HLSL->GLSL conerter: allowed providing null HLSL source code pointer in which case the source will be loaded from the input stream factory

2 files changed, 92 insertions, 4 deletions

diff --git a/Graphics/HLSL2GLSLConverterLib/include/HLSL2GLSLConverterImpl.h b/Graphics/HLSL2GLSLConverterLib/include/HLSL2GLSLConverterImpl.h
index 6da944b1..7dfd0c19 100644
--- a/Graphics/HLSL2GLSLConverterLib/include/HLSL2GLSLConverterImpl.h
+++ b/Graphics/HLSL2GLSLConverterLib/include/HLSL2GLSLConverterImpl.h
@@ -83,25 +83,70 @@ namespace Diligent
 
 namespace Diligent
 {
+    /// HLSL to GLSL shader source code converter implementation
     class HLSL2GLSLConverterImpl
     {
     public:
         static const HLSL2GLSLConverterImpl& GetInstance();
+
+        /// Conversion attributes
         struct ConversionAttribs
         {
+            /// Shader source input stream factory. Used to load shader source when HLSLSource is null as
+            /// well as to load shader includes.
             IShaderSourceInputStreamFactory*    pSourceStreamFactory       = nullptr;
+
+            /// Optional pointer to a conversion stream.
             IHLSL2GLSLConversionStream**        ppConversionStream         = nullptr;
+
+            /// HLSL source code. Can be null, in which case the source code will be loaded from the
+            /// input stream factory (that must not be null in this case) using InputFileName.
             const Char*                         HLSLSource                 = nullptr;
+
+            /// Number of symbols in HLSLSource string. Ignored if HLSLSource is null.
             size_t                              NumSymbols                 = 0;
+
+            /// Shader entry point.
             const Char*                         EntryPoint                 = nullptr;
+
+            /// Shader type. See Diligent::SHADER_TYPE.
             SHADER_TYPE                         ShaderType                 = SHADER_TYPE_UNKNOWN;
+
+            /// Whether to include GLSL definitions supporting HLSL->GLSL conversion.
             bool                                IncludeDefinitions         = false;
+
+            /// Input file name. If HLSLSource is not null, this name will only be used for
+            /// information purposes. If HLSLSource is null, the name will be used to load
+            /// shader source from the input stream factory.
             const Char*                         InputFileName              = nullptr;
+
+            /// Combined texture sampler suffix.
             const Char*                         SamplerSuffix              = "_sampler";
+
+            /// Whether to use in-out location qualifiers. 
+            /// This requires separate shader objects extension:
+            /// https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_separate_shader_objects.txt
             bool                                UseInOutLocationQualifiers = true;
         };
 
