 0.2;
+  analyser.fftSize = FFT_SIZE;
+
+  const audioProcessor = audioCtx.createScriptProcessor(FFT_SIZE*2, 1, 1);
+  audioProcessor.onaudioprocess = () => {
+    fresh = true;
+    // bitcount returns array which is half the FFT_SIZE
+    spectrum = new Uint8Array(analyser.frequencyBinCount);
+
+    // getByteFrequencyData returns amplitude for each bin
+    // analyser.getByteFrequencyData(spectrum);
+    // getByteTimeDomainData gets volumes over the sample time
+    // analyser.getByteTimeDomainData(self.spectrum);
+
+    volume = getRMS(spectrum);
+    // get peak - a hack when our volumes are low
+    if (volume > VOLUME_THRESHOLD) VOLUME_THRESHOLD = volume;
+    volume = self.vol;
+  }
+
+  const input = audioCtx.createMediaStreamSource(microphone);
+  input.connect(analyser);
+  analyser.connect(audioProcessor);
+  // audioProcessor.connect(audioCtx.destination);
+
 
   const instance = new p5(( sketch ) => {
     sketch.setup = () => {
@@ -39,27 +81,16 @@ async function main() {
     let bars = [];
 
     sketch.draw = () => {
+      if (!fresh) {
+        return;
+      }
+
+      fresh = false;
+
       sketch.background(0);
 
-      const volume = mic.getLevel();
-      const x = getRandomX();
-      bars.push({
-        volume,
-      //  pitch,
-        x,
-      });
-
-      const newBars = [];
-      for (const bar of bars) {
-        bar.volume = bar.volume / 1.5;
-        if (bar.volume <= THRESHOLD) {
-          continue;
-        }
-        drawBar(bar);
-        newBars.push(bar);
-      };
-
-      bars = newBars;
+      for (const pitch of spectrum) {
+      }
     };
   });
 }