refactor(srp): move native scene feature registration into backend setup

docs/used/SRP_URP_NativeSceneFeatureRegistrationOwnershipPlan_2026-04-21_完成归档.md

@@ -0,0 +1,86 @@
+# SRP / URP Native Scene Feature Registration Ownership Plan
+
+## Background
+
+Current native gaussian splat / volumetric scene feature passes have already
+been lifted into a managed URP-facing wrapper layer:
+
+- `UniversalRendererData` owns the default feature list
+- managed URP records native scene features explicitly
+- native dispatch now uses stable `NativeSceneFeaturePassId`
+
+But one C++ ownership seam is still dirty:
+
+- `BuiltinForwardPipeline` constructor silently registers default native scene
+  feature passes
+- that means pipeline instantiation itself still decides which first-party
+  native scene features exist
+- the default backend asset / scene draw backend factory do not own that policy
+
+This keeps an avoidable hidden side effect inside the pipeline runtime object.
+
+## Goal
+
+Move default native scene feature registration out of
+`BuiltinForwardPipeline` construction and into explicit backend
+configuration/factory ownership.
+
+After this phase:
+
+- `BuiltinForwardPipeline` only owns execution/runtime state
+- default native scene feature availability is configured by
+  backend asset/factory code
+- default backend asset creation and default scene draw backend creation share
+  the same setup path
+
+## Scope
+
+### Step 1. Remove constructor-side feature registration
+
+- stop registering default scene features inside
+  `BuiltinForwardPipeline::BuiltinForwardPipeline()`
+
+### Step 2. Centralize configured builtin forward creation
+
+- introduce one explicit setup path for default builtin forward scene features
+- use that path from `BuiltinForwardPipelineAsset`
+- use that path from default scene draw backend creation / fallback creation
+
+### Step 3. Verify no behavior regression
+
+- rebuild old `XCEditor`
+- run old editor smoke until `SceneReady`
+
+## Non-goals
+
+- changing gaussian splat runtime logic
+- changing volumetric runtime logic
+- moving shadow runtime in this phase
+- deferred renderer work
+- editor / new_editor work
+
+## Exit Criteria
+
+- `BuiltinForwardPipeline` constructor no longer performs implicit native scene
+  feature registration
+- default builtin forward backend creation still exposes gaussian splat /
+  volumetric native features through the explicit factory path
+- old editor `XCEditor` Debug build passes
+- old editor smoke reaches `SceneReady`
+
+## Result
+
+Completed on 2026-04-21.
+
+- removed constructor-side default native scene feature registration from
+  `BuiltinForwardPipeline`
+- centralized configured builtin forward creation in
+  `BuiltinForwardSceneSetup`
+- routed builtin forward asset creation, default scene draw backend creation,
+  and host fallback creation through the same configured pipeline path
+
+## Verification
+
+- `cmake --build . --config Debug --target XCEditor`
+- old editor smoke passed
+- `SceneReady elapsed_ms=5493 first_frame_ms=614`

engine/src/Rendering/Internal/RenderPipelineFactory.cpp

@@ -5,6 +5,7 @@
 
 #include "Rendering/Execution/DirectionalShadowExecutionState.h"
 #include "Rendering/Pipelines/BuiltinForwardPipeline.h"
+#include "Rendering/Pipelines/Internal/BuiltinForwardSceneSetup.h"
 #include "Rendering/Pipelines/ManagedScriptableRenderPipelineAsset.h"
 #include "Rendering/Pipelines/ScriptableRenderPipelineHost.h"
 #include "Rendering/Passes/BuiltinDepthOnlyPass.h"
@@ -160,7 +161,14 @@ std::unique_ptr<SceneDrawBackend> CreateSceneDrawBackendFromAsset(
 }
 
 std::unique_ptr<SceneDrawBackend> CreateDefaultSceneDrawBackend() {
-    return std::make_unique<Pipelines::BuiltinForwardPipeline>();
+    if (std::unique_ptr<SceneDrawBackend> sceneDrawBackend =
+            TryCreateSceneDrawBackendFromAsset(
+                CreateDefaultPipelineBackendAsset());
+        sceneDrawBackend != nullptr) {
+        return sceneDrawBackend;
+    }
+
+    return Pipelines::Internal::CreateConfiguredBuiltinForwardPipeline();
 }
 
