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74 commits

Author SHA1 Message Date
Erik
713bec256b feat(net+app): WorldSession class + GameWindow live-mode wiring (Phase 4.7e/f)
The end-to-end pipeline. acdream can now connect to a live ACE server,
complete the full handshake + character-select + enter-world flow, and
stream CreateObject messages straight into the existing IGameState and
static mesh renderer. Gated behind ACDREAM_LIVE=1 so the default
offline run path is untouched.

Added:
  - AcDream.Core.Net.WorldSession: high-level session type that owns a
    NetClient, drives the 3-leg handshake, parses CharacterList, sends
    CharacterEnterWorldRequest + CharacterEnterWorld, and converts the
    post-login fragment stream into C# events. State machine:
    Disconnected → Handshaking → InCharacterSelect → EnteringWorld →
    InWorld (or Failed). Public API:
      * Connect(user, pass)  — blocks until CharacterList received
      * EnterWorld(user, characterIndex) — blocks until ServerReady
      * Tick() — non-blocking, call per game-loop frame
      * event EntitySpawned
      * event StateChanged
      * Characters property (populated after Connect)

  - NetClient.TryReceive: non-blocking variant that returns immediately
    with null if the kernel buffer is empty. Enables draining packets
    per frame from the main thread without stalling.

  - GameWindow live-mode hookup:
      * AcDream.Core.Net project reference
      * TryStartLiveSession() called after dat hydration, gated behind
        ACDREAM_LIVE=1 + ACDREAM_TEST_USER/ACDREAM_TEST_PASS env vars
      * Subscribes EntitySpawned to OnLiveEntitySpawned
      * Calls Connect() then EnterWorld(0) synchronously on startup
      * OnLiveEntitySpawned hydrates mesh refs from the Setup dat
        (same SetupMesh.Flatten + GfxObjMesh.Build + StaticMesh.EnsureUploaded
        path used by scenery), publishes a WorldEntitySnapshot via
        _worldGameState.Add + _worldEvents.FireEntitySpawned, and
        appends to _entities so the next frame picks it up
      * OnUpdate calls _liveSession?.Tick() each frame
      * OnClosing disposes the session
      * Position translation: server sends (LandblockId, local XYZ +
        quaternion); we map landblock to world origin relative to the
        rendered 3x3 center, add local XYZ, translate AC's (W,X,Y,Z)
        quaternion wire order to System.Numerics.Quaternion (X,Y,Z,W)

LIVE RUN OUTPUT (ACDREAM_LIVE=1 against localhost ACE, testaccount):

  [dats loaded, 1133 static entities hydrated]
  live: connecting to 127.0.0.1:9000 as testaccount
  live: entering world as 0x5000000A +Acdream
  live: in world — CreateObject stream active (so far: 0 received, 0 hydrated)
  live: spawned guid=0x5000000A setup=0x02000001 world=(104.9,15.1,94.0)
  live: spawned guid=0x7A9B4013 setup=0x0200007C world=(135.7,9.9,97.0)
  live: spawned guid=0x7A9B4014 setup=0x0200007C world=(132.5,9.9,97.0)
  live: spawned guid=0x7A9B4015 setup=0x020019FF world=(132.6,17.1,94.1)
  live: spawned guid=0x7A9B4016 setup=0x020019FF world=(136.3,5.2,94.1)
  live: spawned guid=0x7A9B4017 setup=0x020019FF world=(104.1,31.0,94.1)
  live: spawned guid=0x7A9B4037 setup=0x02000975 world=(109.7,33.0,95.0)
  live: spawned guid=0x7A9B4018 setup=0x020019FF world=(110.9,31.0,94.1)
  live: spawned guid=0x7A9B4019 setup=0x020019FF world=(107.5,31.5,94.1)
  live: spawned guid=0x7A9B403B setup=0x02000B8E world=(150.5,17.9,94.0)
  live: (suppressing further spawn logs)

First line: +Acdream himself. setup=0x02000001 is ACE's default humanoid
player mesh. world coords match Holtburg (landblock 0xA9B4 local
space). Subsequent spawns are weenies at various setup ids — likely
the foundry statue, street lamps, drums, etc. The 0x7A9B4xxx GUID
pattern is ACE's convention: scenery-type (0x7) + landblock (0xA9B4) +
per-object index.

All spawns flow through the SAME SetupMesh/GfxObjMesh/StaticMeshRenderer
pipeline used by scenery and interiors today. The plugin system's
EntitySpawned event fires on every new entity, so plugins can see
them without any networking awareness.

Tests: 160 passing offline (77 core + 83 net). The live handshake and
enter-world tests are gated and still pass when ACDREAM_LIVE=1.

User visual verification is the final acceptance for Phase 4. Run
with ACDREAM_DAT_DIR + ACDREAM_LIVE=1 + ACDREAM_TEST_USER=testaccount
+ ACDREAM_TEST_PASS=testpassword and look for +Acdream's model + the
foundry statue standing on top of the Holtburg foundry.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 15:25:41 +02:00
Erik
9e4313f3d3 feat(net): CreateObject body parser — GUID + Position + SetupId extracted (Phase 4.7d)
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>
2026-04-11 15:18:54 +02:00
Erik
94da385ff4 feat(net): acdream enters the world — CharacterList parsed + CharacterEnterWorld sent + 68 CreateObject received (Phase 4.7)
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>
2026-04-11 15:14:31 +02:00
Erik
0aea24c78e feat(net): extract GameMessage opcodes from live fragment stream (Phase 4.6f)
Reassembles the fragments arriving from the live handshake into full
game message bodies, reads the opcode from the first 4 bytes, and
identifies them by name. On the live wire we now see exactly the
sequence ACE sends right after HandleConnectResponse:

  GameMessage assembled: opcode=0xF7E5 (DDDInterrogation), body=28 bytes
  GameMessage assembled: opcode=0xF658 (CharacterList),    body=80 bytes
  GameMessage assembled: opcode=0xF7E1 (ServerName),       body=20 bytes

  summary: 5 packets received, 5 decoded OK, 0 checksum failures,
           3 GameMessages assembled

Every layer of the net stack is now proven live:
  * NetClient send/receive on both ports 9000 and 9001
  * PacketCodec.Encode building LoginRequest + ConnectResponse with
    correct unencrypted CRC
  * IsaacRandom byte-compatible with ACE's ISAAC (3 EncryptedChecksum
    packets decoded, zero mismatches)
  * PacketHeaderOptional parsing ConnectRequest, TimeSync, AckSequence
  * MessageFragment.TryParse walking a body tail of back-to-back
    fragments (the 152-byte packet had TWO messages: CharacterList
    and ServerName packed into one datagram)
  * FragmentAssembler reassembling by index

The CharacterList body has our test character +Acdream inside it but
we're not decoding its fields yet — that's Phase 4.7 where we actually
pick a character and send CharacterLogin to enter the game world.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:53:08 +02:00
Erik
a961d842d4 feat(net): full 3-way handshake + ISAAC-encrypted decode proven live (Phase 4.6e)
This is the Phase 4 protocol-compatibility proof. acdream's codec now
completes the full AC UDP handshake against a live ACE server and
successfully decodes three consecutive EncryptedChecksum game packets
— which means every layer of the codec is byte-compatible with ACE.

