From cb69b1ed017dc6f991443fc0cd1b42ce4b9dbe37 Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Sat, 21 Jan 2017 15:53:18 +0100
Subject: [PATCH] Renderer/ShaderAst: Add ConditionalStatement

---
 include/Nazara/Renderer/ShaderAst.inl     |  6 ++++++
 include/Nazara/Renderer/ShaderBuilder.hpp |  1 +
 include/Nazara/Renderer/ShaderWriter.hpp  |  9 +++++++++
 src/Nazara/Renderer/ShaderAst.cpp         | 13 +++++++++++++
 src/Nazara/Renderer/ShaderWriter.cpp      | 13 +++++++++++++
 5 files changed, 42 insertions(+)

diff --git a/include/Nazara/Renderer/ShaderAst.inl b/include/Nazara/Renderer/ShaderAst.inl
index b23078f0a..b03045386 100644
--- a/include/Nazara/Renderer/ShaderAst.inl
+++ b/include/Nazara/Renderer/ShaderAst.inl
@@ -53,6 +53,12 @@ namespace Nz
 		{
 		}
 
+		inline ConditionalStatement::ConditionalStatement(const String& condition, StatementPtr statementPtr) :
+		conditionName(condition),
+		statement(std::move(statementPtr))
+		{
+		}
+
 		template<typename... Args>
 		StatementBlock::StatementBlock(Args&& ...args) :
 		statements({std::forward<Args>(args)...})
diff --git a/include/Nazara/Renderer/ShaderBuilder.hpp b/include/Nazara/Renderer/ShaderBuilder.hpp
index 0cfefca7e..e642ea8d3 100644
--- a/include/Nazara/Renderer/ShaderBuilder.hpp
+++ b/include/Nazara/Renderer/ShaderBuilder.hpp
@@ -57,6 +57,7 @@ namespace Nz { namespace ShaderBuilder
 	constexpr BuiltinBuilder Builtin;
 	constexpr GenBuilder<ShaderAst::StatementBlock> Block;
 	constexpr GenBuilder<ShaderAst::Branch> Branch;
+	constexpr GenBuilder<ShaderAst::ConditionalStatement> ConditionalStatement;
 	constexpr GenBuilder<ShaderAst::Constant> Constant;
 	constexpr BinOpBuilder<ShaderAst::BinaryType::Divide> Divide;
 	constexpr BinOpBuilder<ShaderAst::BinaryType::Equality> Equal;
diff --git a/include/Nazara/Renderer/ShaderWriter.hpp b/include/Nazara/Renderer/ShaderWriter.hpp
index 35baf3959..13ef6e367 100644
--- a/include/Nazara/Renderer/ShaderWriter.hpp
+++ b/include/Nazara/Renderer/ShaderWriter.hpp
@@ -8,8 +8,10 @@
 #define NAZARA_SHADERWRITER_HPP
 
 #include <Nazara/Prerequesites.hpp>
+#include <Nazara/Core/String.hpp>
 #include <Nazara/Renderer/Config.hpp>
 #include <Nazara/Renderer/ShaderAst.hpp>
+#include <unordered_set>
 
 namespace Nz
 {
@@ -21,6 +23,10 @@ namespace Nz
 			ShaderWriter(ShaderWriter&&) = delete;
 			virtual ~ShaderWriter();
 
+			void EnableCondition(const String& name, bool cond);
+
+			bool IsConditionEnabled(const String& name) const;
+
 			virtual Nz::String Generate(const ShaderAst::StatementPtr& node) = 0;
 
 			virtual void RegisterFunction(const String& name, ShaderAst::StatementPtr node, std::initializer_list<ShaderAst::NamedVariablePtr> parameters, ShaderAst::ExpressionType ret) = 0;
@@ -37,6 +43,9 @@ namespace Nz
 			virtual void Write(const ShaderAst::NodePtr& node) = 0;
 			virtual void Write(const ShaderAst::StatementBlock& node) = 0;
 			virtual void Write(const ShaderAst::SwizzleOp& node) = 0;
+
+		private:
+			std::unordered_set<String> m_conditions;
 	};
 }
 
diff --git a/src/Nazara/Renderer/ShaderAst.cpp b/src/Nazara/Renderer/ShaderAst.cpp
index 71b4b27cf..ef6860d68 100644
--- a/src/Nazara/Renderer/ShaderAst.cpp
+++ b/src/Nazara/Renderer/ShaderAst.cpp
@@ -19,6 +19,19 @@ namespace Nz { namespace ShaderAst
 	}
 
 
+	void ConditionalStatement::Register(ShaderWriter& visitor)
+	{
+		if (visitor.IsConditionEnabled(conditionName))
+			statement->Register(visitor);
+	}
+
+	void ConditionalStatement::Visit(ShaderWriter& visitor)
+	{
+		if (visitor.IsConditionEnabled(conditionName))
+			statement->Visit(visitor);
+	}
+
+
 	void StatementBlock::Register(ShaderWriter& visitor)
 	{
 		for (auto& statementPtr : statements)
diff --git a/src/Nazara/Renderer/ShaderWriter.cpp b/src/Nazara/Renderer/ShaderWriter.cpp
index 8ca48da3e..c862572ab 100644
--- a/src/Nazara/Renderer/ShaderWriter.cpp
+++ b/src/Nazara/Renderer/ShaderWriter.cpp
@@ -8,4 +8,17 @@
 namespace Nz
 {
 	ShaderWriter::~ShaderWriter() = default;
+
+	void ShaderWriter::EnableCondition(const String& name, bool cond)
+	{
+		if (cond)
+			m_conditions.insert(name);
+		else
+			m_conditions.erase(name);
+	}
+
+	bool ShaderWriter::IsConditionEnabled(const String & name) const
+	{
+		return m_conditions.count(name) != 0;
+	}
 }