Initial commit. Implement music sync features.

rhythm_game/music_sync/beat_update.gd

@@ -0,0 +1,26 @@
+class_name BeatUpdate
+
+## Beat this frame.
+var current: float
+
+## Beat last frame.
+var previous: float
+
+
+## Beat updated forward in time.
+func forward() -> bool:
+	return current > previous
+
+
+## Beat updated backward in time.
+func backward() -> bool:
+	return current < previous
+
+
+func new_beat() -> bool:
+	return floori(previous) != floori(current)
+
+
+func _init(current_beat: float = 0.0, previous_beat: float = 0.0) -> void:
+	current = current_beat
+	previous = previous_beat