feat(tracker, gioui): add little "*" symbol to indicate if a pattern is unique

tracker/gioui/track.go

@@ -275,7 +275,7 @@ func (t *Tracker) layoutTracks(gtx C) D {
 		lastRow = l - 1
 	}
 	op.Offset(f32.Pt(0, float32(trackRowHeight*firstRow))).Add(gtx.Ops)
-	for _, trk := range t.Song().Score.Tracks {
+	for trkIndex, trk := range t.Song().Score.Tracks {
 		stack := op.Save(gtx.Ops)
 		for row := firstRow; row <= lastRow; row++ {
 			pat := row / t.Song().Score.RowsPerPattern
@@ -292,6 +292,10 @@ func (t *Tracker) layoutTracks(gtx C) D {
 				paint.ColorOp{Color: trackerPatMarker}.Add(gtx.Ops)
 				widget.Label{}.Layout(gtx, textShaper, trackerFont, trackerFontSize, patternIndexToString(s))
 			}
+			if s >= 0 && patRow == 1 && t.IsPatternUnique(trkIndex, s) {
+				paint.ColorOp{Color: mediumEmphasisTextColor}.Add(gtx.Ops)
+				widget.Label{}.Layout(gtx, textShaper, trackerFont, trackerFontSize, "*")
+			}
 			op.Offset(f32.Pt(patmarkWidth, 0)).Add(gtx.Ops)
 			if t.EditMode() == tracker.EditTracks && t.Cursor().Row == patRow && t.Cursor().Pattern == pat {
 				paint.ColorOp{Color: trackerActiveTextColor}.Add(gtx.Ops)

tracker/model.go

@@ -31,6 +31,7 @@ type Model struct {
 	maxID            int
 	filePath         string
 	changedSinceSave bool
+	patternUseCount  [][]int
 
 	prevUndoType    string
 	undoSkipCounter int
@@ -238,6 +239,7 @@ func (m *Model) DeleteTrack(forward bool) {
 	}
 	m.selectionCorner = m.cursor
 	m.clampPositions()
+	m.computePatternUseCounts()
 	m.notifyScoreChange()
 }
 
@@ -377,9 +379,21 @@ func (m *Model) SetCurrentPattern(pat int) {
 		track.Order = append(track.Order, -1)
 	}
 	track.Order[m.cursor.Pattern] = pat
+	m.computePatternUseCounts()
 	m.notifyScoreChange()
 }
 
+func (m *Model) IsPatternUnique(track, pattern int) bool {
+	if track < 0 || track >= len(m.patternUseCount) {
+		return false
+	}
+	p := m.patternUseCount[track]
+	if pattern < 0 || pattern >= len(p) {
+		return false
+	}
+	return p[pattern] <= 1
+}
+
 func (m *Model) SetSongLength(value int) {
 	if value < 1 {
 		value = 1
@@ -390,6 +404,7 @@ func (m *Model) SetSongLength(value int) {
 	m.saveUndo("SetSongLength", 10)
 	m.song.Score.Length = value
 	m.clampPositions()
+	m.computePatternUseCounts()
 	m.notifyScoreChange()
 }
 
@@ -464,6 +479,7 @@ func (m *Model) AddOrderRow(after bool) {
 	m.song.Score.Length++
 	m.selectionCorner = m.cursor
 	m.clampPositions()
+	m.computePatternUseCounts()
 	m.notifyScoreChange()
 }
 
@@ -486,6 +502,7 @@ func (m *Model) DeleteOrderRow(forward bool) {
 	m.song.Score.Length--
 	m.selectionCorner = m.cursor
 	m.clampPositions()
+	m.computePatternUseCounts()
 	m.notifyScoreChange()
 }
 
@@ -668,6 +685,7 @@ func (m *Model) DeletePatternSelection() {
 			}
 		}
 	}
+	m.computePatternUseCounts()
 	m.notifyScoreChange()
 }
 
@@ -987,6 +1005,7 @@ func (m *Model) setSongNoUndo(song sointu.Song) {
 		m.assignUnitIDs(instr.Units)
 	}
 	m.clampPositions()
+	m.computePatternUseCounts()
 	m.notifySamplesPerRowChange()
 	m.notifyPatchChange()
 	m.notifyScoreChange()
@@ -1044,6 +1063,30 @@ func (m *Model) assignUnitIDs(units []sointu.Unit) {
 	}
 }
 
+func (m *Model) computePatternUseCounts() {
+	for i, track := range m.song.Score.Tracks {
+		for len(m.patternUseCount) <= i {
+			m.patternUseCount = append(m.patternUseCount, nil)
+		}
+		for j := range m.patternUseCount[i] {
+			m.patternUseCount[i][j] = 0
+		}
+		for j := 0; j < m.song.Score.Length; j++ {
+			if j >= len(track.Order) {
+				break
+			}
+			p := track.Order[j]
+			for len(m.patternUseCount[i]) <= p {
+				m.patternUseCount[i] = append(m.patternUseCount[i], 0)
+			}
+			if p < 0 {
+				continue
+			}
+			m.patternUseCount[i][p]++
+		}
+	}
+}
+
 func clamp(a, min, max int) int {
 	if a < min {
 		return min