/
audio.go
127 lines (101 loc) · 2.41 KB
/
audio.go
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package main
import (
"math"
"github.com/gordonklaus/audio"
)
var tones Tones
type Tones struct {
audio.MultiVoice
}
func (t *Tones) Sing() float64 { return math.Tanh(t.MultiVoice.Sing() / 4) }
func (t *Tones) Done() bool { return false }
var playControl audio.PlayControl
func startAudio() {
playControl = audio.PlayAsync(&tones)
}
func stopAudio() {
playControl.Stop()
}
type pressedTone struct {
Amp audio.Control
Osc audio.FixedFreqSineOsc
}
func newPressedTone(freq float64) *pressedTone {
v := &pressedTone{}
v.Amp.SetPoints([]*audio.ControlPoint{{0, -12}, {9999, -12}})
v.Osc.SetFreq(freq)
return v
}
func (v *pressedTone) attack(amp float64) {
a := v.Amp.Sing()
t := .15
if amp < a {
t = 4
}
v.Amp.SetPoints([]*audio.ControlPoint{{0, a}, {t, amp}, {9999, amp}})
}
func (v *pressedTone) release() {
a := v.Amp.Sing()
v.Amp.SetPoints([]*audio.ControlPoint{{0, a}, {4, -12}})
}
func (v *pressedTone) amp() float64 {
return math.Exp2(v.Amp.Sing())
}
func (v *pressedTone) Sing() float64 {
return math.Exp2(v.Amp.Sing()) * math.Tanh(2*v.Osc.Sine())
}
func (v *pressedTone) Done() bool {
return v.Amp.Done()
}
type pluckedTone struct {
Amp *audio.Control
Osc audio.FixedFreqSineOsc
}
func newPluckedTone(amp, freq float64) *pluckedTone {
v := &pluckedTone{Amp: audio.NewControl([]*audio.ControlPoint{{0, -12}, {.05, amp}, {4, -12}})}
v.Osc.SetFreq(freq)
return v
}
func (v *pluckedTone) amp() float64 {
return math.Exp2(v.Amp.Sing())
}
func (v *pluckedTone) Sing() float64 {
return math.Exp2(v.Amp.Sing()) * math.Tanh(2*v.Osc.Sine())
}
func (v *pluckedTone) Done() bool {
return v.Amp.Done()
}
type bowedTone struct {
amp_, targetAmp float64
ampChan chan float64
Osc audio.FixedFreqSineOsc
}
func newBowedTone(freq float64) *bowedTone {
v := &bowedTone{amp_: -8, targetAmp: -8, ampChan: make(chan float64, 100)}
v.Osc.SetFreq(freq)
return v
}
func (v *bowedTone) attack(amp float64) {
select {
case v.ampChan <- amp:
default:
}
}
func (v *bowedTone) amp() float64 {
return math.Exp2(v.amp_)
}
func (v *bowedTone) Sing() float64 {
select {
case targetAmp := <-v.ampChan:
v.targetAmp = math.Max(v.targetAmp, targetAmp)
default:
}
decay := 3.0 / 48000
v.targetAmp -= decay
da := 16.0 / 48000
v.amp_ += math.Min(da, math.Max(-da, v.targetAmp-v.amp_))
return math.Exp2(v.amp_) * math.Tanh(2*v.Osc.Sine())
}
func (v *bowedTone) Done() bool {
return v.amp_ < -12
}