Return struct values by output pointer for C API compatibility (#765)

Change these methods to return values by reference (output pointer)
instead of by value:
- ITopLevelAS::GetBuildInfo
- ITopLevelAS::GetScratchBufferSizes
- IBottomLevelAS::GetScratchBufferSizes
- IEngineFactoryVk::GetVulkanVersion

Author: TheMostDiligent

Graphics/GraphicsEngine/include/BottomLevelASBase.hpp

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2022 Diligent Graphics LLC
+ *  Copyright 2019-2026 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -176,7 +176,7 @@ class BottomLevelASBase : public DeviceObjectBase<typename EngineImplTraits::Bot
     }
 
     /// Implementation of IBottomLevelAS::GetScratchBufferSizes()
-    virtual ScratchBufferSizes DILIGENT_CALL_TYPE GetScratchBufferSizes() const override final
+    virtual const ScratchBufferSizes& DILIGENT_CALL_TYPE GetScratchBufferSizes() const override final
     {
         return this->m_ScratchSize;
     }

Graphics/GraphicsEngine/include/TopLevelASBase.hpp

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2025 Diligent Graphics LLC
+ *  Copyright 2019-2026 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -266,7 +266,7 @@ class TopLevelASBase : public DeviceObjectBase<typename EngineImplTraits::TopLev
     }
 
     /// Implementation of ITopLevelAS::GetBuildInfo().
-    virtual TLASBuildInfo DILIGENT_CALL_TYPE GetBuildInfo() const override final
+    virtual const TLASBuildInfo& DILIGENT_CALL_TYPE GetBuildInfo() const override final
     {
         return m_BuildInfo;
     }
@@ -286,7 +286,7 @@ class TopLevelASBase : public DeviceObjectBase<typename EngineImplTraits::TopLev
     }
 
     /// Implementation of ITopLevelAS::GetScratchBufferSizes().
-    virtual ScratchBufferSizes DILIGENT_CALL_TYPE GetScratchBufferSizes() const override final
+    virtual const ScratchBufferSizes& DILIGENT_CALL_TYPE GetScratchBufferSizes() const override final
     {
         return this->m_ScratchSize;
     }

Graphics/GraphicsEngine/interface/BottomLevelAS.h

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2025 Diligent Graphics LLC
+ *  Copyright 2019-2026 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -321,7 +321,7 @@ DILIGENT_BEGIN_INTERFACE(IBottomLevelAS, IDeviceObject)
     /// Returns the scratch buffer info for the current acceleration structure.
 
     /// \return ScratchBufferSizes object, see Diligent::ScratchBufferSizes.
-    VIRTUAL ScratchBufferSizes METHOD(GetScratchBufferSizes)(THIS) CONST PURE;
+    VIRTUAL const ScratchBufferSizes REF METHOD(GetScratchBufferSizes)(THIS) CONST PURE;
 
 
     /// Returns the native acceleration structure handle specific to the underlying graphics API

Graphics/GraphicsEngine/interface/TopLevelAS.h

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2025 Diligent Graphics LLC
+ *  Copyright 2019-2026 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -180,13 +180,13 @@ DILIGENT_BEGIN_INTERFACE(ITopLevelAS, IDeviceObject)
     /// \return TLASBuildInfo object, see Diligent::TLASBuildInfo.
     ///
     /// \note Access to the TLAS must be externally synchronized.
-    VIRTUAL TLASBuildInfo METHOD(GetBuildInfo)(THIS) CONST PURE;
+    VIRTUAL const TLASBuildInfo REF METHOD(GetBuildInfo)(THIS) CONST PURE;
 
 
     /// Returns scratch buffer info for the current acceleration structure.
 
     /// \return ScratchBufferSizes object, see Diligent::ScratchBufferSizes.
-    VIRTUAL ScratchBufferSizes METHOD(GetScratchBufferSizes)(THIS) CONST PURE;
+    VIRTUAL const ScratchBufferSizes REF METHOD(GetScratchBufferSizes)(THIS) CONST PURE;
 
 
     /// Returns native acceleration structure handle specific to the underlying graphics API

Graphics/GraphicsEngineVulkan/interface/EngineFactoryVk.h

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2025 Diligent Graphics LLC
+ *  Copyright 2019-2026 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -111,7 +111,7 @@ DILIGENT_BEGIN_INTERFACE(IEngineFactoryVk, IEngineFactory)
     /// Returns the supported Vulkan version. If Vulkan is not supported, returns 0.
 