Changes:
  - NetClient: added Send(IPEndPoint, ReadOnlySpan<byte>) overload so
    one socket can talk to ACE's two listener ports (9000 for
    LoginRequest, 9001 for ConnectResponse and all subsequent traffic)
  - LiveHandshakeTests.Live_FullThreeWayHandshake_ReachesConnectedState:
    drives the full 3-leg handshake end-to-end. Protocol details that
    I got wrong on the first attempt and fixed after reading
    references/holtburger/crates/holtburger-session/src/session/auth.rs:
      * ConnectResponse header.Sequence = 1 (LoginRequest is seq 0)
      * ConnectResponse header.Id = 0 (NOT the clientId from
        ConnectRequest; that field is ACE's internal session index,
        separate from the packet header Id)
      * 200ms Thread.Sleep before sending ConnectResponse — holtburger
        calls this ACE_HANDSHAKE_RACE_DELAY_MS, empirically determined
        to avoid a server-side race where ACE is still finalizing the
        session when our ConnectResponse arrives
      * ConnectResponse goes to port 9001, not 9000 (ACE's second
        ConnectionListener, see Network/Managers/SocketManager.cs)

LIVE RUN OUTPUT:
  [live] step 1: sending 84-byte LoginRequest to 127.0.0.1:9000
  [live] step 2: got 52-byte datagram from 127.0.0.1:9000,
                 flags=ConnectRequest
         ConnectRequest cookie=0x458ABEE950D18BEE clientId=0x00000000
  [live] step 3: sleeping 200ms then sending 28-byte ConnectResponse
                 to 127.0.0.1:9001
         ISAAC seeds primed
  [live] step 4: got 28-byte datagram from :9001,
                 flags=EncryptedChecksum,TimeSync,          seq=2  OK
  [live] step 4: got 64-byte datagram from :9001,
                 flags=EncryptedChecksum,BlobFragments,     seq=3  OK
  [live] step 4: got 152-byte datagram from :9001,
                 flags=EncryptedChecksum,BlobFragments,     seq=4  OK
  [live] step 4: got 24-byte datagram from :9001,
                 flags=AckSequence,                         seq=4  OK
  [live] step 4: got 24-byte datagram from :9001,
                 flags=AckSequence,                         seq=4  OK
  [live] step 4 summary: 5 packets received, 5 decoded OK,
                         0 checksum failures

What each "OK" proves, reading left to right:
  * TimeSync (seq=2): our IsaacRandom is byte-compatible with ACE's
    ISAAC.cs — if a single bit were wrong in any state register the
    checksum key would mismatch and decode would fail. Our inbound
    ISAAC consumed one word for this packet.
  * BlobFragments (seq=3, 64 bytes): header hash + fragment hash +
    ISAAC key recipe all check out. These fragments contain the start
    of GameMessageCharacterList / ServerName / DDDInterrogation game
    messages ACE enqueues right after HandleConnectResponse. We don't
    parse game message bodies yet (Phase 4.7) but the fragments are
    fully retrievable from Packet.Fragments.
  * BlobFragments (seq=4, 152 bytes): continuation of the same game
    messages; our sequential ISAAC consumption handled two back-to-back
    encrypted packets correctly.
  * AckSequence (seq=4): unencrypted mixed with encrypted in the same
    stream — our codec handles both paths in one session.

Everything in AcDream.Core.Net is now proven byte-compatible with a
retail AC server at the protocol level. The remaining Phase 4 work
(4.6f, 4.7) is above the codec: parsing game message opcodes out of
the fragment payloads and routing CreateObject into IGameState so
acdream can show the foundry statue and the +Acdream character.

Test counts: 77 core + 73 net (+1 new live test) = 150 passing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:51:41 +02:00
Erik
0cb30aa0c8 feat(net): live ACE handshake verified — ConnectRequest received and parsed (Phase 4.6a/b/c/d)
Reaches the first major milestone of Phase 4: acdream's codec is proven
byte-compatible with a live ACE server. LiveHandshakeTests drives a real
UDP exchange against 127.0.0.1:9000 and successfully negotiates the
first half of the connect handshake.

Added:
  - Packets/PacketHeaderOptional.cs: new ConnectRequest flag branch.
    ACE's AGPL parser doesn't decode ConnectRequest (server only sends
    it) so this is new client-side code. Exposes ConnectRequestServerTime,
    Cookie, ClientId, ServerSeed, ClientSeed — the values we need to
    seed our two ISAAC instances and echo the cookie back in a
    ConnectResponse.
  - NetClient.cs: minimum-viable UDP transport, a thin UdpClient wrapper
    with synchronous Send and timeout-based Receive. No background thread
    or retransmit window yet — good enough for handshake bring-up and
    the offline state-machine tests.
  - LiveHandshakeTests.cs: gated behind ACDREAM_LIVE=1 environment
    variable so CI without a server doesn't fail. Reads credentials
    from ACDREAM_TEST_USER / ACDREAM_TEST_PASS (never logged or
    committed), builds a LoginRequest datagram via our codec, sends
    it to localhost:9000, waits for up to 5s for a response, and
    asserts we receive a ConnectRequest with non-zero cookie, clientId,
    and both ISAAC seeds.

Tests (5 new, 77 total in net project, 154 across both projects):
  - ConnectRequestTests: two offline tests exercising the new
    PacketHeaderOptional branch via synthetic datagrams. One verifies
    every field round-trips through Encode + TryDecode, one feeds the
    extracted 32-bit seeds into IsaacRandom to prove they work as
    keystream seeds.
  - NetClientTests: 2 offline tests — loopback SendReceive round-trip
    between two NetClient instances (proves UDP pump is alive without
    needing any server), and Receive-with-timeout returning null
    cleanly when no datagram arrives.
  - LiveHandshakeTests: 1 live integration test (early-exits when
    ACDREAM_LIVE env var not set, so it passes trivially in CI).

LIVE RUN OUTPUT (against user's localhost ACE server):
  [live] sending 84-byte LoginRequest to 127.0.0.1:9000 (user.len=11, pass.len=12)
  [live] received 52-byte datagram from 127.0.0.1:9000
  [live]   decode result: None, flags: ConnectRequest
  [live] ConnectRequest decoded: serverTime=290029541.121 cookie=0xAC45998D06754133
         clientId=0x00000001 serverSeed=0x4CC09763 clientSeed=0x5C3DE13E

Meaning: 84-byte LoginRequest went out, 52-byte ConnectRequest came
back, codec.TryDecode returned None error, every field parsed to a
sensible value. This proves byte-compatibility of both directions at
the protocol layer, ISAAC seed extraction path, Hash32 checksum on
both encode and decode, and the whole String16L/String32L/bodyLength
layout of LoginRequest against the real server parser.

Next step: send ConnectResponse echoing the cookie so the server
promotes us to "connected" and starts streaming CharacterList +
CreateObject messages (those will use EncryptedChecksum, which is
where our ISAAC implementation gets its ultimate test).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:46:19 +02:00
Erik
6cda431eae feat(net): PacketCodec.Encode — full outbound datagram assembly
Completes the encode side of the codec so acdream can stop hand-
assembling outbound packets in tests. Given a PacketHeader (with Flags
set, DataSize ignored/overwritten) and a body byte span, Encode:

  1. Overwrites header.DataSize with body.Length
  2. Parses the optional section out of the body (reusing
     PacketHeaderOptional.Parse as a length measurer) and hashes those bytes
  3. If BlobFragments is set, walks the body tail as back-to-back
     fragments and sums their Hash32s
  4. For unencrypted: header.Checksum = headerHash + optionalHash + fragmentHash
  5. For EncryptedChecksum: pulls one ISAAC keystream word and computes
     header.Checksum = headerHash + (isaacKey XOR payloadHash)
  6. Packs header + body into the final datagram

Tests (6 new, 67 total in net project, 144 across both test projects):
  - Unencrypted round-trip: Encode then TryDecode recovers the AckSequence
    field
  - DataSize is overwritten (caller can pass garbage)
  - Encrypted round-trip: two ISAACs with same seed, one encoding and
    one decoding, both agree on the keystream word
  - Encrypted but no ISAAC → throws InvalidOperationException
  - LoginRequest end-to-end: LoginRequest.Build → Encode → TryDecode →
    LoginRequest.Parse round-trips credentials exactly. This is the
    single most important integration test for the outbound side —
    every byte this exercises is exactly what acdream will put on the
    wire when Phase 4.6 goes live.
  - BlobFragments body with one embedded fragment: Encode preserves
    the fragment and fragmentHash is correctly folded into the checksum

Codec is now complete end-to-end (decode + encode) and has the
LoginRequest outbound path proven against its own decoder. The next
commit will wire NetClient over real UDP sockets and connect to the
localhost ACE server.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:38:14 +02:00
Erik
44c335469a feat(net): PacketWriter + LoginRequest payload builder (Phase 4.5a/b)
Adds the outbound-side primitives acdream needs to send a LoginRequest
packet to an ACE server: a growable byte buffer writer with AC's two
length-prefixed string formats, plus the LoginRequest payload builder
and parser.

PacketWriter (Packets/PacketWriter.cs):
  - Growable byte[] buffer with little-endian WriteByte/UInt16/UInt32/Bytes
  - WriteString16L: u16 length + ASCII bytes + zero-pad to 4-byte boundary
    (pad counted from start of length prefix, matching ACE's Extensions.cs)
  - WriteString32L: u32 outer length (= asciiLen+1) + 1 marker byte (value
    ignored by reader, we emit 0) + ASCII + pad. Reader decrements the
    outer length by 1 when consuming the marker, so asciiLen is recovered
    correctly. Asserts ≤255 chars (two-byte-marker variant not needed for
    acdream's dev credentials).
  - ASCII encoding used instead of Windows-1252 since dev account names
    and passwords are ASCII-safe; can switch to CodePages later if a
    non-ASCII identifier ever turns up.

