tunings/synthesizer.js at master · lbarjak/tunings · GitHub

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
//based on https://github.com/uber5001/CanvasKeyboard

import adsr from './adsr.js'
import Tunings from './tunings.js'

export default class Synthesizer {
    static instance
    //singleton factory
    static getInstance() {
        if (!Synthesizer.instance) {
            Synthesizer.instance = new Synthesizer()
        }
        return Synthesizer.instance
    }
    constructor() {
        this.oscillators = []
        this.context = new (window.AudioContext ||
            window.webkitAudioContext ||
            window.mozAudioContext ||
            window.oAudioContext ||
            window.msAudioContext)()
        this.context.resume()
        this.tunings = new Tunings()
        this.tuningEqual = this.tunings.tuningEqual
        this.tuningCircleOfFifth = this.tunings.tuningCircleOfFifth
    }

    noteOn(note, channel) {
        if (channel > 1) {
            console.log('There is not a tunning on this channel!')
            return null
        }
        if (!this.oscillators[note]) {
            this.oscillators[note] = {}
            this.oscillators[note][channel] = false
        }
        if (!this.oscillators[note][channel]) {
            //sine, square, sawtooth, triangle, custom
            this.oscillators[note][channel] = this.context.createOscillator()
            //this.oscillators[note][channel].type = 'sine'
            this.oscillators[note][channel].type = 'square'
            this.oscillators[note][channel] = new adsr(
                this.context,
                0,
                2,
                0.3,
                0.3
            )
            if (channel == 0) {
                this.oscillators[note][
                    channel
                ].frequency.value = this.tuningEqual[note]
                this.gainL = this.context.createGain()
                this.gainL.gain.value = 0.1
                this.pannerL = this.context.createStereoPanner()
                this.pannerL.pan.value = -0.5
                this.oscillators[note][channel].connect(this.gainL)
                this.gainL.connect(this.pannerL)
                this.pannerL.connect(this.context.destination)

                console.log(
                    'equal',
                    note,
                    channel,
                    this.oscillators[note][channel].frequency.value + ' Hz'
                )
            }
            if (channel == 1) {
                this.oscillators[note][
                    channel
                ].frequency.value = this.tuningCircleOfFifth[note]
                this.gainR = this.context.createGain()
                this.gainR.gain.value = 0.1
                this.pannerR = this.context.createStereoPanner()
                this.pannerR.pan.value = 0.5
                this.oscillators[note][channel].connect(this.gainR)
                this.gainR.connect(this.pannerR)
                this.pannerR.connect(this.context.destination)
                console.log(
                    'fifth',
                    note,
                    channel,
                    this.oscillators[note][channel].frequency.value + ' Hz'
                )
            }
            this.oscillators[note][channel].start(this.context.currentTime)
        }
    }
    noteOff(note, channel) {
        if (channel > 1) {
            console.log('There is not a tunning on this channel!')
            return null
        }
        if (this.oscillators[note][channel]) {
            this.oscillators[note][channel].stop(this.context.currentTime)
            this.oscillators[note][channel] = false
        }
    }
}