Add Music Player (#49)

* Adding MusicConductor

* Added selectable songs and player visibility toggle

* Refinements to the music system

* SongInfo compatability with various audio formats

* Moved UI reqs to editor description; flipped conditions to exclude music .import files

* Made selection of the first music track extension-agnostic

* Fixed visual bug with play/pause button when interacting with progress slider

1 files changed, 68 insertions, 0 deletions

diff --git a/game/src/MusicConductor/MusicConductor.gd b/game/src/MusicConductor/MusicConductor.gd
new file mode 100644
index 0000000..a463d6d
--- /dev/null
+++ b/game/src/MusicConductor/MusicConductor.gd
@@ -0,0 +1,68 @@
+extends Node
+
+# SS-67
+@export_dir var musicDir : String
+@export_file var firstSongName : String
+
+var selectedTrack = 0
+var availableSongs : Array[SongInfo] = []
+var autoPlayNextSong : bool = true
+
+func getAllSongNames() -> Array[String]:
+	var songNames : Array[String] = []
+	for si in availableSongs:
+		songNames.append(si.readableName)
+	return songNames
+
+func getCurrentSongIndex() -> int:
+	return selectedTrack
+
+func getCurrentSongName() -> String:
+	return availableSongs[selectedTrack].readableName
+
+func scrubSongByPercentage(percentage: float) -> void:
+	var percentInSeconds : float = (percentage / 100.0) * $AudioStreamPlayer.stream.get_length()
+	$AudioStreamPlayer.play(percentInSeconds)
+
+func getCurrentSongProgressPercentage() -> float:
+	return 100 * ($AudioStreamPlayer.get_playback_position() / $AudioStreamPlayer.stream.get_length())
+
+func isPaused() -> bool:
+	return $AudioStreamPlayer.stream_paused
+
+func togglePlayPause() -> void:
+	$AudioStreamPlayer.stream_paused = !$AudioStreamPlayer.stream_paused
+	
+func startCurrentSong() -> void:
+	$AudioStreamPlayer.stream = availableSongs[selectedTrack].loadedStream
+	$AudioStreamPlayer.play()
+
+# SS-70
+func startSongByIndex(id: int) -> void:
+	selectedTrack = id
+	startCurrentSong()
+
+# SS-69
+func nextSong() -> void:
+	selectedTrack = (selectedTrack + 1) % len(availableSongs)
+	startCurrentSong()
+
+func prevSong() -> void:
+	selectedTrack = (len(availableSongs) - 1) if (selectedTrack == 0) else (selectedTrack - 1)
+	startCurrentSong()
+
+# Called when the node enters the scene tree for the first time.
+func _ready():
+	var dir = DirAccess.open(musicDir)
+	for fname in dir.get_files():
+		if !fname.ends_with(".import"):
+			if fname.get_basename() == firstSongName:
+				selectedTrack = availableSongs.size()
+			availableSongs.append(SongInfo.new(musicDir, fname))
+	startCurrentSong()
+
+
+func _on_audio_stream_player_finished():
+	if autoPlayNextSong:
+		nextSong()
+		startCurrentSong()