[Net] Modularize multiplayer, expose MultiplayerAPI to extensions.

- RPC configurations are now dictionaries.
- Script.get_rpc_methods renamed to Script.get_rpc_config.
- Node.rpc[_id] and Callable.rpc now return an Error.
- Refactor MultiplayerAPI to allow extension.
- New MultiplayerAPI.rpc method with Array argument (for scripts).
- Move the default MultiplayerAPI implementation to a module.

1 files changed, 304 insertions, 0 deletions

diff --git a/modules/multiplayer/multiplayer_synchronizer.cpp b/modules/multiplayer/multiplayer_synchronizer.cpp
new file mode 100644
index 0000000000..621d62c4c7
--- /dev/null
+++ b/modules/multiplayer/multiplayer_synchronizer.cpp
@@ -0,0 +1,304 @@
+/*************************************************************************/
+/*  multiplayer_synchronizer.cpp                                         */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 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.                */
+/*************************************************************************/
+
+#include "multiplayer_synchronizer.h"
+
+#include "core/config/engine.h"
+#include "scene/main/multiplayer_api.h"
+
+Object *MultiplayerSynchronizer::_get_prop_target(Object *p_obj, const NodePath &p_path) {
+	if (p_path.get_name_count() == 0) {
+		return p_obj;
+	}
+	Node *node = Object::cast_to<Node>(p_obj);
+	ERR_FAIL_COND_V_MSG(!node || !node->has_node(p_path), nullptr, vformat("Node '%s' not found.", p_path));
+	return node->get_node(p_path);
+}
+
+void MultiplayerSynchronizer::_stop() {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+#endif
+	Node *node = is_inside_tree() ? get_node_or_null(root_path) : nullptr;
+	if (node) {
+		get_multiplayer()->object_configuration_remove(node, this);
+	}
+}
+
+void MultiplayerSynchronizer::_start() {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+#endif
+	Node *node = is_inside_tree() ? get_node_or_null(root_path) : nullptr;
+	if (node) {
+		get_multiplayer()->object_configuration_add(node, this);
+		_update_process();
+	}
+}
+
+void MultiplayerSynchronizer::_update_process() {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+#endif
+	Node *node = is_inside_tree() ? get_node_or_null(root_path) : nullptr;
+	if (!node) {
+		return;
+	}
+	set_process_internal(false);
+	set_physics_process_internal(false);
+	if (!visibility_filters.size()) {
+		return;
+	}
+	switch (visibility_update_mode) {
+		case VISIBILITY_PROCESS_IDLE:
+			set_process_internal(true);
+			break;
+		case VISIBILITY_PROCESS_PHYSICS:
+			set_physics_process_internal(true);
+			break;
+		case VISIBILITY_PROCESS_NONE:
+			break;
+	}
+}
+
+Error MultiplayerSynchronizer::get_state(const List<NodePath> &p_properties, Object *p_obj, Vector<Variant> &r_variant, Vector<const Variant *> &r_variant_ptrs) {
+	ERR_FAIL_COND_V(!p_obj, ERR_INVALID_PARAMETER);
+	r_variant.resize(p_properties.size());
+	r_variant_ptrs.resize(r_variant.size());
+	int i = 0;
+	for (const NodePath &prop : p_properties) {
+		bool valid = false;
+		const Object *obj = _get_prop_target(p_obj, prop);
+		ERR_FAIL_COND_V(!obj, FAILED);
+		r_variant.write[i] = obj->get(prop.get_concatenated_subnames(), &valid);
+		r_variant_ptrs.write[i] = &r_variant[i];
+		ERR_FAIL_COND_V_MSG(!valid, ERR_INVALID_DATA, vformat("Property '%s' not found.", prop));
+		i++;
+	}
+	return OK;
+}
+
+Error MultiplayerSynchronizer::set_state(const List<NodePath> &p_properties, Object *p_obj, const Vector<Variant> &p_state) {
+	ERR_FAIL_COND_V(!p_obj, ERR_INVALID_PARAMETER);
+	int i = 0;
