Decodes the CreateObject (0xF745) game message body far enough to hand
an entity off to acdream's existing IGameState/MeshRenderer pipeline.
Ported from ACE's WorldObject_Networking.cs (SerializeCreateObject,
SerializeModelData, SerializePhysicsData) and Position.cs.
Scope: the parser extracts exactly three fields —
- GUID (u32 right after the opcode)
- ServerPosition (landblockId + XYZ + rotation quaternion), if the
Position bit is set in the PhysicsDescriptionFlag
- SetupTableId (setup dat id for the visual mesh chain), if the
CSetup bit is set
Everything else in a CreateObject body (weenie header, object description,
motion tables, palettes, texture overrides, animation frames, velocity,
acceleration, omega, scale, friction, elasticity, translucency,
default scripts, sequence timestamps, ...) is consumed-or-skipped with
just enough bytes to advance past the correct flag-gated sections.
The parser stops at the end of PhysicsData — we don't need weenie-header
fields for rendering placement.
Components parsed in order (all from ACE's serialize routines):
1. Opcode u32 (must be 0xF745)
2. u32 GUID
3. ModelData header (byte 0x11 marker, byte subPaletteCount,
byte textureChangeCount, byte animPartChangeCount), followed by
PackedDword palette/subPalette fields, texture change records,
anim part change records, aligned to 4 bytes at end
4. u32 PhysicsDescriptionFlag
5. u32 PhysicsState (skipped)
6. Conditional Movement/AnimationFrame section
7. Conditional Position section (LandblockId, X, Y, Z, RW, RX, RY, RZ)
8. Conditional MTable/STable/PeTable u32 ids (all skipped)
9. Conditional CSetup u32 (extracted as SetupTableId)
The PackedDword reader is a new helper: AC's variable-width uint format
where values ≤ 32767 encode as a u16, larger values use a marker bit in
the top of the first u16 and a continuation u16. Ported from
Extensions.WritePackedDword.
LIVE RUN AGAINST THE ACE SERVER (test account, Holtburg):
step 4: CharacterList received account=testaccount count=2
character: id=0x5000000A name=+Acdream
character: id=0x50000008 name=+Wdw
sent CharacterEnterWorldRequest
step 6: CharacterEnterWorldServerReady received
sent CharacterEnterWorld(guid=0x5000000A)
step 8 summary: 83 GameMessages assembled, 68 CreateObject,
68 parsed, 52 w/position, 68 w/setup
First 10 parsed CreateObjects:
guid=0x5000000A lb=0xA9B40021 xyz=(104.89,15.05,94.01) setup=0x02000001
guid=0x80000600 no position setup=0x02000181
guid=0x800005FF no position setup=0x02000B77
guid=0x80000603 no position setup=0x02000176
guid=0x80000604 no position setup=0x02000D5C
guid=0x80000694 no position setup=0x020005FF
guid=0x80000697 no position setup=0x02000921
guid=0x80000601 no position setup=0x02000179
guid=0x80000605 no position setup=0x02000155
guid=0x80000695 no position setup=0x020005FF
The first line is +Acdream himself — GUID matches what we picked from
CharacterList, landblock 0xA9B4 is Holtburg (the area we already render),
setup 0x02000001 is the default humanoid player mesh. The other 67 are
NPCs/weenies/scenery-weenies in the same area; the 16 without positions
are inventory items whose position is inherited from the parent.
ALL 68 CreateObjects parsed cleanly — no short reads, no format errors.
Phase 4.7d proves byte-level compatibility with ACE's outbound network
serialization format. The remaining Phase 4 work (WorldSession type +
GameWindow wiring) is glue code above a codec that now speaks the real
AC wire format.
Tests: 77 core + 83 net (+1 live test) = 161 passing, all green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Drives the full post-handshake flow on a live ACE server. After the
3-way handshake completes, acdream:
1. Reassembles CharacterList and parses out every character on the
account (tested against testaccount which has two: +Acdream and
+Wdw). Full field decode: GUIDs, names, delete-delta, slotCount,
accountName, turbine chat, ToD flag.
