Metadata-Version: 2.4
Name: pygoattracker
Version: 0.1.0
Summary: Pure-Python reader, writer, and player for GoatTracker 2 (.SNG) songs
Author: Josh Bailey
License:                                  Apache License
                                   Version 2.0, January 2004
                                http://www.apache.org/licenses/
        
           TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
        
           1. Definitions.
        
              "License" shall mean the terms and conditions for use, reproduction,
              and distribution as defined by Sections 1 through 9 of this document.
        
              "Licensor" shall mean the copyright owner or entity authorized by
              the copyright owner that is granting the License.
        
              "Legal Entity" shall mean the union of the acting entity and all
              other entities that control, are controlled by, or are under common
              control with that entity. For the purposes of this definition,
              "control" means (i) the power, direct or indirect, to cause the
              direction or management of such entity, whether by contract or
              otherwise, or (ii) ownership of fifty percent (50%) or more of the
              outstanding shares, or (iii) beneficial ownership of such entity.
        
              "You" (or "Your") shall mean an individual or Legal Entity
              exercising permissions granted by this License.
        
              "Source" form shall mean the preferred form for making modifications,
              including but not limited to software source code, documentation
              source, and configuration files.
        
              "Object" form shall mean any form resulting from mechanical
              transformation or translation of a Source form, including but
              not limited to compiled object code, generated documentation,
              and conversions to other media types.
        
              "Work" shall mean the work of authorship, whether in Source or
              Object form, made available under the License, as indicated by a
              copyright notice that is included in or attached to the work
              (an example is provided in the Appendix below).
        
              "Derivative Works" shall mean any work, whether in Source or Object
              form, that is based on (or derived from) the Work and for which the
              editorial revisions, annotations, elaborations, or other modifications
              represent, as a whole, an original work of authorship. For the purposes
              of this License, Derivative Works shall not include works that remain
              separable from, or merely link (or bind by name) to the interfaces of,
              the Work and Derivative Works thereof.
        
              "Contribution" shall mean any work of authorship, including
              the original version of the Work and any modifications or additions
              to that Work or Derivative Works thereof, that is intentionally
              submitted to Licensor for inclusion in the Work by the copyright owner
              or by an individual or Legal Entity authorized to submit on behalf of
              the copyright owner. For the purposes of this definition, "submitted"
              means any form of electronic, verbal, or written communication sent
              to the Licensor or its representatives, including but not limited to
              communication on electronic mailing lists, source code control systems,
              and issue tracking systems that are managed by, or on behalf of, the
              Licensor for the purpose of discussing and improving the Work, but
              excluding communication that is conspicuously marked or otherwise
              designated in writing by the copyright owner as "Not a Contribution."
        
              "Contributor" shall mean Licensor and any individual or Legal Entity
              on behalf of whom a Contribution has been received by Licensor and
              subsequently incorporated within the Work.
        
           2. Grant of Copyright License. Subject to the terms and conditions of
              this License, each Contributor hereby grants to You a perpetual,
              worldwide, non-exclusive, no-charge, royalty-free, irrevocable
              copyright license to reproduce, prepare Derivative Works of,
              publicly display, publicly perform, sublicense, and distribute the
              Work and such Derivative Works in Source or Object form.
        
           3. Grant of Patent License. Subject to the terms and conditions of
              this License, each Contributor hereby grants to You a perpetual,
              worldwide, non-exclusive, no-charge, royalty-free, irrevocable
              (except as stated in this section) patent license to make, have made,
              use, offer to sell, sell, import, and otherwise transfer the Work,
              where such license applies only to those patent claims licensable
              by such Contributor that are necessarily infringed by their
              Contribution(s) alone or by combination of their Contribution(s)
              with the Work to which such Contribution(s) was submitted. If You
              institute patent litigation against any entity (including a
              cross-claim or counterclaim in a lawsuit) alleging that the Work
              or a Contribution incorporated within the Work constitutes direct
              or contributory patent infringement, then any patent licenses
              granted to You under this License for that Work shall terminate
              as of the date such litigation is filed.
        
