Add a framework-free skin SDK package, a 16:9 stage, canvas skins, showpieces, and audio reactivity to the built-in skins

.changeset/player-variant-lane-channels.md

@@ -0,0 +1,5 @@
+---
+'@be-music/player': minor
+---
+
+Add `resolvePlayVariantLaneChannels` to `@be-music/player/core/lane-layout`: the full lane set of a chart's play variant (5 / 7 / 9 / 10 / 14 / 24 / 48 KEY) in rendering order, whether or not the chart puts notes on every lane. 9 KEY picks the PMS layout when the chart uses `22..25` and the BME layout otherwise, and lanes in use outside the variant are kept.

.changeset/player-web-full-lanes.md

@@ -0,0 +1,5 @@
+---
+'@be-music/player-web': patch
+---
+
+Fix sparse charts playing on only the lanes they use: a chart with notes on a single lane laid out a single lane. Gameplay now lays out every lane of the chart's play variant (5 / 7 / 9 / 10 / 14 / 24 / 48 KEY), so the playfield, key bindings, and skins always show the whole keyboard.

.changeset/skin-sdk-package.md

@@ -0,0 +1,10 @@
+---
+'@be-music/skin-sdk': minor
+---
+
+Add `@be-music/skin-sdk`, the package be-music skins for the browser player are written against. It imports no rendering framework: the player hands a skin a canvas and plain per-frame data, and the skin draws with whatever it brings (the Canvas 2D API, raw WebGL / WebGPU, PixiJS, three.js, …).
+
+- Skin contract: `BeMusicSkin` and its surface and frame types (gameplay, select, result), `defineBeMusicSkin`, `validateBeMusicSkin`, and `BE_MUSIC_SKIN_API_VERSION`. A skin declares its metadata (id, semantic version, author), the canvas context it wants, optional `setup` / `teardown` hooks for its own renderer, and one `draw` per screen.
+- Stage and layout: `wideStage` and its BGA placement, `resolveGameplayLayout`, `resolveLaneRuns`, the lane geometry the player lays lanes out with (IIDX lane widths, the double-play gap, keyboard modes), and `resolveBeMusicLaneKind`.
+- Play state and sound: judgement words, moments (count-in, combo milestones, the clear line, full combo, combo break), effect levels, the loading caption, and `audioDrive` / `bandLevel` over the `BeMusicAudioFrame` analysis.
+- Song and result facts: the song entry types, select-row facts, result lamp and track rows, plus tabular figure layout and motion helpers.

README.ja.md

@@ -16,6 +16,7 @@ TypeScript + pnpm workspaces で構成した BMS/BMSON ツールチェーンで
 - `@be-music/player-tui`: autoplay、keyboard play、Music Select、BGA、SEA build を扱う terminal UI と `bms-player` CLI frontend
 - `@be-music/lr2-skin`: Lunatic Rave 2 skin parser、asset resolver、theme loader を renderer 非依存で提供する package
 - `@be-music/beatoraja-skin`: beatoraja JSON/Lua skin parser、normalizer、theme loader を renderer 非依存で提供する package
+- `@be-music/skin-sdk`: browser player 向け be-music スキンを書くための描画フレームワーク非依存の SDK
 - `@be-music/player-web`: 選曲、built-in default / LR2 / beatoraja skin 描画、gameplay、result scene、録画を扱う browser PixiJS player core
 - `@be-music/player-web-demo`: folder / ZIP drop、LR2 / beatoraja theme、debug control、browser 再生を接続する private Vite demo
 - `@be-music/editor`: CLI エディタ (インポート・編集・エクスポート)
@@ -151,6 +152,13 @@ tag は `@be-music/package-name@x.y.z` 形式で作成されます。
 - `property[]`、`filepath[]`、category group、custom offset、wildcard source path、case-insensitive asset を解決
 - image、imageset、value、float-value、text、slider、note、judge、gauge、graph、BPM graph、timing graph、song-list、custom event、destination、PM character element を normalize
 
