Revert "feat(render): Campaign V slice V4d-2 - move terrain onto the RHI"

This reverts commit b064668b63.

src/AcDream.App/Composition/WorldRenderComposition.cs

@@ -32,6 +32,7 @@ internal sealed record WorldRenderFoundation(
     string ShadersDirectory,
     BindlessSupport Bindless,
     TerrainAtlas TerrainAtlas,
+    Shader TerrainShader,
     SceneLightingUboBinding SceneLighting,
     DebugLineRenderer DebugLines,
     BitmapFont? DebugFont,
@@ -61,6 +62,7 @@ internal sealed record WorldRenderDependencies(
 internal interface IGameWindowWorldRenderPublication
 {
     void PublishBindlessSupport(BindlessSupport value);
+    void PublishTerrainShader(Shader value);
     void PublishSceneLighting(SceneLightingUboBinding value);
     void PublishDebugLines(DebugLineRenderer value);
     void PublishHudResources(BitmapFont font, TextRenderer text);
@@ -87,6 +89,7 @@ internal interface IWorldRenderCompositionFactory
         IDatReaderWriter dats,
         BindlessSupport bindless);
     void SetTerrainAnisotropic(TerrainAtlas atlas, int level);
+    Shader CreateTerrainShader(GL gl, string shadersDirectory);
     SceneLightingUboBinding CreateSceneLighting(GL gl);
     DebugLineRenderer CreateDebugLines(
         AcDream.App.Rendering.Gpu.IGpuDevice device,
@@ -100,8 +103,8 @@ internal interface IWorldRenderCompositionFactory
         string shadersDirectory);
     TerrainModernRenderer CreateTerrain(
         GL gl,
-        AcDream.App.Rendering.Gpu.IGpuDevice device,
+        BindlessSupport bindless,
-        ICurrentGpuFrameSource frameSource,
+        Shader shader,
         TerrainAtlas atlas,
         IGpuResourceRetirementQueue retirement);
     WorldTerrainBuildContext CreateTerrainBuildContext(
@@ -212,6 +215,13 @@ internal sealed class RetailWorldRenderCompositionFactory
     public void SetTerrainAnisotropic(TerrainAtlas atlas, int level) =>
         atlas.SetAnisotropic(level);
 
+    public Shader CreateTerrainShader(GL gl, string shadersDirectory) =>
+        new(
+            gl,
+            Path.Combine(shadersDirectory, "terrain_modern.vert"),
+            Path.Combine(shadersDirectory, "terrain_modern.frag"),
+            includeCommonPreamble: true);
+
     public SceneLightingUboBinding CreateSceneLighting(GL gl) => new(gl);
 
     public DebugLineRenderer CreateDebugLines(
@@ -234,11 +244,11 @@ internal sealed class RetailWorldRenderCompositionFactory
 
     public TerrainModernRenderer CreateTerrain(
         GL gl,
-        AcDream.App.Rendering.Gpu.IGpuDevice device,
+        BindlessSupport bindless,
-        ICurrentGpuFrameSource frameSource,
+        Shader shader,
         TerrainAtlas atlas,
         IGpuResourceRetirementQueue retirement) =>
-        new(gl, device, frameSource, atlas, retirement);
+        new(gl, bindless, shader, atlas, retirement);
 
     public WorldTerrainBuildContext CreateTerrainBuildContext(
         uint initialCenterLandblockId,
@@ -386,6 +396,7 @@ internal enum WorldRenderCompositionPoint
     EnvironmentInitialized,
     BindlessPublished,
     TerrainAtlasAcquired,
+    TerrainShaderPublished,
     SceneLightingPublished,
     DebugLinesPublished,
     DebugFontCreated,
@@ -472,9 +483,12 @@ internal sealed class WorldRenderCompositionPhase
                 AppContext.BaseDirectory,
                 "Rendering",
                 "Shaders");
-            // Campaign V slice V4d: terrain no longer needs a Shader composed
+            Shader terrainShader = AcquireAndPublish(
-            // for it — its IGpuPipeline compiles terrain_modern itself, from
+                scope,
-            // the same sources with the same shared preamble.
+                "terrain shader",
+                () => _factory.CreateTerrainShader(gl, shadersDirectory),
+                _publication.PublishTerrainShader,
+                WorldRenderCompositionPoint.TerrainShaderPublished);
             SceneLightingUboBinding sceneLighting = AcquireAndPublish(
                 scope,
                 "scene lighting",
@@ -499,8 +513,8 @@ internal sealed class WorldRenderCompositionPhase
                 "terrain renderer",
                 () => _factory.CreateTerrain(
                     gl,
-                    _dependencies.GpuDevice,
+                    bindless,
-                    _dependencies.GpuFrameSource,
+                    terrainShader,
                     terrainAtlas,
                     _dependencies.ResourceRetirement),
                 _publication.PublishTerrain,
@@ -573,6 +587,7 @@ internal sealed class WorldRenderCompositionPhase
                     shadersDirectory,
                     bindless,
                     terrainAtlas,
+                    terrainShader,
                     sceneLighting,
                     debugLines,
                     debugFont,

