gb.ts

import {
    Emulator,
    EmulatorBase,
    Feature,
    PixelFormat,
    RomInfo
} from "./react/app";
import { PALETTES } from "./palettes";

import {
    Cartridge,
    default as _wasm,
    GameBoy,
    PadKey,
    PpuMode
} from "./lib/boytacean.js";
import info from "./package.json";
import { base64ToBuffer, bufferToBase64 } from "./util";

declare const require: any;

const LOGIC_HZ = 4194304;

const VISUAL_HZ = 59.7275;
const IDLE_HZ = 10;

/**
 * The rate at which the local storage RAM state flush
 * operation is going to be performed, this value is the
 * number of seconds in between flush operations (eg: 5 seconds).
 */
const STORE_RATE = 5;

const SAMPLE_RATE = 2;

const KEYS_NAME: Record<string, number> = {
    ArrowUp: PadKey.Up,
    ArrowDown: PadKey.Down,
    ArrowLeft: PadKey.Left,
    ArrowRight: PadKey.Right,
    Start: PadKey.Start,
    Select: PadKey.Select,
    A: PadKey.A,
    B: PadKey.B
};

const ROM_PATH = require("../../res/roms/20y.gb");

/**
 * Top level class that controls the emulator behaviour
 * and "joins" all the elements together to bring input/output
 * of the associated machine.
 */
export class GameboyEmulator extends EmulatorBase implements Emulator {
    /**
     * The Game Boy engine (probably coming from WASM) that
     * is going to be used for the emulation.
     */
    private gameBoy: GameBoy | null = null;

    /**
     * The descriptive name of the engine that is currently
     * in use to emulate the system.
     */
    private _engine: string | null = null;

    private logicFrequency: number = LOGIC_HZ;
    private visualFrequency: number = VISUAL_HZ;
    private idleFrequency: number = IDLE_HZ;