Renderer/ShaderAst: Add input and outputs variables

include/Nazara/Renderer/GlslWriter.hpp

@@ -44,20 +44,24 @@ namespace Nz
 
 		private:
 			struct Function;
+			using VariableContainer = std::set<std::pair<ShaderAst::ExpressionType, String>>;
 
 			void Append(ShaderAst::Builtin builtin);
 			void Append(ShaderAst::ExpressionType type);
 			void Append(const String& txt);
 			void AppendCommentSection(const String& section);
 			void AppendFunction(Function& func);
-			void AppendLine(const Nz::String& txt = Nz::String());
+			void AppendLine(const String& txt = String());
+
+			void DeclareVariables(const VariableContainer& variables, const String& keyword = String(), const String& section = String());
 
 			void EnterScope();
 			void LeaveScope();
 
+
 			struct Function
 			{
-				std::set<std::pair<ShaderAst::ExpressionType, String>> variables;
+				VariableContainer variables;
 				std::vector<ShaderAst::NamedVariablePtr> parameters;
 				ShaderAst::ExpressionType retType;
 				ShaderAst::StatementPtr node;
@@ -66,7 +70,9 @@ namespace Nz
 
 			struct State
 			{
-				std::set<std::pair<ShaderAst::ExpressionType, String>> m_uniforms;
+				VariableContainer inputs;
+				VariableContainer outputs;
+				VariableContainer uniforms;
 				StringStream stream;
 				unsigned int indentLevel = 0;
 			};

include/Nazara/Renderer/ShaderAst.hpp

@@ -55,9 +55,11 @@ namespace Nz
 		enum class VariableType
 		{
 			Builtin,
+			Input,
+			Output,
 			Parameter,
-			Variable,
+			Uniform,
-			Uniform
+			Variable
 		};
 
 		//////////////////////////////////////////////////////////////////////////

include/Nazara/Renderer/ShaderBuilder.hpp

@@ -50,6 +50,8 @@ namespace Nz { namespace ShaderBuilder
 	constexpr GenBuilder<ShaderAst::Branch> Branch;
 	constexpr GenBuilder<ShaderAst::Constant> Constant;
 	constexpr GenBuilder<ShaderAst::ExpressionStatement> ExprStatement;
+	constexpr VarBuilder<ShaderAst::VariableType::Input> Input;
+	constexpr VarBuilder<ShaderAst::VariableType::Output> Output;
 	constexpr VarBuilder<ShaderAst::VariableType::Parameter> Parameter;
 	constexpr VarBuilder<ShaderAst::VariableType::Uniform> Uniform;
 	constexpr VarBuilder<ShaderAst::VariableType::Variable> Variable;

src/Nazara/Renderer/GlslWriter.cpp

@@ -31,23 +31,10 @@ namespace Nz
 		AppendLine(String::Number(m_glslVersion));
 		AppendLine();
 
-		// Uniforms
+		// Global variables (uniforms, input and outputs)
-		if (!state.m_uniforms.empty())
+		DeclareVariables(state.uniforms, "uniform", "Uniforms");
-		{
+		DeclareVariables(state.inputs,   "in",      "Inputs");
-			AppendCommentSection("Uniforms");
+		DeclareVariables(state.outputs,  "out",     "Outputs");
-			AppendLine();
-
-			for (const auto& pair : state.m_uniforms)
-			{
-				Append("uniform ");
-				Append(pair.first);
-				Append(" ");
-				Append(pair.second);
-				AppendLine(";");
-			}
-
-			AppendLine();
-		}
 
 		Function entryPoint;
 		entryPoint.name = "main"; //< GLSL has only one entry point name possible
@@ -73,9 +60,18 @@ namespace Nz
 	void GlslWriter::RegisterVariable(ShaderAst::VariableType kind, const String& name, ShaderAst::ExpressionType type)
 	{
 		NazaraAssert(m_currentState, "This function should only be called while processing an AST");
+		NazaraAssert(kind != ShaderAst::VariableType::Builtin, "Builtin variables should not be registered");
 
 		switch (kind)
 		{
+			case ShaderAst::VariableType::Input:
+				m_currentState->inputs.insert(std::make_pair(type, name));
+				break;
+
+			case ShaderAst::VariableType::Output:
+				m_currentState->outputs.insert(std::make_pair(type, name));
+				break;
+
 			case ShaderAst::VariableType::Parameter:
 			{
 				if (m_currentFunction)
@@ -105,7 +101,7 @@ namespace Nz
 			}
 
 			case ShaderAst::VariableType::Uniform:
-				m_currentState->m_uniforms.insert(std::make_pair(type, name));
+				m_currentState->uniforms.insert(std::make_pair(type, name));
 				break;
 
 			case ShaderAst::VariableType::Variable:
@@ -320,15 +316,7 @@ namespace Nz
 
 		EnterScope();
 		{
-			for (const auto& pair : func.variables)
+			DeclareVariables(func.variables);
-			{
-				Append(pair.first);
-				Append(" ");
-				Append(pair.second);
-				AppendLine(";");
-			}
-
-			AppendLine();
 
 			Write(func.node);
 		}
@@ -342,6 +330,34 @@ namespace Nz
 		m_currentState->stream << txt << '\n' << String(m_currentState->indentLevel, '\t');
 	}
 
+	void GlslWriter::DeclareVariables(const VariableContainer& variables, const String& keyword, const String& section)
+	{
+		if (!variables.empty())
+		{
+			if (!section.IsEmpty())
+			{
+				AppendCommentSection("Uniforms");
+				AppendLine();
+			}
+
+			for (const auto& pair : variables)
+			{
+				if (!keyword.IsEmpty())
+				{
+					Append(keyword);
+					Append(" ");
+				}
+
+				Append(pair.first);
+				Append(" ");
+				Append(pair.second);
+				AppendLine(";");
+			}
+
+			AppendLine();
+		}
+	}
+
 	void GlslWriter::EnterScope()
 	{
 		NazaraAssert(m_currentState, "This function should only be called while processing an AST");