src/AcDream.App/Rendering/GameWindow.cs

@@ -48,6 +48,9 @@ public sealed class GameWindow :
     private GL? _gl;
     private IInputContext? _input;
     private TerrainModernRenderer? _terrain;
+    /// <summary>Phase N.5b: terrain_modern.vert/.frag program. Owned by
+    /// <see cref="_terrain"/> at draw time but allocated + disposed here.</summary>
+    private Shader? _terrainModernShader;
     private CameraController? _cameraController;
     private IDatReaderWriter? _dats;
     private IPreparedAssetSource? _preparedAssets;
@@ -894,6 +897,12 @@ public sealed class GameWindow :
             value,
             "bindless support");
 
+    void IGameWindowWorldRenderPublication.PublishTerrainShader(Shader value) =>
+        PublishCompositionOwner(
+            ref _terrainModernShader,
+            value,
+            "terrain shader");
+
     void IGameWindowWorldRenderPublication.PublishSceneLighting(
         SceneLightingUboBinding value) =>
         PublishCompositionOwner(
@@ -1672,6 +1681,7 @@ public sealed class GameWindow :
             _wbMeshAdapter,
             _meshShader,
             _terrain,
+            _terrainModernShader,
             _sceneLightingUbo,
             _debugLines,
             _textRenderer,

src/AcDream.App/Rendering/GameWindowLifetime.cs

@@ -118,6 +118,7 @@ internal sealed record RenderShutdownRoots(
     WbMeshAdapter? MeshAdapter,
     Shader? MeshShader,
     TerrainModernRenderer? Terrain,
+    Shader? TerrainShader,
     SceneLightingUboBinding? SceneLighting,
     DebugLineRenderer? DebugLines,
     TextRenderer? TextRenderer,
@@ -454,6 +455,7 @@ internal static class GameWindowShutdownManifest
             [
                 Hard("mesh shader", () => render.MeshShader?.Dispose()),
                 Hard("terrain", () => render.Terrain?.Dispose()),
+                Hard("terrain shader", () => render.TerrainShader?.Dispose()),
                 Hard("scene lighting", () => render.SceneLighting?.Dispose()),
                 Hard("debug lines", () => render.DebugLines?.Dispose()),
                 Hard("text renderer", () => render.TextRenderer?.Dispose()),

src/AcDream.App/Rendering/Shaders/terrain_modern.frag

@@ -30,26 +30,15 @@ out vec4 fragColor;
 // Campaign V slice V2b (2026-07-27): uTerrainHandle/uAlphaHandle (uvec2, raw
 // ARB_bindless_texture handles) became uTextureIndexA/uTextureIndexB (slots
 // into the binding=9 handle table, ACDREAM_TEXTURE_HANDLE in common.glsl).
-// Named to match the pinned GpuPushConstants.TextureIndexA/B fields, so slice
+// Named to match the pinned GpuPushConstants.TextureIndexA/B fields so V4d's
-// V4d's move onto push constants was a rename rather than a redesign. The GL
+// move to push constants is a rename, not a redesign — there is no
-// backend maps each push-constant field to the correspondingly named uniform,
+// push-constant plumbing yet, so these stay plain uniforms for now.
-// which is why these stay declared exactly as they are.
 uniform uint uTextureIndexA;
 uniform uint uTextureIndexB;
+uniform float uTexTiling[36];
 #define uTerrain sampler2DArray(ACDREAM_TEXTURE_HANDLE(uTextureIndexA))
 #define uAlpha   sampler2DArray(ACDREAM_TEXTURE_HANDLE(uTextureIndexB))
 
