NovaJS

A browser port of Escape Velocity Nova by Ambrosia Software / ATMOS, focused on faithfully reimplementing the original engine.

This fork is single-player and deployed live at:

https://jmars.github.io/NovaJS/

It reads the real EV Nova game data and ships in the browser; no Nova data is committed to the repo (see below).

Controls (standard EV Nova)

• Arrow keys to move
• Spacebar to fire
• L while moving slowly over a planet to land
• Tab to select a target / R for nearest target
• W to choose a secondary weapon / Left Shift to fire it
• Hold A to point toward your target
• M to open the map and jump / J to jump
• Arrow keys scroll the outfitter / shipyard to see more items

Status

This is a faithful single-player reimplementation of the original engine, not a from-scratch approximation. Engine behavior is recovered from the original EV_Nova.dat binary via Ghidra and ported exactly — see docs/FIDELITY.md for the per-subsystem audit (which behaviors are byte-verified against the binary vs. still approximated).

Implemented so far, ported from the binary:

• Spawning — event-driven system population (jump-in / landing / liftoff / boarding) with the binary's per-system dûde table, përs peripherals, and flët draw (docs/FIDELITY.md).
• NPC AI — acquisition (strength×odds filter, police-assist, player square), govt-difference retaliation with the suppression cascade, aggress-driven fleeing, trader travel + landing, interceptor comm-scan, pursuit memory, per-system legal records.
• Combat — projectile/beam/blast damage with the binary's order, friendly-fire and owner rules, splash semantics.
• Economy — trade prices/bands, cargo decay, capture odds, booty, outfit purchase/sell/trade-in recovered from the binary.
• RNG — the engine's Park-Miller LCG, seeded from the pilot, replacing any approximation.
• UI — spaceport (outfitter / shipyard / trade / missions / bar / comm), landing, and the system map.

Copyright

Escape Velocity Nova is copyrighted by Ambrosia Software. NovaJS claims no rights to any EV Nova data. The goal is a Nova engine that interprets Nova files without shipping Nova data itself:

• The game data (Nova_Data/) is downloaded at deploy time from the game-data GitHub release, never committed to git.
• The original binary EV_Nova.dat is shipped as the game-binary GitHub release purely as the reverse-engineering reference; it is not distributed as part of the game and is not required to play the deployed site.

Getting Started

Prerequisites

• node.js and npm
• A copy of EV Nova's game data (Nova Files + Plug-ins in .ndat or Mac resource-fork format) — Windows .res is not yet supported.

Installing

git clone https://github.com/jmars/NovaJS.git
cd NovaJS/
npm install

Place your game data under nova/Nova_Data/:

mkdir -p nova/Nova_Data
cp -r /path/to/EV\ Nova.app/Contents/Resources/Nova\ Files/ ./nova/Nova_Data/
mkdir -p nova/Nova_Data/Plug-ins/
# drop any plug-ins (.ndat) into nova/Nova_Data/Plug-ins/

Running locally (dev server)

npm run build:browser          # bundle the client (nova/src/browser_bundle.js)
npm run generate:static -- --layout files --out dist-dev
node nova/server.ts            # express dev server on port 8000
# open http://localhost:8000

Building the static site (what the live deploy uses)

npm run build:site             # builds dist-site/ (index.html + bundle + range-indexed game data)
# serve dist-site/ with any static host that supports HTTP Range requests

Tests

Headless jasmine specs (no browser needed):

npm run test:headless          # 700+ specs

Type-check:

npx tsc --noEmit -p tsconfig.json

Deployment

Pushing to main deploys to GitHub Pages via the included GitHub Actions workflow: it downloads the game-data release, runs npm run build:site, and publishes dist-site/. The deployed game loads game data lazily via HTTP Range requests, so the entry page revalidates every load (a redeploy takes effect on the next reload).

Reverse engineering

EV_Nova.dat is analyzed with Ghidra (tools/ghidra_12.1.3_PUBLIC); the headless analysis scripts live in ghidra_scripts/, and scripts/regenerate_ghidra.sh rebuilds the analyzed project from the binary + scripts. See docs/FIDELITY.md for the live audit of which engine behaviors match the binary.

Project Structure

• nova — the client + engine (browser.ts is the entry point; nova/src/nova_plugin/ holds the gameplay systems).
• novaparse — parses Nova files and Plug-ins.
• novadatainterface — the data interface implemented by novaparse and consumed by nova.
• nova_ecs — the Entity Component System used by NovaJS.
• docs/FIDELITY.md — the fidelity audit: which subsystems are byte-verified against the binary, which are still approximated.

Known Bugs

• Beam weapons do not clip after colliding with a target (they pass through).
• Some engine subsystems are still approximated — see docs/FIDELITY.md for the exact list and their status.