[hdSt] Refactor scene index plugin registration.

Hardcode input args in _AppendSceneIndex instead of registration.
This is part of a series of a changes to remove the use of inputArgs in the registration API as preparatory work to simplify scene index plugin registration in Hydra.

(Internal change: 2388899)

Author: rajabala

pxr/imaging/hdSt/implicitSurfaceSceneIndexPlugin.cpp

@@ -29,25 +29,10 @@ TF_REGISTRY_FUNCTION(HdSceneIndexPlugin)
 {
     const HdSceneIndexPluginRegistry::InsertionPhase insertionPhase = 0;
 
-    // Configure the scene index to generate the mesh for each of the implicit
-    // primitives since Storm doesn't natively support any.
-    HdDataSourceBaseHandle const toMeshSrc =
-        HdRetainedTypedSampledDataSource<TfToken>::New(
-            HdsiImplicitSurfaceSceneIndexTokens->toMesh);
-
-    HdContainerDataSourceHandle const inputArgs =
-        HdRetainedContainerDataSource::New(
-            HdPrimTypeTokens->sphere, toMeshSrc,
-            HdPrimTypeTokens->cube, toMeshSrc,
-            HdPrimTypeTokens->cone, toMeshSrc,
-            HdPrimTypeTokens->cylinder, toMeshSrc,
-            HdPrimTypeTokens->capsule, toMeshSrc,
-            HdPrimTypeTokens->plane, toMeshSrc);
-
     HdSceneIndexPluginRegistry::GetInstance().RegisterSceneIndexForRenderer(
         _pluginDisplayName,
         _tokens->sceneIndexPluginName,
-        inputArgs,
+        /* inputArgs = */ nullptr,
         insertionPhase,
         HdSceneIndexPluginRegistry::InsertionOrderAtStart);
 }
@@ -65,7 +50,27 @@ HdSt_ImplicitSurfaceSceneIndexPlugin::_AppendSceneIndex(
     const HdSceneIndexBaseRefPtr &inputScene,
     const HdContainerDataSourceHandle &inputArgs)
 {
-    return HdsiImplicitSurfaceSceneIndex::New(inputScene, inputArgs);
+    // Define inputArgs here instead of in the TF_REGISTRY_FUNCTION block.
+    // In the future, we may consider renaming the inputArgs parameter to
+    // something like "sceneIndexGraphCreateArgs" to allow the app and renderer
+    // plugin to provide arguments for scene indices instantiated via the
+    // scene index plugin system.
+       // Configure the scene index to generate the mesh for each of the implicit
+    // primitives since Storm doesn't natively support any.
+    HdDataSourceBaseHandle const toMeshSrc =
+        HdRetainedTypedSampledDataSource<TfToken>::New(
+            HdsiImplicitSurfaceSceneIndexTokens->toMesh);
+
+    HdContainerDataSourceHandle const localInputArgs =
+        HdRetainedContainerDataSource::New(
+            HdPrimTypeTokens->sphere, toMeshSrc,
+            HdPrimTypeTokens->cube, toMeshSrc,
+            HdPrimTypeTokens->cone, toMeshSrc,
+            HdPrimTypeTokens->cylinder, toMeshSrc,
+            HdPrimTypeTokens->capsule, toMeshSrc,
+            HdPrimTypeTokens->plane, toMeshSrc);
+
+    return HdsiImplicitSurfaceSceneIndex::New(inputScene, localInputArgs);
 }
 
 PXR_NAMESPACE_CLOSE_SCOPE

pxr/imaging/hdSt/unboundMaterialPruningSceneIndexPlugin.cpp

@@ -48,22 +48,10 @@ TF_REGISTRY_FUNCTION(HdSceneIndexPlugin)
     // scnee index.
     const HdSceneIndexPluginRegistry::InsertionPhase insertionPhase = 900;
 
