[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, 407 insertions, 0 deletions

diff --git a/modules/webrtc/library_godot_webrtc.js b/modules/webrtc/library_godot_webrtc.js
new file mode 100644
index 0000000000..b75996b1f3
--- /dev/null
+++ b/modules/webrtc/library_godot_webrtc.js
@@ -0,0 +1,407 @@
+/*************************************************************************/
+/*  library_godot_webrtc.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 GodotRTCDataChannel = {
+	// Our socket implementation that forwards events to C++.
+	$GodotRTCDataChannel__deps: ['$IDHandler', '$GodotOS'],
+	$GodotRTCDataChannel: {
+
+		connect: function(p_id, p_on_open, p_on_message, p_on_error, p_on_close) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+
+			ref.binaryType = 'arraybuffer';
+			ref.onopen = function (event) {
+				p_on_open();
+			};
+			ref.onclose = function (event) {
+				p_on_close();
+			};
+			ref.onerror = function (event) {
+				p_on_error();
+			};
+			ref.onmessage = function(event) {
+				var buffer;
+				var is_string = 0;
+				if (event.data instanceof ArrayBuffer) {
+					buffer = new Uint8Array(event.data);
+				} else if (event.data instanceof Blob) {
+					console.error("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 {
+					console.error("Unknown message type");
+					return;
+				}
+				var len = buffer.length*buffer.BYTES_PER_ELEMENT;
+				var out = _malloc(len);
+				HEAPU8.set(buffer, out);
+				p_on_message(out, len, is_string);
+				_free(out);
+			}
+		},
+
+		close: function(p_id) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			ref.onopen = null;
+			ref.onmessage = null;
+			ref.onerror = null;
+			ref.onclose = null;
+			ref.close();
+		},
+
+		get_prop: function(p_id, p_prop, p_def) {
+			const ref = IDHandler.get(p_id);
+			return (ref && ref[p_prop] !== undefined) ? ref[p_prop] : p_def;
+		},
+	},
+
+	godot_js_rtc_datachannel_ready_state_get: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return 3; // CLOSED
+		}
+
+		switch(ref.readyState) {
+			case "connecting":
+				return 0;
+			case "open":
+				return 1;
+			case "closing":
+				return 2;
+			case "closed":
+				return 3;
+		}
+		return 3; // CLOSED
+	},
+
+	godot_js_rtc_datachannel_send: function(p_id, p_buffer, p_length, p_raw) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return 1;
+		}
+
+		const bytes_array = new Uint8Array(p_length);
+		for (var i = 0; i < p_length; i++) {
+			bytes_array[i] = getValue(p_buffer + i, 'i8');
+		}
+
+		if (p_raw) {
+			ref.send(bytes_array.buffer);
+		} else {
+			const string = new TextDecoder('utf-8').decode(bytes_array);
+			ref.send(string);
+		}
+	},
+
+	godot_js_rtc_datachannel_is_ordered: function(p_id) {
+		return IDHandler.get_prop(p_id, 'ordered', true);
+	},
+
+	godot_js_rtc_datachannel_id_get: function(p_id) {
+		return IDHandler.get_prop(p_id, 'id', 65535);
+	},
+
+	godot_js_rtc_datachannel_max_packet_lifetime_get: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return 65535;
+		}
+		if (ref['maxPacketLifeTime'] !== undefined) {
+			return ref['maxPacketLifeTime'];
+		} else if (ref['maxRetransmitTime'] !== undefined) {
+			// Guess someone didn't appreciate the standardization process.