 } // namespace Internal

engine/src/Rendering/Pipelines/BuiltinForwardPipeline.cpp

@@ -6,9 +6,7 @@ namespace XCEngine {
 namespace Rendering {
 namespace Pipelines {
 
-BuiltinForwardPipeline::BuiltinForwardPipeline() {
-    Internal::RegisterBuiltinForwardSceneFeatures(m_forwardSceneFeatureHost);
-}
+BuiltinForwardPipeline::BuiltinForwardPipeline() = default;
 
 BuiltinForwardPipeline::~BuiltinForwardPipeline() {
     Shutdown();
@@ -28,7 +26,7 @@ SceneRenderFeaturePass* BuiltinForwardPipeline::GetForwardSceneFeaturePass(size_
 }
 
 std::unique_ptr<RenderPipeline> BuiltinForwardPipelineAsset::CreatePipeline() const {
-    return std::make_unique<BuiltinForwardPipeline>();
+    return Internal::CreateConfiguredBuiltinForwardPipeline();
 }
 
 } // namespace Pipelines

engine/src/Rendering/Pipelines/Internal/BuiltinForwardSceneSetup.cpp

@@ -2,7 +2,7 @@
 
 #include "Rendering/Features/BuiltinGaussianSplatPass.h"
 #include "Rendering/Features/BuiltinVolumetricPass.h"
-#include "Rendering/SceneRenderFeatureHost.h"
+#include "Rendering/Pipelines/BuiltinForwardPipeline.h"
 
 #include <memory>
 
@@ -11,9 +11,20 @@ namespace Rendering {
 namespace Pipelines {
 namespace Internal {
 
-void RegisterBuiltinForwardSceneFeatures(SceneRenderFeatureHost& featureHost) {
-    featureHost.AddFeaturePass(std::make_unique<Features::BuiltinGaussianSplatPass>());
-    featureHost.AddFeaturePass(std::make_unique<Features::BuiltinVolumetricPass>());
+void ConfigureBuiltinForwardPipeline(
+    BuiltinForwardPipeline& pipeline) {
+    pipeline.AddForwardSceneFeaturePass(
+        std::make_unique<Features::BuiltinGaussianSplatPass>());
+    pipeline.AddForwardSceneFeaturePass(
+        std::make_unique<Features::BuiltinVolumetricPass>());
+}
+
+std::unique_ptr<BuiltinForwardPipeline>
+CreateConfiguredBuiltinForwardPipeline() {
+    std::unique_ptr<BuiltinForwardPipeline> pipeline =
+        std::make_unique<BuiltinForwardPipeline>();
+    ConfigureBuiltinForwardPipeline(*pipeline);
+    return pipeline;
 }
 
 } // namespace Internal

engine/src/Rendering/Pipelines/Internal/BuiltinForwardSceneSetup.h

@@ -1,14 +1,19 @@
 #pragma once
 
+#include <memory>
+
 namespace XCEngine {
 namespace Rendering {
 
-class SceneRenderFeatureHost;
-
 namespace Pipelines {
+class BuiltinForwardPipeline;
+
 namespace Internal {
 
-void RegisterBuiltinForwardSceneFeatures(SceneRenderFeatureHost& featureHost);
+void ConfigureBuiltinForwardPipeline(
+    BuiltinForwardPipeline& pipeline);
+std::unique_ptr<BuiltinForwardPipeline>
+CreateConfiguredBuiltinForwardPipeline();
 
 } // namespace Internal
 } // namespace Pipelines

engine/src/Rendering/Pipelines/ScriptableRenderPipelineHost.cpp

@@ -3,6 +3,7 @@
 #include "Rendering/Execution/DirectionalShadowExecutionState.h"
 #include "Rendering/Internal/RenderPipelineFactory.h"
 #include "Rendering/Pipelines/BuiltinForwardPipeline.h"
+#include "Rendering/Pipelines/Internal/BuiltinForwardSceneSetup.h"
 #include "Rendering/Pipelines/ManagedScriptableRenderPipelineAsset.h"
 #include "Rendering/Passes/BuiltinDepthOnlyPass.h"
 #include "Rendering/Passes/BuiltinObjectIdPass.h"
@@ -30,7 +31,7 @@ std::unique_ptr<RenderPipelineBackend> CreatePipelineBackendFromAsset(
         }
     }
 
-    return std::make_unique<BuiltinForwardPipeline>();
+    return Internal::CreateConfiguredBuiltinForwardPipeline();
 }
 
 } // namespace