Added battles in networking

GAME_STATE_ARCHITECTURE.md

@@ -429,8 +429,10 @@ there is no prediction or rollback.
 
 Current boundaries remain:
 
-- client intent is limited to `SetCharacterDestinationCommand`; server presence
-  changes use `SetCharacterEnabledCommand` in tick bundles;
+- client intent is limited to `SetCharacterDestinationCommand`,
+  `SetCharacterTargetCommand`, `ClearCharacterAttackTargetCommand`, and
+  `TryCharacterAttackComboCommand`; server presence changes use
+  `SetCharacterEnabledCommand` in tick bundles;
 - player characters must already exist in the initial state and campaign slot
   list; dynamic spawning and reconnect history are not implemented;
 - authentication and automatic checkpoint resynchronization are absent;

WEBSOCKET_NETWORKING.md

@@ -5,10 +5,13 @@
 The Windows WebSocket transport uses Boost.Asio and Boost.Beast to run a
 server-sequenced deterministic lockstep simulation. A client receives one
 authoritative state at a completed tick boundary. After that, the server sends
-	only numbered tick messages containing ordered destination and presence
-	commands (or an empty command list).
+	only numbered tick messages containing ordered destination, combat-intent,
+	and presence commands (or an empty command list).
 
-Client intent is intentionally limited to `SetCharacterDestinationCommand`.
+Client intent is intentionally limited to
+`SetCharacterDestinationCommand`, `SetCharacterTargetCommand`,
+`ClearCharacterAttackTargetCommand`, and
+`TryCharacterAttackComboCommand`.
 The server also sends `SetCharacterEnabledCommand` in tick bundles when a
 configured player slot connects or disconnects.
 
@@ -27,9 +30,10 @@ configured player slot connects or disconnects.
   the newly connected client.
 - The initial message contains the state, completed snapshot tick, assigned
   player ID, tick duration, two-tick input delay, and compatibility fingerprint.
-- Destination inputs cross from the Asio thread through a queue. The simulation
-  thread validates client sequence numbers, replaces client identity with the
-  assigned slot, and schedules commands two ticks in the future.
+- Destination and character-action inputs cross from the Asio thread through a
+  queue. The simulation thread validates client sequence numbers, replaces
+  client identity with the assigned slot, and schedules commands two ticks in
+  the future.
 - Every tick is broadcast, including ticks with no commands. No periodic state
   snapshots are sent.
 
@@ -44,8 +48,8 @@ configured player slot connects or disconnects.
   consumers and transitional runtime-state bindings continue to work.
 - Camera orientation lives in host-owned `LocationLocalState`, so incoming
   authoritative snapshots cannot overwrite camera movement.
-- `submit()` serializes destination intent only. Other command variants remain
-  local no-ops for a remote connection.
+- `submit()` serializes destination and tagged character-action intent. Other
+  command variants remain local no-ops for a remote connection.
 - Tick bundles are buffered by ID. The replica advances only while the next
   contiguous tick is available, applying its commands before one exact 100 ms
   simulation step.
@@ -106,13 +110,19 @@ Message types are:
 - `initial_state` (server to client): one state snapshot and lockstep metadata;
 - `destination_input` (client to server): monotonic client sequence and a
   centimetre-normalized finite target;
-- `tick` (server to client): tick ID, globally sequenced destination and
-  character-presence commands, and post-tick diagnostic state hash;
+- `character_action` (client to server): monotonic client sequence, an action
+  tag (`set_target`, `clear_attack_target`, or `try_attack_combo`), and a
+  target ID for `set_target`;
+- `tick` (server to client): tick ID, globally sequenced destination,
+  character-action, and character-presence commands, and post-tick diagnostic
+  state hash;
 - `error` (server to client): invalid input, incompatibility, or full server.
 
 Protocol v1 is not compatible. Malformed payloads, non-finite or out-of-range
-coordinates, duplicate client sequences, and unsupported commands cannot enter
-the authoritative command stream.
+coordinates, duplicate client sequences, empty action IDs, and unsupported
+commands cannot enter the authoritative command stream. The server derives the
+location and player character from the assigned connection slot; clients cannot
+use these actions to control another player or an NPC.
 
