Split shader generation to a new module

include/Nazara/Shader/SpirvWriter.inl

@@ -0,0 +1,111 @@
+// Copyright (C) 2020 Jérôme Leclercq
+// This file is part of the "Nazara Engine - Shader generator"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Shader/SpirvWriter.hpp>
+#include <cassert>
+#include <type_traits>
+#include <Nazara/Shader/Debug.hpp>
+
+namespace Nz
+{
+	inline std::size_t SpirvWriter::Section::Append(const char* str)
+	{
+		return Append(std::string_view(str));
+	}
+
+	inline std::size_t SpirvWriter::Section::Append(const std::string_view& str)
+	{
+		std::size_t offset = GetOutputOffset();
+
+		std::size_t size4 = CountWord(str);
+		for (std::size_t i = 0; i < size4; ++i)
+		{
+			UInt32 codepoint = 0;
+			for (std::size_t j = 0; j < 4; ++j)
+			{
+				std::size_t pos = i * 4 + j;
+				if (pos < str.size())
+					codepoint |= UInt32(str[pos]) << (j * 8);
+			}
+
+			Append(codepoint);
+		}
+
+		return offset;
+	}
+
+	inline std::size_t SpirvWriter::Section::Append(const std::string& str)
+	{
+		return Append(std::string_view(str));
+	}
+
+	inline std::size_t SpirvWriter::Section::Append(UInt32 value)
+	{
+		std::size_t offset = GetOutputOffset();
+		data.push_back(value);
+
+		return offset;
+	}
+
+	inline std::size_t SpirvWriter::Section::Append(std::initializer_list<UInt32> codepoints)
+	{
+		std::size_t offset = GetOutputOffset();
+
+		for (UInt32 cp : codepoints)
+			Append(cp);
+
+		return offset;
+	}
+
+	template<typename ...Args>
+	std::size_t SpirvWriter::Section::Append(Opcode opcode, const Args&... args)
+	{
+		unsigned int wordCount = 1 + (CountWord(args) + ... + 0);
+		std::size_t offset = Append(opcode, WordCount{ wordCount });
+		if constexpr (sizeof...(args) > 0)
+			(Append(args), ...);
+
+		return offset;
+	}
+
+	template<typename T>
+	std::size_t SpirvWriter::Section::Append(T value)
+	{
+		return Append(static_cast<UInt32>(value));
+	}
+
+	template<typename T>
+	unsigned int SpirvWriter::Section::CountWord(const T& value)
+	{
+		return 1;
+	}
+
+	template<typename T1, typename T2, typename ...Args>
+	unsigned int SpirvWriter::Section::CountWord(const T1& value, const T2& value2, const Args&... rest)
+	{
+		return CountWord(value) + CountWord(value2) + (CountWord(rest) + ...);
+	}
+
+	inline unsigned int SpirvWriter::Section::CountWord(const char* str)
+	{
+		return CountWord(std::string_view(str));
+	}
+
+	inline unsigned int Nz::SpirvWriter::Section::CountWord(const std::string& str)
+	{
+		return CountWord(std::string_view(str));
+	}
+
+	inline unsigned int SpirvWriter::Section::CountWord(const std::string_view& str)
+	{
+		return (static_cast<unsigned int>(str.size() + 1) + sizeof(UInt32) - 1) / sizeof(UInt32); //< + 1 for null character
+	}
+
+	std::size_t SpirvWriter::Section::GetOutputOffset() const
+	{
+		return data.size();
+	}
+}
+
+#include <Nazara/Shader/DebugOff.hpp>