BIGGERBIGGER

Net.h

@@ -0,0 +1,66 @@
+#ifndef NET_CLASS
+#define NET_CLASS
+
+#include <cstdint>
+#include <string>
+#include <vector>
+#include <glm/glm.hpp>
+#include <glm/gtc/quaternion.hpp>
+
+// Multiplayer UDP link for a LAN pit. One player hosts (UDP port 27015), everyone else joins by IP.
+// Clients send their own transform to the host every frame; the host relays everyone's
+// transform to everyone else. The host is player id 0, joiners get ids 1, 2, 3, ...
+// All Winsock code lives in Net.cpp so windows.h never leaks into the rest of the engine.
+
+struct NetState {
+    glm::vec3 position = glm::vec3(0.0f);
+    glm::quat rotation = glm::quat(1.0f, 0.0f, 0.0f, 0.0f);
+    bool      sliding = false;
+};
+
+// A state received for some other player.
+struct NetUpdate {
+    uint8_t  id = 0;
+    NetState state;
+};
+
+class Lan {
+public:
+    enum class Mode { Off, Host, Client };
+
+    // Total players in the pit, host included.
+    static constexpr int MaxPlayers = 8;
+
+    Lan();
+    ~Lan();
+
+    // Opens the socket. For Client, hostIp is the host's IPv4 address. Returns false on failure.
+    bool Start(Mode mode, const std::string& hostIp);
+    void Stop();
+
+    Mode GetMode() const { return mode; }
+    bool IsActive() const { return active; }
+
+    // Call once per frame with our own state.
+    void Send(const NetState& state);
+    // Drains all waiting packets and appends the other players' newest states to 'out'.
+    void Receive(std::vector<NetUpdate>& out);
+
+    // Host: at least one player has joined. Client: the host has been heard from in the last 2 s.
+    bool IsConnected() const;
+    // Host only: number of joined players, not counting the host.
+    int PeerCount() const;
+
+    // This machine's IPv4 addresses (for the host to read out to the joiners).
+    static std::string LocalAddresses();
+
+private:
+    struct Impl;
+    Impl* impl;
+    Mode mode = Mode::Off;
+    bool active = false;
+};
+
+inline Lan* lan = nullptr;
+
+#endif