 WebSocket ordering is not used as simulation time. Integer tick IDs are the
 only authoritative clock. The server uses `steady_clock` only to pace its loop,

server/tests/NetworkProtocolTests.cpp

@@ -60,12 +60,38 @@ int main()
 		parsedInput.target.isApprox(Eigen::Vector3f(1.23f, 0.f, -5.68f)),
 		"destination input was not normalized");
 
+	FRG::CharacterActionInputMessage actionInput{
+		8, "set_target", "hostile_npc"};
+	FRG::CharacterActionInputMessage parsedActionInput;
+	require(
+		FRG::parseCharacterActionInputMessage(
+			FRG::makeCharacterActionInputMessage(actionInput),
+			parsedActionInput, error),
+		"character action input did not round trip");
+	require(
+		parsedActionInput.clientSequence == 8 &&
+		parsedActionInput.action == "set_target" &&
+		parsedActionInput.targetId == "hostile_npc",
+		"character action input fields did not round trip");
+	require(
+		!FRG::parseCharacterActionInputMessage(
+			R"({"protocolVersion":2,"type":"character_action","payload":{"clientSequence":1,"action":"unknown","targetId":""}})",
+			parsedActionInput, error),
+		"unknown character action was accepted");
+	require(
+		!FRG::parseCharacterActionInputMessage(
+			R"({"protocolVersion":2,"type":"character_action","payload":{"clientSequence":1,"action":"set_target","targetId":""}})",
+			parsedActionInput, error),
+		"empty attack target was accepted");
+
 	FRG::TickMessage tick;
 	tick.tickId = 43;
 	tick.commands.push_back(FRG::ScheduledDestinationCommand{
 		1, "player", parsedInput.target});
 	tick.commands.push_back(FRG::ScheduledCharacterEnabledCommand{
 		2, "uni_exterior", "player2", true});
+	tick.commands.push_back(FRG::ScheduledCharacterActionCommand{
+		3, "player", "set_target", "hostile_npc"});
 	tick.stateHash = "0123456789abcdef";
 	FRG::TickMessage parsedTick;
 	require(
@@ -73,11 +99,15 @@ int main()
 			FRG::makeTickMessage(tick), parsedTick, error),
 		"tick message did not round trip");
 	require(
-		parsedTick.tickId == 43 && parsedTick.commands.size() == 2 &&
+		parsedTick.tickId == 43 && parsedTick.commands.size() == 3 &&
 		std::holds_alternative<FRG::ScheduledCharacterEnabledCommand>(
 			parsedTick.commands[1]) &&
 		std::get<FRG::ScheduledCharacterEnabledCommand>(
-			parsedTick.commands[1]).enabled,
+			parsedTick.commands[1]).enabled &&
+		std::holds_alternative<FRG::ScheduledCharacterActionCommand>(
+			parsedTick.commands[2]) &&
+		std::get<FRG::ScheduledCharacterActionCommand>(
+			parsedTick.commands[2]).targetId == "hostile_npc",
 		"tick contents did not round trip");
 
 	require(
@@ -134,12 +164,20 @@ int main()
 		"scheduled commands were not finalized in stable order");
 
 	timeline.scheduleCharacterEnabled("uni_exterior", "player2", true);
+	timeline.scheduleCharacterAction("player", "clear_attack_target");
 	const FRG::TickMessage presenceTick = timeline.advance();
 	require(
 		presenceTick.commands.size() == 1 &&
 		std::holds_alternative<FRG::ScheduledCharacterEnabledCommand>(
 			presenceTick.commands[0]),
 		"character enabled command was not scheduled for the next tick");
+	const FRG::TickMessage actionTick =
+		timeline.advance();
+	require(
+		actionTick.commands.size() == 1 &&
+		std::holds_alternative<FRG::ScheduledCharacterActionCommand>(
+			actionTick.commands[0]),
+		"character action was not scheduled with input delay");
 
 	return EXIT_SUCCESS;
 }

server/tests/WebsocketLockstepTests.cpp

@@ -104,6 +104,55 @@ int main()
 		}),
 		"client did not consume finalized lockstep ticks");
 
