Initial commit

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/net.h

@@ -0,0 +1,84 @@
+#pragma once
+
+#include "protocol.h"
+#include <map>
+#include <memory>
+#include <vector>
+
+struct Game;
+
+enum NetState
+{
+    NET_OFFLINE,
+    NET_CONNECTING,
+    NET_JOINING,
+    NET_LOBBY
+};
+
+// A binary message from another member, on the reliable channel (in order, never lost) or the inputs one (either may
+// fail).
+struct NetPacket
+{
+    int from = -1;
+    bool isReliable = true;
+    std::string bytes;
+};
+
+// Someone in the lobby (this screen's player too): their server id and name, whether a direct connection to them is
+// open, and the round trip over it in milliseconds (-1 until measured). This screen's own member is always connected.
+struct NetMember
+{
+    int id = -1;
+    std::string name;
+    bool isConnected = false;
+    float ping = -1;
+};
+
+// Online play: a WebSocket to the server (see protocol.h) to make or join a lobby and pass signaling, and a
+// WebRTC data channel to each other member, connected directly. A newcomer connects out to everyone already there.
+// The network calls back on its own threads (on desktop), so everything it reports is queued and handled in update,
+// once a frame on the main thread. Members are in the order they joined, so the first hosts. Error holds why the last
+// request failed or the connection was lost, until the next request.
+class Net
+{
+public:
+    Net();
+    ~Net();
+
+    void lobby_create(Game& game);
+    void lobby_join(Game& game, const char* code);
+    void lobby_leave();
+    void update();
+    void shutdown();
+    void heartbeat();
+    void send(int to, const std::string& bytes, bool isReliable);
+    void kick_send(int member, const std::string& reason);
+    bool is_connected_all();
+
+    NetState state = NET_OFFLINE;
+    std::string code;
+    std::string error;
+    int selfId = -1;
+    int hostId = -1;
+    std::vector<NetMember> members;
+    // Binary messages from other members, oldest first, for the session to take.
+    std::vector<NetPacket> packets;
+    // Lines for the chat log from the server (like this screen being kicked), oldest first, for the chat to take.
+    std::vector<std::string> notices;
+    // Members the server said were kicked, with the reason (empty for none given).
+    std::map<int, std::string> kicks;
+
+private:
+    struct Impl;
+    std::unique_ptr<Impl> impl;
+
+    void request_send(Game& game, const std::string& request);
+    void send_now(int to, const std::string& bytes, bool isReliable);
+    void text_send(int to, const std::string& text);
+    void text_send_now(int to, const std::string& text);
+    void message_handle(const std::string& text);
+    void peer_open(int id, bool isOfferer);
+    void peer_close(int id);
+    void signal_handle(int from, const std::string& payload);
+    NetMember* member_get(int id);
+};