Deno desktop stuff

desktop/main.ts

@@ -0,0 +1,86 @@
+/// <reference lib="deno.desktop" />
+
+// the desktop app: the web client in a bundled chromium (deno desktop's cef backend), so people whose browser has no
+// webgpu (firefox) can still play. it joins servers like the browser does, and runs its own game server for
+// singleplayer, like minecraft java. build it with deno task desktop, see the desktop/ docs for how deno desktop works
+import { fromFileUrl, join } from "@std/path";
+import { type Host, serve_static, start_host } from "../server/host.ts";
+
+// where the project was built from: build/ and server_mods/ are bundled into the app with --include
+const ROOT = fromFileUrl(new URL("../", import.meta.url));
+const BUILD_DIR = join(ROOT, "build");
+
+// the server the address field starts with. "" leaves it empty for the player to fill in
+const config: { server?: string } = JSON.parse(
+	await Deno.readTextFile(new URL("./config.json", import.meta.url)),
+);
+const default_server = Deno.env.get("BWORLD_SERVER") ?? config.server ?? "";
+
+const win = new Deno.BrowserWindow({ title: "bworld", width: 1280, height: 720 });
+
+// the singleplayer game server, started the first time singleplayer connects so players who only join other servers
+// don't get a world made for them
+let host: Host | undefined;
+
+function singleplayer_host(): Host {
+	if (!host) {
+		const worlds = join(data_dir(), "worlds");
+		Deno.mkdirSync(worlds, { recursive: true });
+		host = start_host({
+			build_dir: BUILD_DIR,
+			server_mods_dir: join(ROOT, "server_mods"),
+			root: ROOT,
+			world_file: join(worlds, "world.json"),
+			on_fatal(message) {
+				console.error(message);
+				alert(`The singleplayer world stopped: ${message}`);
+				Deno.exit(1);
+			},
+		});
+	}
+	return host;
+}
+
+// the world gets saved before the app closes
+win.addEventListener("close", async (event) => {
+	if (!host) {
+		return;
+	}
+	event.preventDefault();
+	try {
+		await host.shutdown();
+	} catch (e) {
+		console.error((e as Error).message);
+	}
+	Deno.exit(0);
+});
+
+// deno desktop binds this to a private local address and opens the window on it, the port given here is ignored
+Deno.serve((req) => {
+	const url = new URL(req.url);
+	if (url.pathname === "/") {
+		// ?server= fills in the address field, without it the field would start with this app's own address.
+		// ?singleplayer shows the singleplayer button, which joins this app's own server
+		const start = new URL("/client/", url);
+		start.searchParams.set("server", default_server);
+		start.searchParams.set("singleplayer", "");
+		return Response.redirect(start, 302);
+	}
+	if (url.pathname === "/ws") {
+		return singleplayer_host().handle(req);
+	}
+	return serve_static(BUILD_DIR, req, url);
+});
+
+// where the app keeps its worlds, the usual place for app data on each os
+function data_dir() {
+	const home = Deno.env.get("HOME") ?? Deno.env.get("USERPROFILE") ?? ".";
+	switch (Deno.build.os) {
+		case "windows":
+			return join(Deno.env.get("APPDATA") ?? join(home, "AppData", "Roaming"), "bworld");
+		case "darwin":
+			return join(home, "Library", "Application Support", "bworld");
+		default:
+			return join(Deno.env.get("XDG_DATA_HOME") ?? join(home, ".local", "share"), "bworld");
+	}
+}