feat(tracker): Add a matrix showing track sequences

tracker/patterns.go

@@ -0,0 +1,57 @@
+package tracker
+
+import (
+	"fmt"
+	"image"
+
+	"gioui.org/f32"
+	"gioui.org/layout"
+	"gioui.org/op"
+	"gioui.org/op/clip"
+	"gioui.org/op/paint"
+	"gioui.org/widget"
+	"github.com/vsariola/sointu"
+)
+
+const patternCellHeight = 12
+const patternCellWidth = 16
+
+func (t *Tracker) layoutPatterns(tracks []sointu.Track, activeTrack, cursorPattern, cursorCol, playingPattern int) layout.Widget {
+	return func(gtx layout.Context) layout.Dimensions {
+		gtx.Constraints.Min.X = patternCellWidth * len(tracks)
+		gtx.Constraints.Max.X = patternCellWidth * len(tracks)
+		gtx.Constraints.Max.Y = 50
+		defer op.Push(gtx.Ops).Pop()
+		clip.Rect{Max: gtx.Constraints.Max}.Add(gtx.Ops)
+		paint.FillShape(gtx.Ops, panelColor, clip.Rect{Max: image.Pt(gtx.Constraints.Max.X, trackRowHeight)}.Op())
+		for i, track := range tracks {
+			pop := op.Push(gtx.Ops)
+			gtx.Constraints.Max.X = patternCellWidth
+			clip.Rect{Max: gtx.Constraints.Max}.Add(gtx.Ops)
+			if activeTrack == i {
+				paint.FillShape(gtx.Ops, activeTrackColor, clip.Rect{
+					Max: gtx.Constraints.Max,
+				}.Op())
+			} else {
+				paint.FillShape(gtx.Ops, inactiveTrackColor, clip.Rect{
+					Max: gtx.Constraints.Max,
+				}.Op())
+			}
+			for j, p := range track.Sequence {
+				if j == playingPattern {
+					paint.FillShape(gtx.Ops, patternPlayColor, clip.Rect{Max: image.Pt(trackWidth, trackRowHeight)}.Op())
+				}
+				if j == cursorPattern {
+					paint.ColorOp{Color: trackerActiveTextColor}.Add(gtx.Ops)
+				} else {
+					paint.ColorOp{Color: trackerTextColor}.Add(gtx.Ops)
+				}
+				widget.Label{}.Layout(gtx, textShaper, trackerFont, trackerFontSize, fmt.Sprintf("%d", p))
+				op.Offset(f32.Pt(0, patternCellHeight)).Add(gtx.Ops)
+			}
+			pop.Pop()
+			op.Offset(f32.Pt(patternCellWidth, 0)).Add(gtx.Ops)
+		}
+		return layout.Dimensions{Size: gtx.Constraints.Max}
+	}
+}