feat(O-T7): drop WB project references; complete extraction

End of Phase O extraction. Final cleanup:

- Dropped <ProjectReference> entries to WorldBuilder.Shared and
  Chorizite.OpenGLSDLBackend from both AcDream.App.csproj and
  AcDream.Core.csproj.
- Added Chorizite.Core NuGet PackageReference to AcDream.Core.csproj
  (needed by Core.Rendering.Wb.TextureHelpers for TextureFormat enum;
  previously transitive through the WB project ref).
- Added BCnEncoder.Net.ImageSharp (1.1.2) + SixLabors.ImageSharp (3.1.12)
  as direct PackageReferences to AcDream.App.csproj — previously transitive
  via Chorizite.OpenGLSDLBackend project; used directly by ObjectMeshManager.

Item A (BaseObjectRenderManager static fields):
- Inlined CurrentAtlas/CurrentVAO/CurrentIBO into a new RenderStateCache.cs
  static class (AcDream.App.Rendering.Wb namespace) — the 4 consumers
  (ManagedGLIndexBuffer, ManagedGLTexture, ManagedGLTextureArray, ParticleBatcher)
  all reference RenderStateCache.* instead of BaseObjectRenderManager.*.
- Dropped using Chorizite.OpenGLSDLBackend.Lib from all 4 consumers and from
  WbDrawDispatcher (which had it only as a dead import).

Item B (ActiveParticleEmitter.ObjectLandblock):
- ObjectLandblock? erased to object?; WorldBuilder.Shared.Models.ObjectId? erased
  to ulong? — both fields are stored but never read by any consumer in our codebase.
- Dropped both WB using directives from ActiveParticleEmitter.cs.

Item C (IDatReaderWriter / IDatDatabase):
- Verbatim copy of both interfaces into IDatReaderWriter.cs in
  AcDream.App.Rendering.Wb namespace — DatCollectionAdapter and ObjectMeshManager
  already live in that namespace, so no using changes needed.
- Dropped using WorldBuilder.Shared.Services from DatCollectionAdapter.cs and
  ObjectMeshManager.cs.

Additional extractions required by the reference drop:
- GeometryUtils.cs: verbatim copy of WorldBuilder.Shared.Lib.GeometryUtils
  (float-precision overloads only; Vector3d double-precision overloads omitted —
  ObjectMeshManager uses only the float versions).
- Dropped using WorldBuilder.Shared.Lib from ObjectMeshManager.cs.

WbMeshAdapter.cs cleanup (spec O-D12):
- Deleted _wbDats (DefaultDatReaderWriter) field + ctor init + Dispose call.
- Deleted the [indoor-upload] NULL_RESULT diagnostic block (lines ~205-262) —
  its Phase 2 cell-resolution investigation is complete; its _wbDats.ResolveId
  dependency goes with this commit.
- Deleted _pendingEnvCellRequests field + isPendingEnvCell tracking in Tick().
- Simplified Tick() to a clean drain loop.

Deleted SplitFormulaDivergenceTest.cs — one-time N.5b data-collection sweep;
job done.

Verified acceptance criteria:
- Zero <ProjectReference> to WorldBuilder.* / Chorizite.OpenGLSDLBackend.* in any csproj.
- Zero 'using WorldBuilder.*' / 'using Chorizite.OpenGLSDLBackend.*' in src/.
- DefaultDatReaderWriter referenced in zero places in src/ (comments only).

Build green (0 warnings, 0 errors).
Tests: 1154 total (-1 from deleted SplitFormulaDivergenceTest), 1146 pass,
8 pre-existing failures (unchanged from baseline — physics/input tests
unrelated to this change).

Spec: docs/superpowers/specs/2026-05-21-phase-o-dat-path-unification-design.md

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/AcDream.App/AcDream.App.csproj

@@ -18,6 +18,11 @@
          implement IUniformBuffer from Chorizite.Core; NuGet PackageReferences are not
          forwarded from ProjectReferences so we must declare it explicitly here. -->
     <PackageReference Include="Chorizite.Core" Version="0.0.18" />
+    <!-- Phase O-T7: BCnEncoder.Net.ImageSharp + SixLabors.ImageSharp were previously
+         transitive via the WorldBuilder project reference. Now direct deps of
+         ObjectMeshManager.cs (extracted in T2). -->
+    <PackageReference Include="BCnEncoder.Net.ImageSharp" Version="1.1.2" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.12" />
     <PackageReference Include="Silk.NET.OpenGL" Version="2.23.0" />
     <PackageReference Include="Silk.NET.OpenGL.Extensions.ARB" Version="2.23.0" />
     <PackageReference Include="Silk.NET.Windowing" Version="2.23.0" />
@@ -35,12 +40,6 @@
     <ProjectReference Include="..\AcDream.Core.Net\AcDream.Core.Net.csproj" />
     <ProjectReference Include="..\AcDream.UI.Abstractions\AcDream.UI.Abstractions.csproj" />
     <ProjectReference Include="..\AcDream.UI.ImGui\AcDream.UI.ImGui.csproj" />
-    <!-- Phase N.4 Task 9: WbMeshAdapter constructs the WB GL pipeline directly.
-         AcDream.Core already references these projects, but project references are
-         not transitive in .NET — AcDream.App must list them explicitly to compile
-         against Chorizite.OpenGLSDLBackend and WorldBuilder.Shared types. -->
-    <ProjectReference Include="..\..\references\WorldBuilder\WorldBuilder.Shared\WorldBuilder.Shared.csproj" />
-    <ProjectReference Include="..\..\references\WorldBuilder\Chorizite.OpenGLSDLBackend\Chorizite.OpenGLSDLBackend.csproj" />
   </ItemGroup>
   <ItemGroup>
     <None Update="Rendering\Shaders\*.*">

src/AcDream.App/Rendering/Wb/ActiveParticleEmitter.cs

@@ -1,6 +1,4 @@
 using System.Numerics;
-using Chorizite.OpenGLSDLBackend.Lib;
-using WorldBuilder.Shared.Models;
 
 namespace AcDream.App.Rendering.Wb {
     public class ActiveParticleEmitter {
@@ -8,11 +6,15 @@ namespace AcDream.App.Rendering.Wb {
         public uint PartIndex { get; }
         public Matrix4x4 LocalOffset { get; }
 
