BlipKit for Godot Engine 4.3

A GDExtension for creating the beautiful sound of old sound chips.

• Generate waveforms: square, triangle, noise, sawtooth, sine, and custom ones using BlipKitTrack
• Create pitch, volume, panning, and duty cycle envelopes using BlipKitInstrument
• Load and play audio samples from AudioStreamWAV using BlipKitSample
• Provides a basic byte code interpreter to generate more complex melodies and reuse patterns

Contents

• Installation
• Introduction
• Usage
• Byte code interpreter
• Classes
• References

Power On!

Installation

1. Search for BlipKit in the AssetLib editor tab
2. Download and install the plugin
3. Enable the plugin in the project settings via the Plugins tab

or...

1. Clone this repository or download the archive
2. Copy the folder addons/detomon.blipkit to your project's addons folder (create it if needed)
3. Enable the plugin in the project settings via the Plugins tab

Introduction

The BlipKitTrack class generates a single waveform. Multiple tracks can be attached to a AudioStreamBlipKit, which then mixes the audio. As with every audio stream, it can be used with AudioStreamPlayer, AudioStreamPlayer2D or AudioStreamPlayer3D nodes.

Time is measured in ticks. Every tick allows properties of the waveform to be updated. The tick rate is 240 ticks per second.

Usage

• Create an AudioStreamPlayer node and add an AudioStreamBlipKit resource
• Attach BlipKitTrack objects to the stream resource
• Change properties of the BlipKitTrack to play notes, change the volume etc.

[!TIP] See the examples directory for some examples.

Class descriptions are available in the Editor via the reference documentation after the extension is loaded, or in the doc/classes directory.

Examples

• Play an iconic startup sound (Power On!):

extends Node

# Create a track.
var _track := BlipKitTrack.new()
# Create an instrument.
var _instr := BlipKitInstrument.new()

# An audio player with an `AudioStreamBlipKit` resource.
@onready var _player: AudioStreamPlayer = $AudioStreamPlayer

func _ready() -> void:
	# Set pitch sequence:
	# - Play lower octave for 18 ticks (defined with `_track.instrument_divider`)
	# - Then play current note as long as the note is playing
	_instr.set_envelope(BlipKitInstrument.ENVELOPE_PITCH, [-12, 0])

	# Set volume envelope:
	# - Set volume to 1.0 for 0 ticks (do not slide from previous value)
	# - Keep volume on 1.0 for 18 ticks
	# - Slide volume to 0.0 for 162 ticks
	_instr.set_envelope(BlipKitInstrument.ENVELOPE_VOLUME, [1.0, 1.0, 0.0], [0, 18, 162])

	# Set duty cycle of square wave to 50%.
	_track.duty_cycle = 8
	# Set instrument.
	_track.instrument = _instr
	# Set number of ticks per envelope sequence value.
	_track.instrument_divider = 18

	# Get the audio stream.
	var stream: AudioStreamBlipKit = _player.stream
	# Attach the track to the audio stream.
	_track.attach(stream)

	# Add a divider and call it every 360 ticks (1.5 seconds).
	_track.add_divider(360, func () -> int:
		# Release previous note to start instrument again.
		_track.release()
		# Play note C on octave 6.
		_track.note = BlipKitTrack.NOTE_C_6

		# Do not change tick rate of divider.
		return 0
	)

Byte code interpreter

The byte code assembler allows to create instructions to play patterns.

• BlipKitAssembler generate byte code from instructions
• BlipKitInterpreter execute the byte code on a BlipKitTrack to change its properties over time

Examples

• Play an iconic startup sound (Power On! Assembler version).
• Play on multiple tracks (Bytecode).

Classes

Overview

• AudioStreamBlipKit
• BlipKitAssembler
• BlipKitBytecode
• BlipKitInstrument
• BlipKitInterpreter
• BlipKitSample
• BlipKitTrack
• BlipKitWaveform

References

Uses the BlipKit library to generate audio.