2. Picks the first character and builds a single-fragment
CharacterEnterWorldRequest (opcode 0xF7C8, empty body beyond opcode)
on the UIQueue, wraps it with EncryptedChecksum + BlobFragments,
consumes one outbound ISAAC keystream word, and sends.
3. Waits for CharacterEnterWorldServerReady (opcode 0xF7DF) to confirm
the server accepted our encrypted outbound packet.
4. Builds CharacterEnterWorld (opcode 0xF657, body = u32 guid +
String16L accountName) and sends as a second fragment with
fragment_sequence 2, packet sequence 3.
5. Drains 10 seconds of post-login traffic: 101 GameMessages assembled,
68 of which are CreateObject (0xF745) — the entities around
+Acdream spawning into our session. Also saw DeleteObject (0xF746),
ObjectDescription (0xF74C), SetState (0xF755), GameEvent (0xF7B0),
LoginCharacterSet (0xF7E0), and a 0x02CD smaller opcode.
This is the Phase 4.7 win: acdream is authenticated, connected,
character-selected, logged in, and actively receiving the world state
stream, all with ZERO protocol errors. Every byte of every packet we
sent to the server was correct — the first bit wrong in our outbound
ISAAC math would have produced silent disconnect instead of 101
successful replies.
Added to AcDream.Core.Net:
- Messages/CharacterList.cs: full parser for opcode 0xF658, ported
from ACE's GameMessageCharacterList writer. Returns structured
record with Characters[], SlotCount, AccountName, UseTurbineChat,
HasThroneOfDestiny. Tested offline with hand-assembled bodies
matching ACE's writer format.
- Messages/CharacterEnterWorld.cs: outbound builders for
CharacterEnterWorldRequest (0xF7C8, opcode-only) and
CharacterEnterWorld (0xF657, opcode + guid + String16L account).
- Messages/GameMessageFragment.cs: helper to wrap a GameMessage body
in a single MessageFragment with correct Id/Count/Index/Queue and
Sequence. Also a Serialize helper to turn a MessageFragment into
packet-body bytes for PacketCodec.Encode. Throws on oversize
(>448 byte) messages; multi-fragment outbound split is TBD.
- GameMessageGroup enum mirroring ACE byte-for-byte (UIQueue = 0x09
is the one we use for enter-world).
Fixed: FragmentAssembler was keying on MessageFragmentHeader.Id, but
ACE's outbound fragment Id is ALWAYS the constant 0x80000000 — the
unique-per-message key is Sequence, matching how ACE's own
NetworkSession.HandleFragment keys its partialFragments dict. Our
live tests happened to work before because every GameMessage we'd
seen was single-fragment (hitting the Count==1 shortcut), but
multi-fragment CreateObject bodies would have silently mixed. Fixed
now and all 7 FragmentAssembler tests still pass with the Sequence-key.
Tests: 9 new offline (4 CharacterList, 2 CharacterEnterWorld, 3
GameMessageFragment), 1 new live (gated by ACDREAM_LIVE=1). Total
77 core + 83 net = 160 passing.
LIVE RUN OUTPUT:
step 4: CharacterList received account=testaccount count=2
character: id=0x5000000A name=+Acdream
character: id=0x50000008 name=+Wdw
choosing character: 0x5000000A +Acdream
sent CharacterEnterWorldRequest: packet.seq=2 frag.seq=1 bytes=40
step 6: CharacterEnterWorldServerReady received
sent CharacterEnterWorld(guid=0x5000000A): packet.seq=3 frag.seq=2 bytes=60
step 8 summary: 101 GameMessages assembled, 68 CreateObject
unique opcodes seen: 0xF7B0, 0xF7E0, 0xF746, 0xF745, 0x02CD,
0xF755, 0xF74C
Phase 4.7 next: start decoding CreateObject bodies to extract GUID +
world position + setup/GfxObj id, so these entities can flow into
IGameState and render in the acdream game window. The foundry statue
is waiting in one of those 68 spawns.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Erik