From a84391cf086e02937ba9fc314af107cd3900acbf Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Thu, 5 Jan 2017 16:41:48 +0100
Subject: [PATCH] Renderer/ShaderAst: Add support for expression type

---
 include/Nazara/Renderer/ShaderAst.hpp | 20 ++++++++++-----
 include/Nazara/Renderer/ShaderAst.inl |  4 +++
 src/Nazara/Renderer/ShaderAst.cpp     | 37 +++++++++++++++++++++++++++
 3 files changed, 55 insertions(+), 6 deletions(-)

diff --git a/include/Nazara/Renderer/ShaderAst.hpp b/include/Nazara/Renderer/ShaderAst.hpp
index 87c00548e..d0d502959 100644
--- a/include/Nazara/Renderer/ShaderAst.hpp
+++ b/include/Nazara/Renderer/ShaderAst.hpp
@@ -43,13 +43,14 @@ namespace Nz
 
 		enum class ExpressionType
 		{
-			Float1, // float
-			Float2, // vec2
-			Float3, // vec3
-			Float4, // vec4
-			Mat4x4, // mat4
+			Boolean, // bool
+			Float1,  // float
+			Float2,  // vec2
+			Float3,  // vec3
+			Float4,  // vec4
+			Mat4x4,  // mat4
 
-			None    // void
+			None     // void
 		};
 
 		enum class VariableType
@@ -91,6 +92,8 @@ namespace Nz
 
 		class NAZARA_RENDERER_API Expression : public Node
 		{
+			public:
+				virtual ExpressionType GetExpressionType() const = 0;
 		};
 
 		class NAZARA_RENDERER_API ExpressionStatement : public Statement
@@ -126,6 +129,8 @@ namespace Nz
 			public:
 				inline Variable(VariableType varKind, ExpressionType varType);
 
+				ExpressionType GetExpressionType() const override;
+
 				ExpressionType type;
 				VariableType   kind;
 		};
@@ -163,6 +168,7 @@ namespace Nz
 			public:
 				inline AssignOp(AssignType Op, VariablePtr Var, ExpressionPtr Right);
 
+				ExpressionType GetExpressionType() const override;
 				void Register(ShaderWriter& visitor) override;
 				void Visit(ShaderWriter& visitor) override;
 
@@ -176,6 +182,7 @@ namespace Nz
 			public:
 				inline BinaryOp(BinaryType Op, ExpressionPtr Left, ExpressionPtr Right);
 
+				ExpressionType GetExpressionType() const override;
 				void Register(ShaderWriter& visitor) override;
 				void Visit(ShaderWriter& visitor) override;
 
@@ -207,6 +214,7 @@ namespace Nz
 			public:
 				inline explicit Constant(float value);
 
+				ExpressionType GetExpressionType() const override;
 				void Register(ShaderWriter& visitor) override;
 				void Visit(ShaderWriter& visitor) override;
 
diff --git a/include/Nazara/Renderer/ShaderAst.inl b/include/Nazara/Renderer/ShaderAst.inl
index b2b5a1f56..3fe505726 100644
--- a/include/Nazara/Renderer/ShaderAst.inl
+++ b/include/Nazara/Renderer/ShaderAst.inl
@@ -3,6 +3,7 @@
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
 #include <Nazara/Renderer/ShaderAst.hpp>
+#include <Nazara/Core/Error.hpp>
 #include <Nazara/Renderer/Debug.hpp>
 
 namespace Nz
@@ -50,6 +51,9 @@ namespace Nz
 		left(std::move(Left)),
 		right(std::move(Right))
 		{
+			//TODO: AstParseError
+			if (left->GetExpressionType() != right->GetExpressionType())
+				throw std::runtime_error("Left expression type must match right expression type");
 		}
 
 		inline Branch::Branch(ExpressionPtr condition, StatementPtr trueStatement, StatementPtr falseStatement)
diff --git a/src/Nazara/Renderer/ShaderAst.cpp b/src/Nazara/Renderer/ShaderAst.cpp
index 8fc554623..7cc3b6313 100644
--- a/src/Nazara/Renderer/ShaderAst.cpp
+++ b/src/Nazara/Renderer/ShaderAst.cpp
@@ -31,6 +31,11 @@ namespace Nz { namespace ShaderAst
 	}
 
 
+	ExpressionType Variable::GetExpressionType() const
+	{
+		return type;
+	}
+
 	void NamedVariable::Register(ShaderWriter& visitor)
 	{
 		visitor.RegisterVariable(kind, name, type);
@@ -52,6 +57,11 @@ namespace Nz { namespace ShaderAst
 	}
 
 
+	ExpressionType AssignOp::GetExpressionType() const
+	{
+		return variable->GetExpressionType();
+	}
+
 	void AssignOp::Register(ShaderWriter& visitor)
 	{
 		variable->Register(visitor);
@@ -64,6 +74,28 @@ namespace Nz { namespace ShaderAst
 	}
 
 
+	ExpressionType BinaryOp::GetExpressionType() const
+	{
+		ShaderAst::ExpressionType exprType = ShaderAst::ExpressionType::None;
+
+		switch (op)
+		{
+			case ShaderAst::BinaryType::Add:
+			case ShaderAst::BinaryType::Divide:
+			case ShaderAst::BinaryType::Multiply:
+			case ShaderAst::BinaryType::Substract:
+				exprType = left->GetExpressionType();
+				break;
+
+			case ShaderAst::BinaryType::Equality:
+				exprType = ExpressionType::Boolean;
+		}
+
+		NazaraAssert(exprType != ShaderAst::ExpressionType::None, "Unhandled builtin");
+
+		return exprType;
+	}
+
 	void BinaryOp::Register(ShaderWriter& visitor)
 	{
 		left->Register(visitor);
@@ -94,6 +126,11 @@ namespace Nz { namespace ShaderAst
 	}
 
 
+	ExpressionType Constant::GetExpressionType() const
+	{
+		return exprType;
+	}
+
 	void Constant::Register(ShaderWriter&)
 	{
 	}