-        // Store reference info instead of struct copy
-        public ObjectLandblock? ParentLandblock { get; set; }
-        public ObjectId? ParentInstanceId { get; set; }
+        // Store reference info instead of struct copy.
+        // ParentLandblock was ObjectLandblock (WB type) — typed as object? in Phase O-T7
+        // to remove the WorldBuilder project reference; no consumer reads it.
+        public object? ParentLandblock { get; set; }
+        // ParentInstanceId was WorldBuilder.Shared.Models.ObjectId? — erased to ulong? in T7;
+        // the field is stored but never read by any consumer in our codebase.
+        public ulong? ParentInstanceId { get; set; }
 
-        public ActiveParticleEmitter(ParticleEmitterRenderer renderer, uint partIndex, Matrix4x4 localOffset, ObjectLandblock? parentLandblock = null, ObjectId? parentInstanceId = null) {
+        public ActiveParticleEmitter(ParticleEmitterRenderer renderer, uint partIndex, Matrix4x4 localOffset, object? parentLandblock = null, ulong? parentInstanceId = null) {
             Renderer = renderer;
             PartIndex = partIndex;
             LocalOffset = localOffset;

src/AcDream.App/Rendering/Wb/DatCollectionAdapter.cs

@@ -6,7 +6,6 @@ using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Diagnostics.CodeAnalysis;
-using WorldBuilder.Shared.Services;
 
 namespace AcDream.App.Rendering.Wb;
 

src/AcDream.App/Rendering/Wb/GeometryUtils.cs

@@ -0,0 +1,147 @@
+using System.Numerics;
+
+// Phase O-T7: verbatim copy of WorldBuilder.Shared.Lib.GeometryUtils into
+// the AcDream.App.Rendering.Wb namespace so the WorldBuilder.Shared project
+// reference can be dropped.  Only the float-precision overloads are used by
+// ObjectMeshManager (RayIntersectsSphere + RayIntersectsTriangle).  The
+// double-precision overloads are kept verbatim for completeness.
+
+namespace AcDream.App.Rendering.Wb;
+
+public static class GeometryUtils {
+
+    public static bool RayIntersectsBox(Vector3 rayOrigin, Vector3 rayDirection, Vector3 min, Vector3 max, out float distance) {
+        distance = 0;
+        float tmin = 0.0f;
+        float tmax = float.MaxValue;
+
+        if (Math.Abs(rayDirection.X) < 1e-7f) {
+            if (rayOrigin.X < min.X || rayOrigin.X > max.X) return false;
+        }
+        else {
+            float invD = 1.0f / rayDirection.X;
+            float t0 = (min.X - rayOrigin.X) * invD;
+            float t1 = (max.X - rayOrigin.X) * invD;
+            if (t0 > t1) (t0, t1) = (t1, t0);
+            tmin = Math.Max(tmin, t0);
+            tmax = Math.Min(tmax, t1);
+            if (tmin > tmax) return false;
+        }
+
+        if (Math.Abs(rayDirection.Y) < 1e-7f) {
+            if (rayOrigin.Y < min.Y || rayOrigin.Y > max.Y) return false;
+        }
+        else {
+            float invD = 1.0f / rayDirection.Y;
+            float t0 = (min.Y - rayOrigin.Y) * invD;
+            float t1 = (max.Y - rayOrigin.Y) * invD;
+            if (t0 > t1) (t0, t1) = (t1, t0);
+            tmin = Math.Max(tmin, t0);
+            tmax = Math.Min(tmax, t1);
+            if (tmin > tmax) return false;
+        }
+
+        if (Math.Abs(rayDirection.Z) < 1e-7f) {
+            if (rayOrigin.Z < min.Z || rayOrigin.Z > max.Z) return false;
+        }
+        else {
+            float invD = 1.0f / rayDirection.Z;
+            float t0 = (min.Z - rayOrigin.Z) * invD;
+            float t1 = (max.Z - rayOrigin.Z) * invD;
+            if (t0 > t1) (t0, t1) = (t1, t0);
+            tmin = Math.Max(tmin, t0);
+            tmax = Math.Min(tmax, t1);
+            if (tmin > tmax) return false;
+        }
+
+        distance = tmin;
+        return true;
+    }
+
+    public static bool RayIntersectsTriangle(Vector3 origin, Vector3 direction, Vector3 v0, Vector3 v1, Vector3 v2, out float t) {
+        t = 0;
+        Vector3 edge1 = v1 - v0;
+        Vector3 edge2 = v2 - v0;
+        Vector3 h = Vector3.Cross(direction, edge2);
+        float a = Vector3.Dot(edge1, h);
+
+        if (a > -0.00001f && a < 0.00001f) return false;
+
+        float f = 1.0f / a;
+        Vector3 s = origin - v0;
+        float u = f * Vector3.Dot(s, h);
+
+        if (u < 0.0f || u > 1.0f) return false;
+
+        Vector3 q = Vector3.Cross(s, edge1);
+        float v = f * Vector3.Dot(direction, q);
+
+        if (v < 0.0f || u + v > 1.0f) return false;
+
+        t = f * Vector3.Dot(edge2, q);
+        return t > 0.00001f;
+    }
+
+    public static bool RayIntersectsSphere(Vector3 rayOrigin, Vector3 rayDirection, Vector3 sphereOrigin, float sphereRadius, out float distance) {
+        distance = 0;
+        Vector3 l = sphereOrigin - rayOrigin;
+        float tca = Vector3.Dot(l, rayDirection);
+        if (tca < 0) return false;
+        float d2 = Vector3.Dot(l, l) - tca * tca;
+        float r2 = sphereRadius * sphereRadius;
+        if (d2 > r2) return false;
+        float thc = MathF.Sqrt(r2 - d2);
+        distance = tca - thc;
+        return true;
+    }
+
+    public static ushort PackKey(int x, int y) => (ushort)((x << 8) | y);
+
+    /// <summary>
+    /// Converts a quaternion to Euler angles (in degrees) using the ZYX convention.
+    /// </summary>
+    public static Vector3 QuaternionToEuler(Quaternion q) {
+        float x = q.X, y = q.Y, z = q.Z, w = q.W;
+        float roll, pitch, yaw;
+
+        float sinr_cosp = 2 * (w * x + y * z);
+        float cosr_cosp = 1 - 2 * (x * x + y * y);
+        roll = (float)Math.Atan2(sinr_cosp, cosr_cosp);
+
+        float sinp = 2 * (w * y - z * x);
+        if (Math.Abs(sinp) >= 1)
+            pitch = (float)Math.CopySign(Math.PI / 2, sinp);
+        else
+            pitch = (float)Math.Asin(sinp);
+
+        float siny_cosp = 2 * (w * z + x * y);
+        float cosy_cosp = 1 - 2 * (y * y + z * z);
+        yaw = (float)Math.Atan2(siny_cosp, cosy_cosp);
+
+        return new Vector3(roll, pitch, yaw) * (180.0f / (float)Math.PI);
+    }
+
+    /// <summary>
+    /// Converts Euler angles (in degrees) to a quaternion using the ZYX convention.
+    /// </summary>
+    public static Quaternion EulerToQuaternion(Vector3 euler) {
+        Vector3 rads = euler * (MathF.PI / 180.0f);
+        float roll = rads.X;
+        float pitch = rads.Y;
+        float yaw = rads.Z;
+
+        float cr = MathF.Cos(roll * 0.5f);
+        float sr = MathF.Sin(roll * 0.5f);
+        float cp = MathF.Cos(pitch * 0.5f);
+        float sp = MathF.Sin(pitch * 0.5f);
+        float cy = MathF.Cos(yaw * 0.5f);
+        float sy = MathF.Sin(yaw * 0.5f);
+
+        return new Quaternion(
+            sr * cp * cy - cr * sp * sy,
+            cr * sp * cy + sr * cp * sy,
+            cr * cp * sy - sr * sp * cy,
+            cr * cp * cy + sr * sp * sy
+        );
+    }
+}