+        /// Converts HLSL source to GLSL
+
+        /// \param [in] Attribs - Conversion attributes.
+        /// \return     Converted GLSL source code.
         String Convert(ConversionAttribs&                  Attribs)const;
+
+        /// Creates a conversion stream
+
+        /// \param [in] InputFileName - Input file name. If HLSLSource is null, this name will be
+        ///                             used to load shader source code from the input stream factory.
+        ///                             If HLSLSource is not null, the name will only be used for information
+        ///                             purposes.
+        /// \param [in] pSourceStreamFactory - Input stream factory that is used to load shader includes as well
+        ///                                    as to load the shader source code if HLSLSource is null.
+        /// \param [in] HLSLSource    - HLSL source code. If this parameter is null, the source will be loaded from
+        ///                             the input stream factory using InputFileName.
+        /// \param [in] NumSymbols    - Number of symbols in the HLSLSource string
+        /// \prarm [out] ppStream     - Memory address where pointer to the created stream will be written
         void CreateStream(const Char*                      InputFileName,
                           IShaderSourceInputStreamFactory* pSourceStreamFactory, 
                           const Char*                      HLSLSource, 
@@ -213,7 +258,23 @@ namespace Diligent
         class ConversionStream : public ObjectBase<IHLSL2GLSLConversionStream>
         {
         public:
-            typedef ObjectBase<IHLSL2GLSLConversionStream> TBase;
+            using TBase = ObjectBase<IHLSL2GLSLConversionStream>;
+
+            /// Conversion stream constructor.
+
+            /// \param [in] pRefCounters  - Pointer to a reference counters object
+            /// \param [in] Converter     - Reference to HLSL2GLSLConverterImpl class instance
+            /// \param [in] InputFileName - Input file name. If HLSLSource is null, this name will be
+            ///                             used to load shader source code from the input stream factory.
+            ///                             If HLSLSource is not null, the name will only be used for information
+            ///                             purposes.
+            /// \param [in] pInputStreamFactory - Input stream factory that is used to load shader includes as well
+            ///                                   as to load the shader source code if HLSLSource is null.
+            /// \param [in] HLSLSource    - HLSL source code. If this parameter is null, the source will be loaded from
+            ///                             the input stream factory using InputFileName.
+            /// \param [in] NumSymbols    - Number of symbols in the HLSLSource string
+            /// \param [in] bPreserveTokens - Whether to preserve original tokens. This must be set to true if the stream
+            ///                               will be used for multiple conversions.
             ConversionStream(IReferenceCounters*              pRefCounters, 
                              const HLSL2GLSLConverterImpl&    Converter, 
                              const char*                      InputFileName,
diff --git a/Graphics/HLSL2GLSLConverterLib/src/HLSL2GLSLConverterImpl.cpp b/Graphics/HLSL2GLSLConverterLib/src/HLSL2GLSLConverterImpl.cpp
index 346cfbcf..db4fe2ae 100644
--- a/Graphics/HLSL2GLSLConverterLib/src/HLSL2GLSLConverterImpl.cpp
+++ b/Graphics/HLSL2GLSLConverterLib/src/HLSL2GLSLConverterImpl.cpp
@@ -4407,6 +4407,26 @@ HLSL2GLSLConverterImpl::ConversionStream::ConversionStream(IReferenceCounters*
     m_Converter                   (Converter),
     m_InputFileName               (InputFileName != nullptr ? InputFileName : "<Unknown>")
 {
+    RefCntAutoPtr<IDataBlob> pFileData;
+    if (HLSLSource == nullptr)
+    {
+        if (InputFileName == nullptr)
+            LOG_ERROR_AND_THROW("Input file name must not be null when HLSL source code is not provided");
+
+        if (pInputStreamFactory == nullptr)
+            LOG_ERROR_AND_THROW("Input stream factory must not be null when HLSL source code is not provided");
+        
+        RefCntAutoPtr<IFileStream> pSourceStream;
+        pInputStreamFactory->CreateInputStream(InputFileName, &pSourceStream);
+        if (pSourceStream == nullptr)
+            LOG_ERROR_AND_THROW("Failed to open shader source file ", InputFileName);
+
+        pFileData = MakeNewRCObj<DataBlobImpl>()(0);
+        pSourceStream->Read(pFileData);
+        HLSLSource = reinterpret_cast<char*>(pFileData->GetDataPtr());
+        NumSymbols = pFileData->GetSize();
+    }
+
     String Source(HLSLSource, NumSymbols);
 
     InsertIncludes( Source, pInputStreamFactory );
@@ -4419,8 +4439,15 @@ String HLSL2GLSLConverterImpl::Convert(ConversionAttribs& Attribs)const
 {
     if (Attribs.ppConversionStream == nullptr)
     {
-        ConversionStream Stream(nullptr, *this, Attribs.InputFileName, Attribs.pSourceStreamFactory, Attribs.HLSLSource, Attribs.NumSymbols, false);
-        return Stream.Convert(Attribs.EntryPoint, Attribs.ShaderType, Attribs.IncludeDefinitions, Attribs.SamplerSuffix, Attribs.UseInOutLocationQualifiers);
+        try
+        {
+            ConversionStream Stream(nullptr, *this, Attribs.InputFileName, Attribs.pSourceStreamFactory, Attribs.HLSLSource, Attribs.NumSymbols, false);
+            return Stream.Convert(Attribs.EntryPoint, Attribs.ShaderType, Attribs.IncludeDefinitions, Attribs.SamplerSuffix, Attribs.UseInOutLocationQualifiers);
+        }
+        catch(std::runtime_error&)
+        {
+            return "";
+        }
     }
     else
     {
@@ -4428,7 +4455,7 @@ String HLSL2GLSLConverterImpl::Convert(ConversionAttribs& Attribs)const
         if (*Attribs.ppConversionStream != nullptr)
         {
             pStream = ValidatedCast<ConversionStream>(*Attribs.ppConversionStream);
-            const auto &FileNameFromStream = pStream->GetInputFileName();
+            const auto& FileNameFromStream = pStream->GetInputFileName();
             if (FileNameFromStream != Attribs.InputFileName)
             {
                 LOG_WARNING_MESSAGE("Input stream was initialized for input file \"", FileNameFromStream, "\" that does not match the name of the file to be converted \"", Attribs.InputFileName, "\". New stream will be created");