Snes9x2005 - WASM

A typescript abstraction around the port of snes9x2005 libretro core for wasm by kazuki-4ys.

Usage

Installation

npm i snes9x2005-wasm

Creating an emulator

const canvasElement = document.getElementById("canvas");
const romData: Uint8Array; //this holds your rom data

const emulator = await Emulator.create(romData, canvasElement, options);

options is optional and of type Partial<EmulatorOption>, it defaults to :

const defaultOption: EmulatorOption = {
  wasmPath: "snes9x_2005.wasm", //URL from the wasm blob (if start with http will be absolute)
  audioOn: true, //start emulation with sound
};

The emulation will start as soon as the emulator object is created.

Note that Emulator.create is async and must be awaited.

Binding Inputs

Two function are made available for you to easilly bind user input to the emulator controls.

type InputMap = {
  [key: KeyboardEvent["key"]]: SNES_CONTROL;
};
function createKeyboardHandles(
  emulator: Emulator,
  map?: InputMap
): {
  keydown: (ev: KeyboardEvent) => void;
  keyup: (ev: KeyboardEvent) => void;
};

Given an emulator and a record of keyboard keys to SNES_CONTROL object createKeyboardHandles will produce keydown and keyup event listener that you can directly bind to the windows object.

function createInputHandle(
  emulator: Emulator
): (input: SNES_CONTROL, on?: boolean) => void;

Given a emulator, return a function that let you set a specific SNES input. on will default to true.

WASM Blob and RomData

The wasm blob is not included in the npm package, you can download it from the GitHub repo or build it yourself using the provided build-esm.sh script.

Rom data needs to be fetched like so before being fed to the emulator.

async function fetchRomData() {
  const response = await fetch("url-to-your-rom");
  const buffer = await response.arrayBuffer();
  return new Uint8Array(buffer);
}

API Reference

export declare class Emulator {
  cvs: HTMLCanvasElement;
  ctx: CanvasRenderingContext2D;
  WASM: SNES9xModule;
  emulationRunning: boolean;
  audioNode: EmulatorAudio;
  audioOn: boolean;
  keyInput: number;
  static create(
    romData: Uint8Array,
    cvs: HTMLCanvasElement,
    options?: Partial<EmulatorOption>
  ): Promise<Emulator>;
  pauseEmulation(): void;
  startEmulation(): void;
  toggleEmulationRun(): void;
  paintNewFrame(buffer: Uint8Array): void;
  saveState(): Uint8Array<ArrayBuffer> | undefined;
  loadState(state: Uint8Array): void;
  loadRom(rom: Uint8Array): void;
}