Module replay 

Replay system: input recording, deterministic playback, scrubbing, ghost.

Architecture

• InputRecorder — captures every input event with frame-accurate timestamps
• ReplayFile — compact binary format: header + seed + input stream
• ReplayPlayer — plays back a replay at configurable speed
• ReplayScrubber — seeks to arbitrary points via state snapshots
• GhostReplay — semi-transparent replay alongside live play
• ReplayExporter — serialize replay to bytes / upload URL
• ReplayVerifier — checksum validation against stored hash

Determinism contract

The game must use only the provided RNG seed and recorded inputs. Any external randomness (system time, thread ID, etc.) breaks determinism.

File format (little-endian binary)

Header (128 bytes):
  magic:      [u8; 4]   = b"PRFE"
  version:    u16
  flags:      u16
  seed:       u64
  frame_count: u32
  duration_ms: u32
  score:      i64
  checksum:   [u8; 32]  (SHA-256 of seed + input stream)
  metadata:   [u8; 64]  (null-padded JSON: class, floor, build)

Input stream:
  for each event:
    frame:    u32
    kind:     u8
    payload:  [u8; 8]

Re-exports

pub use rollback::RollbackSession;

pub use rollback::PlayerInput;

pub use rollback::FrameInput;

pub use rollback::GameState;

pub use rollback::NetworkStats;

Modules

rollback

Rollback networking support — deterministic state snapshots, input prediction, and reconciliation for peer-to-peer fighting/action games.

Structs

GhostReplay

Plays a replay alongside live gameplay, representing a “ghost” opponent.

InputEvent

A single recorded input event.

InputRecorder

Records inputs during gameplay.

ReplayFile

A complete recorded replay.

ReplayMetadata

ReplayPlayer

Plays back a ReplayFile, emitting input events frame by frame.

ReplaySnapshot

ReplayVerifier

Validates a replay file’s integrity.

Enums

InputKind

Compressed input event kind byte.

PlaybackState

VerifyResult