[HTML5] Port JavaScript inline code to libraries.

The API is implemented in javascript, and generates C functions that can
be called from godot.
This allows much cleaner code replacing all `EM_ASM` calls in our C++
code with plain C function calls.
This also gets rid of few hacks and comes with few optimizations (e.g.
custom cursor shapes should be much faster now).

1 files changed, 187 insertions, 0 deletions

diff --git a/modules/websocket/library_godot_websocket.js b/modules/websocket/library_godot_websocket.js
new file mode 100644
index 0000000000..f7d3195807
--- /dev/null
+++ b/modules/websocket/library_godot_websocket.js
@@ -0,0 +1,187 @@
+/*************************************************************************/
+/*  library_godot_websocket.js                                           */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+var GodotWebSocket = {
+
+	// Our socket implementation that forwards events to C++.
+	$GodotWebSocket__deps: ['$IDHandler'],
+	$GodotWebSocket: {
+		// Connection opened, report selected protocol
+		_onopen: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return; // Godot object is gone.
+			}
+			let c_str = GodotOS.allocString(ref.protocol);
+			callback(c_str);
+			_free(c_str);
+		},
+
+		// Message received, report content and type (UTF8 vs binary)
+		_onmessage: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return; // Godot object is gone.
+			}
+			var buffer;
+			var is_string = 0;
+			if (event.data instanceof ArrayBuffer) {
+				buffer = new Uint8Array(event.data);
+			} else if (event.data instanceof Blob) {
+				alert("Blob type not supported");
+				return;
+			} else if (typeof event.data === "string") {
+				is_string = 1;
+				var enc = new TextEncoder("utf-8");
+				buffer = new Uint8Array(enc.encode(event.data));
+			} else {
+				alert("Unknown message type");
+				return;
+			}
+			var len = buffer.length*buffer.BYTES_PER_ELEMENT;
+			var out = _malloc(len);
+			HEAPU8.set(buffer, out);
+			callback(out, len, is_string);
+			_free(out);
+		},
+
+		// An error happened, 'onclose' will be called after this.
+		_onerror: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return; // Godot object is gone.
+			}
+			callback();
+		},
+
+		// Connection is closed, this is always fired. Report close code, reason, and clean status.
+		_onclose: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return; // Godot object is gone.
+			}
+			let c_str = GodotOS.allocString(event.reason);
+			callback(event.code, c_str, event.wasClean ? 1 : 0);
+			_free(c_str);
+		},
+
+		// Send a message
+		send: function(p_id, p_data) {
+			const ref = IDHandler.get(p_id);
+			if (!ref || ref.readyState != ref.OPEN) {
+				return 1; // Godot object is gone or socket is not in a ready state.
+			}
+			ref.send(p_data);
+			return 0;
+		},
+
+		create: function(socket, p_on_open, p_on_message, p_on_error, p_on_close) {
+			const id = IDHandler.add(socket);
+			socket.onopen = GodotWebSocket._onopen.bind(null, id, p_on_open);
+			socket.onmessage = GodotWebSocket._onmessage.bind(null, id, p_on_message);
+			socket.onerror = GodotWebSocket._onerror.bind(null, id, p_on_error);
+			socket.onclose = GodotWebSocket._onclose.bind(null, id, p_on_close);
+			return id;
+		},
+
+		// Closes the JavaScript WebSocket (if not already closing) associated to a given C++ object.
+		close: function(p_id, p_code, p_reason) {
+			const ref = IDHandler.get(p_id);
+			if (ref && ref.readyState < ref.CLOSING) {
+				const code = p_code;
+				const reason = UTF8ToString(p_reason);
+				ref.close(code, reason);
+			}
+		},
+
+		// Deletes the reference to a C++ object (closing any connected socket if necessary).
+		destroy: function(p_id) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			GodotWebSocket.close(p_id, 1001, '');
+			IDHandler.remove(p_id);
+			ref.onopen = null;
+			ref.onmessage = null;
+			ref.onerror = null;
+			ref.onclose = null;
+		},
+	},
+
+	godot_js_websocket_create: function(p_ref, p_url, p_proto, p_on_open, p_on_message, p_on_error, p_on_close) {
+		const on_open = GodotOS.get_func(p_on_open).bind(null, p_ref);
+		const on_message = GodotOS.get_func(p_on_message).bind(null, p_ref);
+		const on_error = GodotOS.get_func(p_on_error).bind(null, p_ref);
+		const on_close = GodotOS.get_func(p_on_close).bind(null, p_ref);
+		const url = UTF8ToString(p_url);
+		const protos = UTF8ToString(p_proto);
+		var socket = null;
+		try {
+			if (protos) {
+				socket = new WebSocket(url, protos.split(","));
+			} else {
+				socket = new WebSocket(url);
+			}
+		} catch (e) {
+			return 0;
+		}
+		socket.binaryType = "arraybuffer";
+		return GodotWebSocket.create(socket, on_open, on_message, on_error, on_close);
+	},
+
+	godot_js_websocket_send: function(p_id, p_buf, p_buf_len, p_raw) {
+		var bytes_array = new Uint8Array(p_buf_len);
+		var i = 0;
+		for(i = 0; i < p_buf_len; i++) {
+			bytes_array[i] = getValue(p_buf + i, 'i8');
+		}
+		var out = bytes_array;
+		if (p_raw) {
+			out = bytes_array.buffer;
+		} else {
+			out = new TextDecoder("utf-8").decode(bytes_array);
+		}
+		return GodotWebSocket.send(p_id, out);
+	},
+
+	godot_js_websocket_close: function(p_id, p_code, p_reason) {
+		const code = p_code;
+		const reason = UTF8ToString(p_reason);
+		GodotWebSocket.close(p_id, code, reason);
+	},
+
+	godot_js_websocket_destroy: function(p_id) {
+		GodotWebSocket.destroy(p_id);
+	},
+};
+
+autoAddDeps(GodotWebSocket, '$GodotWebSocket')
+mergeInto(LibraryManager.library, GodotWebSocket);