+	for (const NodePath &prop : p_properties) {
+		Object *obj = _get_prop_target(p_obj, prop);
+		ERR_FAIL_COND_V(!obj, FAILED);
+		obj->set(prop.get_concatenated_subnames(), p_state[i]);
+		i += 1;
+	}
+	return OK;
+}
+
+bool MultiplayerSynchronizer::is_visibility_public() const {
+	return peer_visibility.has(0);
+}
+
+void MultiplayerSynchronizer::set_visibility_public(bool p_visible) {
+	set_visibility_for(0, p_visible);
+}
+
+bool MultiplayerSynchronizer::is_visible_to(int p_peer) {
+	if (visibility_filters.size()) {
+		Variant arg = p_peer;
+		const Variant *argv[1] = { &arg };
+		for (Callable filter : visibility_filters) {
+			Variant ret;
+			Callable::CallError err;
+			filter.call(argv, 1, ret, err);
+			ERR_FAIL_COND_V(err.error != Callable::CallError::CALL_OK || ret.get_type() != Variant::BOOL, false);
+			if (!ret.operator bool()) {
+				return false;
+			}
+		}
+	}
+	return peer_visibility.has(0) || peer_visibility.has(p_peer);
+}
+
+void MultiplayerSynchronizer::add_visibility_filter(Callable p_callback) {
+	visibility_filters.insert(p_callback);
+	_update_process();
+}
+
+void MultiplayerSynchronizer::remove_visibility_filter(Callable p_callback) {
+	visibility_filters.erase(p_callback);
+	_update_process();
+}
+
+void MultiplayerSynchronizer::set_visibility_for(int p_peer, bool p_visible) {
+	if (peer_visibility.has(p_peer) == p_visible) {
+		return;
+	}
+	if (p_visible) {
+		peer_visibility.insert(p_peer);
+	} else {
+		peer_visibility.erase(p_peer);
+	}
+	update_visibility(p_peer);
+}
+
+bool MultiplayerSynchronizer::get_visibility_for(int p_peer) const {
+	return peer_visibility.has(p_peer);
+}
+
+void MultiplayerSynchronizer::set_visibility_update_mode(VisibilityUpdateMode p_mode) {
+	visibility_update_mode = p_mode;
+	_update_process();
+}
+
+MultiplayerSynchronizer::VisibilityUpdateMode MultiplayerSynchronizer::get_visibility_update_mode() const {
+	return visibility_update_mode;
+}
+
+void MultiplayerSynchronizer::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_root_path", "path"), &MultiplayerSynchronizer::set_root_path);
+	ClassDB::bind_method(D_METHOD("get_root_path"), &MultiplayerSynchronizer::get_root_path);
+
+	ClassDB::bind_method(D_METHOD("set_replication_interval", "milliseconds"), &MultiplayerSynchronizer::set_replication_interval);
+	ClassDB::bind_method(D_METHOD("get_replication_interval"), &MultiplayerSynchronizer::get_replication_interval);
+
+	ClassDB::bind_method(D_METHOD("set_replication_config", "config"), &MultiplayerSynchronizer::set_replication_config);
+	ClassDB::bind_method(D_METHOD("get_replication_config"), &MultiplayerSynchronizer::get_replication_config);
+
+	ClassDB::bind_method(D_METHOD("set_visibility_update_mode", "mode"), &MultiplayerSynchronizer::set_visibility_update_mode);
+	ClassDB::bind_method(D_METHOD("get_visibility_update_mode"), &MultiplayerSynchronizer::get_visibility_update_mode);
+	ClassDB::bind_method(D_METHOD("update_visibility", "for_peer"), &MultiplayerSynchronizer::update_visibility, DEFVAL(0));
+
+	ClassDB::bind_method(D_METHOD("set_visibility_public", "visible"), &MultiplayerSynchronizer::set_visibility_public);
+	ClassDB::bind_method(D_METHOD("is_visibility_public"), &MultiplayerSynchronizer::is_visibility_public);
+
+	ClassDB::bind_method(D_METHOD("add_visibility_filter", "filter"), &MultiplayerSynchronizer::add_visibility_filter);
+	ClassDB::bind_method(D_METHOD("remove_visibility_filter", "filter"), &MultiplayerSynchronizer::remove_visibility_filter);
