createOverridenCopy add position parameter and a new function for GLSLCompiler

Author: Erfan-Ahmadi

include/nbl/asset/utils/IGLSLCompiler.h

@@ -84,6 +84,28 @@ class NBL_API IGLSLCompiler final : public IShaderCompiler
 			system::logger_opt_ptr logger = nullptr,
 			const E_SPIRV_VERSION targetSpirvVersion = ESV_1_6) const;
 
+		/*
+		 If original code contains #version specifier,
+			then the filled fmt will be placed onto the next line after #version in the output buffer. If not, fmt will be placed into the
+			beginning of the output buffer.
+		*/
+		template<typename... Args>
+		static core::smart_refctd_ptr<ICPUShader> createOverridenCopy(const ICPUShader* original, const char* fmt, Args... args)
+		{
+			uint32_t position = 0u;
+			if (original != nullptr)
+			{
+				auto origCodeBuffer = original->getContent();
+				auto origCode = std::string_view(reinterpret_cast<const char*>(origCodeBuffer->getPointer()), origCodeBuffer->getSize());
+				auto start = origCode.find("#version");
+				auto end = origCode.find("\n", start);
+				if (end != std::string_view::npos)
+					position = end + 1u;
+			}
+
+			return IShaderCompiler::createOverridenCopy(original, position, fmt, args...);
+		}
+
 		static inline const char* getStorageImageFormatQualifier(const asset::E_FORMAT format)
 		{
 			switch (format)

include/nbl/asset/utils/IShaderCompiler.h

@@ -55,16 +55,15 @@ class NBL_API IShaderCompiler : public core::IReferenceCounted
 			Creates a formatted copy of the original
 
 			@param original An original High Level shader (must contain high level language code and must not be a nullptr).
+			@param position if original != nullptr, is the position in the code to insert the formatted string to the original shader code
 			@param fmt A string with c-like format, which will be filled with data from ...args
 			@param ...args Data to fill fmt with
 			@returns shader containing fmt filled with ...args, placed before the original code.
 
-			If original == nullptr, the output buffer will only contain the data from fmt. If original code contains #version specifier,
-			then the filled fmt will be placed onto the next line after #version in the output buffer. If not, fmt will be placed into the
-			beginning of the output buffer.
+			If original == nullptr, the output buffer will only contain the data from fmt.
 		*/
 		template<typename... Args>
-		static core::smart_refctd_ptr<ICPUShader> createOverridenCopy(const ICPUShader* original, const char* fmt, Args... args)
+		static core::smart_refctd_ptr<ICPUShader> createOverridenCopy(const ICPUShader* original, uint32_t position, const char* fmt, Args... args)
 		{
 			assert(original == nullptr || (!original->isADummyObjectForCache() && original->isContentHighLevelLanguage()));
 
@@ -95,30 +94,34 @@ class NBL_API IShaderCompiler : public core::IReferenceCounted
 
 			nbl::core::smart_refctd_ptr<ICPUBuffer> outBuffer = nbl::core::make_smart_refctd_ptr<ICPUBuffer>(outSize);
 
-			size_t versionDirectiveLength = 0;
-
-			std::string_view origCode;
+			auto origCode = std::string_view(reinterpret_cast<const char*>(original->getContent()->getPointer()), origLen);
 			auto outCode = reinterpret_cast<char*>(outBuffer->getPointer());
-			if (original!=nullptr)
+
+			if (position < origLen)
 			{
-				origCode = std::string_view(reinterpret_cast<const char*>(original->getContent()->getPointer()),origLen);
-				auto start = origCode.find("#version");
-				auto end = origCode.find("\n",start);
-				if (end!=std::string_view::npos)
-					versionDirectiveLength = end+1u;
-			}
+				// Copy whatever comes before position
+				std::copy_n(origCode.data(), position, outCode);
+				outCode += position;
 
-			std::copy_n(origCode.data(),versionDirectiveLength,outCode);
-			outCode += versionDirectiveLength;
+				// Copy formatted string
+				outCode += sprintf(outCode,fmt,std::forward<Args>(args)...);
 
-			outCode += sprintf(outCode,fmt,std::forward<Args>(args)...);
+				// Copy the rest of the original code
+				auto epilogueLen = origLen - position;
+				std::copy_n(origCode.data() + position, epilogueLen, outCode);
+				outCode += epilogueLen;
 
-			auto epilogueLen = origLen-versionDirectiveLength;
-			std::copy_n(origCode.data()+versionDirectiveLength,epilogueLen,outCode);
-			outCode += epilogueLen;
-			*outCode = 0; // terminating char
+				// terminating char
+				*outCode = 0;
 
-			return nbl::core::make_smart_refctd_ptr<ICPUShader>(std::move(outBuffer), original->getStage(), original->getContentType(), std::string(original->getFilepathHint()));
+				return nbl::core::make_smart_refctd_ptr<ICPUShader>(std::move(outBuffer), original->getStage(), original->getContentType(), std::string(original->getFilepathHint()));
+			}
+			else
+			{
+				// Position isn't valid.
+				assert(false);
+				return nullptr;
+			}
 		}
 
 		virtual IShader::E_CONTENT_TYPE getCodeContentType() const = 0;

src/nbl/asset/interchange/CGLTFLoader.cpp

@@ -51,7 +51,7 @@ using namespace nbl::asset;
 
 				auto unspecializedShader = core::make_smart_refctd_ptr<asset::ICPUShader>(std::move(glsl), stage, asset::ICPUShader::E_CONTENT_TYPE::ECT_GLSL, stage != ICPUShader::ESS_VERTEX ? "?IrrlichtBAW glTFLoader FragmentShader?" : "?IrrlichtBAW glTFLoader VertexShader?");
 				if (extraDefine)
-					unspecializedShader = IShaderCompiler::createOverridenCopy(unspecializedShader.get(),"%s",extraDefine);
+					unspecializedShader = IGLSLCompiler::createOverridenCopy(unspecializedShader.get(),"%s",extraDefine);
 
 				ICPUSpecializedShader::SInfo specInfo({},nullptr,"main");
 				auto shader = core::make_smart_refctd_ptr<asset::ICPUSpecializedShader>(std::move(unspecializedShader),std::move(specInfo));