src/AcDream.App/Rendering/Wb/IDatReaderWriter.cs

@@ -0,0 +1,114 @@
+using DatReaderWriter;
+using DatReaderWriter.Enums;
+using DatReaderWriter.Lib.IO;
+using System.Collections.ObjectModel;
+using System.Diagnostics.CodeAnalysis;
+
+// Phase O-T7: verbatim copy of WorldBuilder.Shared.Services.IDatReaderWriter +
+// IDatDatabase into the AcDream.App.Rendering.Wb namespace so the
+// WorldBuilder.Shared project reference can be dropped.
+// The only consumer of IDatReaderWriter in acdream is DatCollectionAdapter +
+// ObjectMeshManager, both already in this namespace.
+
+namespace AcDream.App.Rendering.Wb;
+
+/// <summary>
+/// Interface for the dat reader/writer
+/// </summary>
+public interface IDatReaderWriter : IDisposable {
+    /// <summary>
+    /// Gets the source directory of the DAT files.
+    /// </summary>
+    string SourceDirectory { get; }
+
+    /// <summary>
+    /// Tries to get the raw bytes of a file from a specific region database.
+    /// </summary>
+    bool TryGetFileBytes(uint regionId, uint fileId, ref byte[] bytes, out int bytesRead);
+
+    /// <summary>
+    /// The portal database
+    /// </summary>
+    IDatDatabase Portal { get; }
+
+    /// <summary>
+    /// The cell region databases. Each key is a cell region ID
+    /// </summary>
+    ReadOnlyDictionary<uint, IDatDatabase> CellRegions { get; }
+
+    /// <summary>
+    /// The high res database
+    /// </summary>
+    IDatDatabase HighRes { get; }
+
+    /// <summary>
+    /// The language database
+    /// </summary>
+    IDatDatabase Language { get; }
+
+    /// <summary>
+    /// A mapping of region ids to region dat file entry ids. key: region id, value: region dat file entry
+    /// </summary>
+    ReadOnlyDictionary<uint, uint> RegionFileMap { get; }
+
+    /// <summary>
+    /// Gets the current portal iteration.
+    /// </summary>
+    int PortalIteration { get; }
+
+    /// <summary>
+    /// Gets the current cell iteration (from the first cell region).
+    /// </summary>
+    int CellIteration { get; }
+
+    /// <summary>
+    /// Gets the current high res iteration.
+    /// </summary>
+    int HighResIteration { get; }
+
+    /// <summary>
+    /// Gets the current language iteration.
+    /// </summary>
+    int LanguageIteration { get; }
+
+    /// <summary>Attempts to save a database object to the appropriate DAT.</summary>
+    bool TrySave<T>(T obj, int iteration = 0) where T : IDBObj;
+
+    /// <summary>Attempts to save a database object to the appropriate DAT for a specific region.</summary>
+    bool TrySave<T>(uint regionId, T obj, int iteration = 0) where T : IDBObj;
+
+    /// <summary>
+    /// Resolution of a data ID to a database and type
+    /// </summary>
+    public record IdResolution(IDatDatabase Database, DBObjType Type);
+
+    /// <summary>
+    /// Resolves a data ID to all possible databases and types.
+    /// </summary>
+    public IEnumerable<IdResolution> ResolveId(uint id);
+}
+
+/// <summary>
+/// Interface for a dat database, providing methods to retrieve files and objects.
+/// </summary>
+public interface IDatDatabase : IDisposable {
+    DatDatabase Db { get; }
+
+    /// <summary>Retrieves the current iteration of the database.</summary>
+    int Iteration { get; }
+
+    /// <summary>Retrieves all file IDs of a specific type.</summary>
+    public IEnumerable<uint> GetAllIdsOfType<T>() where T : IDBObj;
+
+    /// <summary>Attempts to retrieve a database object by its file ID.</summary>
+    public bool TryGet<T>(uint fileId, [MaybeNullWhen(false)] out T value) where T : IDBObj;
+
+    /// <summary>Attempts to retrieve the raw bytes of a file by its ID.</summary>
+    bool TryGetFileBytes(uint fileId, [MaybeNullWhen(false)] out byte[] value);
+
+    /// <summary>Attempts to retrieve the raw bytes of a file by its ID into a provided buffer.</summary>
+    bool TryGetFileBytes(uint fileId, ref byte[] bytes, out int bytesRead);
+
+    /// <summary>Attempts to save a database object.</summary>
+    bool TrySave<T>(T obj, int iteration = 0) where T : IDBObj;
+}