+	client->submit(FRG::SetCharacterTargetCommand{
+		"stale_location", "spoofed_character", "hostile_npc"});
+	std::this_thread::sleep_for(std::chrono::milliseconds(20));
+	server.update();
+	server.update();
+	require(
+		waitFor([&]() {
+			client->update(0);
+			secondClient->update(0);
+			return client->snapshot()->players.at("player").state.attackTargetId ==
+					"hostile_npc" &&
+				secondClient->snapshot()->players.at("player").state.attackTargetId ==
+					"hostile_npc" &&
+				authoritative.snapshot()->players.at("player").state.attackTargetId ==
+					"hostile_npc";
+		}),
+		"target command was not delayed and rebroadcast");
+
+	client->submit(FRG::ClearCharacterAttackTargetCommand{
+		"stale_location", "spoofed_character"});
+	std::this_thread::sleep_for(std::chrono::milliseconds(20));
+	server.update();
+	server.update();
+	require(
+		waitFor([&]() {
+			client->update(0);
+			secondClient->update(0);
+			return client->snapshot()->players.at("player").state.attackTargetId.empty() &&
+				secondClient->snapshot()->players.at("player").state.attackTargetId.empty() &&
+				authoritative.snapshot()->players.at("player").state.attackTargetId.empty();
+		}),
+		"clear attack target command was not delayed and rebroadcast");
+
+	client->submit(FRG::TryCharacterAttackComboCommand{
+		"stale_location", "spoofed_character"});
+	std::this_thread::sleep_for(std::chrono::milliseconds(20));
+	server.update();
+	server.update();
+	require(
+		waitFor([&]() {
+			client->update(0);
+			secondClient->update(0);
+			return client->snapshot()->revision ==
+					secondClient->snapshot()->revision &&
+				client->snapshot()->revision ==
+					authoritative.snapshot()->revision;
+		}),
+		"attack combo command was not rebroadcast in lockstep");
+
 	secondClient.reset();
 	std::this_thread::sleep_for(std::chrono::milliseconds(50));
 	server.update();

src/game_server/NetworkProtocol.cpp

@@ -96,6 +96,27 @@ nlohmann::json targetJson(const Eigen::Vector3f& target)
 	return nlohmann::json::array({target.x(), target.y(), target.z()});
 }
 
+bool validCharacterAction(
+	const std::string& action, const std::string& targetId,
+	std::string& error)
+{
+	if (action != "set_target" &&
+		action != "clear_attack_target" &&
+		action != "try_attack_combo") {
+		error = "unsupported character action";
+		return false;
+	}
+	if (action == "set_target" && targetId.empty()) {
+		error = "set_target requires a targetId";
+		return false;
+	}
+	if (action != "set_target" && !targetId.empty()) {
+		error = "targetId is only valid for set_target";
+		return false;
+	}
+	return true;
+}
+
 } // namespace
 
 std::string makeInitialStateMessage(const InitialStateMessage& message)
@@ -159,6 +180,16 @@ std::uint64_t LockstepTimeline::scheduleCharacterEnabled(
 	return sequence;
 }
 
+std::uint64_t LockstepTimeline::scheduleCharacterAction(
+	const std::string& playerId, std::string action, std::string targetId)
+{
+	const std::uint64_t sequence = nextCommandSequence_++;
+	pending_[currentTick_ + inputDelayTicks_].push_back(
+		ScheduledCharacterActionCommand{
+			sequence, playerId, std::move(action), std::move(targetId)});
+	return sequence;
+}
+
 TickMessage LockstepTimeline::advance()
 {
 	TickMessage result;
@@ -191,6 +222,38 @@ bool parseDestinationInputMessage(
 	return readTarget(payload["target"], message.target, error);
 }
 
+std::string makeCharacterActionInputMessage(
+	const CharacterActionInputMessage& message)
+{
+	return envelope("character_action", {
+		{"clientSequence", message.clientSequence},
+		{"action", message.action},
+		{"targetId", message.targetId}
+	});
+}
+
+bool parseCharacterActionInputMessage(
+	const std::string& text, CharacterActionInputMessage& message,
+	std::string& error)
+{
+	nlohmann::json payload;
+	if (!parseEnvelope(text, "character_action", payload, error))
+		return false;
+	if (!readTick(payload, "clientSequence", message.clientSequence, error))
+		return false;
+	if (!payload.contains("action") || !payload["action"].is_string()) {
+		error = "action is required";
+		return false;
+	}
+	message.action = payload["action"].get<std::string>();
+	message.targetId = payload.value("targetId", std::string());
+	if (!payload.contains("targetId") || !payload["targetId"].is_string()) {
+		error = "targetId must be a string";
+		return false;
+	}
+	return validCharacterAction(message.action, message.targetId, error);
+}
+
 std::string makeTickMessage(const TickMessage& message)
 {
 	nlohmann::json commands = nlohmann::json::array();
@@ -205,13 +268,23 @@ std::string makeTickMessage(const TickMessage& message)
 					{"target", targetJson(command.target)}
 				});
 			} else {
-				commands.push_back({
-					{"type", "character_enabled"},
-					{"commandSequence", command.commandSequence},
-					{"locationId", command.locationId},
-					{"characterId", command.characterId},
-					{"enabled", command.enabled}
-				});
+				if constexpr (std::is_same_v<T, ScheduledCharacterEnabledCommand>) {
+					commands.push_back({
+						{"type", "character_enabled"},
+						{"commandSequence", command.commandSequence},
+						{"locationId", command.locationId},
+						{"characterId", command.characterId},
+						{"enabled", command.enabled}
+					});
+				} else {
+					commands.push_back({
+						{"type", "character_action"},
+						{"commandSequence", command.commandSequence},
+						{"playerId", command.playerId},
+						{"action", command.action},
+						{"targetId", command.targetId}
+					});
+				}
 			}
 		}, scheduled);
 	}
@@ -274,6 +347,24 @@ bool parseTickMessage(
 				return false;
 			}
 			command = std::move(enabled);
+		} else if (type == "character_action") {
+			ScheduledCharacterActionCommand action;
+			action.commandSequence = previousSequence;
+			if (!value.contains("playerId") || !value["playerId"].is_string() ||
+				!value.contains("action") || !value["action"].is_string() ||
+				!value.contains("targetId") || !value["targetId"].is_string()) {
+				error = "invalid character action command";
+				return false;
+			}
+			action.playerId = value["playerId"].get<std::string>();
+			action.action = value["action"].get<std::string>();
+			action.targetId = value["targetId"].get<std::string>();
+			if (action.playerId.empty() ||
+				!validCharacterAction(action.action, action.targetId, error)) {
+				if (error.empty()) error = "invalid character action command";
+				return false;
+			}
+			command = std::move(action);
 		} else {
 			error = "unsupported scheduled command type";
 			return false;

