Add: phase based sine wave oscillator and comment GDscript

1 files changed, 18 insertions, 6 deletions

diff --git a/klangfarb/main.gd b/klangfarb/main.gd
index 82f8ce9..fb29c8c 100644
--- a/klangfarb/main.gd
+++ b/klangfarb/main.gd
@@ -1,22 +1,34 @@
 extends AudioStreamPlayer
-var playback: AudioStreamPlayback = null
 
+# controllable frequency interface
+export(float, 20, 8000, 10) var freq = 440.0
+
+# load the GDNative script connected to the rust lib
 var SineWave = preload("res://SineWave.gdns")
+# make an instance of our one "class" in rust lib
 var wave = SineWave.new()
-var freq = 440.0
+
+# initialize the Godot stream we fill up with samples
+var playback: AudioStreamPlayback = null
 
 func _fill_buffer() -> void:
+	# get count of Frames (sample, sample) available in stream
 	var to_fill = playback.get_frames_available()
-	print(to_fill)
 	if to_fill > 0:
+		# ask Rust to generate N frames at freq
+		# Array<Vector2> gets pushed to the 
+		# playback stream buffer
 		playback.push_buffer(wave.frames(freq, to_fill)) 
 
 func _process(_delta):
-	_fill_buffer()
+		_fill_buffer()
 
 func _ready() -> void:
-	self.stream.mix_rate = freq * 256
-	wave.set_sample_rate(freq * 256)
+	# ensure Godot/Sine have the same sample rate
+	wave.set_sample_rate(self.stream.mix_rate)
+	# get our AudioStreamPlayback object
 	playback = self.get_stream_playback()
+	# prefill the stream's sample buffer (which feeds DAC)
 	_fill_buffer()
+	# start the audio
 	self.play()