+			return ref['maxRetransmitTime'];
+		}
+		return 65535;
+	},
+
+	godot_js_rtc_datachannel_max_retransmits_get: function(p_id) {
+		return IDHandler.get_prop(p_id, 'maxRetransmits', 65535);
+	},
+
+	godot_js_rtc_datachannel_is_negotiated: function(p_id, p_def) {
+		return IDHandler.get_prop(p_id, 'negotiated', 65535);
+	},
+
+	godot_js_rtc_datachannel_label_get: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref || !ref.label) {
+			return 0;
+		}
+		return GodotOS.allocString(ref.label);
+	},
+
+	godot_js_rtc_datachannel_protocol_get: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref || !ref.protocol) {
+			return 0;
+		}
+		return GodotOS.allocString(ref.protocol);
+	},
+
+	godot_js_rtc_datachannel_destroy: function(p_id) {
+		GodotRTCDataChannel.close(p_id);
+		IDHandler.remove(p_id);
+	},
+
+	godot_js_rtc_datachannel_connect: function(p_id, p_ref, p_on_open, p_on_message, p_on_error, p_on_close) {
+		const onopen = GodotOS.get_func(p_on_open).bind(null, p_ref);
+		const onmessage = GodotOS.get_func(p_on_message).bind(null, p_ref);
+		const onerror = GodotOS.get_func(p_on_error).bind(null, p_ref);
+		const onclose = GodotOS.get_func(p_on_close).bind(null, p_ref);
+		GodotRTCDataChannel.connect(p_id, onopen, onmessage, onerror, onclose);
+	},
+
+	godot_js_rtc_datachannel_close: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		GodotRTCDataChannel.close(p_id);
+	},
+};
+
+autoAddDeps(GodotRTCDataChannel, '$GodotRTCDataChannel');
+mergeInto(LibraryManager.library, GodotRTCDataChannel);
+
+var GodotRTCPeerConnection = {
+
+	$GodotRTCPeerConnection__deps: ['$IDHandler', '$GodotOS', '$GodotRTCDataChannel'],
+	$GodotRTCPeerConnection: {
+		onstatechange: function(p_id, p_conn, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			var state = 5; // CLOSED
+			switch(p_conn.iceConnectionState) {
+				case "new":
+					state = 0;
+				case "checking":
+					state = 1;
+				case "connected":
+				case "completed":
+					state = 2;
+				case "disconnected":
+					state = 3;
+				case "failed":
+					state = 4;
+				case "closed":
+					state = 5;
+			}
+			callback(state);
+		},
+
+		onicecandidate: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref || !event.candidate) {
+				return;
+			}
+
+			let c = event.candidate;
+			let candidate_str = GodotOS.allocString(c.candidate);
+			let mid_str = GodotOS.allocString(c.sdpMid);
+			callback(mid_str, c.sdpMLineIndex, candidate_str);
+			_free(candidate_str);
+			_free(mid_str);
+		},
+
+		ondatachannel: function(p_id, callback, event) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+
+			const cid = IDHandler.add(event.channel);
+			callback(cid);
+		},
+
+		onsession: function(p_id, callback, session) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			let type_str = GodotOS.allocString(session.type);
+			let sdp_str = GodotOS.allocString(session.sdp);
+			callback(type_str, sdp_str);
+			_free(type_str);
+			_free(sdp_str);
+		},
+
+		onerror: function(p_id, callback, error) {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return;
+			}
+			console.error(error);
+			callback();
+		},
+	},
+
+	godot_js_rtc_pc_create: function(p_config, p_ref, p_on_state_change, p_on_candidate, p_on_datachannel) {
+		const onstatechange = GodotOS.get_func(p_on_state_change).bind(null, p_ref);
+		const oncandidate = GodotOS.get_func(p_on_candidate).bind(null, p_ref);
+		const ondatachannel = GodotOS.get_func(p_on_datachannel).bind(null, p_ref);
+
