1 files changed, 144 insertions, 0 deletions
diff --git a/platform/javascript/js/engine/engine.js b/platform/javascript/js/engine/engine.js
new file mode 100644
index 0000000000..d14e0e5806
--- /dev/null
+++ b/platform/javascript/js/engine/engine.js
@@ -0,0 +1,144 @@
+const Engine = (function () {
+	const preloader = new Preloader();
+
+	let loadPromise = null;
+	let loadPath = '';
+	let initPromise = null;
+
+	function load(basePath) {
+		if (loadPromise == null) {
+			loadPath = basePath;
+			loadPromise = preloader.loadPromise(`${loadPath}.wasm`);
+			requestAnimationFrame(preloader.animateProgress);
+		}
+		return loadPromise;
+	}
+
+	function unload() {
+		loadPromise = null;
+	}
+
+	/** @constructor */
+	function Engine(opts) { // eslint-disable-line no-shadow
+		this.config = new EngineConfig(opts);
+		this.rtenv = null;
+	}
+
+	Engine.prototype.init = /** @param {string=} basePath */ function (basePath) {
+		if (initPromise) {
+			return initPromise;
+		}
+		if (loadPromise == null) {
+			if (!basePath) {
+				initPromise = Promise.reject(new Error('A base path must be provided when calling `init` and the engine is not loaded.'));
+				return initPromise;
+			}
+			load(basePath);
+		}
+		preloader.setProgressFunc(this.config.onProgress);
+		let config = this.config.getModuleConfig(loadPath, loadPromise);
+		const me = this;
+		initPromise = new Promise(function (resolve, reject) {
+			Godot(config).then(function (module) {
+				module['initFS'](me.config.persistentPaths).then(function (fs_err) {
+					me.rtenv = module;
+					if (me.config.unloadAfterInit) {
+						unload();
+					}
+					resolve();
+					config = null;
+				});
+			});
+		});
+		return initPromise;
+	};
+
+	/** @type {function(string, string):Object} */
+	Engine.prototype.preloadFile = function (file, path) {
+		return preloader.preload(file, path);
+	};
+
+	/** @type {function(...string):Object} */
+	Engine.prototype.start = function (override) {
+		this.config.update(override);
+		const me = this;
+		return me.init().then(function () {
+			if (!me.rtenv) {
+				return Promise.reject(new Error('The engine must be initialized before it can be started'));
+			}
+
+			let config = {};
+			try {
+				config = me.config.getGodotConfig(function () {
+					me.rtenv = null;
+				});
+			} catch (e) {
+				return Promise.reject(e);
+			}
+			// Godot configuration.
+			me.rtenv['initConfig'](config);
+
+			// Preload GDNative libraries.
+			const libs = [];
+			me.config.gdnativeLibs.forEach(function (lib) {
+				libs.push(me.rtenv['loadDynamicLibrary'](lib, { 'loadAsync': true }));
+			});
+			return Promise.all(libs).then(function () {
+				return new Promise(function (resolve, reject) {
+					preloader.preloadedFiles.forEach(function (file) {
+						me.rtenv['copyToFS'](file.path, file.buffer);
+					});
+					preloader.preloadedFiles.length = 0; // Clear memory
+					me.rtenv['callMain'](me.config.args);
+					initPromise = null;
+					resolve();
+				});
+			});
+		});
+	};
+
+	Engine.prototype.startGame = function (override) {
+		this.config.update(override);
+		// Add main-pack argument.
+		const exe = this.config.executable;
+		const pack = this.config.mainPack || `${exe}.pck`;
+		this.config.args = ['--main-pack', pack].concat(this.config.args);
+		// Start and init with execName as loadPath if not inited.
+		const me = this;
+		return Promise.all([
+			this.init(exe),
+			this.preloadFile(pack, pack),
+		]).then(function () {
+			return me.start.apply(me);
+		});
+	};
+
+	Engine.prototype.copyToFS = function (path, buffer) {
+		if (this.rtenv == null) {
+			throw new Error('Engine must be inited before copying files');
+		}
+		this.rtenv['copyToFS'](path, buffer);
+	};
+
+	Engine.prototype.requestQuit = function () {
+		if (this.rtenv) {
+			this.rtenv['request_quit']();
+		}
+	};
+
+	// Closure compiler exported engine methods.
+	/** @export */
+	Engine['isWebGLAvailable'] = Utils.isWebGLAvailable;
+	Engine['load'] = load;
+	Engine['unload'] = unload;
+	Engine.prototype['init'] = Engine.prototype.init;
+	Engine.prototype['preloadFile'] = Engine.prototype.preloadFile;
+	Engine.prototype['start'] = Engine.prototype.start;
+	Engine.prototype['startGame'] = Engine.prototype.startGame;
+	Engine.prototype['copyToFS'] = Engine.prototype.copyToFS;
+	Engine.prototype['requestQuit'] = Engine.prototype.requestQuit;
+	return Engine;
+}());
+if (typeof window !== 'undefined') {
+	window['Engine'] = Engine;
+}