go-qwertysynth

Very loose reinterpretation of spencerharmon/qwertysynth in Go.

Portions (C) ebitengine.org and Hajime Hoshi.

What is it?

This is a keyboard-operated synthesizer. It's not a very good one, at that.

What systems does it work on?

• Windows (Windows 2000 or newer)
  • Sound Card
    • WinMM (WAVE_MAPPER device)
    • DirectSound (via optional build flag: directsound)
    • PulseAudio (via optional build flag: pulseaudio) - NOTE: Not recommended except for WSL (Linux) builds!
• Linux
  • Sound Card
    • PulseAudio

How do I build this thing?

What you need

For a Windows build, we recommend the following:

• Windows 2000 (or newer) - we used Windows 10 Pro (Windows 10 Version 20H2)
• Visual Studio Code
  • Go extension for VSCode v0.19.0 (or newer)
  • Go v1.18.1 (or newer)

For a non-Windows (e.g.: Linux) build, we recommend the following:

• Ubuntu 20.04 (or newer) - we used Ubuntu 20.04.1 LTS running in WSL2

• Go v1.18.1 (or newer)

• The following libraries (versions listed are for Ubuntu 20.04):

  • libxcursor-dev (1:1.2.0-2)
  • libxi-dev (2:1.7.10-0ubuntu1)
  • libxinerama-dev (2:1.1.4-2)
  • libxrandr-dev (2:1.5.2-0ubuntu1)
  • libxxf86vm-dev (1:1.1.4-1build1)
  • libglfw3-dev (3.3.2-1)
  • libx11-dev (2:1.6.9-2ubuntu1.2)

  On Ubuntu, you can get these libraries with this command:

  sudo apt install libx11-dev libxcursor-dev libxrandr-dev libxinerama-dev libxi-dev libglfw3-dev libxxf86vm-dev -y

• On WSL2, we recommend using VcXsrv 1.20.8.1.

How to build (on Windows)

1. First, load the project folder in VSCode. If this is the first time you've ever opened a Go project, VSCode will splash up a thousand alerts asking to install various things for Go. Allow it to install them before continuing on.
2. Next, open a Terminal for powershell.
3. Enter the following commands

   go mod download
   go build

   When the command completes, you should now have the go-qwertysynth.exe file - run it with .\go-qwertysynth.exe play to start!

How to build (on Linux)

1. Build the player with the following commands

   go mod download
   go build

   When the command completes, you should now have the go-qwertysynth file - run it with ./go-qwertysynth play to start!

NOTE: In order to use PulseAudio, you must have your PULSE_SERVER connection string environment variable configured:

• e.g.:

  PULSE_SERVER=tcp:127.0.0.1:4713

  (Take note that there are bugs associated with TCP connection strings; see bugs section below) For more information about the PULSE_SERVER environment variable, please see the PulseAudio documentation.

Waveform Configuration

Waveforms are configured using settings strings. An example setting string looks like this:

sine,adsr:1s:80ms:-12.75db:1s,frequency:1.125,amplitude:16

The components of the above string are:

• name of the waveform generator to be used (sine)
• envelope settings (adsr) which are comprised of the following items:
  • attack duration (1s)
  • decay duration (80ms)
  • sustain level (-12.75db)
  • release duration (1s)
• additional waveform parameters:
  • the desired default waveform frequency (frequency) to be used (1.125 - in Hertz)
  • the desired default waveform amplitude (amplitude) to be used (16 - as a strict multiplier, but can be specified as dBv attenuation (db))

Supported Waveform Generators and Parameters

Waveforms:

Identifier	Name
sine, sin	Sine
square, sqr	Square
triangle, tri	Triangle

Parameters:

Identifier	Name	Default	Notes
frequency freq f	Frequency	C-4	C-4 = 261.626 Hz, usually, but depends on configured scale for synth machine used
amplitude amp a	Amplitude	1.0	For amplitude modulator, this is full volume For frequency modulator, this is 1 full note microtone that the synth machine understands

Envelope

Envelopes are based on a simple ADSR mechanism. See Waveform Configuration above for more information.

FM Modulation

When configured (i.e.: the waveform configuration is not empty or blank), a waveform will be applied to an amplitude modulator waveform as a note microtone (Microtone) value.