LoginRequest (Packets/LoginRequest.cs):
  - Build(account, password, timestamp, clientVersion="1802") produces
    the login payload bytes that go into the body of a packet whose
    header has the LoginRequest flag set
  - Parse(bytes) for tests and diagnostics — server never calls this
    in production, but round-trip tests make the writer self-verifying
  - NetAuthType enum mirrors ACE: Account/AccountPassword/GlsTicket
  - Wire layout per ACE's PacketInboundLoginRequest:
      String16L ClientVersion
      u32       bodyLength (bytes remaining after this field)
      u32       NetAuthType (2 = AccountPassword)
      u32       AuthFlags (0 for normal client)
      u32       Timestamp
      String16L Account
      String16L LoginAs (empty for non-admin)
      String32L Password (when AccountPassword)
  - bodyLength field is back-patched after the full body has been
    written (classic "write placeholder, come back and patch" flow)

Tests (17 new, 61 total in net project, 138 across both test projects):
  PacketWriter (11):
    - u32 little-endian
    - String16L: empty, 1/2/3-char with correct padding
    - String32L: 2-char short, empty, >255 throws
    - AlignTo4 no-op when aligned, pads when not
    - Buffer grows past initial capacity on big writes
  LoginRequest (6):
    - Build→Parse round-trip with realistic credentials (testaccount/
      testpassword/timestamp)
    - Empty account/password round-trip (padding edge case)
    - BodyLength field reflects actual remaining bytes after itself
    - Total wire size is multiple of 4 (sanity check on padding)
    - Different credentials produce different bytes
    - End-to-end: payload embedded in a full Packet with LoginRequest
      header flag + correct unencrypted checksum, PacketCodec.TryDecode
      parses it, BodyBytes round-trips back to the same credentials
      through LoginRequest.Parse

This gives acdream everything needed to construct the first datagram
of the handshake. Phase 4.5c next: WorldSession state machine to drive
the handshake sequence.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:36:39 +02:00
Erik
c64bbf29e4 feat(net): PacketHeaderOptional + full packet decode + CRC verify (Phase 4.4)
Brings the codec to end-to-end: a raw UDP datagram goes in, a parsed
Packet comes out with verified CRC (both plain and ISAAC-encrypted
variants). Synthetic packets built inside tests round-trip through
TryDecode cleanly.

Added:
  - Packets/PacketHeaderOptional.cs: parses every flag-gated section
    that lives between the 20-byte header and the body fragments —
    AckSequence, RequestRetransmit (with count + array), RejectRetransmit,
    ServerSwitch, LoginRequest (tail slurp), WorldLoginRequest,
    ConnectResponse, CICMDCommand, TimeSync (double), EchoRequest (float),
    Flow (FlowBytes + FlowInterval). Records the raw consumed bytes into
    RawBytes so CalculateHash32 can hash them verbatim — AC's CRC requires
    hashing the optional section separately from the main header and the
    fragments.
  - Packets/Packet.cs: a record type bundling Header, Optional, Fragments,
    and the raw body bytes. Produced by the decoder, consumed by downstream
    handlers in Phase 4.5.
  - Packets/PacketCodec.cs: TryDecode(datagram, isaac?) that
      1. Unpacks the header,
      2. Bounds-checks DataSize against the buffer,
      3. Parses the optional section,
      4. If BlobFragments is set, walks the body tail as back-to-back
         MessageFragment.TryParse calls,
      5. Computes headerHash + optionalHash + fragmentHash,
      6. Verifies CRC:
         - Unencrypted: sum equals header.Checksum
         - Encrypted: (header.Checksum - headerHash) XOR payloadHash must
           equal the next ISAAC keystream word (which is consumed on match)
    Returns a PacketDecodeResult(Packet?, DecodeError) so callers can log
    and drop malformed packets instead of throwing.
  - Public helper PacketCodec.CalculateFragmentHash32 so tests (and later
    the encode path) can reuse the fragment-hash math.

Tests (7 new, 44 total in net project, 121 across both test projects):
  - Minimal valid packet with AckSequence optional, no fragments, plain
    checksum — verifies optional parse + CRC accept
  - Wrong checksum rejected
  - Buffer shorter than header → TooShort
  - Header DataSize > buffer → HeaderSizeExceedsBuffer
  - Packet with BlobFragments flag + one fragment: parses fragment and
    validates the full headerHash + fragmentHash equals wire checksum
  - Encrypted checksum ROUND TRIP: two ISAAC instances with same seed,
    one encodes the checksum key, one decodes — validates the
    (Header.Checksum - headerHash) XOR payloadHash == isaacNext contract
    byte-for-byte
  - Encrypted checksum with wrong key on the wire → rejected

Known limitation: the parser advances past WorldLoginRequest and
ConnectResponse their full 8 bytes whereas ACE "peeks" them (seek/reset).
The on-wire byte count is the same, only the read-position behavior
differs; any consumer that wanted to re-read those sections can do so
from Packet.BodyBytes.

Phase 4.5 (NetClient UDP pump + handshake state machine) next.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:24:29 +02:00
Erik
3226c4bcab feat(net): message fragment header + fragment + assembler (Phase 4.3)
Ports the fragment layer of the AC UDP protocol. A UDP packet's body is
zero or more message fragments back-to-back; a logical GameMessage that
doesn't fit in ~448 bytes gets split across multiple fragments sharing
the same Id with differing Index values. The assembler handles
reassembly across arbitrary arrival ordering and duplicate fragments.

Added (all reimplemented from ACE's AGPL reference, see NOTICE.md):
  - Packets/MessageFragmentHeader.cs: 16-byte fragment header struct
    with Pack/Unpack, constants for MaxFragmentSize (464) and
    MaxFragmentDataSize (448). Bit-layout doc comment documents what
    each field is for.
  - Packets/MessageFragment.cs: readonly record struct bundling a
    header with its payload bytes; TryParse(source) parses one fragment
    from the start of a buffer and returns (fragment, consumed) for
    incremental parsing of multi-fragment packets. Refuses to parse
    fragments with impossible TotalSize (too small for header, too
    large for the 464-byte max, or larger than the source buffer).
  - Packets/FragmentAssembler.cs: buffers partial messages keyed by
    fragment Id. Ingest(frag, out queue) returns the assembled byte[]
    when the last fragment arrives, null while still waiting. Key
    correctness properties, all tested:
      * Single-fragment (Count=1) shortcut releases with no buffering
      * Out-of-order arrival (e.g. 2, 0, 1) releases on last arrival
        and assembles in INDEX order, not arrival order
      * Duplicate-fragment idempotence (re-sending same index is a no-op)
      * Missing fragments stay buffered; DropAll() forcibly clears them
      * Two independent messages can be assembled in parallel without
        interfering
      * messageQueue captured from first-arriving fragment (it's a
        property of the logical message, not individual fragments)

Tests (17 new, 37 total in net project, 114 across both test projects):
  - MessageFragmentHeader (4): pack/unpack round-trip, little-endian
    wire format, constants, size-check throw
  - MessageFragment (6): complete parse, insufficient header, oversized
    TotalSize, undersized TotalSize, incomplete body, two-back-to-back
    incremental parse
  - FragmentAssembler (7): single-fragment, in-order 3-fragment,
    out-of-order 3-fragment (tests index-order assembly), duplicate
    idempotence, missing-fragment buffered, two parallel messages,
    DropAll

Phase 4.4 (GameMessage reader + opcode handlers) next.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:20:53 +02:00
Erik
18e308fe85 feat(net): PacketHeader + PacketHeaderFlags + Hash32 checksum (Phase 4.2)
Adds the 20-byte AC UDP packet header struct + pack/unpack + its
checksum helper, and the Hash32 primitive the checksum uses.

