feat(tracker): add menu item to export .wav

Also refactor the common functions for .wav export into base package so that both sointu-play and tracker can use same functions.

tracker/gioui/files.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"path/filepath"
+	"time"
 
 	"gioui.org/app"
 	"gopkg.in/yaml.v3"
@@ -82,3 +83,33 @@ func (t *Tracker) saveSong(filename string) bool {
 	t.SetChangedSinceSave(false)
 	return true
 }
+
+func (t *Tracker) exportWav(pcm16 bool) {
+	filename, err := dialog.File().Filter(".wav file", "wav").Title("Export .wav").Save()
+	if err != nil {
+		return
+	}
+	var extension = filepath.Ext(filename)
+	if extension == "" {
+		filename = filename + ".wav"
+	}
+	synth, err := t.synthService.Compile(t.Song().Patch)
+	if err != nil {
+		t.Alert.Update(fmt.Sprintf("Error compiling the patch during export: %v", err), Error, time.Second*3)
+		return
+	}
+	for i := 0; i < 32; i++ {
+		synth.Release(i)
+	}
+	data, _, err := sointu.Play(synth, t.Song()) // render the song to calculate its length
+	if err != nil {
+		t.Alert.Update(fmt.Sprintf("Error rendering the song during export: %v", err), Error, time.Second*3)
+		return
+	}
+	buffer, err := sointu.Wav(data, pcm16)
+	if err != nil {
+		t.Alert.Update(fmt.Sprintf("Error converting to .wav: %v", err), Error, time.Second*3)
+		return
+	}
+	ioutil.WriteFile(filename, buffer, 0644)
+}

tracker/gioui/layout.go

@@ -39,6 +39,22 @@ func (t *Tracker) Layout(gtx layout.Context) {
 	for t.ConfirmSongDialog.BtnCancel.Clicked() {
 		t.ConfirmSongDialog.Visible = false
 	}
+	dstyle = ConfirmDialog(t.Theme, t.WaveTypeDialog, "Export .wav in int16 or float32 sample format?")
+	dstyle.ShowAlt = true
+	dstyle.OkStyle.Text = "Int16"
+	dstyle.AltStyle.Text = "Float32"
+	dstyle.Layout(gtx)
+	for t.WaveTypeDialog.BtnOk.Clicked() {
+		t.exportWav(true)
+		t.WaveTypeDialog.Visible = false
+	}
+	for t.WaveTypeDialog.BtnAlt.Clicked() {
+		t.exportWav(false)
+		t.WaveTypeDialog.Visible = false
+	}
+	for t.WaveTypeDialog.BtnCancel.Clicked() {
+		t.WaveTypeDialog.Visible = false
+	}
 }
 
 func (t *Tracker) confirmedSongAction() {

tracker/gioui/songpanel.go

@@ -61,6 +61,8 @@ func (t *Tracker) layoutMenuBar(gtx C) D {
 		case 3:
 			t.SaveSongAsFile()
 		case 4:
+			t.WaveTypeDialog.Visible = true
+		case 5:
 			t.TryQuit()
 		}
 		clickedItem, hasClicked = t.Menus[0].Clicked()
@@ -93,6 +95,7 @@ func (t *Tracker) layoutMenuBar(gtx C) D {
 			MenuItem{IconBytes: icons.FileFolder, Text: "Open Song", ShortcutText: shortcutKey + "O"},
 			MenuItem{IconBytes: icons.ContentSave, Text: "Save Song", ShortcutText: shortcutKey + "S"},
 			MenuItem{IconBytes: icons.ContentSave, Text: "Save Song As..."},
+			MenuItem{IconBytes: icons.ImageAudiotrack, Text: "Export Wav..."},
 			MenuItem{IconBytes: icons.ActionExitToApp, Text: "Quit"},
 		)),
 		layout.Rigid(t.layoutMenu("Edit", &t.MenuBar[1], &t.Menus[1], unit.Dp(160),

tracker/gioui/tracker.go

@@ -70,6 +70,7 @@ type Tracker struct {
 	PatternOrderScrollBar *ScrollBar
 	ConfirmInstrDelete    *Dialog
 	ConfirmSongDialog     *Dialog
+	WaveTypeDialog        *Dialog
 	ConfirmSongActionType int
 	window                *app.Window
 
@@ -82,6 +83,7 @@ type Tracker struct {
 	errorChannel chan error
 	quitted      bool
 	audioContext sointu.AudioContext
+	synthService sointu.SynthService
 
 	*tracker.Model
 }
@@ -165,8 +167,10 @@ func New(audioContext sointu.AudioContext, synthService sointu.SynthService, syn
 		PatternOrderScrollBar: &ScrollBar{Axis: layout.Vertical},
 		ConfirmInstrDelete:    new(Dialog),
 		ConfirmSongDialog:     new(Dialog),
+		WaveTypeDialog:        new(Dialog),
 		errorChannel:          make(chan error, 32),
 		window:                window,
+		synthService:          synthService,
 	}
 	t.Model = tracker.NewModel()
 	vuBufferObserver := make(chan []float32)