Modern open-source C# .NET 10 Asheron's Call client. Faithful port of retail client behaviour to Silk.NET with a plugin API.
Find a file
Erik 2c10dd4d67 docs(phys L.2g): design spec for dynamic PhysicsState toggling (doors)
L.2d slice 1.5 ship identified the Holtburg doorway blocker as a closed
Door entity (Setup 0x020019FF) whose PhysicsState.Ethereal bit flips
when the player Uses the door. The L.2d shape-fidelity work doesn't
cover this — the door's collision shape is correct; what's missing is
honoring the *runtime* state change.

L.2g is the new sub-phase that handles it. Scope is narrow:

  * Parse inbound GameMessageSetState (0xF74B).
  * Plumb the new PhysicsState value into ShadowObjectRegistry's
    cached per-entity state so the existing CollisionExemption.IsExempt
    already-in-place short-circuit sees up-to-date bits.
  * Verify the Holtburg inn-door scenario: walk in blocked, Use door,
    walk through, auto-close blocks again after 30s.
  * Confirm UpdateMotion (NonCombat, On/Off) drives non-creature
    entities (door swing animation).

Why a new L.2 sub-letter (and not B.4 or Door-special-case): the wire
mechanism (SetState flipping Ethereal) is also how ACE handles activated
traps, opened chests, spell projectiles becoming ethereal. Generic
infrastructure with doors as the verification scenario; lane is the
informal sixth "dynamic state."

Roadmap state:
  * L.2 plan-of-record adds the L.2g section after L.2f.
  * Milestones doc M1 phase list extended `a-f` -> `a-g`.
  * CLAUDE.md status pointer + "next phase candidates" list updated to
    name L.2g slice 1 implementation as the natural next step.

Risk: low. Wire-byte width has a hex-dump fallback path in slice 1
(holtburger says 12 bytes, ACE writes 16, capture settles it). ETHEREAL
plumbing already exists; we feed it new data. No resolver changes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-12 21:00:36 +02:00
docs docs(phys L.2g): design spec for dynamic PhysicsState toggling (doors) 2026-05-12 21:00:36 +02:00
memory fix(physics): L.4 — steep airborne hits slide-tangent (interim, deviates from retail) 2026-04-30 13:22:07 +02:00
references phase(N.0): wire up WorldBuilder fork as submodule + project refs 2026-05-08 08:51:49 +02:00
src fix(phys L.2d slice 1.5): probe captures hit poly under StepSphereUp recursion 2026-05-12 19:25:32 +02:00
tests feat(phys L.2d slice 1): BSP-hit diagnostic probe + plan-of-record correction 2026-05-12 19:14:34 +02:00
tools docs(issues): #37 — Investigation 2 narrows bug to SubPalette coverage gaps 2026-05-05 14:45:50 +02:00
.gitignore phase(N.4): SHIP — flag default-on + finalize plan + roadmap 2026-05-08 18:01:23 +02:00
.gitmodules phase(N.0): wire up WorldBuilder fork as submodule + project refs 2026-05-08 08:51:49 +02:00
AcDream.slnx feat(ui): AcDream.UI.ImGui backend — Hexa.NET.ImGui + Silk.NET input bridge 2026-04-25 00:29:09 +02:00
CLAUDE.md docs(phys L.2g): design spec for dynamic PhysicsState toggling (doors) 2026-05-12 21:00:36 +02:00
README.md docs: add docs/ISSUES.md tactical issue tracker + CLAUDE.md rules 2026-04-25 00:08:15 +02:00

acdream

A modern open-source C# / .NET 10 Asheron's Call client.

Faithful port of the retail client's behaviour to Silk.NET with a modern, plugin-friendly architecture. The code is modern; the behaviour is retail.

Status: playable pre-alpha. You can log in to an ACE server, walk and run through Dereth, see other players animate correctly, watch the day-night cycle, hear ambient audio, and take weapons out. Many systems are still stubbed or in-progress — see roadmap.

Stack

  • Language: C# .NET 10
  • Graphics: Silk.NET (OpenGL 4.3)
  • Audio: OpenAL via Silk.NET
  • Dat parsing: Chorizite.DatReaderWriter
  • Networking: Custom UDP + ISAAC cipher + game-message layer, wire-compatible with ACEmulator server

What works

  • Connecting to a local ACEmulator (ACE) server on 127.0.0.1:9000
  • Character selection and login
  • Rendering Dereth terrain with retail-correct texture blending, per-vertex lighting, and road overlays
  • Static scenery (buildings, trees, scenery objects) via EnvCell walker
  • Animated characters (own + remote) with walk / run / strafe / jump / turn / attack motions sourced from the retail motion tables
  • Network sync with remote players — you can watch other characters animate correctly, including speeds and directional motion
  • Day-night cycle driven from the retail Region dat (0x13000000) — correct DayGroup picking via the retail LCG, correct keyframe interpolation, correct per-keyframe sky-object replace
  • Weather (rain/snow particles synced from the server via the retail DayGroup name)
  • Sky dome, stars, moon, clouds, sun — each rendered from the retail Region's SkyObjects with texture scrolling and alpha fade
  • Plugin host with live event replay-on-subscribe

What's stubbed or in-progress

  • Indoor transitions (building interiors) — disabled, Phase B.3 pending
  • Combat — animation works, damage math not wired
  • Lightning visual — the retail PhysicsScript-driven flash is researched but not wired (see docs/research/2026-04-23-lightning-real.md)
  • TimeSync drift — we only sync calendar on login, not periodically, so acdream's in-game clock gradually drifts from retail's
  • Landscape draw distance — currently ACDREAM_STREAM_RADIUS=2 (~400m) vs retail's several kilometres

See docs/plans/2026-04-11-roadmap.md for the ordered phase list. See docs/ISSUES.md for the rolling list of known bugs + small deferred features (tactical, bug-level; the roadmap is strategic, phase-level).