Microtones are synth machine specific implementations, but are usually defined as rational mini-steps between notes.

Synth Machines

In order to generate a waveform and sample it for playback, a synth machine must be configured.

Supported synth machines:

Identifier	Name	Details
xm	FastTracker II	64 microtones of 1.5625 cents per microtone between notes 12 notes per octave Central octave is 4 A440 (equal) tuning
it	Impulse Tracker	64 microtones of 1.5625 cents per microtone between notes 12 notes per octave Central octave is 5 A440 (equal) tuning

Synth machines can also be configured with a tuning system. Available tuning systems include:

Identifier	Name	Details
default		Use the default value specified by the machine
equal-A415 A415	A415 (equal)	A-4 is identified to be exactly 415.0 Hz Twelve-tone equal temperament
equal-A427 A427	A427 (equal)	A-4 is identified to be exactly 427.0 Hz Twelve-tone equal temperament
equal-A428 A428	A428 (equal)	A-4 is identified to be exactly 428.0 Hz Twelve-tone equal temperament
equal-A429 A429	A429 (equal)	A-4 is identified to be exactly 429.0 Hz Twelve-tone equal temperament
equal-A430 A430	A430 (equal)	A-4 is identified to be exactly 430.0 Hz Twelve-tone equal temperament
equal-A432 A432	A432 (equal)	A-4 is identified to be exactly 432.0 Hz Twelve-tone equal temperament
equal-A435 A435	A435 (equal)	A-4 is identified to be exactly 435.0 Hz Twelve-tone equal temperament
equal-A440 A440	A440 (equal)	A-4 is identified to be exactly 440.0 Hz Twelve-tone equal temperament
equal-A444 A444	A444 (equal)	A-4 is identified to be exactly 444.0 Hz Twelve-tone equal temperament
equal-A466 A466	A466 (equal)	A-4 is identified to be exactly 466.0 Hz Twelve-tone equal temperament
equal-scientific scientific	Scientific (equal)	C-4 is identified to be exactly 256.0 Hz Twelve-tone equal temperament
equal-53 53TET 53	53-TET (equal)	A-4 is identified to be exactly 440.0 Hz 53 tone equal temperament
just-harmonic harmonic	Harmonic (just)	C-4 is identified to be 261.626 Hz Twelve-tone just intonation
just-pythagorean pythagorean	Pythagorean (just)	D-4 is identified to be 288.325 Hz Twelve-tone just intonation

Synth Mode

You can access this via the play command-line parameter. For more details about settings of this mode, add the --help command-line parameter.

Keyboard Legend (for Twelve-tone intonations):

• Q key-row starts with C-5 on XM and C-6 on IT
• A key-row starts with C-4 on XM and C-5 on IT
• Z key-row starts with C-3 on XM and C-4 on IT
  • Note: there are not enough keys present on this row to get a full octave, so key mappings for A# and B are unavailable.
• Escape (Esc) to quit
• Page Up (Pg Up) to increase keyboard octave
• Page Down (Pg Dn) to decrease keyboard octave

Hold note keys to sustain notes; release the note keys to decay them.

Release note keys while holding Shift to cut/stop them.

Note: US English keyboard layout works best

Tracker Mode

Included is a silly little tracker. It has a single portion of the song The Celebrated Chop Waltz by Euphemia Allen (originally published under the pseudonym Arthur de Lulli) attached.

You can access this via the play tracker command-line parameters. For more details about settings of this mode, add the --help command-line parameter.

Quirks

Item	Notes
windows winmm	Setting the number of channels to more than 2 may cause WinMM and/or qwertysynth to do unusual things. You might be able to get a hardware 4-channel capable card (such as the Aureal Vortex 2 AU8830) to work, but driver inconsistencies and weirdnesses in WinMM will undoubtedly cause needless strife.
pulseaudio	PulseAudio support is offered through a Pure Go interface originally created by Johann Freymuth, called jfreymuth/pulse. While it seems to work pretty well, it does have some inconsistencies when compared to the FreeDesktop supported C interface. If you see an error about there being a "missing port in address" specifically when using a TCP connection string, make sure to append the default port specifier of :4713 to the end of the PULSE_SERVER environment variable.
windows directsound	DirectSound integration is not great code. It works well enough after recent code changes fixing event support, but it's still pretty ugly.