Replace hardcoded WotLK protocol constants with a data-driven architecture
supporting Classic 1.12.1, TBC 2.4.3, and WotLK 3.3.5a. Each expansion
has JSON profiles for opcodes, update fields, and DBC layouts, plus C++
polymorphic packet parsers for binary format differences (movement flags,
speed fields, transport data, spline format, char enum layout).
Key components:
- ExpansionRegistry: scans Data/expansions/*/expansion.json at startup
- OpcodeTable: logical enum <-> wire values loaded from JSON
- UpdateFieldTable: field indices loaded from JSON per expansion
- DBCLayout: schema-driven DBC field lookups replacing magic numbers
- PacketParsers: WotLK/TBC/Classic parsers with correct flag positions
- Multi-manifest AssetManager: layered manifests with priority ordering
- HDPackManager: overlay texture packs with expansion compatibility
- Auth screen expansion picker replacing hardcoded version dropdown
Game name uses big-endian (not reversed), platform/os/locale use
little-endian with chars reversed and null at end (not beginning).
Protocol version is 8 for WoW 3.3.5a, not 3.
Three critical bugs fixed:
- LOGON_CHALLENGE request: set protocol byte to 0x03 (was 0x00) and
reverse FourCC strings (game/platform/os/locale) to match real client
- Response parsers: remove double-read of opcode byte that shifted all
field reads by one, preventing successful auth with real servers
- LOGON_PROOF response sizes: success=32 bytes, failure=4 bytes to match
TrinityCore/AzerothCore format
Also adds missing auth result codes (0x13-0x20, 0xFF) including
IGR_WITHOUT_BNET (0x17) which Warmane was returning.