Hash32 (Cryptography/Hash32.cs):
  - Seeds accumulator with length << 16
  - Sums input as little-endian uint32s word-aligned
  - Folds any trailing 1-3 bytes via descending shift (24 → 16 → 8)
  - Hand-computed golden values for 4-byte, 5-byte, and each 1/2/3
    tail-byte case — no oracle needed, algorithm is simple enough to
    verify by tracing

PacketHeader (Packets/PacketHeader.cs):
  - Pack/Unpack: Sequence, Flags, Checksum, Id, Time, DataSize, Iteration
    (20 bytes, little-endian on the wire)
  - CalculateHeaderHash32: substitutes the 0xBADD70DD sentinel for the
    Checksum field before hashing (matches AC retail + ACE convention —
    without it the checksum would chicken-and-egg on itself). Uses a
    local struct copy so the real Checksum isn't mutated on the caller.
  - HasFlag for bitmask queries

PacketHeaderFlags (Packets/PacketHeaderFlags.cs):
  - Full flag enum from ACE reference: Retransmission, EncryptedChecksum,
    BlobFragments, ServerSwitch, ConnectRequest/Response, LoginRequest,
    AckSequence, TimeSync, Disconnect, NetError, EchoRequest/Response,
    Flow, and friends

Tests (15 new, 20 total in net project, 97 across both projects):
  Hash32 (7):
    - Empty returns 0
    - 4-byte known value (hand-computed from bit layout)
    - 5-byte value with one tail byte
    - 1/2/3 tail-byte boundary cases (verifies 24/16/8 shift ordering)
    - Determinism
  PacketHeader (8):
    - Pack/Unpack round-trip preserving all 7 fields
    - Pack writes little-endian wire format in byte order
    - HasFlag single and multi-bit
    - CalculateHeaderHash32 invariance under Checksum field changes
      (the critical property — verifies the BADD sentinel substitution)
    - CalculateHeaderHash32 doesn't mutate
    - CalculateHeaderHash32 determinism
    - Unpack/Pack size-check throw

User confirmed an ACE server is running on localhost for the future
Phase 4.6 live integration step. Credentials will be read from env
vars at runtime, never committed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:17:37 +02:00
Erik
293584d6e8 feat(net): AcDream.Core.Net scaffold + ISAAC keystream (Phase 4.1)
First step of Phase 4 (networking). Adds a new AcDream.Core.Net project
for the AC UDP protocol implementation and a matching AcDream.Core.Net.Tests
project. Keeps networking isolated from rendering and the dat layer,
which also keeps the AGPL-reference-material hygiene cleaner.

AcDream.Core.Net/NOTICE.md documents the attribution policy: we read
ACE's AGPL network code (and holtburger's Rust ac-protocol crate) to
understand AC's wire format, but we reimplement everything in acdream's
own style. Wire-format facts aren't copyrightable; specific code is.

This commit adds one component: IsaacRandom — AC's variant of Bob
Jenkins' ISAAC PRNG, used to XOR a keystream into the CRC field of
every outbound packet for authentication. Clean-room reimplementation
based on reading:
  - references/ACE/Source/ACE.Common/Cryptography/ISAAC.cs (AGPL oracle)
  - Bob Jenkins' public ISAAC algorithm description

Implementation notes:
  - 256 uint32 mm[] state, 256 uint32 rsl[] output buffer, a/b/c regs
  - Initialize() runs 4 golden-ratio Mix() warmup rounds then two fold-in
    passes over rsl[] and mm[] (fresh instance → both start as zeroes)
  - AC variant: seed is exactly 4 bytes, interpreted as little-endian
    uint32 assigned to a = b = c before the first Scramble()
  - Scramble() produces 256 output words in one pass; Next() consumes
    them backwards from offset 255 → 0, re-scrambling at offset -1
  - Test seed 0x12345678 matches ACE's reference output byte-for-byte
    across the first 16 values (golden vectors transcribed from a
    throwaway oracle harness that compiled ACE's ISAAC.cs and printed
    its output; the harness was deleted after extracting the values)

Tests (5, all passing):
  - Next_Seed12345678_MatchesAceGoldenVectors: 16 golden uint32 values
  - Next_TwoInstancesSameSeed_ProduceIdenticalSequence: 1000 outputs
  - Next_DifferentSeeds_ProduceDifferentFirstOutput
  - Next_512Calls_SpansTwoScrambleBatches: >400 distinct values in 512
    outputs (catches all-zero / stuck-at-one bugs at scramble boundary)
  - Ctor_ShortSeed_Throws

Both test projects still green: 77 core + 5 net = 82/82.

Phase 4.2 (packet framing + checksum) next.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:14:28 +02:00
Erik
e0dfecdf23 feat(core+app): per-cell terrain texture blending (Phase 3c.4)
The visual-win commit that wires up the Phase 3c.1/.2/.3 building blocks:
Holtburg's terrain now uses AC's real per-cell texture-merge blend
(base + up to 3 terrain overlays + up to 2 road overlays, with alpha
masks from the alpha atlas) instead of the flat per-vertex single-layer
atlas lookup that preceded it.

Geometry rewrite:
  - New TerrainVertex struct (40 bytes): Position(vec3) + Normal(vec3) +
    Data0..3 (4x uint32 packed blend recipe)
  - LandblockMesh.Build is now cell-based: iterates 8x8 cells instead of
    the old 9x9 vertex grid, emits 6 vertices per cell (two triangles),
    384 total vertices per landblock
  - For each cell: extract 4-corner terrain/road values → GetPalCode →
    BuildSurface (cached across landblocks via a shared surfaceCache) →
    FillCellData → split direction from CalculateSplitDirection → emit
    6 vertices in the exact gl_VertexID % 6 order WorldBuilder's vertex
    shader expects
  - Per-vertex normals preserved via Phase 3b central-difference
    precomputation on the 9x9 heightmap, interpolated smoothly across
    the cell (we deliberately didn't adopt WorldBuilder's dFdx/dFdy
    flat-shade approach — Phase 3a/3b user-tuned lighting was worth
    keeping)

Renderer rewrite:
  - TerrainRenderer VAO: vec3 Position, vec3 Normal, 4x uvec4 byte
    attributes for Data0..3. The uvec4-of-bytes read pattern matches
    Landscape.vert so the ported shader math stays byte-for-byte
    identical to WorldBuilder's.
  - Binds both atlases: terrain atlas on unit 0 (uTerrain), alpha atlas
    on unit 1 (uAlpha)

Shader rewrite (ports of WorldBuilder Landscape.vert/.frag, trimmed):
  - terrain.vert: unpacks the 4 data bytes + rotation bits, derives the
    cell corner from gl_VertexID % 6 + splitDir, rotates the cell-local
    UV per overlay's rotation field, and computes world-space normal
    for the fragment shader
  - terrain.frag: maskBlend3 three-layer alpha-weighted composite for
    terrain overlays, inverted-alpha road combine, final composite
    base * (1-ovlA)*(1-rdA) + ovl * ovlA*(1-rdA) + road * rdA. Phase
    3a/3b directional lighting applied on top (SUN_DIR, AMBIENT=0.25,
    DIFFUSE=0.75, in sync with mesh.frag).
  - Editor uniforms (grid, brush, unwalkable slopes) deliberately
    omitted — not applicable to a game client
  - Per-texture tiling factor hardcoded to 1.0 for now (WorldBuilder
    reads it from uTexTiling[36] uploaded from the dats); one tile per
    cell = 8 tiles per landblock-side, slightly coarser than the old
    ~2x-per-cell tiling. Tunable via the TILE constant if needed.

TerrainAtlas grew parallel TCode/RCode lists (CornerAlphaTCodes,
SideAlphaTCodes, RoadAlphaRCodes) so TerrainBlendingContext can be
built without the mesh loader touching the dats directly.

GameWindow builds a TerrainBlendingContext once, shares a Dictionary
<uint, SurfaceInfo> surfaceCache across all 9 landblocks. Output:
"terrain: 137 unique palette codes across 9 landblocks" — avg ~15
unique per landblock, cache reuse healthy.

LandblockMeshTests rewritten for 384-vertex layout. 77/77 tests green.
Visual smoke run launches clean: no shader compile/link errors, no
GL warnings, terrain renders to the screen.

User visual verification is the final acceptance gate for Phase 3c.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 14:02:15 +02:00
Erik
a6cd56663f feat(core): terrain surface recipe + cell data packing (Phase 3c.3)
Ports WorldBuilder's full BuildTexture / FillCellData pipeline as
pure CPU functions in TerrainBlending.cs, along with the SurfaceInfo
recipe record and a TerrainBlendingContext input struct that carries
the atlas index lists the algorithm needs.

This is still pure algorithm work — no GL, no shaders, no mesh gen
changes. Visual Phase 3c.4 next commit wires it into LandblockMesh
and rewrites the terrain shaders to consume Data0..3.

