mattromano · Oct 10, 2026 · Oct 15, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -0,0 +1,55 @@
+# Changelog
+
+All notable changes to the Drum Highway plugin. The format follows
+[Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versions follow `plugin.json`.
+
+## [Unreleased]
+
+Version 4.1.0 in `plugin.json`.
+
+### Added
+- **Rock Band-style scoring** from a JavaScript port of YARG.Core's drums engine (`assets/engine.js`,
+  LGPL-3.0, see `NOTICE.md`): ±70 ms hit window, multiplier up to x4 (x8 in star power), pro-drums
+  cymbal/tom lanes, accent/ghost dynamics bonus, stars, and star power with fill activation. Driven
+  through `assets/session.js`, which also adds spot-on timing, roll and drum-solo bonuses. The 2D view
+  marks hits / misses from the engine and shows a score HUD when **Score** is on.
+- **Difficulty per player** — Easy, Medium, Hard, Expert, Expert+ (`drums_difficulty_v1`), from the
+  settings panel, the HUD badge or D / Shift+D; Expert drops the double-kick notes. Easier levels, star
+  power, fills and solos come from the drum tab's feedpak 1.20.0 gameplay metadata; without it the song
+  plays Expert (plus Expert+ when the chart has double-kick notes, e.g. a legacy chart with GM 35 kicks),
+  without star power.
+- **Assists** — auto kick / auto cymbals up to a chosen difficulty (played on the drum sound at their own
+  volume), hit-timing presets (Relaxed / Forgiving / Normal / Precision), **Pro cymbals** toggle and an
+  input **Offset** (ms) for audio / MIDI latency.
+- **Timing meter** under the score: the last 24 hits early / late on a ±100 ms bar, their median, and the
+  input offset that would centre them, with an **Apply** button.
+- **Star power without fills**: on charts with star power phrases but no drum fills, press **Enter** or
+  hit the **SP pad** (settings: off, hi-hat pedal, ride bell, splash or china; `drums_sp_pad_v1`) to
+  activate it. With fills, the note that ends a fill activates it, as before.
+- **Results card** at the end of the song (single view, Score on): total score with the bonuses, best
+  score per song and difficulty (`drums.best:<song>|<difficulty>` in `localStorage`), stars, accuracy,
+  notes hit, best streak / full combo and where the points came from.
+- The drum view on a part that isn't drums (no drum tab, arrangement not named Drums / Percussion) shows
+  "This song has no drums" or "Pick the Drums part" and plays / scores nothing, instead of reading guitar
+  notes as drum notes.
+
+### Changed
+- Hit timing: the view draws and scores on a smoothed per-highway clock (interpolated between the
+  player's audio samples, like core's 3D highway), a pad hit is timed when the MIDI message arrived
+  (its timestamp, when the MIDI provider passes one) rather than at the last frame, and the engine runs
+  60 ms behind the frame clock so a hit struck just before a frame is judged at its own time instead of
+  being moved forward to the frame.
+- The input offset applies to the engine's clock as well as to the hits, so a positive offset no longer
+  leaves a late-registered hit facing a note the engine has already missed.
+- MIDI velocity reaches the engine as 0..1 (velocity / 127); velocity 1 used to count as full strength.
+- Auto kick / auto cymbals are timed from the audio clock (mapped to the stems plugin's audio context
+  when it is there), scheduled 100 ms ahead by one forward-only schedule shared by all drum views and
+  cancelled on pause / seek: no more late or doubled auto notes.
+- Splitscreen: kit hits go to the focused drum view if it is on screen, else to the drum view that is,
+  so a hidden main-player drum view no longer swallows them.
+- A scoring file that failed to load is loaded again on the next try (its dead `<script>` element is
+  removed).
+- A drum-tab hit is an accent only when the tab marks it (`a`, feedpak 1.20.0) or, for older tabs, when it
+  has a written velocity of 100 or more; a hit with no velocity is no longer drawn as an accent. A kick
+  marked `x2` is a double kick (GM 35).
+- The "Hits" checkbox is now **Score**.
diff --git a/LICENSE.GPL-3.0 b/LICENSE.GPL-3.0
diff --git a/LICENSE.LGPL-3.0 b/LICENSE.LGPL-3.0
@@ -0,0 +1,165 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
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+ of this license document, but changing it is not allowed.
+
+
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+License, supplemented by the additional permissions listed below.
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diff --git a/NOTICE.md b/NOTICE.md
@@ -0,0 +1,26 @@
+# Licensing notice for the drums plugin
+
+Most of this plugin is original code under the **MIT** license (see `README.md`). That includes
+`screen.js`, `assets/session.js`, `plugin.json`, the other assets and the tests other than
+`tests/engine.test.js`.
+
+Two files are ports of [YARG.Core](https://github.com/YARC-Official/YARG.Core) and are licensed under the
+**GNU Lesser General Public License v3.0** (full text in [`LICENSE.LGPL-3.0`](LICENSE.LGPL-3.0); the LGPL
+builds on the GNU GPL v3.0, whose text is in [`LICENSE.GPL-3.0`](LICENSE.GPL-3.0)):
+
+| File | Status |
+|------|--------|
+| `assets/engine.js` | LGPL-3.0. JavaScript port, with modifications, of YARG.Core's drums engine (`Engine/Drums/DrumsEngine.cs`, `Engine/Drums/Engines/YargDrumsEngine.cs`, `DrumsEngineParameters.cs`, `DrumsStats.cs`, `Engine/BaseEngine*.cs`, `BaseStats.cs`, `HitWindowSettings.cs`, `Chart/Notes/DrumNote.cs`, `Note.cs`, drum activation flags from `InstrumentDifficultyExtensions.cs`, and defaults from `Game/Presets/EnginePreset*.cs`). It also takes the drum star thresholds from YARG's `DrumsPlayer.cs` (LGPL-3.0). Copyright (c) YARC (YARG) contributors. |
+| `tests/engine.test.js` | LGPL-3.0. Tests for `engine.js`, partly ported from `YARG.Core.UnitTests/Engine/DrumEngineTester.cs` and `DrumsStatsTests.cs`. |
+
+`assets/engine.js` is a standalone, unminified script with no dependencies, shipped as its own file and
+loaded at runtime. `screen.js` and `assets/session.js` only use it through its public API
+(`window.DrumsEngine` / `require('./engine.js')`), so they remain separate MIT works that use the Library
+as described in LGPL-3.0 section 4 ("Combined Works"). You may replace `assets/engine.js` with a modified
+version. A modified `assets/engine.js` that you distribute is conveyed under LGPL-3.0 or, as LGPL-3.0
+section 2(b) allows, under the GPL-3.0 (without the LGPL's additional permissions), with its source
+available either way. Combining an LGPL-3.0 file with MIT code this way is permitted by both licenses, and
+both are compatible with feedBack's AGPL-3.0.
+
+The header of `assets/engine.js` lists every behaviour that deviates from YARG ("Deviations from YARG").
+The scoring look and feel imitates rhythm-game drum tracks but uses no artwork, fonts or logos from them.