src/game_server/NetworkProtocol.h

@@ -28,6 +28,12 @@ struct DestinationInputMessage {
 	Eigen::Vector3f target = Eigen::Vector3f::Zero();
 };
 
+struct CharacterActionInputMessage {
+	std::uint64_t clientSequence = 0;
+	std::string action;
+	std::string targetId;
+};
+
 struct ScheduledDestinationCommand {
 	std::uint64_t commandSequence = 0;
 	std::string playerId;
@@ -41,9 +47,17 @@ struct ScheduledCharacterEnabledCommand {
 	bool enabled = false;
 };
 
+struct ScheduledCharacterActionCommand {
+	std::uint64_t commandSequence = 0;
+	std::string playerId;
+	std::string action;
+	std::string targetId;
+};
+
 using ScheduledCommand = std::variant<
 	ScheduledDestinationCommand,
-	ScheduledCharacterEnabledCommand>;
+	ScheduledCharacterEnabledCommand,
+	ScheduledCharacterActionCommand>;
 
 struct TickMessage {
 	std::uint64_t tickId = 0;
@@ -63,6 +77,9 @@ public:
 	std::uint64_t scheduleCharacterEnabled(
 		const std::string& locationId, const std::string& characterId,
 		bool enabled);
+	std::uint64_t scheduleCharacterAction(
+		const std::string& playerId, std::string action,
+		std::string targetId = {});
 	TickMessage advance();
 
 private:
@@ -78,6 +95,11 @@ bool parseInitialStateMessage(
 std::string makeDestinationInputMessage(const DestinationInputMessage& message);
 bool parseDestinationInputMessage(
 	const std::string& text, DestinationInputMessage& message, std::string& error);
+std::string makeCharacterActionInputMessage(
+	const CharacterActionInputMessage& message);
+bool parseCharacterActionInputMessage(
+	const std::string& text, CharacterActionInputMessage& message,
+	std::string& error);
 std::string makeTickMessage(const TickMessage& message);
 bool parseTickMessage(
 	const std::string& text, TickMessage& message, std::string& error);

src/game_server/WebsocketGameClient.cpp

@@ -177,6 +177,16 @@ void WebsocketGameClient::submit(const GameCommand& command)
 			std::get_if<SetCharacterDestinationCommand>(&command)) {
 		impl_->send(makeDestinationInputMessage(
 			{nextClientSequence_++, destination->target}));
+	} else if (const auto* target =
+			std::get_if<SetCharacterTargetCommand>(&command)) {
+		impl_->send(makeCharacterActionInputMessage(
+			{nextClientSequence_++, "set_target", target->targetId}));
+	} else if (std::holds_alternative<ClearCharacterAttackTargetCommand>(command)) {
+		impl_->send(makeCharacterActionInputMessage(
+			{nextClientSequence_++, "clear_attack_target", {}}));
+	} else if (std::holds_alternative<TryCharacterAttackComboCommand>(command)) {
+		impl_->send(makeCharacterActionInputMessage(
+			{nextClientSequence_++, "try_attack_combo", {}}));
 	}
 }
 
