too many things

src/td/simulation/CommandApply.cpp

@@ -0,0 +1,15 @@
+#include <td/simulation/CommandApply.h>
+
+namespace td {
+namespace sim {
+
+CommandApply::CommandApply(const game::World& a_World, WorldSnapshot& a_Snapshot) : m_World(a_World), m_Snapshot(a_Snapshot) {}
+
+void CommandApply::Handle(const protocol::cdata::SpawnTroop& a_SpawnTroop) {
+	auto zombie = std::make_shared<game::Zombie>(0, *a_SpawnTroop.m_Level, a_SpawnTroop.m_Sender);
+	zombie->GetPosition() = a_SpawnTroop.m_Position;
+	m_Snapshot.m_Mobs.push_back(zombie);
+}
+
+}  // namespace sim
+}  // namespace td

src/td/simulation/GameHistory.cpp

@@ -0,0 +1,44 @@
+#include <td/simulation/GameHistory.h>
+
+namespace td {
+namespace game {
+
+GameHistory::GameHistory() : m_History(std::numeric_limits<HistorySizeType>::max()), m_Cursor(0) {}
+
+void GameHistory::SetLockStep(HistorySizeType a_Index, protocol::LockStep&& a_LockStep) {
+	m_History[a_Index] = std::move(a_LockStep);
+}
+
+const protocol::LockStep& GameHistory::GetLockStep(HistorySizeType a_Index) const {
+	return *m_History[a_Index];
+}
+
+bool GameHistory::HasLockStep(HistorySizeType a_Index) const {
+	return m_History[a_Index].has_value();
+}
+
+const protocol::LockStep& GameHistory::GetNextStep() {
+	return GetLockStep(m_Cursor++);
+}
+
+bool GameHistory::HasNextStep() const {
+	return HasLockStep(m_Cursor);
+}
+
+void GameHistory::FromPacket(td::protocol::pdata::LockSteps&& a_Steps) {
+	for (int i = 0; i < LOCKSTEP_BUFFER_SIZE; i++) {
+		protocol::LockStep& step = a_Steps.m_LockSteps[i];
+		SetLockStep(i + a_Steps.m_FirstFrameNumber, std::move(step));
+	}
+}
+
+td::protocol::packets::LockStepsPacket GameHistory::ToPacket(HistorySizeType a_StartIndex) {
+	Array<protocol::LockStep, LOCKSTEP_BUFFER_SIZE> steps;
+	for (int i = 0; i < LOCKSTEP_BUFFER_SIZE; i++) {
+		steps[i] = GetLockStep(a_StartIndex + i);
+	}
+	return {a_StartIndex, std::move(steps)};
+}
+
+}  // namespace game
+}  // namespace td

src/td/simulation/RealTimeSimulation.cpp

@@ -0,0 +1,32 @@
+#include <td/simulation/RealTimeSimulation.h>
+
+#include <chrono>
+
+namespace td {
+namespace sim {
+
+std::uint64_t GetTime() {
+	return static_cast<std::uint64_t>(
+		std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock().now().time_since_epoch()).count());
+}
+
+RealTimeSimulation::RealTimeSimulation(game::World& a_World, GameHistory&& a_History, std::uint64_t a_StepTime) :
+	m_StepTime(a_StepTime),
+	m_World(a_World),
+	m_History(std::move(a_History)),
+	m_CurrentTime(0),
+	m_LastTime(GetTime()),
+	m_CurrentStep(0) {}
+
+void RealTimeSimulation::Update() {
+	m_CurrentTime += GetTime() - m_LastTime;
+	m_LastTime = GetTime();
+	if (m_CurrentTime > m_StepTime) {
+		m_World.Tick(m_History[m_CurrentStep], FpFloat(m_StepTime) / FpFloat(1000));
+		m_CurrentStep++;
+		m_CurrentTime -= m_StepTime;
+	}
+}
+
+}  // namespace sim
+}  // namespace td

src/td/simulation/WorldTicker.cpp

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+#include <td/simulation/WorldTicker.h>
+
+#include <td/simulation/system/EntityMove.h>
+#include <td/simulation/CommandApply.h>
+
+#define ADD_SYSTEM(class) std::move(std::make_unique<class>())
+
+namespace td {
+namespace sim {
+
+WorldTicker::WorldTicker() {
+	AddSystem<EntityMove>();
+}
+
+WorldSnapshot WorldTicker::NextStep(
+	const game::World& a_World, const WorldSnapshot& a_PreviousState, const protocol::LockStep& a_LockStep, FpFloat a_Delta) {
+	WorldSnapshot next = CreateNext(a_PreviousState);
+	ApplySteps(a_World, next, a_LockStep);
+	Tick(a_World, next, a_Delta);
+	return next;
+}
+
+void WorldTicker::ApplySteps(const game::World& a_World, WorldSnapshot& a_State, const protocol::LockStep& a_LockStep) {
+	CommandApply cmdHandler(a_World, a_State);
+	for (const auto& cmd : a_LockStep) {
+		cmd->Dispatch(cmdHandler);
+	}
+}
+
+void WorldTicker::Tick(const game::World& a_World, WorldSnapshot& a_State, FpFloat a_Delta) {
+	for (const auto& system : m_Systems) {
+		system->Tick(a_World, a_State, a_Delta);
+	}
+}
+
+WorldSnapshot WorldTicker::CreateNext(const WorldSnapshot& a_PreviousState) {
+	return a_PreviousState;
+}
+
+}  // namespace sim
+}  // namespace td

src/td/simulation/system/EntityMove.cpp

@@ -0,0 +1,13 @@
+#include <td/simulation/system/EntityMove.h>
+
+namespace td {
+namespace sim {
+
+void EntityMove::Tick(const game::World& a_World, WorldSnapshot& a_State, FpFloat a_Delta) {
+	for (auto& mob : a_State.m_Mobs) {
+		mob->GetPosition().x += a_Delta;
+	}
+}
+
+}  // namespace sim
+}  // namespace td