Godot Audio Generator

audiogen.gd

extends Node2D

var playback = null
var phase = 0.1

const hz = 1024
const notes = {'s':0.01,'do':0.8,'re':0.9,'mi':1.01,'fa':1.06,'sol':1.18,'la':1.34,'si':1.52}

# Q: DO, W: RE, E: MI, R: FA, T: SOL, Y: LA, U: SI
const keys = {81:'do',87:'re',69:'mi',82:'fa',84:'sol',89:'la',85:'si'}

func _fill_buffer():
	var to_fill = playback.get_frames_available()
	while (to_fill > 0):
		playback.push_frame(Vector2(1.0, 1.0) *  sin(phase * (PI * 2.0)))
		phase = fmod((phase + (1.0 / (hz / 8.0))), 1.0)
		to_fill -= 1

func _ready():
	playback = $AudioStreamPlayer.get_stream_playback()
	_fill_buffer()
	$AudioStreamPlayer.play()
	set_process(true)

func _input(event):
	if event is InputEventKey and event.scancode in keys.keys():
		$AudioStreamPlayer.pitch_scale = notes[keys[event.scancode]]
		$mute.stop()

func _process(delta):
	_fill_buffer()
	if $mute.is_stopped():
		$mute.start()

func _on_mute_timeout():
	$AudioStreamPlayer.pitch_scale = 0.01
  

audiogen.tscn

[gd_scene load_steps=3 format=2]

[ext_resource path="res://audiogen.gd" type="Script" id=1]

[sub_resource type="AudioStreamGenerator" id=1]

[node name="Audiogen" type="Node2D"]
position = Vector2( 12, 6.27181 )
script = ExtResource( 1 )

[node name="AudioStreamPlayer" type="AudioStreamPlayer" parent="."]
stream = SubResource( 1 )
pitch_scale = 0.01

[node name="mute" type="Timer" parent="."]
process_mode = 0
wait_time = 0.5
autostart = true
[connection signal="timeout" from="mute" to="." method="_on_mute_timeout"]

default_bus_layout.tres

[gd_resource type="AudioBusLayout" load_steps=2 format=2]

[sub_resource type="AudioEffectReverb" id=1]
resource_name = "Reverb"
damping = 0.35
spread = 0.27
hipass = 0.4
dry = 0.06
wet = 0.32

[resource]
bus/0/effect/0/effect = SubResource( 1 )
bus/0/effect/0/enabled = true