a start of a wrapper around mgba

website/src/App.tsx

@@ -1,24 +1,18 @@
-import React from 'react';
+import React, { useState } from 'react';
-import logo from './logo.svg';
+import { Mgba } from './mgba';
-import './App.css';
 
 function App() {
+
+  const [onGame, setOnGame] = useState(false);
+  const [volume, setVolume] = useState(1.0);
+
   return (
-    <div className="App">
+    <div>
-      <header className="App-header">
+      {
-        <img src={logo} className="App-logo" alt="logo" />
+        onGame && <><Mgba gameUrl="/game.gba" volume={volume} />
-        <p>
+          <input type="range" value={volume} min="0" max="1" step="0.05" onChange={(e) => setVolume(Number(e.target.value))}></input></>
-          Edit <code>src/App.tsx</code> and save to reload.
+      }
-        </p>
+      <button onClick={() => setOnGame(!onGame)}>{onGame ? "End Game" : "Start Game"}</button>
-        <a
-          className="App-link"
-          href="https://reactjs.org"
-          target="_blank"
-          rel="noopener noreferrer"
-        >
-          Learn React
-        </a>
-      </header>
     </div>
   );
 }

website/src/index.tsx

@@ -1,8 +1,6 @@
 import React from 'react';
 import ReactDOM from 'react-dom/client';
-import './index.css';
 import App from './App';
-import reportWebVitals from './reportWebVitals';
 
 const root = ReactDOM.createRoot(
   document.getElementById('root') as HTMLElement
@@ -12,8 +10,3 @@ root.render(
     <App />
   </React.StrictMode>
 );
-
-// If you want to start measuring performance in your app, pass a function
-// to log results (for example: reportWebVitals(console.log))
-// or send to an analytics endpoint. Learn more: https://bit.ly/CRA-vitals
-reportWebVitals();

website/src/mgba.tsx

@@ -0,0 +1,97 @@
+import { FC, useEffect, useRef, useState } from "react";
+import mGBA from "./vendor/mgba";
+
+type Module = any;
+
+interface MgbaProps {
+    gameUrl: string,
+    volume?: Number,
+}
+
+enum MgbaState {
+    Uninitialised,
+    Initialising,
+    Initialised,
+}
+
+const MGBA_ROM_DIRECTORY = "/data/games";
+
+
+export const Mgba: FC<MgbaProps> = ({ gameUrl, volume }) => {
+
+    const canvas = useRef(null);
+    const mgbaModule = useRef<Module>({});
+
+    const [state, setState] = useState(MgbaState.Uninitialised);
+
+    useEffect(() => {
+        if (state !== MgbaState.Initialised) return;
+        (async () => {
+            const game = await fetch(gameUrl);
+            const gameData = await game.arrayBuffer();
+
+            const gamePath = `${MGBA_ROM_DIRECTORY}/${gameUrl}`;
+            mgbaModule.current.FS.writeFile(gamePath, new Uint8Array(gameData));
+            mgbaModule.current.loadGame(gamePath);
+        })()
+    }, [state, gameUrl]);
+
+    // init mgba
+    useEffect(() => {
+        (async () => {
+
+            if (canvas === null) return;
+            if (state !== MgbaState.Uninitialised) return;
+
+            setState(MgbaState.Initialising);
+
+            mgbaModule.current = {
+                canvas: canvas.current,
+                locateFile: (file: string) => {
+                    if (file === "mgba.wasm") {
+                        return "/vendor/mgba.wasm";
+                    }
+                    return file;
+                }
+            };
+
+            mGBA(mgbaModule.current).then((module: Module) => {
+                mgbaModule.current = module;
+                module.FSInit();
+                setState(MgbaState.Initialised);
+            });
+        }
+        )();
+
+        if (state === MgbaState.Initialised)
+            return () => {
+                try {
+                    mgbaModule.current.quitGame();
+                    mgbaModule.current.quitMgba();
+                } catch { }
+            };
+    }, [state]);
+
+    useEffect(() => {
+        if (state !== MgbaState.Initialised) return;
+        mgbaModule.current.setVolume(volume ?? 1.0);
+    }, [state, volume]);
+
+    return <>
+
+        <canvas ref={canvas}></canvas>
+        <button onClick={() => {
+            if (state !== MgbaState.Initialised) return;
+            mgbaModule.current.saveState(0);
+        }}>Save State</button>
+        <button onClick={() => {
+            if (state !== MgbaState.Initialised) return;
+            mgbaModule.current.loadState(0);
+        }}>Load State</button>
+        <button onClick={() => {
+            if (state !== MgbaState.Initialised) return;
+            mgbaModule.current.quickReload(0);
+        }}>Restart</button>
+
+    </>;
+};