Building + running

Requires:

  • .NET 10 SDK
  • A retail Asheron's Call dat directory (Turbine/Microsoft property — supply your own). Contains client_portal.dat, client_cell_1.dat, client_highres.dat, client_local_English.dat.
  • A running ACE (ACEmulator) server on 127.0.0.1:9000 (or override via env var)

Launch (PowerShell on Windows — bash has trouble with the apostrophe in "Asheron's Call"):

$env:ACDREAM_DAT_DIR   = "$env:USERPROFILE\Documents\Asheron's Call"
$env:ACDREAM_LIVE      = "1"
$env:ACDREAM_TEST_HOST = "127.0.0.1"
$env:ACDREAM_TEST_PORT = "9000"
$env:ACDREAM_TEST_USER = "testaccount"
$env:ACDREAM_TEST_PASS = "testpassword"
dotnet run --project src\AcDream.App\AcDream.App.csproj -c Debug

Offline CLI dat inspector (no server needed):

dotnet run --project src/AcDream.Cli -- "C:\path\to\Asheron's Call"

Diagnostic env vars

Variable Effect
ACDREAM_DUMP_SKY=1 Per-second dump of the interpolated SkyKeyframe values + per-SkyObject draw info + texture alpha histograms
ACDREAM_DUMP_MOTION=1 Dump every inbound UpdateMotion + resulting SetCycle
ACDREAM_STREAM_RADIUS=N Tune landblock visible-window radius (default 2 = 5×5)
ACDREAM_NO_AUDIO=1 Suppress OpenAL init
ACDREAM_DAY_GROUP=N Force a specific DayGroup index for A/B-testing weather presets
ACDREAM_RUN_SKILL=N / ACDREAM_JUMP_SKILL=N Client-side run/jump skill (default 200)

Layout

src/
  AcDream.App/                   rendering + audio + main loop (Silk.NET)
  AcDream.Core/                  game state, meshing, physics, sky, weather, lighting
  AcDream.Core.Net/              UDP + ISAAC + game-message layer
  AcDream.Cli/                   offline dat-inspector console app
  AcDream.Plugin.Abstractions/   plugin host interfaces
  AcDream.Plugins.Smoke/         example plugin

tests/
  AcDream.Core.Tests/            xUnit tests (742 passing)
  AcDream.Core.Net.Tests/        network-layer tests

tools/
  RetailTimeProbe/               Win32 P/Invoke ReadProcessMemory probe of
                                 the live retail acclient.exe — dumps
                                 TimeOfDay + sky-lighting globals so we
                                 can compare against acdream's state
  SkyObjectInspect/              dat-inspector for Region sky objects

references/                      vendored read-only reference code — ACE,
                                 ACViewer, WorldBuilder, holtburger,
                                 AC2D, Chorizite, DatReaderWriter.
                                 Gitignored.

docs/
  architecture/                  single-source-of-truth architecture doc
  plans/                         phase roadmaps + per-phase specs
  research/                      decompile-derived research, per-phase
                                 findings, deep-dive agent reports
  audit/                         phase-completion audits

Development workflow

All AC-specific behaviour is ported from the decompiled retail client (docs/research/decompiled/). The workflow is:

  1. Decompile first. Find the matching function in the decompiled client.
  2. Cross-reference. Check against ACE's C# port and ACViewer / WorldBuilder.
  3. Write pseudocode. Translate C to readable pseudocode first.
  4. Port faithfully. Translate line-by-line, preserving variable names and control flow.
  5. Conformance test. Add tests using golden values from retail.
  6. Integrate surgically. Minimise churn in the surrounding pipeline.

Guessing at AC-specific algorithms is explicitly forbidden — see CLAUDE.md for the full workflow rationale and the list of failure modes we've paid for in the past.

Reference repos

We cross-reference five external projects for every retail behaviour:

  • ACE (ACEmulator) — authoritative server-side protocol
  • ACViewer — MonoGame dat viewer; good for character appearance
  • WorldBuilder — Silk.NET dat editor; matches our stack
  • Chorizite.ACProtocol — clean-room C# protocol library
  • holtburger — most complete non-retail client; Rust TUI, full client-side behaviour
  • AC2D — C++ AC-client emulator; has the real terrain split formula and 0xF61C movement packet format

See CLAUDE.md for which reference is authoritative for which domain.

Licence

Not yet chosen. All external reference code is vendored under its own licence; see references/*/LICENSE. The acdream source code itself is unreleased — not yet distributed to the public. Once the licence choice is made it will go in a top-level LICENSE file.

The AC dat files and the game's intellectual property remain the property of Microsoft / Turbine. This project does not distribute any of those files or assets — you must supply your own retail install.