rpgmard-wasm

WebAssembly bindings for rpgmad-lib, generated via wasm-bindgen. A thin wrapper around the Rust reference implementation - useful when you want behavior guaranteed identical to the Rust crate without a second, hand-maintained implementation.

Install

npm install rpgmard-wasm

API

Two functions (see src/lib.rs for full doc comments):

function decryptArchive(archiveData: Uint8Array): ArchiveEntry[];
function encryptArchive(entries: ArchiveEntry[], engine: Engine): Uint8Array;

plus the ArchiveEntry class (path/data, both Uint8Array) and the Engine enum (Older = 1, VXAce = 3) - Older covers RPG Maker XP/VX's .rgssad/.rgss2a, VXAce covers VX Ace's .rgss3a.

The reference Decrypter::decrypt returns an iterator borrowing its input buffer - that can't cross the JS/WASM call boundary (a call only lives for the duration of the call), so these two functions copy data in and out instead: decryptArchive takes ownership of the input and returns independent, owned entries; encryptArchive returns a freshly-allocated archive buffer.

Usage

import init, { decryptArchive, Engine } from "rpgmard-wasm";

await init(); // instantiates the wasm module - do this once, before first use

const archiveData = new Uint8Array(await Deno.readFile("Game.rgss3a"));

for (const entry of decryptArchive(archiveData)) {
    console.log(new TextDecoder().decode(entry.path));
}

encryptArchive goes the other way, packing entries back into an archive for a given engine:

import init, { encryptArchive, ArchiveEntry, Engine } from "rpgmard-wasm";

await init();

const entries = [new ArchiveEntry(new TextEncoder().encode("Data/Scripts.rvdata2"), scriptBytes)];
const archiveData = encryptArchive(entries, Engine.VXAce);

Under Node/Bun, init()'s default fetch()-based loading doesn't apply - pass the .wasm bytes explicitly instead:

import { readFile } from "node:fs/promises";
import init, { decryptArchive } from "rpgmard-wasm";

await init(
  await readFile(new URL("./rpgmard_wasm_bg.wasm", import.meta.resolve("rpgmard-wasm"))),
);

Building

wasm-pack build --release --target web

Requires the wasm32-unknown-unknown rustup target (rustup target add wasm32-unknown-unknown) and wasm-pack (cargo binstall wasm-pack). Output goes to pkg/ (gitignored): the compiled .wasm, a JS glue module, a .d.ts, and the package.json this crate publishes to npm from.