Module recording 

Recording, replay, and world snapshots.

Port of recording.c / recording.h / recording_replay.c / world_snapshot.c.

SPDX-FileCopyrightText: 2026 Erin Catto SPDX-License-Identifier: MIT

Re-exports

pub use ops::RecOp;

pub use player::validate_replay;

pub use player::RecPlayer;

pub use snapshot::clone_world_via_snapshot;

pub use snapshot::compute_layout_hash;

pub use snapshot::deserialize_into_shell;

pub use snapshot::serialize_world;

pub use snapshot::SNAP_FLAG_DOUBLE_PRECISION;

pub use snapshot::SNAP_FLAG_VALIDATION;

pub use snapshot::SNAP_LAYOUT_VERSION;

pub use snapshot::SNAP_MAGIC;

pub use snapshot::SNAP_VERSION;

Modules

dispatch

Op-stream dispatcher for recording replay.

ops

Recording op table generated from recording_ops.inl. Opcode constants; the framed write helpers live in write_ops/.

player

Recording player and validate-replay. Port of recording_replay.c player API.

query_replay

Spatial-query replay helpers. Port of recording_replay.c query dispatch.

snapshot

World snapshot serialize/deserialize. Port of world_snapshot.c — field-by-field for Vec-backed Rust pools.

Structs

GeometryEntry

One entry per unique geometry blob. (b3GeometryEntry)

GeometryRegistry

Growable array of geometry entries with content-hash dedup. (b3GeometryRegistry)

RecBuffer

Growable append-only byte buffer. Doubles on demand. count_only tallies size without allocating. (b3RecBuffer)

RecHeader

Fixed 48-byte recording header. (b3RecHeader)

RecTag

Interned query tag. (b3RecTag)

Recording

User-owned recording buffer. (b3Recording)

RegistrySlot

Resolved geometry slot for deserialization. (b3RegistrySlot)

SnapReader

Bounds-checked read cursor for snapshot images. (b3SnapReader)

Enums

GeometryKind

Geometry kinds for the trailing registry section. (b3GeometryKind)

Constants

REC_MAGIC

Magic ‘B3RC’ little-endian. (B3_REC_MAGIC)

REC_VERSION_MAJOR

Major recording version. (B3_REC_VERSION_MAJOR)

REC_VERSION_MINOR

Minor recording version. (B3_REC_VERSION_MINOR)

SNAP_FNV_INIT

FNV-1a 64-bit constants. (B3_SNAP_FNV_*)

SNAP_FNV_PRIME

Functions

fnv_mix_position

Mix a world position at full width. (b3FnvMixPosition)

hash64_blob

Content hash for geometry blobs. (b3Hash64Blob)

hash_world_state

Hash live body transforms and awake velocities. (b3HashWorldState)

record_op

Record a void mutator if a session is active.

start_recording

Start recording into a user-owned buffer. (b3StartRecordingIntoBuffer / b3World_StartRecording)

stop_recording

Stop recording and finalize the buffer. (b3StopRecordingInternal / b3World_StopRecording)

with_recording

Invoke f on the active recording, if any.

world_public_id

Public world id matching C’s { worldId+1, generation }.