From fa163b3884b1d7d418affe51ae83d4e9a8c91e76 Mon Sep 17 00:00:00 2001
From: Veikko Sariola <veikko.sariola@gmail.com>
Date: Mon, 7 Dec 2020 11:43:14 +0200
Subject: [PATCH] feat(sointu-cli): Add ability to adjust HOLD value of the
 patterns

---
 go4k/cmd/sointu-cli/main.go |  7 +++++++
 go4k/song.go                | 22 ++++++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/go4k/cmd/sointu-cli/main.go b/go4k/cmd/sointu-cli/main.go
index 4f62f1f..05375c9 100644
--- a/go4k/cmd/sointu-cli/main.go
+++ b/go4k/cmd/sointu-cli/main.go
@@ -27,6 +27,7 @@ func main() {
 	exactLength := flag.Bool("e", false, "When outputting the C header file, calculate the exact length of song by rendering it once. Only useful when using SPEED opcodes.")
 	rawOut := flag.Bool("r", false, "Output the rendered song as .raw stereo float32 buffer, to standard output unless otherwise specified.")
 	directory := flag.String("d", "", "Directory where to output all files. The directory and its parents are created if needed. By default, everything is placed in the same directory where the original song file is.")
+	hold := flag.Int("o", -1, "New value to be used as the hold value")
 	flag.Usage = printUsage
 	flag.Parse()
 	if flag.NArg() == 0 || *help {
@@ -105,6 +106,12 @@ func main() {
 				return fmt.Errorf("Error playing: %v", err)
 			}
 		}
+		if *hold > -1 {
+			err = song.UpdateHold(byte(*hold))
+			if err != nil {
+				return fmt.Errorf("error updating the hold value of the song: %v", err)
+			}
+		}
 		if *headerOut {
 			maxSamples := 0 // 0 means it is calculated automatically
 			if *exactLength {
diff --git a/go4k/song.go b/go4k/song.go
index 6688a71..5f07143 100644
--- a/go4k/song.go
+++ b/go4k/song.go
@@ -112,3 +112,25 @@ func Play(synth Synth, song Song) ([]float32, error) {
 	}
 	return buffer, nil
 }
+
+func (s *Song) UpdateHold(newHold byte) error {
+	if newHold == 0 {
+		return errors.New("hold value cannot be 0, 0 is reserved for release")
+	}
+	for _, pat := range s.Patterns {
+		for _, v := range pat {
+			if v > s.Hold && v <= newHold {
+				return errors.New("song uses note values greater or equal to the new hold value")
+			}
+		}
+	}
+	for _, pat := range s.Patterns {
+		for i, v := range pat {
+			if v > 0 && v <= s.Hold {
+				pat[i] = newHold
+			}
+		}
+	}
+	s.Hold = newHold
+	return nil
+}