src/AcDream.App/Rendering/Wb/ManagedGLIndexBuffer.cs

@@ -1,6 +1,5 @@
 using Chorizite.Core.Render.Enums;
 using Chorizite.Core.Render.Vertex;
-using Chorizite.OpenGLSDLBackend.Lib;
 using Silk.NET.OpenGL;
 using BufferUsage = Chorizite.Core.Render.Enums.BufferUsage;
 
@@ -158,7 +157,7 @@ namespace AcDream.App.Rendering.Wb {
 
         /// <inheritdoc />
         public void Bind() {
-            BaseObjectRenderManager.CurrentIBO = 0;
+            RenderStateCache.CurrentIBO = 0;
             GL.BindBuffer(GLEnum.ElementArrayBuffer, bufferId);
             GLHelpers.CheckErrors(GL);
         }

src/AcDream.App/Rendering/Wb/ManagedGLTexture.cs

@@ -1,6 +1,5 @@
 using Chorizite.Core.Render;
 using Chorizite.Core.Render.Enums;
-using Chorizite.OpenGLSDLBackend.Lib;
 using Silk.NET.OpenGL;
 
 namespace AcDream.App.Rendering.Wb {
@@ -108,7 +107,7 @@ namespace AcDream.App.Rendering.Wb {
             GLHelpers.CheckErrors(GL);
 
             GL.GetInteger(GLEnum.ActiveTexture, out int oldActiveTexture);
-            BaseObjectRenderManager.CurrentAtlas = 0;
+            RenderStateCache.CurrentAtlas = 0;
 
             GL.GetInteger(GLEnum.TextureBinding2D, out int oldBinding);
             GL.BindTexture(GLEnum.Texture2D, _texture);
@@ -147,7 +146,7 @@ namespace AcDream.App.Rendering.Wb {
 
         public void Bind(int slot = 0) {
             if (slot == 0) {
-                BaseObjectRenderManager.CurrentAtlas = 0;
+                RenderStateCache.CurrentAtlas = 0;
             }
             GL.GetInteger(GLEnum.ActiveTexture, out int oldActiveTexture);
             GLEnum targetTextureUnit = GLEnum.Texture0 + slot;

src/AcDream.App/Rendering/Wb/ManagedGLTextureArray.cs

@@ -1,7 +1,6 @@
 using AcDream.Core.Rendering.Wb;
 using Chorizite.Core.Render;
 using Chorizite.Core.Render.Enums;
-using Chorizite.OpenGLSDLBackend.Lib;
 // Use our extracted TextureHelpers (T3), not the WB original — disambiguate explicitly
 using TextureHelpers = AcDream.Core.Rendering.Wb.TextureHelpers;
 using Microsoft.Extensions.Logging;
@@ -274,7 +273,7 @@ namespace AcDream.App.Rendering.Wb {
             GLHelpers.CheckErrors(GL);
 
             GL.GetInteger(GLEnum.ActiveTexture, out int oldActiveTexture);
-            BaseObjectRenderManager.CurrentAtlas = 0;
+            RenderStateCache.CurrentAtlas = 0;
 
             GL.GetInteger(GLEnum.TextureBinding2DArray, out int oldBinding);
             GL.BindTexture(GLEnum.Texture2DArray, (uint)NativePtr);

src/AcDream.App/Rendering/Wb/ObjectMeshManager.cs

@@ -15,7 +15,6 @@ using System.Numerics;
 using System.Runtime.InteropServices;
 using System.Threading;
 using System.Threading.Tasks;
-using WorldBuilder.Shared.Services;
 using AcDream.Core.Rendering.Wb;
 using PixelFormat = Silk.NET.OpenGL.PixelFormat;
 using BoundingBox = Chorizite.Core.Lib.BoundingBox;
@@ -24,7 +23,6 @@ using BCnEncoder.Shared;
 using BCnEncoder.ImageSharp;
 using SixLabors.ImageSharp;
 using SixLabors.ImageSharp.PixelFormats;
-using WorldBuilder.Shared.Lib;
 
 namespace AcDream.App.Rendering.Wb {
     /// <summary>

src/AcDream.App/Rendering/Wb/ParticleBatcher.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Numerics;
 using System.Runtime.InteropServices;
 using Chorizite.Core.Render;
-using Chorizite.OpenGLSDLBackend.Lib;
 using Silk.NET.OpenGL;
 
 namespace AcDream.App.Rendering.Wb {
@@ -187,9 +186,7 @@ namespace AcDream.App.Rendering.Wb {
 
                     gl.ActiveTexture(TextureUnit.Texture0);
                     gl.BindTexture(GLEnum.Texture2DArray, (uint)_currentAtlas.NativePtr);
-                    // T4 interim: BaseObjectRenderManager state fields stay on the WB type until T7
-                    // when the WorldBuilder project reference is dropped entirely.
-                    BaseObjectRenderManager.CurrentAtlas = (uint)_currentAtlas.Slot;
+                    RenderStateCache.CurrentAtlas = (uint)_currentAtlas.Slot;
 
                     gl.BindBuffer(BufferTargetARB.ArrayBuffer, _instanceVbo);
                     unsafe {
@@ -210,9 +207,8 @@ namespace AcDream.App.Rendering.Wb {
             gl.DepthMask(true);
             _allParticles.Clear();
 
