3 files changed, 28 insertions(+), 5 deletions(-)

M go.mod
M go.sum
M main.go

@@ 13,6 13,7 @@ require (
 	gioui.org/cpu v0.0.0-20210817075930-8d6a761490d2 // indirect
 	gioui.org/shader v1.0.6 // indirect
 	github.com/benoitkugler/textlayout v0.1.1 // indirect
+	github.com/fogleman/ease v0.0.0-20170301025033-8da417bf1776 // indirect
 	github.com/gioui/uax v0.2.1-0.20220325163150-e3d987515a12 // indirect
 	github.com/go-text/typesetting v0.0.0-20220411150340-35994bc27a7b // indirect
 	golang.org/x/exp/shiny v0.0.0-20220516143420-24438e51023a // indirect

@@ 12,6 12,8 @@ github.com/benoitkugler/textlayout v0.1.1 h1:hizE/085xAeY8q7gwV00uHR2Q27KYB2g1HW
 github.com/benoitkugler/textlayout v0.1.1/go.mod h1:o+1hFV+JSHBC9qNLIuwVoLedERU7sBPgEFcuSgfvi/w=
 github.com/benoitkugler/textlayout-testdata v0.1.1 h1:AvFxBxpfrQd8v55qH59mZOJOQjtD6K2SFe9/HvnIbJk=
 github.com/cloudfoundry/jibber_jabber v0.0.0-20151120183258-bcc4c8345a21/go.mod h1:po7NpZ/QiTKzBKyrsEAxwnTamCoh8uDk/egRpQ7siIc=
+github.com/fogleman/ease v0.0.0-20170301025033-8da417bf1776 h1:VRIbnDWRmAh5yBdz+J6yFMF5vso1It6vn+WmM/5l7MA=
+github.com/fogleman/ease v0.0.0-20170301025033-8da417bf1776/go.mod h1:9wvnDu3YOfxzWM9Cst40msBF1C2UdQgDv962oTxSuMs=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
 github.com/gioui/uax v0.2.1-0.20220325163150-e3d987515a12 h1:1bjaB/5IIicfKpP4k0s30T2WEw//Kh00zULa8DQ0cxA=

@@ 39,6 39,7 @@ import (
 	"gioui.org/op/paint"
 	"gioui.org/widget"
 	"gioui.org/widget/material"
+	"github.com/fogleman/ease"
 	"github.com/hajimehoshi/oto/v2"
 	"github.com/lucasb-eyer/go-colorful"
 	"golang.org/x/exp/maps"


@@ 274,20 275,22 @@ type Pipe struct {
 	player  oto.Player
 	playing bool
 	since   time.Time
+	paused  time.Time
 	freq    float64
 	col     color.NRGBA
 }
 
 func (p *Pipe) Play(now time.Time) {
-	if !p.playing {
+	if !p.playing && p.paused != now {
 		p.since = now
 	}
 	p.playing = true
 	p.player.Play()
 }
 
-func (p *Pipe) Pause() {
+func (p *Pipe) Pause(now time.Time) {
 	p.playing = false
+	p.paused = now
 	p.player.Pause()
 }
 


@@ 306,7 309,7 @@ func run(w *app.Window) error {
 		if event.State == key.Press {
 			players[idx].Play(now)
 		} else {
-			players[idx].Pause()
+			players[idx].Pause(now)
 		}
 	}
 


@@ 372,12 375,29 @@ func run(w *app.Window) error {
 					lowestFreq := freqs[0]
 					for i, pipe := range players {
 						if pipe.playing {
+							op.InvalidateOp{}.Add(gtx.Ops)
 							offset := op.Offset(f32.Point{X: float32(math.Round(float64(width * float32(i))))}).Push(gtx.Ops)
 							rect := rect
 							proportion := 1 / (pipe.freq / lowestFreq)
-							height := int(math.Round(float64(gtx.Constraints.Max.Y) * proportion))
+							heightF := float64(gtx.Constraints.Max.Y) * proportion
+							height := int(math.Round(heightF))
 							gap := gtx.Constraints.Max.Y - height
-							rect.Min.Y += gap
+							rect.Min.Y = gap
+
+							lightFill := pipe.col
+							lightFill.A = 100
+							paint.FillShape(gtx.Ops, lightFill, rect.Op())
+
+							duration := float64(gtx.Now.Sub(pipe.since).Milliseconds()) / 2000
+							if duration > 1 {
+								duration = 1
+							} else {
+								duration = ease.OutQuint(duration)
+							}
+
+							height = int(math.Round(heightF * duration))
+							gap = gtx.Constraints.Max.Y - height
+							rect.Min.Y = gap
 
 							paint.FillShape(gtx.Ops, pipe.col, rect.Op())
 							offset.Pop()