           4. Redistribution. You may reproduce and distribute copies of the
              Work or Derivative Works thereof in any medium, with or without
              modifications, and in Source or Object form, provided that You
              meet the following conditions:
        
              (a) You must give any other recipients of the Work or
                  Derivative Works a copy of this License; and
        
              (b) You must cause any modified files to carry prominent notices
                  stating that You changed the files; and
        
              (c) You must retain, in the Source form of any Derivative Works
                  that You distribute, all copyright, patent, trademark, and
                  attribution notices from the Source form of the Work,
                  excluding those notices that do not pertain to any part of
                  the Derivative Works; and
        
              (d) If the Work includes a "NOTICE" text file as part of its
                  distribution, then any Derivative Works that You distribute must
                  include a readable copy of the attribution notices contained
                  within such NOTICE file, excluding those notices that do not
                  pertain to any part of the Derivative Works, in at least one
                  of the following places: within a NOTICE text file distributed
                  as part of the Derivative Works; within the Source form or
                  documentation, if provided along with the Derivative Works; or,
                  within a display generated by the Derivative Works, if and
                  wherever such third-party notices normally appear. The contents
                  of the NOTICE file are for informational purposes only and
                  do not modify the License. You may add Your own attribution
                  notices within Derivative Works that You distribute, alongside
                  or as an addendum to the NOTICE text from the Work, provided
                  that such additional attribution notices cannot be construed
                  as modifying the License.
        
              You may add Your own copyright statement to Your modifications and
              may provide additional or different license terms and conditions
              for use, reproduction, or distribution of Your modifications, or
              for any such Derivative Works as a whole, provided Your use,
              reproduction, and distribution of the Work otherwise complies with
              the conditions stated in this License.
        
           5. Submission of Contributions. Unless You explicitly state otherwise,
              any Contribution intentionally submitted for inclusion in the Work
              by You to the Licensor shall be under the terms and conditions of
              this License, without any additional terms or conditions.
              Notwithstanding the above, nothing herein shall supersede or modify
              the terms of any separate license agreement you may have executed
              with Licensor regarding such Contributions.
        
           6. Trademarks. This License does not grant permission to use the trade
              names, trademarks, service marks, or product names of the Licensor,
              except as required for reasonable and customary use in describing the
              origin of the Work and reproducing the content of the NOTICE file.
        
           7. Disclaimer of Warranty. Unless required by applicable law or
              agreed to in writing, Licensor provides the Work (and each
              Contributor provides its Contributions) on an "AS IS" BASIS,
              WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
              implied, including, without limitation, any warranties or conditions
              of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
              PARTICULAR PURPOSE. You are solely responsible for determining the
              appropriateness of using or redistributing the Work and assume any
              risks associated with Your exercise of permissions under this License.
        
           8. Limitation of Liability. In no event and under no legal theory,
              whether in tort (including negligence), contract, or otherwise,
              unless required by applicable law (such as deliberate and grossly
              negligent acts) or agreed to in writing, shall any Contributor be
              liable to You for damages, including any direct, indirect, special,
              incidental, or consequential damages of any character arising as a
              result of this License or out of the use or inability to use the
              Work (including but not limited to damages for loss of goodwill,
              work stoppage, computer failure or malfunction, or any and all
              other commercial damages or losses), even if such Contributor
              has been advised of the possibility of such damages.
        
           9. Accepting Warranty or Additional Liability. While redistributing
              the Work or Derivative Works thereof, You may choose to offer,
              and charge a fee for, acceptance of support, warranty, indemnity,
              or other liability obligations and/or rights consistent with this
              License. However, in accepting such obligations, You may act only
              on Your own behalf and on Your sole responsibility, not on behalf
              of any other Contributor, and only if You agree to indemnify,
              defend, and hold each Contributor harmless for any liability
              incurred by, or claims asserted against, such Contributor by reason
              of your accepting any such warranty or additional liability.
        
           END OF TERMS AND CONDITIONS
        
           APPENDIX: How to apply the Apache License to your work.
        
              To apply the Apache License to your work, attach the following
              boilerplate notice, with the fields enclosed by brackets "[]"
              replaced with your own identifying information. (Don't include
              the brackets!)  The text should be enclosed in the appropriate
              comment syntax for the file format. We also recommend that a
              file or class name and description of purpose be included on the
              same "printed page" as the copyright notice for easier
              identification within third-party archives.
        
           Copyright [yyyy] [name of copyright owner]
        
           Licensed under the Apache License, Version 2.0 (the "License");
           you may not use this file except in compliance with the License.
           You may obtain a copy of the License at
        
               http://www.apache.org/licenses/LICENSE-2.0
        
           Unless required by applicable law or agreed to in writing, software
           distributed under the License is distributed on an "AS IS" BASIS,
           WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
           See the License for the specific language governing permissions and
           limitations under the License.
        
