Network System

Overview

Free Eggbert supports up to 4 simultaneous network players via DirectPlay (DirectX 3). The implementation spans two files:

• src/network.cpp — CNetwork class: DirectPlay session management, lobby browsing, transport selection
• src/decnet.cpp — CDecor network methods: in-game tick-by-tick synchronization, packet send/receive, event replay

Session Lifecycle

The multiplayer flow is driven by WM_PHASE_* messages dispatched by CEvent:

1. WM_PHASE_SERVICE — Player selects the DirectPlay transport (IPX, TCP/IP, modem)
2. WM_PHASE_SESSION — Browse existing sessions (up to MAXSESSION=100 shown) or create a new one
3. WM_PHASE_MULTI — Pre-game lobby; players wait until the host starts the game
4. WM_PHASE_PLAY — Synchronized gameplay; each player sends a NetPacket every game tick

Packet Flow (Per Tick)

Every game tick during WM_PHASE_PLAY:

1. Each player constructs a NetPacket from their current input (KEY_* bitmask), position (blupiPosX/Y), animation state (blupiIcon, blupiChannel), and vehicle (blupiTransport)
2. Up to 5 NetMessage game events are embedded in the packet
3. The packet is broadcast via CNetwork::Send() to all other players
4. Each client receives packets, replays the events in decnet.cpp

Packet Types (PK_*)

Game Events (MESS_*)

Up to MAXMESSAGEPERPACKET (5) game events can be piggy-backed in each NetPacket. They use NetMessage structs with a type field set to one of these constants:

Personal Bombs

In multiplayer mode, each player has their own colored personal bomb type. These are fired and tracked independently per player, allowing bombs to be attributed to their owner:

Data Structures

See Data Structures — NetPacket for the full NetPacket and NetMessage struct field tables.

Network Limits

Related Pages

• CNetwork module — session management class
• NetPacket / NetMessage structs
• Game Phases Reference — WM_PHASE_SERVICE, WM_PHASE_SESSION, WM_PHASE_MULTI
• Object Types — TYPE_BOMBEPERSO1–4