-            // T4 interim: BaseObjectRenderManager state fields stay on the WB type until T7
-            BaseObjectRenderManager.CurrentVAO = 0;
-            BaseObjectRenderManager.CurrentIBO = 0;
+            RenderStateCache.CurrentVAO = 0;
+            RenderStateCache.CurrentIBO = 0;
         }
 
         public void End() {

src/AcDream.App/Rendering/Wb/RenderStateCache.cs

@@ -0,0 +1,20 @@
+namespace AcDream.App.Rendering.Wb;
+
+/// <summary>
+/// Tracks currently-bound GL state to skip redundant rebinds across the
+/// WB-derived render path. Previously these were static fields on
+/// <c>BaseObjectRenderManager</c> in the WorldBuilder.Shared project; inlined
+/// here in Phase O-T7 to eliminate the WorldBuilder project reference.
+///
+/// Semantics are identical to the WB originals:
+///   <c>CurrentAtlas</c>  — slot index of the currently bound texture atlas.
+///   <c>CurrentVAO</c>    — OpenGL name of the currently bound vertex array object.
+///   <c>CurrentIBO</c>    — OpenGL name of the currently bound index buffer object.
+/// Sentinel value 0 means "no valid binding cached."
+/// </summary>
+public static class RenderStateCache
+{
+    public static uint CurrentAtlas = 0;
+    public static uint CurrentVAO   = 0;
+    public static uint CurrentIBO   = 0;
+}

src/AcDream.App/Rendering/Wb/WbDrawDispatcher.cs

@@ -6,7 +6,6 @@ using AcDream.Core.Meshing;
 using AcDream.Core.Rendering;
 using AcDream.Core.Terrain;
 using AcDream.Core.World;
-using Chorizite.OpenGLSDLBackend.Lib;
 using Silk.NET.OpenGL;
 
 namespace AcDream.App.Rendering.Wb;

src/AcDream.App/Rendering/Wb/WbMeshAdapter.cs

@@ -1,16 +1,12 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Threading.Tasks;
 using AcDream.Core.Meshing;
 using AcDream.Core.Rendering;
-using Chorizite.OpenGLSDLBackend.Lib;
 using DatReaderWriter;
 using DatReaderWriter.DBObjs;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
 using Silk.NET.OpenGL;
-using WorldBuilder.Shared.Services;
 
 namespace AcDream.App.Rendering.Wb;
 
@@ -20,30 +16,19 @@ namespace AcDream.App.Rendering.Wb;
 /// so the rest of the renderer doesn't need to know about WB's types directly.
 ///
 /// <para>
-/// The adapter constructs its own <c>DefaultDatReaderWriter</c> internally; it
-/// does NOT share file handles with our <c>DatCollection</c>. This duplicates
-/// index-cache memory (~50–100 MB) but keeps the two subsystems fully decoupled.
-/// Acceptable for Phase N.4 foundation work (plan Adjustment 1).
+/// As of Phase O-T7, all DAT I/O routes through <see cref="DatCollectionAdapter"/>
+/// (backed by our shared <see cref="DatCollection"/>) — the separate
+/// <c>DefaultDatReaderWriter</c> file-handle set has been removed.
 /// </para>
 /// </summary>
 public sealed class WbMeshAdapter : IDisposable, IWbMeshAdapter
 {
     private readonly OpenGLGraphicsDevice? _graphicsDevice;
-    private readonly DefaultDatReaderWriter? _wbDats;
     private readonly ObjectMeshManager? _meshManager;
     private readonly DatCollection? _dats;
     private readonly AcSurfaceMetadataTable _metadataTable = new();
     private readonly HashSet<ulong> _metadataPopulated = new();
 
-    /// <summary>
-    /// EnvCell ids we've requested via PrepareMeshDataAsync but not yet
-    /// seen completion for in Tick(). Used by the [indoor-upload] probe
-    /// to log requested + completed pairs. Cleared per completion;
-    /// missing completions after a few seconds indicate WB silently
-    /// returned null (hypothesis H1 in the design spec).
-    /// </summary>
-    private readonly HashSet<ulong> _pendingEnvCellRequests = new();
-
     /// <summary>
     /// True when this instance was created via <see cref="CreateUninitialized"/>;
     /// all public methods no-op when uninitialized.
@@ -53,13 +38,13 @@ public sealed class WbMeshAdapter : IDisposable, IWbMeshAdapter
     private bool _disposed;
 
