65 lines
1.6 KiB
JavaScript
65 lines
1.6 KiB
JavaScript
export class Synth {
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// SYNTH VOICE CONSTRUCTOR
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constructor(audio, type, env = {
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a: 0.2,
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r: 0.5,
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}) {
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this.audio = audio
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this.t = this.audio.currentTime
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this.env = {
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a: env.a,
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r: env.r,
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}
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// PRIMARY GAIN
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this.gain = this.audio.createGain()
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this.gain.gain.value = 0
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// PRIMARY VOICE
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this.primVoice = this.audio.createOscillator()
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this.primVoice.type = typeof type === 'string' ? type : 'sine'
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this.primVoice.connect(this.gain)
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this.primVoice.start()
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// MOD GAIN
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this.modGain = this.audio.createGain()
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this.modGain.gain.value = 0
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this.modGain.connect(this.gain)
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// MOD VOICE
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this.modVoice = this.audio.createOscillator()
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this.modVoice.type = 'triangle'
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this.modVoice.connect(this.modGain)
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this.modVoice.start()
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}
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// OSC -> ADSR -> GAIN
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noteOn(freq) {
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// note frequency
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this.freq = freq ? freq : (Math.random() * 350) + 150
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this.primVoice.frequency.setValueAtTime(this.freq, this.t)
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this.modVoice.frequency.setValueAtTime(this.freq - 20, this.t)
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// clear preScheduled events
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this.gain.gain.cancelScheduledValues(this.audio.currentTime)
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// attack
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this.gain.gain.setTargetAtTime(0.45, this.t + this.env.a, 0.2)
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}
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noteOff() {
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// release
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this.gain.gain.setTargetAtTime(0.0, this.t + this.env.r, 1)
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}
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mod() {
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this.modGain.gain.cancelScheduledValues(this.audio.currentTime)
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// attack
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this.modGain.gain.setTargetAtTime(0.8, this.audio.currentTime, 0.5)
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// release
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this.modGain.gain.setTargetAtTime(0.8, this.audio.currentTime + 0.4, 0.5)
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}
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}
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