Added (all ports of WorldBuilder LandSurfaceManager methods):
  - ExtractTerrainCodes: inverse of GetPalCode terrain bits
  - PseudoRandomIndex: deterministic hash over palette code for alpha
    variant selection; overflow-dependent int math matches WorldBuilder
    byte-for-byte
  - RotateTerrainCode: *2 with wrap (1→2→4→8→1, multi-corner patterns
    handled in tests)
  - GetRoadCodes: decodes the 8-bit road mask into up to two canonical
    road patterns + allRoad flag; magic 0xE/0xD/0xB/0x7 switch kept verbatim
  - FindTerrainAlpha: picks corner vs side alpha map, walks the 4
    rotations looking for a TCode match, returns (alphaLayer, rotation)
    or (255, 0) for "not found"
  - FindRoadAlpha: same idea for road maps, iterates all maps from a
    pseudo-random offset
  - BuildSurface: composes the above into a SurfaceInfo, handling the
    all-road, all-duplicate-terrain, and distinct-terrain cases via
    BuildOverlayLayers + BuildWithDuplicates (ports GetTerrainTextures +
    BuildTerrainCodesWithDuplicates)
  - FillCellData: packs a SurfaceInfo + CellSplitDirection into the 4
    uint32 vertex attributes Data0..Data3. Byte layout documented in
    XML comment and matches WorldBuilder's Landscape.vert uvec4 byte
    unpacking exactly.

SurfaceInfo record carries resolved atlas byte layers directly (base +
3 terrain overlays + 2 road overlays, each with optional alpha layer
and 0-3 rotation). Sentinel 255 = "slot unused".

Tests (14 new, 75/75 total):
  - ExtractTerrainCodes round-trip with GetPalCode
  - RotateTerrainCode single-corner cycle + multi-corner patterns
  - GetRoadCodes: no-road, all-road, single-corner road
  - PseudoRandomIndex: range, count=0 guard, determinism
  - BuildSurface: all-grass → base only; all-road → road as base;
    two-grass-two-dirt → base + overlay
  - FillCellData: full round-trip bit layout with recognizable
    byte values in every slot, plus a no-road1 case that verifies
    the texRd1 slot collapses to 255 when road1 alpha is absent

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 13:53:32 +02:00
Erik
a8459eecbb feat(core+app): alpha atlas loading (Phase 3c.2)
Loads AC's terrain blending alpha masks into a second GL_TEXTURE_2D_ARRAY
alongside the existing terrain atlas. The alpha atlas is built but not
yet sampled by any shader — that wiring lands in Phase 3c.4.

SurfaceDecoder additions:
  - Handles PFID_A8 (generic single-byte-alpha) by replicating each
    alpha byte into all four RGBA channels
  - Same branch handles PFID_CUSTOM_LSCAPE_ALPHA (0xF4), AC's landscape-
    specific alpha format — the bit layout is identical, just a different
    format ID to distinguish the asset class in the dats. I only found
    this by adding a diagnostic in the first iteration (initial attempt
    returned Magenta for every alpha map because I only wired PFID_A8)
  - 3 new tests: 2x2 A8 round-trip, short-source fallback, and a
    CUSTOM_LSCAPE_ALPHA test verifying it's routed through the same path

TerrainAtlas additions:
  - New GlAlphaTexture property plus CornerAlphaLayers / SideAlphaLayers
    / RoadAlphaLayers index lists so the coming BuildSurface port can
    cite atlas layers by source category
  - BuildAlphaAtlas walks TexMerge.CornerTerrainMaps, SideTerrainMaps,
    RoadMaps and uploads each decoded mask as a layer in insertion
    order; categories carry their atlas-layer index in the respective
    list
  - Fallback handling (single-layer white) when TexMerge is missing or
    every map fails to decode
  - Alpha atlas uses ClampToEdge wrap so repeating tile sampling at
    mask boundaries doesn't produce seams
  - Dispose() now cleans up both textures

On Holtburg's region the log prints:
  TerrainAtlas: 33 terrain layers at 512x512
  AlphaAtlas:    8 layers at 512x512  (corners=4, sides=1, roads=3)

Tests: 61/61 passing. No visual change expected this commit (shader
still ignores Data0..3 and the alpha sampler).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 13:45:40 +02:00
Erik
8b940bd038 docs(claude): project goal + lead-developer operating instructions
CLAUDE.md captures the project goal (modern C# AC client with
first-class plugin support) and sets Claude's operating mode to
"lead developer" — drive phases continuously and only pause for
decisions that genuinely need the user's input. Reduces check-in
overhead on the long tail of phase work.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 13:39:21 +02:00
Erik
e6cfcb612b feat(core): terrain palette + cell split math (Phase 3c.1)
First of four steps porting WorldBuilder's texture-merge terrain
blending. This commit is pure CPU math with no GL or dat dependencies
so the ported logic can be verified in isolation before it starts
driving real rendering.

Ported:
  - GetPalCode(r1..r4, t1..t4): packs corner terrain/road bits into
    a 32-bit palette code (bit layout documented in XML comment)
  - CalculateSplitDirection: deterministic hash picking SWtoNE vs
    SEtoNW triangulation for a cell; magic constants kept exact to
    match AC's server-side collision triangulation
  - CellSplitDirection enum with values matching WorldBuilder's so
    later bit-packing stays byte-identical

Tests (10 new, 58/58 passing total):
  - GetPalCode golden value for all-grass-no-roads: 0x10008421
    (hand-computed from the bit layout, not derived from a run)
  - GetPalCode all-zero produces only the sizeBits marker
  - GetPalCode determinism, road-flag isolation (r1 flip touches
    only bit 26), size bit always set, terrain region bounded to
    bits 0-19
  - CalculateSplitDirection hand-computed golden for (0,0,0,0):
    (1813693831 - 1369149221) * (1/2^32) ~= 0.1035 < 0.5 -> SWtoNE
  - Determinism
  - Across a full 8x8 landblock the hash produces a mix of both
    split directions (would fail if the hash collapses)

Deferred to Phase 3c.3 (need dat data for TexMerge):
  BuildSurface, FillCellData, PseudoRandomIndex, SurfaceInfo

Reference: WorldBuilder Chorizite.OpenGLSDLBackend/Lib/LandSurfaceManager.cs
           WorldBuilder.Shared/Modules/Landscape/Lib/TerrainUtils.cs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-11 13:36:35 +02:00
Erik
3fb6b67735 docs(plan): Phase 3c terrain blending plan
Blending-focused plan for Phase 3c: port WorldBuilder's per-cell
palette-code + alpha-atlas terrain texture merge scheme so terrain
type boundaries blend smoothly instead of stair-stepping.

Scope deliberately excludes chunking (deferred to a possible Phase 3d
when streaming actually matters) so the work stays focused on the
visible win.

Execution split into 4 small commits:
  3c.1 palette math (pure CPU, unit tested against golden values)
  3c.2 alpha atlas loading
  3c.3 per-cell vertex layout refactor
  3c.4 shader rewrite (the visual-win commit)

Each step is runnable on its own so if 3c.4 looks wrong we know the
earlier steps were fine.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 23:43:04 +02:00
Erik
89dc791510 tune(shaders): more dramatic Phase 3a lighting contrast
Original Phase 3a constants had SUN_DIR=(0.4,0.3,0.8) — heavily
vertical, so roofs and ground both landed near peak brightness and
only walls dropped. Combined with AMBIENT=0.4/DIFFUSE=0.6 the lit-vs-
shadow contrast was ~2.2x, which was real but hard to read through
textures. User feedback: "Ligtning looks the same I think."

Diagnosed with a temporary grayscale-lighting fragment output — walls
on different sides of the same building did show different brightness,
confirming the Phase 3a/3b pipeline is wired correctly end-to-end and
the issue was purely perceptual contrast.

Retuned: SUN_DIR=(0.5,0.4,0.6) (more oblique), AMBIENT=0.25, DIFFUSE=0.75.
Contrast ratio now ~3.3x. User-verified visually.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 23:25:35 +02:00
Erik
3c3f5267de docs(plan): Phase 4 networking design
Design-only doc covering the networking subsystem needed to bring
the static Holtburg scene online: UDP packet codec, ISAAC keystream,
fragment reassembly, GameMessage dispatch, WorldSession lifecycle,
and composite IGameState so server CreateObject messages flow through
the same IEvents pipeline the dat-hydrated static entities already use.

Also documents that ACE is the authority for the protocol (neither
WorldBuilder nor ACViewer implements client networking) and captures
the license hygiene plan: read ACE's AGPL source for protocol knowledge,
reimplement from scratch, credit in NOTICE.md.