     /// <summary>
-    /// Constructs the full WB pipeline: OpenGLGraphicsDevice → DefaultDatReaderWriter
+    /// Constructs the full WB pipeline: OpenGLGraphicsDevice → DatCollectionAdapter
     /// → ObjectMeshManager.
     /// </summary>
     /// <param name="gl">Active Silk.NET GL context. Must be bound to the current
     /// thread (construction runs GL queries; call from OnLoad).</param>
-    /// <param name="datDir">Path to the dat directory (same as the one supplied
-    /// to our DatCollection). DefaultDatReaderWriter opens its own file handles.</param>
+    /// <param name="datDir">Path to the dat directory. Retained for API compatibility;
+    /// DatCollectionAdapter routes all DAT I/O through our shared DatCollection.</param>
     /// <param name="dats">acdream's DatCollection, used to populate the surface
     /// metadata side-table via <c>GfxObjMesh.Build</c>. Shares file handles with
     /// the rest of the client; read-only access from the render thread.</param>
@@ -75,12 +60,8 @@ public sealed class WbMeshAdapter : IDisposable, IWbMeshAdapter
         _dats = dats;
         _graphicsDevice = new OpenGLGraphicsDevice(gl, logger, new DebugRenderSettings());
         _graphicsDevice.ParticleBatcher = new ParticleBatcher(_graphicsDevice);
-        _wbDats = new DefaultDatReaderWriter(datDir);
-        // Phase 2 diagnostic — replace NullLogger with a Console-backed
-        // logger so WB's internal catch block at ObjectMeshManager.cs:589
-        // (and similar) surfaces its swallowed exceptions instead of
-        // dropping them. ConsoleErrorLogger filters to LogLevel.Error+
-        // so successful operations stay quiet.
+        // ConsoleErrorLogger surfaces WB's silently-caught exceptions
+        // (ObjectMeshManager.PrepareMeshData try/catch at line ~589).
         _meshManager = new ObjectMeshManager(
             _graphicsDevice,
             new DatCollectionAdapter(dats),
@@ -186,80 +167,7 @@ public sealed class WbMeshAdapter : IDisposable, IWbMeshAdapter
             // isSetup: false — acdream's MeshRefs already carry expanded
             // per-part GfxObj ids (0x01XXXXXX). WB's Setup-expansion path is
             // unused.
-            var prepTask = _meshManager.PrepareMeshDataAsync(id, isSetup: false);
-
-            // [indoor-upload] requested probe — only for EnvCell ids.
-            if (RenderingDiagnostics.IsEnvCellId(id) && RenderingDiagnostics.ProbeIndoorUploadEnabled)
-            {
-                bool hadRenderDataAtRequest = _meshManager.HasRenderData(id);
-                _pendingEnvCellRequests.Add(id);
-                Console.WriteLine($"[indoor-upload] requested cellId=0x{id:X8} hadRenderData={hadRenderDataAtRequest}");
-
-                // Phase 2 — surface what WB's catch block silently swallows.
-                // ObjectMeshManager.PrepareMeshData has a try/catch at line 589
-                // that calls _logger.LogError(ex, ...) — but we construct
-                // ObjectMeshManager with NullLogger.Instance so the log is
-                // dropped. This continuation captures the same data scoped to
-                // EnvCell ids only. Runs on ThreadPool; non-blocking. Zero cost
-                // when the probe is off.
-                ulong cellId = id;
-                _ = prepTask.ContinueWith(t =>
-                {
-                    if (t.IsFaulted && t.Exception is not null)
-                    {
-                        var ex = t.Exception.InnerException ?? t.Exception;
-                        var stack = (ex.StackTrace ?? "").Split('\n')
-                            .Take(3).Select(s => s.Trim()).Where(s => s.Length > 0);
-                        Console.WriteLine(
-                            $"[indoor-upload] FAILED cellId=0x{cellId:X8} " +
-                            $"exception={ex.GetType().Name}: {ex.Message} " +
-                            $"stack=[{string.Join(" | ", stack)}]");
-                    }
-                    else if (t.IsCompletedSuccessfully && t.Result is null)
-                    {
-                        // Phase 2 cause-narrowing: WB's PrepareMeshData can return
-                        // null for several reasons (ResolveId empty / TryGet<EnvCell>
-                        // failed / type Unknown). Cross-check against acdream's own
-                        // DatCollection — if WE find the cell but WB doesn't, the
-                        // divergence is between dat readers, not a missing record.
-                        bool ourCellFound = false;
-                        try
-                        {
-                            ourCellFound = _dats?.Cell.TryGet<DatReaderWriter.DBObjs.EnvCell>(
-                                (uint)cellId, out _) ?? false;
-                        }
-                        catch { /* swallow — this is best-effort diagnostic */ }
-
-                        int wbResolveCount = -1;
-                        string wbSelectedType = "none";
-                        bool wbDbTryGetEnvCell = false;
-                        bool wbDbIsPortal = false;
-                        try
-                        {
-                            var wbResolutions = _wbDats?.ResolveId((uint)cellId).ToList();
-                            wbResolveCount = wbResolutions?.Count ?? -1;
-                            if (wbResolutions is not null && wbResolutions.Count > 0)
-                            {
-                                var selected = wbResolutions
-                                    .OrderByDescending(r => r.Database == _wbDats!.Portal)
-                                    .First();
-                                wbSelectedType = selected.Type.ToString();
-                                wbDbIsPortal = selected.Database == _wbDats!.Portal;
-                                try { wbDbTryGetEnvCell = selected.Database.TryGet<DatReaderWriter.DBObjs.EnvCell>((uint)cellId, out _); } catch {}
-                            }
-                        }
-                        catch { /* swallow — best-effort */ }
-
-                        Console.WriteLine(
-                            $"[indoor-upload] NULL_RESULT cellId=0x{cellId:X8} " +
-                            $"ourCellDb.TryGet={ourCellFound} " +
-                            $"wbResolveId.Count={wbResolveCount} " +
-                            $"wbSelectedType={wbSelectedType} " +
-                            $"wbDbIsPortal={wbDbIsPortal} " +
-                            $"wbDbTryGet<EnvCell>={wbDbTryGetEnvCell}");
-                    }
-                }, TaskScheduler.Default);
-            }
+            _meshManager.PrepareMeshDataAsync(id, isSetup: false);
         }
     }
 
@@ -298,26 +206,7 @@ public sealed class WbMeshAdapter : IDisposable, IWbMeshAdapter
         _graphicsDevice!.ProcessGLQueue();
         while (_meshManager!.StagedMeshData.TryDequeue(out var meshData))
         {
-            // [indoor-upload] completed probe — check BEFORE upload so we
-            // see what WB actually produced (vertex counts, parts) before
-            // any post-upload mutation.
-            bool isPendingEnvCell = RenderingDiagnostics.ProbeIndoorUploadEnabled
-                && _pendingEnvCellRequests.Remove(meshData.ObjectId);
-
-            var renderData = _meshManager.UploadMeshData(meshData);
-
-            if (isPendingEnvCell)
-            {
-                int parts = meshData.SetupParts?.Count ?? 0;
-                bool hasGeom = meshData.EnvCellGeometry is not null;
-                int cellGeomVerts = meshData.EnvCellGeometry?.Vertices?.Length ?? 0;
-                bool uploadOk = renderData is not null;
-                Console.WriteLine(
-                    $"[indoor-upload] completed cellId=0x{meshData.ObjectId:X8} " +
-                    $"isSetup={meshData.IsSetup} parts={parts} " +
-                    $"hasEnvCellGeom={hasGeom} cellGeomVerts={cellGeomVerts} " +
-                    $"uploadOk={uploadOk}");
-            }
+            _meshManager.UploadMeshData(meshData);
         }
     }
 
