TDD: PakRoundTripTests written first, confirmed a compile failure
against the not-yet-existing PakWriter/PakReader types.
PakWriter streams [header placeholder][64-byte-aligned blobs][TOC sorted
by key], then seeks back and finalizes the header once TocOffset/TocCount
are known (plan: "TOC last" so the writer doesn't need blob count
up front). PakReader mmaps the whole file once, loads the TOC into a
sorted array for O(log n) binary-search lookup, and verifies each blob's
CRC-32 LAZILY on first access (cached per-index so a corrupt blob logs
exactly once and is thereafter always treated as missing rather than
handing back garbage bytes). No locks anywhere — the mapped memory is
immutable for the reader's lifetime by construction.
CRC-32 implemented directly (standard IEEE 802.3 table-driven variant)
rather than adding a System.IO.Hashing package reference, keeping
AcDream.Content's dependency surface minimal per its existing
"no GL binaries" intent.
9 tests green: header round-trip, every-key-found, blob deep-equality
via the Task 3 comparator, missing-key returns false, corrupted-blob
(single flipped byte) is detected and treated as missing while leaving
sibling blobs unaffected, 64-byte blob alignment, and TOC binary search
cross-checked against a linear scan for both present and absent keys.
TDD: ObjectMeshDataSerializerTests + the shared ObjectMeshDataEquality
field-by-field comparator (reused by Task 6's equivalence suite) written
first, confirmed a compile failure against the not-yet-existing
ObjectMeshDataSerializer type.
Serializes EVERY field of the ObjectMeshData family per the plan's
normative layout: primitives raw LE, arrays as count:i32+payload,
blittable arrays (VertexPositionNormalTexture[], ushort[], byte[]) via
MemoryMarshal.AsBytes bulk copy, TextureBatches written sorted by the
(Width, Height, Format) key tuple for run-to-run determinism regardless
of dictionary insertion order, nullable fields as present:byte+value.
EnvCellGeometry nests recursively (MeshExtractor can populate one level
today; the serializer supports arbitrary depth rather than assuming it).
Namespace-trap finding: StagedEmitter.Emitter resolves to
DatReaderWriter.DBObjs.ParticleEmitter (the dat DBObj, verified via
reflection against the pinned Chorizite.DatReaderWriter 2.1.7 package
and confirmed live by MeshExtractor's `emitter.HwGfxObjId.DataId` call
site compiling), NOT AcDream.Core.Vfx.ParticleEmitter (the runtime
particle-simulation type with a live Particle[] pool that would NOT be
serializable asset data). All ~31 of its fields are written explicitly
rather than delegating to its own Pack/Unpack, which require a live
DatBinWriter/DatBinReader bound to a DatDatabase — coupling our pak's
determinism to a third-party wire-format helper we don't control the
versioning of.
33 tests green: 9 round-trip fixtures (empty/vertices+indices/multi
texture-batch-groups/setup-parts/emitters/nullable-present/nullable-
absent/edge-lines/nested-EnvCellGeometry), same-instance-twice byte-
identity, and dictionary-insertion-order-independence (two orders ->
identical bytes) plus a key-sort-order assertion on the raw bytes.
TDD: PakKeyTests + PakFormatTests written first (confirmed a compile
failure against the not-yet-existing AcDream.Content.Pak namespace),
then PakKey (64-bit type:u8|fileId:u32|reserved:u24 compose/decompose)
and PakFormat (64-byte PakHeader, 24-byte PakTocEntry) implemented to
the normative layout in the MP1b plan. 21 tests green, including a key-
ordering test proving ascending numeric key order equals ascending
(type, fileId) tuple order (the TOC binary-search precondition) and an
explicit byte-offset test for both structs.
New xunit test project for the Content layer (rule 6: tests live in the
project matching the layer under test). ProjectReference to
AcDream.Content; TreatWarningsAsErrors + LangVersion latest per MP1b's
csproj requirements. Registered in AcDream.slnx. Placeholder PakKeyTests
smoke test becomes the real Task 2 suite next.
