Formalize scene viewport transform gizmo overlay provider

editor/src/Viewport/SceneViewportOverlayProviders.cpp

@@ -450,6 +450,28 @@ public:
     }
 };
 
+class SceneViewportTransformGizmoOverlayProvider final : public ISceneViewportOverlayProvider {
+public:
+    const char* GetName() const override {
+        return "SceneViewportTransformGizmoOverlayProvider";
+    }
+
+    void AppendOverlay(
+        const SceneViewportOverlayBuildContext& context,
+        SceneViewportOverlayFrameData& frameData) const override {
+        if (!context.IsValid() ||
+            context.transformGizmoOverlayState == nullptr ||
+            !context.transformGizmoOverlayState->HasAnyVisibleGizmo()) {
+            return;
+        }
+
+        const SceneViewportTransformGizmoHandleBuildInputs inputs =
+            BuildSceneViewportTransformGizmoHandleBuildInputs(*context.transformGizmoOverlayState);
+        AppendTransformGizmoScreenTriangles(frameData, inputs);
+        AppendTransformGizmoHandleRecords(frameData, inputs);
+    }
+};
+
 } // namespace
 
 void SceneViewportOverlayProviderRegistry::AddProvider(
@@ -491,10 +513,15 @@ std::unique_ptr<ISceneViewportOverlayProvider> CreateSceneViewportLightOverlayPr
     return std::make_unique<SceneViewportLightOverlayProvider>();
 }
 
+std::unique_ptr<ISceneViewportOverlayProvider> CreateSceneViewportTransformGizmoOverlayProvider() {
+    return std::make_unique<SceneViewportTransformGizmoOverlayProvider>();
+}
+
 SceneViewportOverlayProviderRegistry BuildDefaultSceneViewportOverlayProviderRegistry() {
     SceneViewportOverlayProviderRegistry registry;
     registry.AddProvider(CreateSceneViewportCameraOverlayProvider());
     registry.AddProvider(CreateSceneViewportLightOverlayProvider());
+    registry.AddProvider(CreateSceneViewportTransformGizmoOverlayProvider());
     return registry;
 }