+		var config = JSON.parse(UTF8ToString(p_config));
+		var conn = null;
+		try {
+			conn = new RTCPeerConnection(config);
+		} catch (e) {
+			console.error(e);
+			return 0;
+		}
+
+		const base = GodotRTCPeerConnection;
+		const id = IDHandler.add(conn);
+		conn.oniceconnectionstatechange = base.onstatechange.bind(null, id, conn, onstatechange);
+		conn.onicecandidate = base.onicecandidate.bind(null, id, oncandidate);
+		conn.ondatachannel = base.ondatachannel.bind(null, id, ondatachannel);
+		return id;
+	},
+
+	godot_js_rtc_pc_close: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		ref.close();
+	},
+
+	godot_js_rtc_pc_destroy: function(p_id) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		ref.oniceconnectionstatechange = null;
+		ref.onicecandidate = null;
+		ref.ondatachannel = null;
+		IDHandler.remove(p_id);
+	},
+
+	godot_js_rtc_pc_offer_create: function(p_id, p_obj, p_on_session, p_on_error) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		const onsession = GodotOS.get_func(p_on_session).bind(null, p_obj);
+		const onerror = GodotOS.get_func(p_on_error).bind(null, p_obj);
+		ref.createOffer().then(function(session) {
+			GodotRTCPeerConnection.onsession(p_id, onsession, session);
+		}).catch(function(error) {
+			GodotRTCPeerConnection.onerror(p_id, onerror, error);
+		});
+	},
+
+	godot_js_rtc_pc_local_description_set: function(p_id, p_type, p_sdp, p_obj, p_on_error) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		const type = UTF8ToString(p_type);
+		const sdp = UTF8ToString(p_sdp);
+		const onerror = GodotOS.get_func(p_on_error).bind(null, p_obj);
+		ref.setLocalDescription({
+			'sdp': sdp,
+			'type': type
+		}).catch(function(error) {
+			GodotRTCPeerConnection.onerror(p_id, onerror, error);
+		});
+	},
+
+	godot_js_rtc_pc_remote_description_set: function(p_id, p_type, p_sdp, p_obj, p_session_created, p_on_error) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		const type = UTF8ToString(p_type);
+		const sdp = UTF8ToString(p_sdp);
+		const onerror = GodotOS.get_func(p_on_error).bind(null, p_obj);
+		const onsession = GodotOS.get_func(p_session_created).bind(null, p_obj);
+		ref.setRemoteDescription({
+			'sdp': sdp,
+			'type': type
+		}).then(function() {
+			if (type != 'offer') {
+				return;
+			}
+			return ref.createAnswer().then(function(session) {
+				GodotRTCPeerConnection.onsession(p_id, onsession, session);
+			});
+		}).catch(function(error) {
+			GodotRTCPeerConnection.onerror(p_id, onerror, error);
+		});
+	},
+
+	godot_js_rtc_pc_ice_candidate_add: function(p_id, p_mid_name, p_mline_idx, p_sdp) {
+		const ref = IDHandler.get(p_id);
+		if (!ref) {
+			return;
+		}
+		var sdpMidName = UTF8ToString(p_mid_name);
+		var sdpName = UTF8ToString(p_sdp);
+		ref.addIceCandidate(new RTCIceCandidate({
+			"candidate": sdpName,
+			"sdpMid": sdpMidName,
+			"sdpMlineIndex": p_mline_idx,
+		}));
+	},
+
+	godot_js_rtc_pc_datachannel_create__deps: ['$GodotRTCDataChannel'],
+	godot_js_rtc_pc_datachannel_create: function(p_id, p_label, p_config) {
+		try {
+			const ref = IDHandler.get(p_id);
+			if (!ref) {
+				return 0;
+			}
+
+			const label = UTF8ToString(p_label);
+			const config = JSON.parse(UTF8ToString(p_config));
+
+			const channel = ref.createDataChannel(label, config);
+			return IDHandler.add(channel);
+		} catch (e) {
+			console.error(e);
+			return 0;
+		}
+	},
+};
+
+autoAddDeps(GodotRTCPeerConnection, '$GodotRTCPeerConnection')
+mergeInto(LibraryManager.library, GodotRTCPeerConnection);