Basic Coordinates and Seasons

A three-screen SceneryStack port of the NAAP Basic Coordinates and Seasons lab: Terrestrial Coordinates, Celestial Coordinates, and Seasons. Built with Vite 8, TypeScript 7, and Biome 2.

Status: all three screens are implemented — the NAAP terrestrial, celestial, and seasons explorers are ported on a shared orthographic sky engine, with localization, projector mode, keyboard/PDOM accessibility, home-screen icons, and unit tests in place.

Features

• Three implemented screens on a shared orthographic sky engine, with model/view separation:
  1. Terrestrial Coordinates (src/terrestrial/) — longitude/latitude on a flat map and a globe (NAAP tc_flat.swf / tc_globe.swf).
  2. Celestial Coordinates (src/celestial/) — right ascension/declination on a flat sky map and a celestial sphere (NAAP cec_flat.swf / cec_sky.swf).
  3. Seasons (src/seasons/) — Earth's orbit, the ecliptic, and how axial tilt produces the seasons (NAAP seasons_ecliptic.swf, the Seasons and Ecliptic Simulator).
• English, French, and Spanish localization via StringManager
• Default and projector color profiles
• Progressive Web App (installable, offline-capable)
• Flash decompile workflow (npm run decompile) for NAAP .swf reference
• Git hooks for Biome pre-commit checks
• Shared GitHub Actions CI via OpenPhysics/Baton

The original lab (astroUNL naap/motion1) and its Flash sources live in the git-ignored NAAP/ directory. npm run decompile extracts readable ActionScript from the five published simulators into NAAP/decompiled/ via JPEXS FFDec (requires Java; one-time npm run decompile -- --setup).

Quick Start

npm install
npm run icons    # generate PNG icons from public/icons/icon.svg
npm start        # dev server → http://localhost:5173

Scripts

Command	Description
npm start / npm run dev	Start Vite dev server
npm run build	Type-check + production build → dist/
npm run build:single	Single self-contained dist/index.html
npm run preview	Preview the production build locally
npm run check	TypeScript type check
npm run lint	Biome lint check
npm run format	Auto-format all files
npm run fix	Lint + auto-fix
npm test	Run Vitest unit tests
npm run icons	Regenerate PNG icons from public/icons/icon.svg
npm run decompile	Extract ActionScript from NAAP Flash .swf sources
npm run clean	Remove dist/

New sims start at version: "0.0.0" in package.json. Bump only when cutting a release (for example npm version patch and a matching git tag). Keep name in kebab-case; it is separate from the SceneryStack sim identifier in src/init.ts.

Tech Stack

Tool	Version	Purpose
SceneryStack	^3.0.0	Simulation framework
Vite	^8	Build tool + dev server
TypeScript	^7	Type-safe JavaScript
Biome	^2.5	Linting + formatting
vite-plugin-pwa	^1	PWA + service worker

License

GNU Affero General Public License v3.0 — see OpenPhysics org license.

Contributing

See OpenPhysics contributing guidelines. Report bugs via GitHub Issues; use org issue templates.