Shader: Add Discard node

src/Nazara/Shader/GlslWriter.cpp

@@ -519,6 +519,11 @@ namespace Nz
 		AppendLine(";");
 	}
 
+	void GlslWriter::Visit(ShaderNodes::Discard& /*node*/)
+	{
+		Append("discard;");
+	}
+
 	void GlslWriter::Visit(ShaderNodes::ExpressionStatement& node)
 	{
 		Visit(node.expression);

src/Nazara/Shader/ShaderAstCloner.cpp

@@ -111,6 +111,11 @@ namespace Nz
 		PushStatement(ShaderNodes::DeclareVariable::Build(CloneVariable(node.variable), CloneExpression(node.expression)));
 	}
 
+	void ShaderAstCloner::Visit(ShaderNodes::Discard& /*node*/)
+	{
+		PushStatement(ShaderNodes::Discard::Build());
+	}
+
 	void ShaderAstCloner::Visit(ShaderNodes::ExpressionStatement& node)
 	{
 		PushStatement(ShaderNodes::ExpressionStatement::Build(CloneExpression(node.expression)));

src/Nazara/Shader/ShaderAstRecursiveVisitor.cpp

@@ -69,6 +69,11 @@ namespace Nz
 			Visit(node.expression);
 	}
 
+	void ShaderAstRecursiveVisitor::Visit(ShaderNodes::Discard& /*node*/)
+	{
+		/* Nothing to do */
+	}
+
 	void ShaderAstRecursiveVisitor::Visit(ShaderNodes::ExpressionStatement& node)
 	{
 		Visit(node.expression);

src/Nazara/Shader/ShaderAstSerializer.cpp

@@ -67,6 +67,11 @@ namespace Nz
 					Serialize(node);
 				}
 
+				void Visit(ShaderNodes::Discard& node) override
+				{
+					Serialize(node);
+				}
+
 				void Visit(ShaderNodes::ExpressionStatement& node) override
 				{
 					Serialize(node);
@@ -242,6 +247,11 @@ namespace Nz
 		Node(node.expression);
 	}
 
+	void ShaderAstSerializerBase::Serialize(ShaderNodes::Discard& /*node*/)
+	{
+		/* Nothing to do */
+	}
+
 	void ShaderAstSerializerBase::Serialize(ShaderNodes::ExpressionStatement& node)
 	{
 		Node(node.expression);
@@ -665,6 +675,7 @@ namespace Nz
 			HandleType(ConditionalExpression);
 			HandleType(ConditionalStatement);
 			HandleType(DeclareVariable);
+			HandleType(Discard);
 			HandleType(ExpressionStatement);
 			HandleType(Identifier);
 			HandleType(IntrinsicCall);

src/Nazara/Shader/ShaderAstVisitorExcept.cpp

@@ -53,6 +53,11 @@ namespace Nz
 		throw std::runtime_error("unhandled DeclareVariable node");
 	}
 
+	void ShaderAstVisitorExcept::Visit(ShaderNodes::Discard& /*node*/)
+	{
+		throw std::runtime_error("unhandled Discard node");
+	}
+
 	void ShaderAstVisitorExcept::Visit(ShaderNodes::ExpressionStatement& /*node*/)
 	{
 		throw std::runtime_error("unhandled ExpressionStatement node");

src/Nazara/Shader/ShaderNodes.cpp

@@ -42,6 +42,12 @@ namespace Nz::ShaderNodes
 	}
 
 
+	void Discard::Visit(ShaderAstVisitor& visitor)
+	{
+		visitor.Visit(*this);
+	}
+
+
 	ExpressionCategory Identifier::GetExpressionCategory() const
 	{
 		return ExpressionCategory::LValue;

src/Nazara/Shader/SpirvAstVisitor.cpp

@@ -346,6 +346,11 @@ namespace Nz
 		}
 	}
 
+	void SpirvAstVisitor::Visit(ShaderNodes::Discard& /*node*/)
+	{
+		m_writer.GetInstructions().Append(SpirvOp::OpKill);
+	}
+
 	void SpirvAstVisitor::Visit(ShaderNodes::ExpressionStatement& node)
 	{
 		Visit(node.expression);