WIP: peak/rms meter visualization

2024-07-22 09:27:09 -07:00
parent 849d12d7a0
commit 1b5cf118e1
3 changed files with 197 additions and 14 deletions
@@ -0,0 +1,141 @@
+package ui
+
+import (
+	"image/color"
+	"math"
+	"time"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/canvas"
+	"fyne.io/fyne/v2/container"
+	"fyne.io/fyne/v2/theme"
+	"fyne.io/fyne/v2/widget"
+)
+
+const (
+	meterRangeDB       = 60
+	rmsSmoothingFactor = 0.8
+	peakHoldFrames     = 60
+)
+
+type PeakFN func() (float64, float64, float64, float64)
+
+type PeakMeter struct {
+	widget.BaseWidget
+	peakFnDB       PeakFN
+	lPeak          float64
+	rPeak          float64
+	lRMS           float64
+	rRMS           float64
+	lPeakHold      float64
+	rPeakHold      float64
+	lPeakHoldFrame uint64
+	rPeakHoldFrame uint64
+	frameCounter   uint64
+
+	lPeakRect     canvas.Rectangle
+	rPeakRect     canvas.Rectangle
+	lRMSRect      canvas.Rectangle
+	rRMSRect      canvas.Rectangle
+	lPeakHoldRect canvas.Rectangle
+	rPeakHoldRect canvas.Rectangle
+	anim          *fyne.Animation
+}
+
+func NewPeakMeter(peakFnDB PeakFN) *PeakMeter {
+	p := &PeakMeter{peakFnDB: peakFnDB}
+	p.ExtendBaseWidget(p)
+	return p
+}
+
+func (p *PeakMeter) Start() {
+	if p.anim != nil {
+		return
+	}
+	p.anim = fyne.NewAnimation(time.Duration(math.MaxInt64) /*until stopped*/, p.tick)
+	p.anim.Start()
+}
+
+func (p *PeakMeter) Stop() {
+	if p.anim != nil {
+		p.anim.Stop()
+		p.anim = nil
+		p.frameCounter = 0
+		p.lPeakHoldFrame = 0
+		p.rPeakHoldFrame = 0
+	}
+}
+
+func (p *PeakMeter) tick(_ float32) {
+	lPeak, rPeak, lRMS, rRMS := p.peakFnDB()
+	p.lPeak = lPeak
+	p.rPeak = rPeak
+	lRMS = math.Max(-96, lRMS)
+	rRMS = math.Max(-96, rRMS)
+	p.lRMS = rmsSmoothingFactor*p.lRMS + (1-rmsSmoothingFactor)*lRMS
+	p.rRMS = rmsSmoothingFactor*p.rRMS + (1-rmsSmoothingFactor)*rRMS
+
+	if lPeak > p.lPeakHold || p.frameCounter-p.lPeakHoldFrame > peakHoldFrames {
+		p.lPeakHold = lPeak
+		p.lPeakHoldFrame = p.frameCounter
+	}
+	if rPeak > p.rPeakHold || p.frameCounter-p.rPeakHoldFrame > peakHoldFrames {
+		p.rPeakHold = rPeak
+		p.rPeakHoldFrame = p.frameCounter
+	}
+
+	p.frameCounter++
+	p.Refresh()
+}
+
+func (p *PeakMeter) CreateRenderer() fyne.WidgetRenderer {
+	c := theme.PrimaryColor().(color.NRGBA)
+	c.A = 128
+	p.lPeakRect.FillColor = c
+	p.rPeakRect.FillColor = c
+	p.lRMSRect.FillColor = c
+	p.rRMSRect.FillColor = c
+	p.lPeakHoldRect.FillColor = theme.ForegroundColor()
+	p.rPeakHoldRect.FillColor = p.lPeakHoldRect.FillColor
+	return widget.NewSimpleRenderer(
+		container.New(
+			&peakMeterLayout{p},
+			&p.lPeakRect, &p.rPeakRect,
+			&p.lRMSRect, &p.rRMSRect,
+			&p.lPeakHoldRect, &p.rPeakHoldRect,
+		),
+	)
+}
+
+type peakMeterLayout struct {
+	p *PeakMeter
+}
+
+func (l *peakMeterLayout) MinSize(_ []fyne.CanvasObject) fyne.Size {
+	return fyne.NewSize(50, 150)
+}
+
+func (l *peakMeterLayout) Layout(objects []fyne.CanvasObject, size fyne.Size) {
+	lPeakH := float32(math.Max(0, meterRangeDB+l.p.lPeak)/meterRangeDB) * size.Height
+	rPeakH := float32(math.Max(0, meterRangeDB+l.p.rPeak)/meterRangeDB) * size.Height
+	lRMSH := float32(math.Max(0, meterRangeDB+l.p.lRMS)/meterRangeDB) * size.Height
+	rRMSH := float32(math.Max(0, meterRangeDB+l.p.rRMS)/meterRangeDB) * size.Height
+	lPeakHoldPos := float32(math.Max(0, meterRangeDB+l.p.lPeakHold)/meterRangeDB) * size.Height
+	rPeakHoldPos := float32(math.Max(0, meterRangeDB+l.p.rPeakHold)/meterRangeDB) * size.Height
+
+	halfW := size.Width / 2
+	objects[0].Move(fyne.NewPos(0, size.Height-lPeakH))
+	objects[0].Resize(fyne.NewSize(halfW, lPeakH))
+	objects[1].Move(fyne.NewPos(halfW, size.Height-rPeakH))
+	objects[1].Resize(fyne.NewSize(halfW, rPeakH))
+	objects[2].Move(fyne.NewPos(0, size.Height-lRMSH))
+	objects[2].Resize(fyne.NewSize(halfW, lRMSH))
+	objects[3].Move(fyne.NewPos(halfW, size.Height-rRMSH))
+	objects[3].Resize(fyne.NewSize(halfW, rRMSH))
+
+	peakHoldHt := theme.SeparatorThicknessSize() * 2
+	objects[4].Move(fyne.NewPos(0, size.Height-lPeakHoldPos-peakHoldHt))
+	objects[4].Resize(fyne.NewSize(halfW, peakHoldHt))
+	objects[5].Move(fyne.NewPos(halfW, size.Height-rPeakHoldPos-peakHoldHt))
+	objects[5].Resize(fyne.NewSize(halfW, peakHoldHt))
+}