Split shader generation to a new module

include/Nazara/Shader/GlslWriter.inl

@@ -0,0 +1,132 @@
+// 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/GlslWriter.hpp>
+#include <type_traits>
+#include <Nazara/Shader/Debug.hpp>
+
+namespace Nz
+{
+	template<typename T>
+	void GlslWriter::Append(const T& param)
+	{
+		NazaraAssert(m_currentState, "This function should only be called while processing an AST");
+
+		m_currentState->stream << param;
+	}
+
+	template<typename T>
+	void GlslWriter::DeclareVariables(const ShaderAst& shader, const std::vector<T>& variables, const std::string& keyword, const std::string& section)
+	{
+		if (!variables.empty())
+		{
+			if (!section.empty())
+				AppendCommentSection(section);
+
+			for (const auto& var : variables)
+			{
+				if constexpr (std::is_same_v<T, ShaderAst::InputOutput>)
+				{
+					if (var.locationIndex)
+					{
+						Append("layout(location = ");
+						Append(*var.locationIndex);
+						Append(") ");
+					}
+
+					if (!keyword.empty())
+					{
+						Append(keyword);
+						Append(" ");
+					}
+
+					Append(var.type);
+					Append(" ");
+					Append(var.name);
+					AppendLine(";");
+				}
+				else if constexpr (std::is_same_v<T, ShaderAst::Uniform>)
+				{
+					if (var.bindingIndex || var.memoryLayout)
+					{
+						Append("layout(");
+
+						bool first = true;
+						if (var.bindingIndex)
+						{
+							if (!first)
+								Append(", ");
+
+							Append("binding = ");
+							Append(*var.bindingIndex);
+
+							first = false;
+						}
+
+						if (var.memoryLayout)
+						{
+							if (!first)
+								Append(", ");
+
+							Append(*var.memoryLayout);
+
+							first = false;
+						}
+
+						Append(") ");
+					}
+
+					if (!keyword.empty())
+					{
+						Append(keyword);
+						Append(" ");
+					}
+
+					std::visit([&](auto&& arg)
+					{
+						using T = std::decay_t<decltype(arg)>;
+						if constexpr (std::is_same_v<T, ShaderNodes::BasicType>)
+						{
+							Append(arg);
+							Append(" ");
+							Append(var.name);
+						}
+						else if constexpr (std::is_same_v<T, std::string>)
+						{
+							const auto& structs = shader.GetStructs();
+							auto it = std::find_if(structs.begin(), structs.end(), [&](const auto& s) { return s.name == arg; });
+							if (it == structs.end())
+								throw std::runtime_error("struct " + arg + " has not been defined");
+
+							const auto& s = *it;
+
+							AppendLine(var.name + "_interface");
+							AppendLine("{");
+							for (const auto& m : s.members)
+							{
+								Append("\t");
+								Append(m.type);
+								Append(" ");
+								Append(m.name);
+								AppendLine(";");
+							}
+							Append("} ");
+							Append(var.name);
+						}
+						else
+							static_assert(AlwaysFalse<T>::value, "non-exhaustive visitor");
+
+					}, var.type);
+
+					AppendLine(";");
+					AppendLine();
+				}
+			}
+
+			AppendLine();
+		}
+	}
+}
+
+#include <Nazara/Shader/DebugOff.hpp>