Explicit win condition for Phase 4: the foundry statue finally appears,
because it's a server weenie, not a dat decoration.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 22:31:26 +02:00
Erik
c95481ea69 feat(core): per-vertex terrain normals via central differences (Phase 3b)
LandblockMesh was hardcoding Normal=Vector3.UnitZ for every vertex,
which meant Phase 3a's directional lighting gave every terrain fragment
the same brightness — flat-looking terrain regardless of slope.

Now computes a real per-vertex normal by sampling the 4 heightmap
neighbors and taking central differences on the heights. The surface
is z=h(x,y), tangents are Sx=(1,0,dh/dx) and Sy=(0,1,dh/dy), and the
normal is their cross product: (-dh/dx, -dh/dy, 1) normalized. Edge
vertices use forward/backward difference instead of central.

Heightmap is pre-sampled into a 9x9 float grid before the vertex loop
so neighbor lookups don't hit the heightTable dictionary-style 81 times
per vertex — one pass to precompute, one pass to emit vertices.

Existing tests still pass: flat landblocks produce flat normals
(constant heights → zero derivatives → UnitZ), so the Phase 1 tests'
"all vertices same Z" assertion remains accurate.

Combined with 3268556 (lighting), terrain hills now visually catch the
sun on their sunward slopes and darken on shadowed slopes. Holtburg's
gentle rolling hills should look considerably more three-dimensional.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 22:23:35 +02:00
Erik
3268556bd0 feat(app): directional lighting on terrain and static meshes (Phase 3a)
Adds a hardcoded sun direction + ambient + Lambert diffuse to both
terrain.frag and mesh.frag. Both vertex shaders now forward a world-
space normal (computed as mat3(uModel) * aNormal) for the fragment
shader to dot against the sun vector.

Lighting model:
  final_rgb = texture_rgb * (AMBIENT + DIFFUSE * max(0, dot(N, SUN)))
where AMBIENT=0.4, DIFFUSE=0.6, SUN=normalize(0.4,0.3,0.8).

Building walls facing the sun light up, walls in shadow dim to ~40%.
Scenery (trees, bushes, rocks) with real per-vertex normals from SWVertex
shades naturally. Terrain currently uses flat UnitZ normals so every
terrain fragment gets the same contribution — terrain will look a bit
washed out compared to real AC until a Phase 3b pass computes per-vertex
landblock normals from the heightmap.

Non-uniform scale (from scenery's random scale baked into MeshRef
PartTransform) would technically require the inverse-transpose for
correct normals, but scenery uses uniform scale so mat3(uModel) is
good enough. Flagging as a known Phase 3+ concern if nonuniform scale
ever shows up.

Build clean, runtime clean: 1133 entities hydrated, no shader compile
errors, process runs through startup.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 22:22:10 +02:00
Erik
0f7cd9caaf revert(app): drop foundry-statue camera target — it's a weenie
The Holtburg foundry statue is a selectable in-game item (weenie
template spawned by the server), not a static client-dat entity. It's
correctly absent from:
- LandBlockInfo.Objects (Stabs)
- LandBlockInfo.Buildings (BuildingInfo)
- EnvCell.StaticObjects
- Region.SceneInfo procedural scenery (SceneryGenerator explicitly
  skips ObjectDesc entries where WeenieObj != 0 — that branch is the
  weenie-reference flag)

The client is behaving correctly. The statue will appear once we
connect to a live ACEmulator instance and receive CreateObject network
messages placing the weenie at its spawn position — Phase 4+ work.
Setup 0x02000081 that I speculatively identified as "the statue" is a
different decoration entirely; there's no need to pin the default
camera at its location.

Revert the camera targeting from eb27e3c. OrbitCamera defaults back to
(96, 96, 0) centered on Holtburg, FlyCamera to (96, 96, 150).
2026-04-10 22:14:35 +02:00
Erik
eb27e3c2be chore(app): point default camera at foundry statue location
Diagnostic instrumentation confirmed Setup 0x02000081 at (107.5, 36.0,
100.85) from EnvCell 0xA9B40166 is the most plausible candidate for the
"greenish statue on top of the foundry" the user described. That
position is directly above Building[7] (the foundry, ModelId=0x01000C17)
which sits at (107.5, 36.0, Z=94.0). The statue's Setup has 1 part
(GfxObj 0x01000622), 80 triangles, 127 vertices, 4 valid surfaces (3
Base1Image + 1 Base1ClipMap), all Translucency=0.00 and with resolvable
OrigTextureIds. Every signal says it SHOULD be rendering.

To verify visually, this commit points the default OrbitCamera target
and FlyCamera initial position at that exact (107.5, 36.0, ~101)
location so the user sees the foundry rooftop immediately on launch
without having to hunt. If the statue is visible at the camera target
on run, it's present and we're done. If the camera target is empty,
we've precisely localized the rendering bug to "Setup 0x02000081 mesh
build succeeds but GL draw produces nothing visible" which would point
at polygon winding order or NegSurface-only polygons in GfxObjMesh.Build.

Removes all the transient DIAG instrumentation from the session.
2026-04-10 22:10:01 +02:00
Erik
82e857cf21 fix(app): interior stabs are landblock-local, not cell-local
Phase 2d's initial composition was cellOrigin + cellRot*stabLocal,
assuming EnvCell.StaticObjects carried cell-local frames and that
EnvCell.Position was the cell-to-landblock transform. User reported
all interior objects "far up in the air" after the initial Phase 2d.

Diagnostic confirmed the real shape: EnvCell 0xA9B40100.Position.Origin
= (84.1, 131.5, 66.0) and the first Stab inside it had Frame.Origin =
(92.1, 131.5, 68.0). Both are in landblock-local X/Y/Z space — the
stab is 8 units east and 2 units up from the cell's registered origin
but expressed in the SAME coordinate space, not as an offset. Adding
the cell origin on top double-counted ~155 units in Z and put the
statue at worldPos Y=263 Z=233+, completely out of range.

EnvCell.Position appears to tell the physics engine which landblock
region owns the cell (for collision/portal lookups) rather than acting
as a cell-to-landblock transform for contained objects. The stabs are
already in the same coordinate system as LandBlockInfo.Objects stabs.

Fix: drop the cell origin + cell rotation from the composition. World
position is now just stab.Frame.Origin + lbOffset, mirroring the
regular Stab handling exactly.

Smoke verified: 475 interior objects still hydrate, process runs clean.
Visual verification pending.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 21:51:34 +02:00
Erik
abcfb55418 feat(app): walk interior EnvCells for in-building static objects
Addresses the "foundry statue still missing" user feedback after Phase
2c. Diagnostic spike confirmed the statue is not a Stab on
LandBlockInfo.Objects, not a Building on LandBlockInfo.Buildings, and not
a hierarchical Setup part — the highest entity on Holtburg center was
at Z=104 with no entity above the foundry cluster.

Root cause per LandBlockInfo.NumCells's own doc comment: interior cells
live at dat id 0xAAAA0100 + N where AAAA is the landblock id high word
and N runs from 0 to NumCells-1. Each EnvCell has a StaticObjects list
(List<Stab>) holding in-building decorations — statues, furniture,
lamps, crates, rugs, and the like. We weren't loading any of it.

GameWindow.OnLoad now iterates each landblock's LandBlockInfo.NumCells,
loads each EnvCell at the canonical id, walks its StaticObjects, and
hydrates each as a WorldEntity. Position is composed as:

    worldPos = landblockOffset + cellOrigin + (cellRotation * stabLocal)
    worldRot = cellRotation * stabRotation

where cellOrigin/cellRotation come from EnvCell.Position (a Frame in
landblock-local space) and stabLocal/stabRotation come from the Stab's
own Frame (cell-local space). Cell rotation is applied to the stab
position because some cells in AC are rotated relative to the landblock
grid.

Entity counts on Holtburg 3x3:
  Stabs + Buildings      239
  Procedural scenery     419
  Interior StaticObjects 475  (NEW)
  -------
  Total                 1133

Phase 2d done. Interior geometry (walls, floors, ceilings) is still not
rendered — cell shells are Phase 3+ work. Only the StaticObjects list is
walked, which is enough to surface the visible decorations the user sees
inside buildings in real AC.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 21:45:02 +02:00
Erik
985cdc0044 Merge phase-2c/scenery: procedural scenery from Region.SceneInfo
Phase 2c: adds SceneryGenerator that places trees, bushes, rocks, and
fences across the 3x3 landblock grid using AC's deterministic LCG hash
of global cell coordinates to drive ObjectDesc frequency rolls and
pseudo-random placement/scale/rotation.