Project-URL: Homepage, https://github.com/anarkiwi/pygoattracker
Project-URL: Source, https://github.com/anarkiwi/pygoattracker
Project-URL: Issues, https://github.com/anarkiwi/pygoattracker/issues
Keywords: sid,c64,goattracker,tracker,chiptune,pyresidfp
Classifier: License :: OSI Approved :: Apache Software License
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3.11
Classifier: Programming Language :: Python :: 3.12
Classifier: Programming Language :: Python :: 3.13
Classifier: Topic :: Multimedia :: Sound/Audio
Requires-Python: >=3.10
Description-Content-Type: text/markdown
License-File: LICENSE
Provides-Extra: audio
Requires-Dist: pyresidfp>=0.17; extra == "audio"
Provides-Extra: dev
Requires-Dist: black>=24; extra == "dev"
Requires-Dist: pylint>=3; extra == "dev"
Requires-Dist: pyresidfp>=0.17; extra == "dev"
Requires-Dist: pytest>=7; extra == "dev"
Requires-Dist: pytest-cov>=4; extra == "dev"
Dynamic: license-file

# pygoattracker

Pure-Python reader, writer, and player for
[GoatTracker 2](https://sourceforge.net/projects/goattracker2/) `.SNG`
songs, with SID register log output and audio rendering through an
emulated SID.

GoatTracker is a family of tracker applications for composing C64/SID
music by Lasse Öörni (Cadaver). pygoattracker implements the GTS5 song
format and the playroutine from first principles, following the
GoatTracker 2.76 format documentation and `gplay.c`.

## Install

```bash
pip install pygoattracker          # read/write/play/register logs
pip install pygoattracker[audio]   # + WAV rendering via pyresidfp
```

No required dependencies: everything except audio rendering is stdlib
only.

## Read a song

```python
from pygoattracker import read_sng

song = read_sng("tune.sng")
print(song.name, song.author, song.copyright)

for instrument in song.instruments:
    print(instrument.name, hex(instrument.attack_decay))

# Patterns are typed rows; orderlists are typed entries.
for row in song.patterns[0].rows[:4]:
    print(row)                      # e.g. "C-4 01000"
print(song.subtunes[0].channels[0].entries)
```

`read_sng` accepts a path, bytes, or a binary file object, and reads
every GoatTracker song generation: GTS5/GTS4/GTS3, GTS2 (early
3-table GoatTracker 2.xx) and GTS! (GoatTracker 1.x). Old formats are
converted on load exactly as GoatTracker 2.76 imports them --
including GT1's inline instrument wavetables, synthesized pulse
programs, filtertable conversion and 0XY-arpeggio extraction -- so
they play and write back as GTS5. The writer always emits GTS5;
GTS5 read -> write round trips are byte-identical.

## Build a song from scratch

```python
from pygoattracker import (
    Instrument, Pattern, Row, Song, write_sng,
)
from pygoattracker.constants import note_value

song = Song(name="DEMO", author="ME", copyright="2026")

# A pulse waveform program: one wavetable row + stop.
wave_ptr = song.wavetable.add(0x41, 0x00)
song.wavetable.add(0xFF, 0x00)

song.instruments.append(
    Instrument(
        attack_decay=0x09,
        sustain_release=0x00,
        wave_ptr=wave_ptr,
        gateoff_timer=2,
        first_wave=0x09,           # test+gate on the init frame
        name="LEAD",
    )
)

pattern = Pattern.empty(16)
pattern.rows[0] = Row(note=note_value("C-4"), instrument=1)
pattern.rows[8] = Row(note=note_value("G-4"), instrument=1)
song.patterns = [pattern]

write_sng(song, "demo.sng")        # loads in GoatTracker 2
```

The writer validates format limits and references (patterns,
instruments, table pointers) before emitting anything; you describe
content, not bytes.

## Play a song: SID register writes

The player ports the GoatTracker 2 playroutine tick for tick:
sequencer (transpose/repeat/restart), funktempo, wave/pulse/filter
table execution including wavetable command execution, speedtable
vibrato/portamento (including note-independent speeds), gateoff timer,
and hard restart.

```python
from pygoattracker import Player, read_sng

player = Player(read_sng("tune.sng"), subtune=0)
for _ in range(50 * 60):                  # one minute at 50 Hz
    for reg, value in player.play_frame():
        print(f"${0xD400 + reg:04X} = ${value:02X}")
```

`play_frame()` returns one PAL frame's register writes in ascending
register order (the first frame initializes all 25 registers).

Not implemented: multispeed playback and the editor's jamming /
mid-song start modes.