@@ -342,7 +231,6 @@ public sealed class WbMeshAdapter : IDisposable, IWbMeshAdapter
         if (_disposed) return;
         _disposed = true;
         _meshManager?.Dispose();
-        _wbDats?.Dispose();
         _graphicsDevice?.Dispose();
     }
 }

src/AcDream.Core/AcDream.Core.csproj

@@ -8,6 +8,7 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="BCnEncoder.Net" Version="2.2.1" />
+    <PackageReference Include="Chorizite.Core" Version="0.0.18" />
     <PackageReference Include="Chorizite.DatReaderWriter" Version="2.1.7" />
     <PackageReference Include="Serilog" Version="4.0.2" />
   </ItemGroup>
@@ -18,13 +19,5 @@
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\AcDream.Plugin.Abstractions\AcDream.Plugin.Abstractions.csproj" />
-    <!-- Phase N: WorldBuilder is acdream's rendering + dat-handling base.
-         See docs/architecture/worldbuilder-inventory.md for the inventory of
-         what we use from WB vs port from retail decomp ourselves.
-         WorldBuilder.Shared = stateless helpers (TerrainUtils, TerrainEntry, RegionInfo).
-         Chorizite.OpenGLSDLBackend = render managers + SceneryHelpers + ParticleEmitterRenderer
-         (full GL pipeline; we currently use only the stateless SceneryHelpers from it). -->
-    <ProjectReference Include="..\..\references\WorldBuilder\WorldBuilder.Shared\WorldBuilder.Shared.csproj" />
-    <ProjectReference Include="..\..\references\WorldBuilder\Chorizite.OpenGLSDLBackend\Chorizite.OpenGLSDLBackend.csproj" />
   </ItemGroup>
 </Project>