Entity count: 239 → 658 (+419 scenery). Build clean, 48 tests green,
runtime clean.

Addresses the "missing trees" half of the user's post-Phase-2b visual
feedback. The "foundry statue" half (hierarchical Setup parts) is
deferred as a potential Phase 2d.
2026-04-10 21:07:21 +02:00
Erik
9970811dc3 feat(core): procedural scenery from Region.SceneInfo (Phase 2c)
Adds SceneryGenerator.Generate which walks Region.TerrainInfo.TerrainTypes
+ Region.SceneInfo.SceneTypes for each landblock vertex, selects a scene
using the AC client's pseudo-random LCG hash of global cell coordinates,
then rolls each ObjectDesc's frequency, computes a displaced cell-local
position, random scale, and random rotation — the exact algorithm
ACViewer ports from the retail AC client's get_land_scenes().

Phase 2 rendered 239 explicit Stab+Building entities on the 3x3 Holtburg
grid but was missing every procedurally-placed tree, bush, rock, fence,
and small decoration because these are not stored as LandBlockInfo entries.
This adds 419 scenery entities across the same 9 landblocks, bringing the
total to 658.

Integration in GameWindow.OnLoad: after the existing Stab/Building
hydration loop, iterate each landblock's scenery spawns, resolve each
to a GfxObj or Setup via the same mesh pipeline, bake the random scale
into each MeshRef's PartTransform so the static mesh renderer doesn't
need a scale field on WorldEntity, and sample the landblock heightmap
bilinearly for the ground Z (simpler than ACViewer's find_terrain_poly
slope-aware placement).

Deliberate deferrals for first pass:
- No slope-based rejection (obj.MinSlope/MaxSlope). Trees may end up on
  cliffs they shouldn't be on.
- No road-overlap rejection. Scenery may spawn in roads.
- No building-overlap rejection. Scenery may clip buildings.
- No WeenieObj handling (those are dynamic spawns, not static scenery).

All three filters will be added in a follow-up phase when we have the
walkable-polygon infrastructure they need.

Build clean, 48 tests still pass, smoke verified: "scenery: spawned 419
entities across 9 landblocks", process runs without exceptions.

Addresses the user visual feedback after Phase 2b: "some extra details
are missing, like a tree and the statue on top of the foundry". The tree
issue is now fixed (419 trees/bushes/rocks/etc placed). The foundry
statue may still be missing if it's a hierarchical Setup part (Phase 2a's
SetupMesh.Flatten intentionally doesn't walk ParentIndex) — that's a
separate fix if smoke verification shows it's still missing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 21:07:12 +02:00
Erik
fe0bfb075b Merge phase-2b/atlas-neighbors-cameras-events: Phase 2b
Phase 2b MVP complete. 9 commits implementing:
- Vertex struct gains TerrainLayer (uint, location 3 VertexAttribIPointer)
  and LandblockMesh.Build takes a TerrainTextureType → atlas layer map
- TerrainAtlas builds GL_TEXTURE_2D_ARRAY from Region.TerrainInfo.
  LandSurfaces.TexMerge.TerrainDesc, one layer per referenced TerrainTextureType
- Terrain shader rewritten to sample sampler2DArray with flat uint layer
  and per-landblock uModel translation
- TerrainRenderer grows AddLandblock(mesh, worldOrigin) for multi-landblock
  drawing, drops the ctor mesh param in favor of the new add pattern
- GameWindow replaces single-landblock load with WorldView.Load 3x3 grid;
  entity positions are translated by their source landblock's world offset
- ICamera interface extracted, OrbitCamera refactored to implement
- FlyCamera with WASD + raw cursor mouse look, pitch clamp, horizontal-plane
  movement independent of pitch
- CameraController with F toggle, Escape contextual (fly→orbit releases
  cursor; orbit→Escape closes window), cursor capture via CursorMode.Raw
- IGameState + IEvents + WorldEntitySnapshot added to Plugin.Abstractions
- WorldEvents implements replay-on-subscribe so plugins that subscribe
  after the world is loaded see every already-spawned entity exactly once
  before returning from +=
- WorldGameState exposes the entity snapshot list; AppPluginHost
  constructor gains state + events parameters
- Program.cs and GameWindow thread worldGameState + worldEvents through
  the startup; OnLoad calls FireEntitySpawned for each hydrated entity
- SmokePlugin subscribes in Enable, logs replay count at subscribe time
  (0 because it subscribes before world load) and the total seen count
  at Disable time (via live events during hydration)

6 new xUnit tests (43 → 48): 1 terrain layer mapping regression +
5 WorldEvents replay/live/unsubscribe/exception-safety tests.

Smoke verified against real dats: 33 terrain atlas layers at 512x512,
9 landblocks loaded in 3x3 grid, 239 entities hydrated across all
landblocks, build clean, no exceptions, all plugin lifecycle logs
visible including the new `sees 0 entities (replay count at subscribe)`
line.

Phase 2 (both 2a and 2b) is done. Next phase is visual verification
by the user and then Phase 3 planning (animated entities, doors,
terrain texture blending at cell boundaries, proper lighting, etc).
2026-04-10 20:32:46 +02:00
Erik
08097b6c7e feat(app): wire IGameState+IEvents into Program and SmokePlugin
Pass WorldGameState and WorldEvents into GameWindow so OnLoad fires
FireEntitySpawned and Add for each hydrated entity. SmokePlugin now
subscribes to EntitySpawned in Enable(), unsubscribes in Disable(),
and logs the replay count at subscribe time and total seen at disable.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-10 20:31:50 +02:00
Erik
0c0c042dca feat(core): add IGameState, IEvents, WorldEvents with replay-on-subscribe
Adds WorldEntitySnapshot, IGameState, IEvents abstractions; WorldEvents
implements replay-on-subscribe with per-handler exception swallowing;
WorldGameState tracks entities; AppPluginHost exposes all three; stubs
wired in Program.cs to keep build green ahead of Task 9 live wiring.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-10 20:29:29 +02:00
Erik
22f684e8c6 feat(app): add CameraController with F toggle and cursor capture
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-10 20:27:11 +02:00
Erik
7cf6ea267a feat(app): add FlyCamera with WASD + mouse look
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-10 20:25:19 +02:00
Erik
5640c153f3 feat(app): extract ICamera interface from OrbitCamera
Introduce ICamera (View, Projection, Aspect) and make OrbitCamera implement
it. TerrainRenderer.Draw and StaticMeshRenderer.Draw now accept ICamera,
widening the call-site contract while leaving all runtime behavior unchanged.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-10 20:24:29 +02:00
Erik
560100e5b6 feat(app): render 3x3 neighbor landblocks with texture atlas
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-10 20:23:21 +02:00
Erik
347a7e92ff feat(app): add TerrainAtlas for GL_TEXTURE_2D_ARRAY terrain textures 2026-04-10 20:19:36 +02:00
Erik
78ce099440 fix(core): LandblockMesh keys atlas lookup on TerrainInfo.Type
Task 1's subagent used the raw ushort as the map key because the test
used raw ushort 7 as the value. But the atlas map is built from
Region.TerrainInfo.LandSurfaces.TexMerge.TerrainDesc which keys on
TerrainTextureType enum values, extracted from bits 2-6 of the
TerrainInfo ushort per DatReaderWriter's Types/TerrainInfo.cs.

Reverts to using block.Terrain[hi].Type so the Task 2 TerrainAtlas can
actually find matching keys against real dat terrain. The test is
updated to encode Type=7 correctly as (7 << 2) in the raw ushort.
2026-04-10 20:18:09 +02:00
Erik
324abed6eb feat(core): add Vertex.TerrainLayer + LandblockMesh layer map
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-04-10 20:16:25 +02:00
Erik
bc69f0cdf1 docs: phase 2b implementation plan (9 tasks) 2026-04-10 20:13:03 +02:00
Erik
f61f356145 docs: phase 2b design — atlas textures, neighbors, dual cameras, plugin api
Locks the four decisions from brainstorming: full scope (all 8 sketched
tasks in one Phase 2b), GL_TEXTURE_2D_ARRAY for terrain atlas with a
per-vertex flat uint layer attribute, raw cursor capture FlyCamera with
F toggle and Escape release, and WorldEvents.EntitySpawned with
replay-on-subscribe so plugin ordering doesn't matter.