     /// This function can be used to check whether Vulkan is supported on the platform.
-    VIRTUAL Version METHOD(GetVulkanVersion)(THIS) CONST PURE;
+    VIRTUAL const Version REF METHOD(GetVulkanVersion)(THIS) PURE;
 };
 DILIGENT_END_INTERFACE
 

Graphics/GraphicsEngineVulkan/src/EngineFactoryVk.cpp

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2025 Diligent Graphics LLC
+ *  Copyright 2019-2026 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -116,10 +116,14 @@ class EngineFactoryVkImpl final : public EngineFactoryBase<IEngineFactoryVk>
         m_EnableDeviceSimulation = true;
     }
 
-    virtual Version DILIGENT_CALL_TYPE GetVulkanVersion() const override final
+    virtual const Version& DILIGENT_CALL_TYPE GetVulkanVersion() override final
     {
-        uint32_t ApiVersion = VulkanUtilities::Instance::GetApiVersion();
-        return {VK_VERSION_MAJOR(ApiVersion), VK_VERSION_MINOR(ApiVersion)};
+        if (m_VulkanVersion == Version{})
+        {
+            uint32_t ApiVersion = VulkanUtilities::Instance::GetApiVersion();
+            m_VulkanVersion     = {VK_VERSION_MAJOR(ApiVersion), VK_VERSION_MINOR(ApiVersion)};
+        }
+        return m_VulkanVersion;
     }
 
     virtual void DILIGENT_CALL_TYPE CreateDearchiver(const DearchiverCreateInfo& CreateInfo,
@@ -140,7 +144,8 @@ class EngineFactoryVkImpl final : public EngineFactoryBase<IEngineFactoryVk>
     // To track that there is only one render device
     RefCntWeakPtr<IRenderDevice> m_wpDevice;
 
-    bool m_EnableDeviceSimulation = false;
+    bool    m_EnableDeviceSimulation = false;
+    Version m_VulkanVersion          = {};
 };
 
 

Tests/IncludeTest/GraphicsEngine/BottomLevelASH_test.c

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2022 Diligent Graphics LLC
+ *  Copyright 2019-2026 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -41,7 +41,7 @@ void TestBottomLevelAS_CInterface(IBottomLevelAS* pBLAS)
     Uint32 GeomCount = IBottomLevelAS_GetActualGeometryCount(pBLAS);
     (void)GeomCount;
 
-    ScratchBufferSizes ScratchSizes = IBottomLevelAS_GetScratchBufferSizes(pBLAS);
+    const ScratchBufferSizes* ScratchSizes = IBottomLevelAS_GetScratchBufferSizes(pBLAS);
     (void)ScratchSizes;
 
     Uint64 NativeHandle = IBottomLevelAS_GetNativeHandle(pBLAS);

Tests/IncludeTest/GraphicsEngine/TopLevelASH_test.c

@@ -1,5 +1,5 @@
 /*
- *  Copyright 2019-2022 Diligent Graphics LLC
+ *  Copyright 2019-2026 Diligent Graphics LLC
  *  Copyright 2015-2019 Egor Yusov
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -35,10 +35,10 @@ void TestTopLevelAS_CInterface(ITopLevelAS* pTLAS)
     TLASInstanceDesc InstDesc = ITopLevelAS_GetInstanceDesc(pTLAS, "Name");
     (void)InstDesc;
 
-    TLASBuildInfo BuildInfo = ITopLevelAS_GetBuildInfo(pTLAS);
+    const TLASBuildInfo* BuildInfo = ITopLevelAS_GetBuildInfo(pTLAS);
     (void)BuildInfo;
 
-    ScratchBufferSizes ScratchSizes = ITopLevelAS_GetScratchBufferSizes(pTLAS);
+    const ScratchBufferSizes* ScratchSizes = ITopLevelAS_GetScratchBufferSizes(pTLAS);
     (void)ScratchSizes;
 
     Uint64 Handle = ITopLevelAS_GetNativeHandle(pTLAS);