From eb6b5620a51ad1b4c182827fae11b6f9118c0420 Mon Sep 17 00:00:00 2001
From: Will Scullin <scullin@scullin.com>
Date: Mon, 20 Jul 2020 17:04:55 -0700
Subject: [PATCH] Audio cleanup.

---
 js/apple2io.js | 19 ++++++++++++-------
 js/ui/audio.js | 16 ++++++++++------
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/js/apple2io.js b/js/apple2io.js
index 8f64efe..dde95f4 100644
--- a/js/apple2io.js
+++ b/js/apple2io.js
@@ -29,6 +29,7 @@ export default function Apple2IO(cpu, callbacks)
     var _paddle = [0.0, 0.0, 0.0, 0,0];
     var _phase = -1;
     var _sample = [];
+    var _sampleIdx = 0;
     var _sampleTime = 0;
     var _didAudio = false;
 
@@ -103,17 +104,18 @@ export default function Apple2IO(cpu, callbacks)
 
     function _tick() {
         var now = cpu.cycles();
-        var phase = _phase > 0 ? _high : _low;
+        var phase = _didAudio ? (_phase > 0 ? _high : _low) : 0.0;
         for (; _sampleTime < now; _sampleTime += _cycles_per_sample) {
-            _sample.push(phase);
-            if (_sample.length >= _sample_size) {
+            _sample[_sampleIdx++] = phase;
+            if (_sampleIdx === _sample_size) {
                 if (_audioListener) {
-                    _audioListener(_didAudio ? _sample : []);
+                    _audioListener(_sample);
                 }
-                _sample = [];
-                _didAudio = false;
+                _sample = new Array(_sample_size);
+                _sampleIdx = 0;
             }
         }
+        _didAudio = false;
     }
 
     function _calcSampleRate() {
@@ -491,8 +493,11 @@ export default function Apple2IO(cpu, callbacks)
             _tapeOffset = -1;
         },
 
-        sampleRate: function sampleRate(rate) {
+        sampleRate: function sampleRate(rate, sample_size) {
             _rate = rate;
+            _sample_size = sample_size
+            _sample = new Array(_sample_size);
+            _sampleIdx = 0;
             _calcSampleRate();
         },
 
diff --git a/js/ui/audio.js b/js/ui/audio.js
index 23acfbf..0117eeb 100644
--- a/js/ui/audio.js
+++ b/js/ui/audio.js
@@ -15,6 +15,9 @@ import { debug } from '../util';
  * Audio Handling
  */
 
+var SAMPLE_SIZE = 1024
+var SAMPLE_RATE = 44000
+
 export default function Audio(io) {
     var sound = true;
     var _samples = [];
@@ -25,8 +28,10 @@ export default function Audio(io) {
     var started = false;
 
     if (AudioContext) {
-        audioContext = new AudioContext();
-        audioNode = audioContext.createScriptProcessor(4096, 1, 1);
+        audioContext = new AudioContext({
+            sampleRate: SAMPLE_RATE
+        });
+        audioNode = audioContext.createScriptProcessor(SAMPLE_SIZE, 1, 1);
 
         audioNode.onaudioprocess = function(event) {
             var data = event.outputBuffer.getChannelData(0);
@@ -52,12 +57,11 @@ export default function Audio(io) {
     function _initAudio(io) {
         if (audioContext) {
             debug('Using Webkit Audio');
-            io.sampleRate(audioContext.sampleRate);
+            io.sampleRate(audioContext.sampleRate, SAMPLE_SIZE);
             io.addSampleListener(function(sample) {
                 if (sound) {
-                    _samples.push(sample);
-                    while (_samples.length > 5) {
-                        _samples.shift();
+                    if (_samples.length < 5) {
+                        _samples.push(sample);
                     }
                 }
             });