github.com/levpaul/webrtc-mmo-server

Go ECS Server

This is a toy project to experience developing a UDP game server for an action MMO style game. The idea is to have MMO type mechanics mixed with a fast paced "real-time" action PVP mechanics. Basically mix FPS netcode with runescape.

TODO:

7 Feb

• Impl propagation system
• Impl player movement system
• Write benchmarking software

BIG ARCH CONCRETE

• Input/output with players is handled via event bus
• Game state is managed via ECS design

BIG ARCH WOOD

• Single map open world - divided into sectors for horizontal scaling
• "Interest" zones for player updates made by dividing map sectors to locales and taking surroundings
• Client/Server prediction + Small Lag compensation UDP net design
• Separate servers for non-gameworld systems, like chat

BIG ARCH VAPEN8TION

• Persistence layer (probably dynamo + redis caches?)
• Are all C in ECS flatbuffer managed?

Network

Brief Architecture

• Each play connects via WebRTC/UDP
• Players sync game state updates with server (60tick? or 20tick?)
• Players send input commands to server
• Server processes input commands at 60fps
• Server sends partial updates to each client at 60fps
• If server has no input from client then server "predicts" client action instead, by repeating previous input
• On subsequent old packets coming in, server can replay them

Brief Details

• Client sends inputs with gametick #
• If client action includes hit-tests for attacks, server rolls back target to client's gametick for hit testing
• If client hits based on what "they saw" then rewrite game state to accept hit