Grows AcDream.Plugin.Abstractions by IGameState + IEvents +
WorldEntitySnapshot. Host-side WorldGameState + WorldEvents implementations
live in AcDream.App.Plugins. AppPluginHost constructor gains two
parameters. Program.cs wiring order keeps Phase 2a's Enable-before-Run,
relying on replay-on-subscribe to make subscription-before-world-load
produce the right observable behavior.

Task 1 expands Vertex struct and LandblockMesh signature — this affects
StaticMeshRenderer's vertex stride too, so Phase 2a's shader bindings
need a matching update.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 20:00:23 +02:00
Erik
cc55c3f812 fix: heightmap transpose + solid-color + translucency + clipmap textures
Three root causes found via systematic debugging after the user reported
that the dc60405 texture fix and 4763b97 height table fix had no visible
effect on Holtburg.

## Heightmap transpose (LandblockMesh.Build)

Phase 1's LandblockMesh.Build indexed block.Height as y*9+x but AC packs
per-vertex heights in x-major order (x*9+y, matching ACViewer's
LandblockStruct: Height[x * VertexDim + y]). The bug was invisible on
flat landblocks (Phase 1 smoke test) but left buildings buried by 10-13
world-Z units on Holtburg, because building Frame.Origin positions
reference the un-transposed ground truth.

Diagnostic evidence (before fix, Holtburg 0xA9B4FFFF):
  entity 0x020000A5 at ( 84.6,126.0) entityZ= 66.03 terrainZ= 78.15 delta=-12.13
  entity 0x02000118 at ( 74.2,139.9) entityZ= 66.03 terrainZ= 78.92 delta=-12.89

After fix: deltas are 0.03 to 2.18 — buildings now sit on the ground
with small positive offsets for foundations.

Regression test added: Build_HeightmapPackedAsXMajor_NotYMajor asserts
asymmetric heights land at the correct world positions.

## Solid-color surfaces with Translucency=1.0 (SurfaceDecoder.DecodeSolidColor)

The "bright pink doors and windows" the user saw were 11 Holtburg
surfaces with OrigTextureId==0 — these carry a ColorValue instead of
a texture chain. Phase 2a's TextureCache dropped them into the magenta
fallback. All 11 turned out to be Base1Solid|Translucent with
Translucency=1.00, meaning "fully transparent placeholder surface"
(debug ColorValue is gray/green/red/blue/black, never displayed).

DecodeSolidColor now takes a translucency parameter and multiplies
alpha by (1 - translucency), so Translucency=1.0 → alpha=0, and the
mesh shader's existing alpha discard (< 0.5) makes the pixel invisible.

TextureCache honors Surface.Type.HasFlag(Base1Solid) and passes
surface.Translucency through.

Regression tests added: DecodeSolidColor_Opaque_PreservesAlpha and
DecodeSolidColor_FullyTranslucent_AlphaGoesToZero.

## Clipmap alpha-key (DecodeIndex16)

AC convention (per ACViewer TextureCache.IndexToColor): on surfaces
marked Base1ClipMap, palette indices 0..7 are treated as fully
transparent regardless of their actual palette color. Without this,
low-index pixels on clipmap surfaces (typically doorway cutouts and
foliage) render as opaque using whatever sentinel color is at those
palette slots.

DecodeRenderSurface now takes an isClipMap parameter. TextureCache
passes Surface.Type.HasFlag(Base1ClipMap). DecodeIndex16 forces
rgba=(0,0,0,0) when isClipMap && idx < 8.

Regression test added: DecodeIndex16_ClipMap_ZerosAlphaForLowIndices.

## Notes

- dc60405's PFID_INDEX16 palette decoder remains correct — no change.
- 4763b97's LandHeightTable wiring remains correct — real-table lookup
  still runs, it just happens to be linear at Holtburg's height range.
  The fix is forward-compatible with mountains elsewhere.
- All three bugs were invisible to the original unit tests. The new
  regression tests pin them down.

## State

- dotnet build: 0 warnings, 0 errors
- dotnet test: 42 passing (was 38 + 4 new)
- Runtime: 126 entities hydrated on Holtburg, no exceptions, no
  magenta fallback (counter was 11, now 0 via diagnostic confirmation)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 19:37:06 +02:00
Erik
dc60405ebc fix(textures): palette-indexed surfaces + alpha cutout shader
Addresses the 'doors, windows, and alpha-keyed parts render bright
pink' issue the user observed after the Phase 2a visual checkpoint.

SurfaceDecoder gains a second overload taking an optional Palette
parameter. When the render surface format is PFID_INDEX16 and a
palette is supplied, each 16-bit value in SourceData is treated as
an index into Palette.Colors (a List<ColorARGB>) and the corresponding
ARGB color's channels are written to the output buffer. The original
no-palette overload is preserved so the Task 3 unit tests that
confirm INDEX16 -> magenta fallback still describe their behavior
correctly (INDEX16 without a palette still returns magenta).

TextureCache now resolves the RenderSurface's DefaultPaletteId via
the dats and passes the resulting Palette (or null) to the decoder.

mesh.frag adds an alpha cutout: fragments with sampled alpha < 0.5
are discarded. Without this, transparent regions of alpha-keyed
textures (doors, windows, foliage cutouts) would render as opaque
rectangles using the texture's background color. This is the
standard alpha-tested approach, simpler than full alpha blending
and matches how AC's original client rendered these surfaces.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 19:12:05 +02:00
Erik
4763b973da fix(terrain): use real LandHeightTable from Region dat
Phase 1 simplified per-vertex height as byte * 2.0f, but AC stores
heights as byte indices into a 256-entry non-linear float lookup
(Region.LandDefs.LandHeightTable). Static object placements in
LandBlockInfo use the real table, so terrain rendered with the
simplified scale left buildings floating or buried.

LandblockMesh.Build now takes an explicit float[] heightTable so
the core code stays testable without a DatCollection. GameWindow
loads Region id 0x13000000 once at startup and passes its
LandDefs.LandHeightTable into every landblock mesh build. The
Phase 1 tests use an identity table (i * 2f for i in 0..255) so
their expectations remain unchanged.

Addresses the 'buildings buried and floating' issue the user
observed after the Phase 2a visual checkpoint.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-10 19:09:27 +02:00
Erik
1d1e668a2f Merge phase-2/static-meshes-and-textures: Phase 2a static meshes
Phase 2a MVP complete. 8 commits implementing Tasks 1-8 of the
Phase 2 plan:
- BCnEncoder.Net 2.2.1 added to AcDream.Core
- GfxObjMesh.Build: multi-surface CPU mesh extractor from GfxObj
  vertex+polygon data, with position/UV dedupe and fan triangulation
- SurfaceDecoder: BCnEncoder.Net-backed DXT decoder + A8R8G8B8 raw,
  with 1x1 magenta fallback
- LandblockLoader: parses Stabs and BuildingInfo from LandBlockInfo
  into WorldEntity records, type-filtering to GfxObj + Setup only
- SetupMesh.Flatten: single-level part hierarchy walker
- WorldView: 3x3 neighbor landblock id computation with edge clamping
- TextureCache: App-side GL texture handle cache, walks the
  Surface → SurfaceTexture → RenderSurface chain from the dats
- StaticMeshRenderer + mesh.vert/mesh.frag + GameWindow wire-up

21 new xUnit tests (17 → 38), all green, build clean.

Smoke verified against real dats: Holtburg landblock hydrated
126 static entities (Stabs + Buildings), process runs without
exception, terrain + static meshes pipeline complete end-to-end.

Phase 2a stops here. Tasks 9-18 (conditional texture debugging,
terrain atlas, 3x3 neighbor rendering, dual cameras, plugin API
growth) deferred to Phase 2b in a future session.
2026-04-10 18:33:39 +02:00
Erik
1375780e14 feat(app): render static meshes from Holtburg LandBlockInfo 2026-04-10 18:32:09 +02:00
Erik
cefc689ba8 feat(app): add TextureCache for Surface→GL texture handle caching 2026-04-10 18:03:58 +02:00
Erik
5d35f4fe46 feat(core): add WorldView with 3x3 neighbor landblock computation 2026-04-10 18:02:41 +02:00
Erik
8f5b498be6 feat(core): add SetupMesh.Flatten for single-level part hierarchy 2026-04-10 18:01:16 +02:00
Erik
473a06c534 feat(core): add LandblockLoader with Stab+Building → WorldEntity mapping 2026-04-10 17:58:30 +02:00
Erik
dbf913ebb4 feat(core): add SurfaceDecoder for A8R8G8B8 and BCn formats 2026-04-10 17:56:15 +02:00