-// Campaign V slice V4d: the per-layer tiling table moved out of a loose
-// `uniform float uTexTiling[36]` and into a uniform block at
-// GpuBindingModel.UniformTerrainTiling. At 144 bytes of payload it cannot ride
-// in the 96-byte GpuPushConstants block (nor Vulkan's guaranteed 128-byte
-// ceiling), and there is no RHI verb for setting a uniform array. std140 pads
-// each array element to 16 bytes, so the block is 576 bytes; the element type
-// is unchanged so uTexTiling[i] reads exactly as it did before.
-layout(std140, ACDREAM_UBO_SET binding = 3) uniform TerrainTiling {
-    float uTexTiling[36];
-};
-
 struct Light {
     vec4 posAndKind;
     vec4 dirAndRange;

tests/AcDream.App.Tests/Composition/WorldRenderCompositionTests.cs

@@ -90,11 +90,7 @@ public sealed class WorldRenderCompositionTests
     }
 
     [Theory]
-    // The "terrain shader" row went with Campaign V slice V4d: terrain's
+    [InlineData("terrain shader", "terrain shader")]
-    // IGpuPipeline compiles terrain_modern itself, so there is no longer a
-    // terrain-shader publication step for a failure to be injected into. The
-    // invariant this theory pins is unchanged and still covered by every row
-    // below.
     [InlineData("scene lighting", "scene lighting")]
     [InlineData("debug lines", "debug lines")]
     [InlineData("HUD", "text renderer|debug font")]
@@ -251,6 +247,9 @@ public sealed class WorldRenderCompositionTests
         public void SetTerrainAnisotropic(TerrainAtlas atlas, int level) =>
             AnisotropicLevel = level;
 
+        public Shader CreateTerrainShader(GL gl, string shadersDirectory) =>
+            Resource<Shader>("terrain shader");
+
         public SceneLightingUboBinding CreateSceneLighting(GL gl) =>
             Resource<SceneLightingUboBinding>("scene lighting");
 
@@ -269,8 +268,8 @@ public sealed class WorldRenderCompositionTests
 
         public TerrainModernRenderer CreateTerrain(
             GL gl,
-            IGpuDevice device,
+            BindlessSupport bindless,
-            ICurrentGpuFrameSource frameSource,
+            Shader shader,
             TerrainAtlas atlas,
             IGpuResourceRetirementQueue retirement) =>
             Resource<TerrainModernRenderer>("terrain");
@@ -351,6 +350,8 @@ public sealed class WorldRenderCompositionTests
 
         public void PublishBindlessSupport(BindlessSupport value) =>
             Fail("bindless");
+        public void PublishTerrainShader(Shader value) =>
+            Fail("terrain shader");
         public void PublishSceneLighting(SceneLightingUboBinding value) =>
             Fail("scene lighting");
         public void PublishDebugLines(DebugLineRenderer value) =>

tests/AcDream.App.Tests/Rendering/TerrainTextureTilingTableTests.cs

@@ -55,14 +55,7 @@ public sealed class TerrainTextureTilingTableTests
             "terrain_modern.frag");
         string shader = File.ReadAllText(shaderPath);
 
-        // Campaign V slice V4d moved the table out of a loose
+        Assert.Contains("uniform float uTexTiling[36];", shader);
-        // `uniform float uTexTiling[36]` and into a std140 block at
-        // GpuBindingModel.UniformTerrainTiling. The element type and count are
-        // what every sample site below depends on, so both are still pinned —
-        // and the binding number is now pinned too, because the shader and
-        // GpuBindingModel have to agree.
-        Assert.Contains("binding = 3) uniform TerrainTiling {", shader);
-        Assert.Contains("float uTexTiling[36];", shader);
         Assert.Contains("baseUV * terrainTiling(pOverlay0.z)", shader);
         Assert.Contains("baseUV * terrainTiling(pOverlay1.z)", shader);
         Assert.Contains("baseUV * terrainTiling(pOverlay2.z)", shader);