-
Notifications
You must be signed in to change notification settings - Fork 21
/
Sound.js
142 lines (110 loc) · 4.45 KB
/
Sound.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
(function () {
"use strict";
function VBASound(emscriptenModule) {
this.emscriptenModule = emscriptenModule;
var AudioContext = window.AudioContext || window.webkitAudioContext;
this.audioCtx = new AudioContext();
this.audioChannels = 2;
this.audioScriptNode = this.audioCtx.createScriptProcessor(512, 2);
this.audioScriptNode.onaudioprocess = this.handleAudioEvent.bind(this);
this.audioScriptNode.connect(this.audioCtx.destination);
this.audioSpareSamplesRingBuffer = new Int16Array(1024 * 16);
this.audioSpareWritePtr = 0;
this.audioSpareReadPtr = 0;
this.spareSamplesAtLastEvent = 0;
}
VBASound.prototype = Object.create(Object.prototype);
VBASound.prototype.constructor = VBASound;
VBASound.prototype.getSampleRate = function () {
return this.audioCtx.sampleRate;
};
VBASound.prototype.currentAudioTime = function () {
return this.audioCtx.currentTime;
};
VBASound.prototype.getNumExtraSamples = function () {
var samples = this.audioSpareWritePtr - this.audioSpareReadPtr;
return samples >= 0 ? samples : (samples + this.audioSpareSamplesRingBuffer.length);
};
VBASound.prototype.resetSound = function () {
};
VBASound.prototype.writeSound = function (pointer8, length16) {
if (pointer8 % 2 === 1) {
console.error("Audio pointer must be 16 bit aligned.");
return;
}
if (length16 % 2 !== 0) {
console.error("Number of audio samples must be even.");
return;
}
var pointer16 = pointer8 >> 1;
var heap16 = this.emscriptenModule.HEAP16;
var i;
for (i = 0; i < length16; i++) {
this.audioSpareSamplesRingBuffer[this.audioSpareWritePtr] = heap16[pointer16 + i];
this.audioSpareWritePtr++;
if (this.audioSpareWritePtr >= this.audioSpareSamplesRingBuffer.length) {
this.audioSpareWritePtr = 0;
}
}
};
VBASound.prototype.handleAudioEvent = function (event) {
if (!hasEmuModule() || !VBAInterface.VBA_get_emulating()) {
return;
}
var audioBuffers = [];
var numChannels = event.outputBuffer.numberOfChannels;
var requiredSamples = event.outputBuffer.length;
var deadlineResult = 1; // Hit
var i, channel;
for (i = 0; i < numChannels; i++) {
audioBuffers.push(event.outputBuffer.getChannelData(i));
}
for (i = 0; i < requiredSamples; i++) {
for (channel = 0; channel < numChannels; channel++) {
if (this.audioSpareReadPtr === this.audioSpareWritePtr) {
audioBuffers[channel][i] = 0;
deadlineResult = 0; // Miss
} else {
audioBuffers[channel][i] = this.audioSpareSamplesRingBuffer[this.audioSpareReadPtr] / 0x4000;
this.audioSpareReadPtr++;
if (this.audioSpareReadPtr >= this.audioSpareSamplesRingBuffer.length) {
this.audioSpareReadPtr -= this.audioSpareSamplesRingBuffer.length;
}
}
}
}
this.spareSamplesAtLastEvent = this.getNumExtraSamples();
vbaPerf.spareAudioSamplesThisSecond.push(this.spareSamplesAtLastEvent);
vbaPerf.audioDeadlineResultsThisSecond.push(deadlineResult);
var frameNum = window.frameNum;
setTimeout(function () {
window.doTimestep(frameNum + 1);
}, 0);
};
// Implementation for browsers without audio support
function IE_VBASound(emscriptenModule) {
this.emscriptenModule = emscriptenModule;
}
IE_VBASound.prototype = Object.create(Object.prototype);
IE_VBASound.prototype.constructor = IE_VBASound;
IE_VBASound.prototype.getSampleRate = function () {
return 44100;
};
IE_VBASound.prototype.currentAudioTime = function () {
return Date.now() / 1000;
};
IE_VBASound.prototype.getNumExtraSamples = function () {
return 0;
};
IE_VBASound.prototype.resetSound = function () {
};
IE_VBASound.prototype.writeSound = function () {
};
IE_VBASound.prototype.handleAudioEvent = function () {
};
if (window.AudioContext) {
module.exports = VBASound;
} else {
module.exports = IE_VBASound;
}
}());