+	ClassDB::bind_method(D_METHOD("set_visibility_for", "peer", "visible"), &MultiplayerSynchronizer::set_visibility_for);
+	ClassDB::bind_method(D_METHOD("get_visibility_for", "peer"), &MultiplayerSynchronizer::get_visibility_for);
+
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "root_path"), "set_root_path", "get_root_path");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "replication_interval", PROPERTY_HINT_RANGE, "0,5,0.001,suffix:s"), "set_replication_interval", "get_replication_interval");
+	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "replication_config", PROPERTY_HINT_RESOURCE_TYPE, "SceneReplicationConfig", PROPERTY_USAGE_NO_EDITOR), "set_replication_config", "get_replication_config");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "visibility_update_mode", PROPERTY_HINT_ENUM, "Idle,Physics,None"), "set_visibility_update_mode", "get_visibility_update_mode");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "public_visibility"), "set_visibility_public", "is_visibility_public");
+
+	BIND_ENUM_CONSTANT(VISIBILITY_PROCESS_IDLE);
+	BIND_ENUM_CONSTANT(VISIBILITY_PROCESS_PHYSICS);
+	BIND_ENUM_CONSTANT(VISIBILITY_PROCESS_NONE);
+
+	ADD_SIGNAL(MethodInfo("visibility_changed", PropertyInfo(Variant::INT, "for_peer")));
+}
+
+void MultiplayerSynchronizer::_notification(int p_what) {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+#endif
+	if (root_path.is_empty()) {
+		return;
+	}
+
+	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE: {
+			_start();
+		} break;
+
+		case NOTIFICATION_EXIT_TREE: {
+			_stop();
+		} break;
+
+		case NOTIFICATION_INTERNAL_PROCESS:
+		case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
+			update_visibility(0);
+		} break;
+	}
+}
+
+void MultiplayerSynchronizer::set_replication_interval(double p_interval) {
+	ERR_FAIL_COND_MSG(p_interval < 0, "Interval must be greater or equal to 0 (where 0 means default)");
+	interval_msec = uint64_t(p_interval * 1000);
+}
+
+double MultiplayerSynchronizer::get_replication_interval() const {
+	return double(interval_msec) / 1000.0;
+}
+
+uint64_t MultiplayerSynchronizer::get_replication_interval_msec() const {
+	return interval_msec;
+}
+
+void MultiplayerSynchronizer::set_replication_config(Ref<SceneReplicationConfig> p_config) {
+	replication_config = p_config;
+}
+
+Ref<SceneReplicationConfig> MultiplayerSynchronizer::get_replication_config() {
+	return replication_config;
+}
+
+void MultiplayerSynchronizer::update_visibility(int p_for_peer) {
+#ifdef TOOLS_ENABLED
+	if (Engine::get_singleton()->is_editor_hint()) {
+		return;
+	}
+#endif
+	Node *node = is_inside_tree() ? get_node_or_null(root_path) : nullptr;
+	if (node && get_multiplayer()->has_multiplayer_peer() && is_multiplayer_authority()) {
+		emit_signal(SNAME("visibility_changed"), p_for_peer);
+	}
+}
+
+void MultiplayerSynchronizer::set_root_path(const NodePath &p_path) {
+	_stop();
+	root_path = p_path;
+	_start();
+}
+
+NodePath MultiplayerSynchronizer::get_root_path() const {
+	return root_path;
+}
+
+void MultiplayerSynchronizer::set_multiplayer_authority(int p_peer_id, bool p_recursive) {
+	Node *node = is_inside_tree() ? get_node_or_null(root_path) : nullptr;
+	if (!node) {
+		Node::set_multiplayer_authority(p_peer_id, p_recursive);
+		return;
+	}
+	get_multiplayer()->object_configuration_remove(node, this);
+	Node::set_multiplayer_authority(p_peer_id, p_recursive);
+	get_multiplayer()->object_configuration_add(node, this);
+}
+
+MultiplayerSynchronizer::MultiplayerSynchronizer() {
+	// Publicly visible by default.
+	peer_visibility.insert(0);
+}