op1r-src - source code of op1r, custom firmware for the Teenage Engineering OP-1 (firmware R246)
Copyright (C) 2026 pcppcp

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public
License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later
version. It is distributed WITHOUT ANY WARRANTY; see the GNU General Public License (LICENSE) for details.

Covered: our source code, our graphics (SVG) and our compiled code, including the code contained in the op1r patch
data (https://github.com/pcppcp/op1r). Anyone who distributes this program or a work based on it (modified patchers, other firmware mods or
products containing this code) must do so under the GPL and provide the complete corresponding source.

ADDITIONAL PERMISSION (GPL-3.0 section 7)
As an additional permission, you may combine this program, or a work based on it, with the Teenage Engineering OP-1
firmware (original or patched) and convey the resulting combination, provided that the parts of the combination
that are this program or based on it are conveyed under the terms of the GPL with this additional permission. The
OP-1 firmware itself is not covered by this license.

CONTRIBUTIONS
Contributions (for example synth / FX plugins, synth_sdk/PLUGINS.md) are accepted under the same terms:
GPL-3.0-or-later with the additional permission above. Contributors keep their copyright lines in their files.

NOT COVERED by this license
- The Teenage Engineering OP-1 firmware and any part of it, including the original firmware bytes in the patch data
  that the patcher uses to verify its input. Copyright Teenage Engineering. This repository contains no firmware;
  the patcher needs your own copy of the official image.
- synth_sdk/l1_patches.json: byte differences inside the firmware's encrypted code (original and patched bytes
  at the patched places only), like the op1r patch data. They are used to verify and patch your own copy.
- Oblique Strategies card texts: by Brian Eno and Peter Schmidt (list from
  https://github.com/ultralazr/op1-oblique-strategies). Not ours and not licensed by us.

THIRD-PARTY CODE (MIT or GPL-3.0, compatible with op1r's GPL-3.0-or-later; their notices are kept)
- Fixed-point ports of Mutable Instruments Clouds and the Elements reverb: original code (c) 2014 Emilie Gillet,
  MIT License.
- grids (synth_sdk/grids, plugins/grids): a port of Mutable Instruments Grids' pattern generator and drum map
  (generated from its resources.cc), original code (c) 2011 Emilie Gillet, GPL-3.0 (AVR code of
  pichenettes/eurorack).
- nostromo (plugins/nostromo): the plate tank's topology, coefficients and output taps after the Synthstrom
  Deluge's "Digital" reverb (src/deluge/dsp/reverb/digital.hpp), (c) 2024 Katherine Whitlock, GPL-3.0, itself
  after J. Dattorro, "Effect Design, Part 1" (1997); fixed-point helpers from plugins/reverb (the Elements port).
- iter-lab.svg and the LZMA settings of op1repacker: (c) 2016 op1hacks, MIT License
  (https://github.com/op1hacks/op1repacker).
- svgfont.py and the Oblique Strategies idea: (c) 2026 Martin Mairinger, MIT License
  (https://github.com/ultralazr/op1-oblique-strategies).