@@ -259,9 +269,18 @@ void WebsocketGameClient::update(std::int64_t)
 				if constexpr (std::is_same_v<T, ScheduledDestinationCommand>) {
 					replica_.submit(SetCharacterDestinationCommand{
 						locationId, command.playerId, command.target, {}});
-				} else {
+				} else if constexpr (std::is_same_v<T, ScheduledCharacterEnabledCommand>) {
 					replica_.submit(SetCharacterEnabledCommand{
 						command.locationId, command.characterId, command.enabled});
+				} else if (command.action == "set_target") {
+					replica_.submit(SetCharacterTargetCommand{
+						locationId, command.playerId, command.targetId});
+				} else if (command.action == "clear_attack_target") {
+					replica_.submit(ClearCharacterAttackTargetCommand{
+						locationId, command.playerId});
+				} else if (command.action == "try_attack_combo") {
+					replica_.submit(TryCharacterAttackComboCommand{
+						locationId, command.playerId});
 				}
 			}, scheduled);
 		}

src/game_server/WebsocketGameServer.cpp

@@ -132,7 +132,9 @@ class WebsocketGameServer::Impl {
 public:
 	struct PendingInput {
 		std::string playerId;
-		DestinationInputMessage input;
+		std::variant<
+			DestinationInputMessage,
+			CharacterActionInputMessage> input;
 	};
 
 	Impl(
@@ -227,17 +229,27 @@ private:
 							std::move(socket), playerId,
 							[this](const std::shared_ptr<ServerSession>& source,
 								const std::string& message) {
-								DestinationInputMessage parsed;
-								std::string parseError;
-								if (!parseDestinationInputMessage(
-										message, parsed, parseError)) {
+								DestinationInputMessage destination;
+								std::string destinationError;
+								if (parseDestinationInputMessage(
+										message, destination, destinationError)) {
+									std::lock_guard<std::mutex> lock(inputsMutex_);
+									pendingInputs_.push_back(
+										{source->playerId(), std::move(destination)});
+									return;
+								}
+								CharacterActionInputMessage action;
+								std::string actionError;
+								if (!parseCharacterActionInputMessage(
+										message, action, actionError)) {
 									source->send(makeErrorMessage(
-										"invalid_input", parseError));
+										"invalid_input", actionError.empty()
+											? destinationError : actionError));
 									return;
 								}
 								std::lock_guard<std::mutex> lock(inputsMutex_);
 								pendingInputs_.push_back(
-									{source->playerId(), std::move(parsed)});
+									{source->playerId(), std::move(action)});
 							},
 							[this](const std::shared_ptr<ServerSession>& source) {
 								if (!source->playerId().empty())
@@ -329,9 +341,20 @@ void WebsocketGameServer::update()
 		lastClientSequences_.erase(playerId);
 	for (const Impl::PendingInput& pending : impl_->takeInputs()) {
 		std::uint64_t& previous = lastClientSequences_[pending.playerId];
-		if (pending.input.clientSequence <= previous) continue;
-		previous = pending.input.clientSequence;
-		timeline_.schedule(pending.playerId, pending.input.target);
+		const std::uint64_t sequence = std::visit(
+			[](const auto& input) { return input.clientSequence; },
+			pending.input);
+		if (sequence <= previous) continue;
+		previous = sequence;
+		std::visit([&](const auto& input) {
+			using T = std::decay_t<decltype(input)>;
+			if constexpr (std::is_same_v<T, DestinationInputMessage>) {
+				timeline_.schedule(pending.playerId, input.target);
+			} else {
+				timeline_.scheduleCharacterAction(
+					pending.playerId, input.action, input.targetId);
+			}
+		}, pending.input);
 	}
 
 	TickMessage tick = timeline_.advance();
@@ -342,9 +365,21 @@ void WebsocketGameServer::update()
 				gameServer_.submit(SetCharacterDestinationCommand{
 					gameServer_.snapshot()->currentLocationId,
 					command.playerId, command.target, {}});
-			} else {
+			} else if constexpr (std::is_same_v<T, ScheduledCharacterEnabledCommand>) {
 				gameServer_.submit(SetCharacterEnabledCommand{
 					command.locationId, command.characterId, command.enabled});
+			} else if (command.action == "set_target") {
+				gameServer_.submit(SetCharacterTargetCommand{
+					gameServer_.snapshot()->currentLocationId,
+					command.playerId, command.targetId});
+			} else if (command.action == "clear_attack_target") {
+				gameServer_.submit(ClearCharacterAttackTargetCommand{
+					gameServer_.snapshot()->currentLocationId,
+					command.playerId});
+			} else if (command.action == "try_attack_combo") {
+				gameServer_.submit(TryCharacterAttackComboCommand{
+					gameServer_.snapshot()->currentLocationId,
+					command.playerId});
 			}
 		}, scheduled);
 	}