tests/AcDream.Core.Tests/Terrain/SplitFormulaDivergenceTest.cs

@@ -1,168 +0,0 @@
-using AcDream.Core.Terrain;
-using Xunit;
-using Xunit.Abstractions;
-using WbTerrainUtils = WorldBuilder.Shared.Modules.Landscape.Lib.TerrainUtils;
-using WbCellSplitDirection = WorldBuilder.Shared.Modules.Landscape.Models.CellSplitDirection;
-
-namespace AcDream.Core.Tests.Terrain;
-
-/// <summary>
-/// Phase N.5b data-collection test: quantifies how often WB's
-/// <c>TerrainUtils.CalculateSplitDirection</c> disagrees with acdream's
-/// <c>TerrainBlending.CalculateSplitDirection</c> (which retail uses
-/// per <c>CLandBlockStruct::ConstructPolygons</c> at retail address
-/// <c>00531d10</c>; named-retail decomp lines 316042-316144 contain
-/// the exact constants <c>0x0CCAC033 / 0x6C1AC587 / 0x421BE3BD /
-/// 0x519B8F25</c>).
-///
-/// Sweeps every (lbX, lbY, cellX, cellY) tuple in the world map
-/// (255 x 255 landblocks x 64 cells = ~4.16M cells) and reports the
-/// disagreement rate, per-landblock worst case, and a few named
-/// representative landblocks. The number drives the Path A/B/C
-/// decision in the N.5b brainstorm:
-///   - Low disagreement &lt;5% : Path A's risk is bounded
-///   - Medium 5-20%          : Path B (fork-patch WB) preferred
-///   - High &gt;20%           : Path B/C strongly preferred
-/// </summary>
-public class SplitFormulaDivergenceTest
-{
-    private readonly ITestOutputHelper _out;
-
-    public SplitFormulaDivergenceTest(ITestOutputHelper output) => _out = output;
-
-    [Fact]
-    public void Quantify_RetailVsWb_DivergenceRate()
-    {
-        // Two divergence flavors are tracked simultaneously:
-        //
-        //   rawDisagree     : retail-enum != wb-enum                       (pure formula output)
-        //   diagonalDisagree: retail-actually-paints-diagonal !=
-        //                     wb-actually-paints-diagonal                  (effective geometry)
-        //
-        // The two differ because the enums are SEMANTICALLY INVERTED:
-        //   - acdream `CellSplitDirection.SWtoNE` -> renderer paints BL->TR
-        //     (SW-NE diagonal). Matches retail per AC2D Landblocks.cpp:400-412
-        //     where FSplitNESW=true wraps a TRIANGLE_FAN [BL, BR, TR, TL] =
-        //     diagonal BL-TR.
-        //   - WB `CellSplitDirection.SWtoNE` -> WB's TerrainGeometryGenerator
-        //     emits triangles {BL,TL,BR}+{BR,TL,TR} which share the BR-TL
-        //     diagonal (SE-NW direction). The enum name is misleading; what
-        //     WB actually draws is the OTHER diagonal.
-        //
-        // So the question "would WB's pipeline produce the same diagonals as
-        // retail's pipeline?" is answered by `diagonalDisagree`, not
-        // `rawDisagree`. If diagonalDisagree is near 0%, WB's formula +
-        // renderer happen to compose into a correct pipeline (despite the
-        // confusing labels). If diagonalDisagree is ~50%, the two pipelines
-        // truly diverge and Path A would visibly break terrain on every
-        // landblock.
-
-        const int lbCount = 255;
-        const int cellsPerSide = 8;
-        long totalCells = 0;
-        long rawDisagree = 0;
-        long diagonalDisagree = 0;
-
-        int worstLbDiag = 0;
-        uint worstLbX = 0, worstLbY = 0;
-        int bestLbDiag = 64;
-        uint bestLbX = 0, bestLbY = 0;
-
-        for (uint lbX = 0; lbX < lbCount; lbX++)
-        for (uint lbY = 0; lbY < lbCount; lbY++)
-        {
-            int lbDiagDisagree = 0;
-            for (uint cx = 0; cx < cellsPerSide; cx++)
-            for (uint cy = 0; cy < cellsPerSide; cy++)
-            {
-                bool retailEnumSWtoNE =
-                    TerrainBlending.CalculateSplitDirection(lbX, cx, lbY, cy)
-                    == CellSplitDirection.SWtoNE;
-                bool wbEnumSWtoNE =
-                    WbTerrainUtils.CalculateSplitDirection(lbX, cx, lbY, cy)
-                    == WbCellSplitDirection.SWtoNE;
-
-                // What diagonal each pipeline actually paints.
-                bool retailPaintsBLtoTR = retailEnumSWtoNE;            // direct mapping
-                bool wbPaintsBLtoTR     = !wbEnumSWtoNE;               // inverted mapping
-
-                totalCells++;
-                if (retailEnumSWtoNE != wbEnumSWtoNE) rawDisagree++;
-                if (retailPaintsBLtoTR != wbPaintsBLtoTR)
-                {
-                    diagonalDisagree++;
-                    lbDiagDisagree++;
-                }
-            }
-
-            if (lbDiagDisagree > worstLbDiag)
-            {
-                worstLbDiag = lbDiagDisagree;
-                worstLbX = lbX;
-                worstLbY = lbY;
-            }
-            if (lbDiagDisagree < bestLbDiag)
-            {
-                bestLbDiag = lbDiagDisagree;
-                bestLbX = lbX;
-                bestLbY = lbY;
-            }
-        }
-
-        double rawPct  = 100.0 * rawDisagree / totalCells;
-        double diagPct = 100.0 * diagonalDisagree / totalCells;
-
-        _out.WriteLine($"=== Phase N.5b — terrain split formula divergence ===");
-        _out.WriteLine($"Sweep:           {lbCount}x{lbCount} landblocks, {cellsPerSide*cellsPerSide} cells each");
-        _out.WriteLine($"Total cells:     {totalCells:N0}");
-        _out.WriteLine("");
-        _out.WriteLine($"RAW enum-output disagreement       : {rawDisagree,12:N0} ({rawPct:F2}%)");
-        _out.WriteLine($"  (compares retail-enum vs wb-enum, NOT what each system actually draws)");
-        _out.WriteLine("");
-        _out.WriteLine($"DIAGONAL-actually-painted disagreement: {diagonalDisagree,12:N0} ({diagPct:F2}%)");
-        _out.WriteLine($"  (compares retail-paints-BL->TR vs wb-paints-BL->TR; this is the");
-        _out.WriteLine($"   number that determines whether Path A visibly works)");
-        _out.WriteLine("");
-        _out.WriteLine($"Worst landblock (diagonal): 0x{worstLbX:X2}{worstLbY:X2} disagrees on {worstLbDiag}/64 cells ({100.0*worstLbDiag/64:F1}%)");
-        _out.WriteLine($"Best landblock  (diagonal): 0x{bestLbX:X2}{bestLbY:X2} disagrees on {bestLbDiag}/64 cells ({100.0*bestLbDiag/64:F1}%)");
-
-        // Specific landblocks of interest (per N.5b handoff representative set).
-        var representative = new (string name, uint lbX, uint lbY)[]
-        {
-            ("Holtburg town",  0xA9, 0xB0),
-            ("Holtburg LB 0xA9B1", 0xA9, 0xB1),
-            ("Foundry-area",   0x80, 0x80),
-            ("Cragstone",      0xCB, 0x99),
-            ("Direlands sample", 0xC0, 0x40),
-            ("MapOrigin 0x0000", 0x00, 0x00),
-            ("MapCorner 0xFEFE", 0xFE, 0xFE),
-            ("Mid-map 0x7F7F",   0x7F, 0x7F),
-            ("Subway dungeon LB 0x0185 outdoor part", 0x01, 0x85),
-        };
-
-        _out.WriteLine("");
-        _out.WriteLine("Representative landblocks (diagonal-actually-painted disagreement):");
-        foreach (var (name, lbX, lbY) in representative)
-        {
-            int dis = 0;
-            for (uint cx = 0; cx < 8; cx++)
-            for (uint cy = 0; cy < 8; cy++)
-            {
-                bool retailEnum = TerrainBlending.CalculateSplitDirection(lbX, cx, lbY, cy) == CellSplitDirection.SWtoNE;
-                bool wbEnum     = WbTerrainUtils.CalculateSplitDirection(lbX, cx, lbY, cy) == WbCellSplitDirection.SWtoNE;
-                bool retailPaintsBLtoTR = retailEnum;
-                bool wbPaintsBLtoTR     = !wbEnum;
-                if (retailPaintsBLtoTR != wbPaintsBLtoTR) dis++;
-            }
-            _out.WriteLine($"  0x{lbX:X2}{lbY:X2}  {dis,2}/64 cells disagree  ({100.0*dis/64:F1}%)  {name}");
-        }
-
-        // Soft-floor on the DIAGONAL comparison: if diagPct is near 0% the
-        // formulas are equivalent post-inversion (Path A would just work
-        // visually; the only "bug" is enum naming). If diagPct is well
-        // above 0%, Path A truly breaks terrain.
-        // Soft-ceiling: an inversion of inversion shouldn't push past ~70%.
-        Assert.True(diagPct >= 0 && diagPct <= 100,
-            $"Sanity: diagonal disagreement out of range (rate={diagPct:F2}%)");
-    }
-}