-    const HdTokenArrayDataSourceHandle bindingPurposesDs =
-        HdRetainedTypedSampledDataSource<VtArray<TfToken>>::New(
-            VtArray<TfToken>({
-                HdTokens->preview,
-                HdMaterialBindingsSchemaTokens->allPurpose,
-            }));
-    
-    const HdContainerDataSourceHandle inputArgs =
-        HdRetainedContainerDataSource::New(
-            HdsiUnboundMaterialPruningSceneIndexTokens->materialBindingPurposes,
-            bindingPurposesDs);
-
     HdSceneIndexPluginRegistry::GetInstance().RegisterSceneIndexForRenderer(
         _pluginDisplayName,
         _tokens->sceneIndexPluginName,
-        inputArgs,
+        /* inputArgs = */ nullptr,
         insertionPhase,
         HdSceneIndexPluginRegistry::InsertionOrderAtStart);
 }
@@ -76,10 +64,29 @@ HdSt_UnboundMaterialPruningSceneIndexPlugin::_AppendSceneIndex(
     const HdSceneIndexBaseRefPtr &inputScene,
     const HdContainerDataSourceHandle &inputArgs)
 {
-    if (_IsEnabled()) {
-        return HdsiUnboundMaterialPruningSceneIndex::New(inputScene, inputArgs);
+    if (!_IsEnabled()) {
+        return inputScene;
     }
-    return inputScene;
+    
+    // Define inputArgs here instead of in the TF_REGISTRY_FUNCTION block.
+    // In the future, we may consider renaming the inputArgs parameter to
+    // something like "sceneIndexGraphCreateArgs" to allow the app and renderer
+    // plugin to provide arguments for scene indices instantiated via the
+    // scene index plugin system.
+    static const HdTokenArrayDataSourceHandle bindingPurposesDs =
+        HdRetainedTypedSampledDataSource<VtArray<TfToken>>::New(
+            VtArray<TfToken>({
+                HdTokens->preview,
+                HdMaterialBindingsSchemaTokens->allPurpose,
+            }));
+
+    static const HdContainerDataSourceHandle localInputArgs =
+        HdRetainedContainerDataSource::New(
+            HdsiUnboundMaterialPruningSceneIndexTokens->materialBindingPurposes,
+            bindingPurposesDs);
+    
+    return HdsiUnboundMaterialPruningSceneIndex::New(
+        inputScene, localInputArgs);
 }
 
 PXR_NAMESPACE_CLOSE_SCOPE

pxr/imaging/hdSt/velocityMotionResolvingSceneIndexPlugin.cpp

@@ -37,15 +37,11 @@ TF_REGISTRY_FUNCTION(HdSceneIndexPlugin)
 {
     // This one should go after implicit surface conversion
     static const HdSceneIndexPluginRegistry::InsertionPhase insertionPhase = 0;
-    const HdContainerDataSourceHandle inputArgs = 
-        HdRetainedContainerDataSource::New(
-            _tokens->fps,
-            // TODO: Get real framerate!
-            HdRetainedTypedSampledDataSource<float>::New(24.0));
+    
     HdSceneIndexPluginRegistry::GetInstance().RegisterSceneIndexForRenderer(
         _pluginDisplayName,
         _tokens->sceneIndexPluginName,
-        inputArgs,
+        /* inputArgs = */ nullptr, 
         insertionPhase,
         HdSceneIndexPluginRegistry::InsertionOrderAtEnd);
 }
@@ -58,7 +54,19 @@ HdSt_VelocityMotionResolvingSceneIndexPlugin::_AppendSceneIndex(
     const HdSceneIndexBaseRefPtr& inputScene,
     const HdContainerDataSourceHandle& inputArgs)
 {
-    return HdsiVelocityMotionResolvingSceneIndex::New(inputScene, inputArgs);
+    // Define inputArgs here instead of in the TF_REGISTRY_FUNCTION block.
+    // In the future, we may consider renaming the inputArgs parameter to
+    // something like "sceneIndexGraphCreateArgs" to allow the app and renderer
+    // plugin to provide arguments for scene indices instantiated via the
+    // scene index plugin system.
+    const HdContainerDataSourceHandle localInputArgs = 
+        HdRetainedContainerDataSource::New(
+            _tokens->fps,
+            // TODO: Get real framerate!
+            HdRetainedTypedSampledDataSource<float>::New(24.0));
+
+    return HdsiVelocityMotionResolvingSceneIndex::New(
+        inputScene, localInputArgs);
 }
 
 PXR_NAMESPACE_CLOSE_SCOPE