DevLog #6 - Server State

Posted on August 21, 2025 by Brinn

TL;DR

• Authoritative loop stable at 200 Hz with delta snapshots.
• RiftNet finalized as a static lib; encryption, compression, and reliable UDP integrated.
• RiftEventBus v1 live (MIT); wired between handler and gameplay.
• RiftPhys bridge in; Bullet backend for vertical slice; server remains authoritative.
• Account/Auth (SQL Server + Argon2) works; account_details live update path next.
• Per-client baselines, UE client hookup, spawn/zone logic, and deterministic playback harness are the short-term focus.

Networking

• Crypto: X25519 KX; AEAD is pluggable (currently AES-GCM). PQC (Kyber hybrid) planned.
• Compression: LZ4 in the fast path.
• Reliability: seq/ack with RFC-6298 RTT/RTO; retransmit + dedupe.
• Snapshots: baseline + delta system; current baseline cadence = 1s (global). Per-client baselines next.
• Observed timings: snapshot 2-3 ms; dispatch < 0.5 ms (modest entities). Frames ~26-94 B depending on delta density.
• Scale so far: clean at 50/500 clients; 5,000 connection soak on local infra.

Server Loop & Determinism

• Input ingestion -> state update -> snapshot emit.
• Canonical FNV-1a hash over serialized fields (sorted IDs) to detect divergence.
• Window stats logged for regression checks.

Serialization & Handlers

• Migration off FlatBuffers to POD structs + custom binary serializer.
• Endian + version guards in progress; goal is to lock the wire format prior to UE integration.

Physics

• IRiftPhysics interface landed; Bullet backend for now.
• Authoritative raycasts/sweeps for RiftStep validation next.
• RiftFSX modules will replace Bullet pieces once the gameplay loop is proven.

Accounts / Web Edge

• CivetWeb + ODBC to SQL Server; Argon2 password hashes; duplicate e-mail/username rejection verified.
• Next: account_details update-on-login without redirect; session token flow hardening.

Client (UE)

• Two executables: Player and Dev/Admin (no dev tools in player build).
• Next: wire handshake -> snapshot ingest -> basic interpolated draw; add runtime perf overlay.

World Systems

• Terrain Service will live as its own server-side module (feeds collision + nav).
• Spawn and Zone scaffolding unlock meaningful crowd tests and occlusion/culling work.

Risks / Gaps

• Per-client baselines pending (bandwidth predictability across diverse RTTs).
• Deterministic playback harness not yet gating builds (hash is diagnostic only).
• Terrain/zone not in -> no real crowd/visibility tests yet.
• UE path is greenfield; expect iteration on input buffering and interpolation.

Next 2 Weeks (to Sept 5, 2025)

1. Per-client baselines + snapshot packing cleanup.
2. UE client handshake -> snapshot ingest -> basic render path.
3. Spawn/Zone scaffolding; simple entity lifecycle (spawn/despawn/update).
4. Deterministic playback (record/replay + canonical hash gate).
5. RiftStep raycasts/sweeps (server authoritative).
6. account_details live update path.