## Write a SID register log

```python
from pygoattracker import iter_register_writes, write_reglog, read_sng

song = read_sng("tune.sng")
writes = iter_register_writes(song, until_loop=True)
write_reglog(writes, "tune.reglog")
```

Logs are one `clock reg val` triple per line (absolute clock in PAL
CPU cycles, decimal, `#` comments). They load straight into pandas:

```python
import pandas as pd

df = pd.read_csv(
    "tune.reglog", sep=" ", comment="#", names=["clock", "reg", "val"]
)
```

`read_reglog` reads the format back as a list of `RegWrite` tuples.

## Render through an emulated SID

```python
from pygoattracker import read_sng, render_wav

render_wav(read_sng("tune.sng"), "tune.wav", seconds=60, model="8580")
```

Rendering drives [pyresidfp](https://pypi.org/project/pyresidfp/)
(reSIDfp emulation), clocking each register write individually at the
same in-frame offsets the register log uses. `render_samples` returns
raw 16-bit samples instead; pass `device=` to use any other emulator
object with `write_register`/`clock`/`sampling_frequency`.

## NinjaTracker 2

[NinjaTracker 2](http://covertbitops.c64.org) songs (the C64 editor's
`N2` work files) read and write through their own typed model:

```python
from pygoattracker import read_nt2, write_nt2

song = read_nt2("tune")            # files saved by the C64 editor
print(song.hr_param, song.first_wave)
for command in song.commands:      # NT2 commands double as instruments
    print(command.name, hex(command.attack_decay))
for row in song.patterns[0].rows[:4]:
    print(row)                     # e.g. "C-2 01 08"
write_nt2(song, "tune.out")
```

Tracks reuse the typed `PlayPattern`/`Transpose` entries (NinjaTracker
transposes are -64..+63 halftones; byte `$FF` is zero -- the format
doc's "$C0 = zero" does not match the player or the example tunes).
The writer emits canonical output: stale editor bytes after pattern
terminators are not preserved, so real files round-trip semantically
(byte-identically when they carry no stale bytes). There is no
NinjaTracker playroutine port; parsing and writing only.

### Convert GoatTracker songs to NinjaTracker 2

```python
from pygoattracker import gt_to_nt2, read_sng, write_nt2

song = read_sng("tune.sng")
report = []
converted = gt_to_nt2(song, errors="drop", report=report)
write_nt2(converted, "tune.nt2")
print(report)   # one line per feature NinjaTracker cannot express
```

NinjaTracker has no tempo, so conversion replays the playroutine's
sequencer/tempo logic (funktempo and FXY commands included) to bake
every row's frame count into NinjaTracker durations; rests merge into
the previous row and long holds split into continuation rows. The
song is simulated for two full loops and must play both identically.
Instruments become commands (vibrato folds into the wavetable),
toneportamento becomes NinjaTracker's slide-to-target, 4XY vibrato
and 8/9/AXY pointers become synthesized legato commands, and 5/6XY
become ADSR commands. ``errors="strict"`` (default) raises
``ConversionError`` on anything inexpressible (free 1/2XY portamento,
7XY/BXY/CXY/DXY, wavetable command execution, notes below C-1,
non-uniform hardrestart setups); ``errors="drop"`` drops and reports
them instead. Some mappings are inherently approximate: pulse widths
quantize to NinjaTracker's mirrored 8-bit register, filter resonance
couples to the passband, and vibrato parameters map by analogy.

## Command line

```bash
pygoattracker info tune.sng        # also detects NinjaTracker 2 files
pygoattracker reglog tune.sng tune.reglog --seconds 30
pygoattracker wav tune.sng tune.wav --seconds 30 --model 6581
pygoattracker nt2 tune.sng tune.nt2 --lenient
```

## Tests

```bash
pip install -e ".[dev]"
./run_tests.sh        # black + pylint + pytest with coverage gate
```

CI (`.github/workflows/ci.yml`) runs black, pylint, and the test suite
with a `--cov-fail-under=85` coverage gate on Python 3.10-3.13, and
builds + smoke tests the wheel. Publishing a GitHub release uploads
sdist + wheel to PyPI via trusted publishing
(`.github/workflows/publish.yml`); Dependabot keeps dependencies and
actions current. The suite also enforces the gates from
within: `tests/test_lint.py` runs black/pylint and
`tests/test_coverage.py` re-runs the suite under coverage and fails
below the floor, so a plain `pytest` cannot pass with lint errors or
insufficient coverage.

The integration tests download three GoatTracker 2 example songs and
the NinjaTracker 2 distribution disk image (SHA-256 pinned; a minimal
1541 reader extracts the six example tunes from the .d64). They verify
byte-identical .SNG round trips plus 500 frames of playback each, and
NinjaTracker round trips against all six tunes; they skip offline.

## License

Apache 2.0 - see [`LICENSE`](LICENSE).