+### be-music skin SDK (`@be-music/skin-sdk`)
+
+- browser player の built-in family 向けスキンの契約。スキンは毎フレームのデータからキャンバスに各画面を描く
+- 描画フレームワークを import しない。フレームワークはスキンが持ち込む（Canvas 2D、WebGL / WebGPU、PixiJS、three.js など）
+- stage、lane layout、moment、判定表示、audio drive、曲情報、motion の helper
+- [be-music スキンの作り方](docs/be-music-skin.ja.md) を参照
+
 ### browser player (`@be-music/player-web` / `@be-music/player-web-demo`)
 
 - dropped folder、ZIP、song / LR2 / beatoraja theme 混在 drop を扱う browser song library

README.md

@@ -16,6 +16,7 @@ BMS/BMSON toolchain composed of TypeScript + pnpm workspaces.
 - `@be-music/player-tui`: Terminal UI and `bms-player` CLI frontend for autoplay, keyboard play, Music Select, BGA, and SEA builds
 - `@be-music/lr2-skin`: Renderer-independent Lunatic Rave 2 skin parser, asset resolver, and theme loader
 - `@be-music/beatoraja-skin`: Renderer-independent beatoraja JSON/Lua skin parser, normalizer, and theme loader
+- `@be-music/skin-sdk`: Framework-free SDK for writing be-music skins for the browser player
 - `@be-music/player-web`: Browser PixiJS player core for song selection, built-in default / LR2 / beatoraja skin rendering, gameplay, result scenes, and recording
 - `@be-music/player-web-demo`: Private Vite demo that wires folder/ZIP drops, LR2/beatoraja themes, debug controls, and browser playback together
 - `@be-music/editor`: CLI editor (import/edit/export)
@@ -151,6 +152,13 @@ The semantics helper of the score is separated into `@be-music/chart`, and `@be-
 - Resolves `property[]`, `filepath[]`, category groups, custom offsets, wildcard source paths, and case-insensitive assets
 - Normalizes image, imageset, value, float-value, text, slider, note, judge, gauge, graph, BPM graph, timing graph, song-list, custom event, destination, and PM character elements
 
+### be-music skin SDK (`@be-music/skin-sdk`)
+
+- Skin contract for the browser player's built-in family: the skin draws each screen onto a canvas from plain per-frame data
+- Imports no rendering framework; a skin brings its own (Canvas 2D, WebGL / WebGPU, PixiJS, three.js, …)
+- Stage, lane layout, moment, judgement word, audio drive, song fact, and motion helpers
+- See [Writing a be-music skin](./docs/be-music-skin.md)
+
 ### browser player (`@be-music/player-web` / `@be-music/player-web-demo`)
 
 - Browser song library for dropped folders, ZIPs, and mixed song/LR2/beatoraja theme drops

docs/README.ja.md

@@ -13,6 +13,7 @@
 - [プレイログ（プレイ履歴）仕様](playlog.ja.md)
 - [LR2 skin 実装メモ](lr2-skin.ja.md)
 - [beatoraja skin 実装メモ](beatoraja-skin.ja.md)
+- [be-music スキンの作り方](be-music-skin.ja.md)
 - [BMS/BMSON 中間表現 (`@be-music/json`) 実装仕様](json-spec.ja.md)
 - [用語集](glossary.ja.md)
 

docs/README.md

@@ -13,6 +13,7 @@ This directory is a Markdown collection of specifications used in the `be-music`
 - [Play log (play history) specification](./playlog.md)
 - [LR2 skin implementation notes](./lr2-skin.md)
 - [beatoraja skin implementation notes](./beatoraja-skin.md)
+- [Writing a be-music skin](./be-music-skin.md)
 - [BMS/BMSON intermediate representation (`@be-music/json`) implementation specification](./json-spec.md)
 - [Glossary](./glossary.md)