begin serversimulation

include/td/simulation/ClientSimulation.h

@@ -0,0 +1,63 @@
+#pragma once
+
+#include <td/game/World.h>
+#include <optional>
+
+namespace td {
+namespace sim {
+
+using GameHistory = std::vector<td::protocol::LockStep>;
+using GameBuffer = std::vector<std::optional<td::protocol::LockStep>>;
+
+// TODO: OnEnd signal
+class ClientSimulation : public protocol::PacketHandler {
+  private:
+	std::uint64_t m_StepTime;
+	game::World& m_World;
+	GameBuffer m_History;
+	std::uint64_t m_CurrentTime;
+	std::uint64_t m_LastTime;
+	std::size_t m_CurrentStep;
+
+	std::shared_ptr<WorldSnapshot> m_LastSnapshot;
+	std::uint64_t m_LastValidStep;
+
+	static const protocol::LockStep EMPTY_LOCKSTEP;
+
+  public:
+	/**
+	 * \brief Replay constructor
+	 * \param a_StepTime in ms
+	 */
+	ClientSimulation(game::World& a_World, GameHistory&& a_History, std::uint64_t a_StepTime);
+
+	/**
+	 * \brief Live update constructor (continuous game updates)
+	 * \param a_StepTime in ms
+	 */
+	ClientSimulation(game::World& a_World, std::uint64_t a_StepTime);
+
+	/**
+	 * \return the progress [0-1] between two steps
+	 */
+	float Update();
+
+	void Handle(const protocol::packets::LockStepsPacket& a_LockSteps) override;
+	void Handle(const protocol::packets::PredictCommandPacket& a_Predict) override;
+
+  private:
+	void Step();
+
+	/**
+	 * \brief Ticks a_Count times
+	 */
+	void FastForward(std::size_t a_Count);
+
+	/**
+	 * \brief Tries to recompute simulation if needed (for example in late command receival)
+	 */
+	void FastReplay();
+};
+
+}  // namespace sim
+}  // namespace td