drafting

tracker/gioui/signal_rail.go

@@ -0,0 +1,96 @@
+package gioui
+
+import (
+	"image"
+	"image/color"
+	"math"
+
+	"gioui.org/f32"
+	"gioui.org/op/clip"
+	"gioui.org/op/paint"
+	"gioui.org/unit"
+	"github.com/vsariola/sointu/tracker"
+)
+
+const numSignalsDrawn = 8
+
+type (
+	SignalRailStyle struct {
+		Color        color.NRGBA
+		LineWidth    unit.Dp
+		PortDiameter unit.Dp
+		PortColor    color.NRGBA
+	}
+
+	SignalRailWidget struct {
+		Style  *SignalRailStyle
+		Signal tracker.Signal
+		Width  unit.Dp
+		Height unit.Dp
+	}
+)
+
+func SignalRail(th *Theme, signal tracker.Signal) SignalRailWidget {
+	return SignalRailWidget{
+		Style:  &th.SignalRail,
+		Signal: signal,
+		Width:  th.UnitEditor.Width,
+		Height: th.UnitEditor.Height,
+	}
+}
+
+func (s SignalRailWidget) Layout(gtx C) D {
+	w := gtx.Dp(s.Width)
+	h := gtx.Dp(s.Height)
+	l := gtx.Dp(s.Style.LineWidth)
+	d := gtx.Dp(s.Style.PortDiameter)
+	c := max(l, d) / 2
+	stride := (w - c*2) / numSignalsDrawn
+	var path clip.Path
+	path.Begin(gtx.Ops)
+	// Draw pass through signals
+	for i := range min(numSignalsDrawn, s.Signal.PassThrough) {
+		x := float32(i*stride + c)
+		path.MoveTo(f32.Pt(x, 0))
+		path.LineTo(f32.Pt(x, float32(h)))
+	}
+	// Draw the routing of input signals
+	for i := range min(len(s.Signal.StackUse.Inputs), numSignalsDrawn-s.Signal.PassThrough) {
+		input := s.Signal.StackUse.Inputs[i]
+		x1 := float32((i+s.Signal.PassThrough)*stride + c)
+		for _, link := range input {
+			x2 := float32((link+s.Signal.PassThrough)*stride + c)
+			path.MoveTo(f32.Pt(x1, 0))
+			path.LineTo(f32.Pt(x2, float32(h/2)))
+		}
+	}
+	// Draw the routing of output signals
+	for i := range min(s.Signal.StackUse.NumOutputs, numSignalsDrawn-s.Signal.PassThrough) {
+		x := float32((i+s.Signal.PassThrough)*stride + c)
+		path.MoveTo(f32.Pt(x, float32(h/2)))
+		path.LineTo(f32.Pt(x, float32(h)))
+	}
+	paint.FillShape(gtx.Ops, s.Style.Color,
+		clip.Stroke{
+			Path:  path.End(),
+			Width: float32(l),
+		}.Op())
+	// Draw the circles on modified signals
+
+	for i := range min(len(s.Signal.StackUse.Modifies), numSignalsDrawn-s.Signal.PassThrough) {
+		if !s.Signal.StackUse.Modifies[i] {
+			continue
+		}
+		var circle clip.Path
+		x := float32((i + s.Signal.PassThrough) * stride)
+		circle.Begin(gtx.Ops)
+		circle.MoveTo(f32.Pt(x, float32(h/2)))
+		f := f32.Pt(x+float32(c), float32(h/2))
+		circle.ArcTo(f, f, float32(2*math.Pi))
+		p := clip.Outline{Path: circle.End()}.Op().Push(gtx.Ops)
+		paint.ColorOp{Color: s.Style.PortColor}.Add(gtx.Ops)
+		paint.PaintOp{}.Add(gtx.Ops)
+		p.Pop()
+	}
+	return D{Size: image.Pt(w, h)}
+}