ShaderNode: Add possibility to set variable name (+ force variables)

src/ShaderNode/DataModels/FragmentOutput.inl

@@ -4,5 +4,6 @@ inline FragmentOutput::FragmentOutput(ShaderGraph& graph) :
 ShaderNode(graph)
 {
 	SetPreviewSize({ 128, 128 });
+	DisableCustomVariableName();
 	EnablePreview(true);
 }

src/ShaderNode/DataModels/InputValue.cpp

@@ -21,6 +21,7 @@ ShaderNode(graph)
 		m_currentInputText = firstInput.name;
 	}
 
+	DisableCustomVariableName();
 	UpdatePreview();
 }
 

src/ShaderNode/DataModels/ShaderNode.cpp

@@ -3,12 +3,13 @@
 #include <QtWidgets/QComboBox>
 #include <QtWidgets/QFormLayout>
 #include <QtWidgets/QLabel>
+#include <QtWidgets/QLineEdit>
 
 ShaderNode::ShaderNode(ShaderGraph& graph) :
 m_previewSize(64, 64),
 m_pixmapLabel(nullptr),
 m_graph(graph),
-m_forceVariable(false),
+m_enableCustomVariableName(true),
 m_isPreviewEnabled(false)
 {
 	m_pixmapLabel = new QLabel;
@@ -51,6 +52,16 @@ void ShaderNode::BuildNodeEdition(QFormLayout* layout)
 	});
 
 	layout->addRow(tr("Preview size"), previewSize);
+
+	if (m_enableCustomVariableName)
+	{
+		QLineEdit* lineEdit = new QLineEdit(QString::fromStdString(m_variableName));
+		connect(lineEdit, &QLineEdit::textChanged, [&](const QString& text)
+		{
+			SetVariableName(text.toStdString());
+		});
+		layout->addRow(tr("Variable name"), lineEdit);
+	}
 }
 
 void ShaderNode::EnablePreview(bool enable)

src/ShaderNode/DataModels/ShaderNode.hpp

@@ -27,13 +27,16 @@ class ShaderNode : public QtNodes::NodeDataModel
 		inline const ShaderGraph& GetGraph() const;
 		inline const std::string& GetVariableName() const;
 
-		void SetPreviewSize(const Nz::Vector2i& size);
+		inline void SetPreviewSize(const Nz::Vector2i& size);
+		inline void SetVariableName(std::string variableName);
 
 		QWidget* embeddedWidget() final;
 
 		void setInData(std::shared_ptr<QtNodes::NodeData>, int) override;
 
 	protected:
+		inline void DisableCustomVariableName();
+		inline void EnableCustomVariableName(bool enable = true);
 		void UpdatePreview();
 
 	private:
@@ -44,7 +47,7 @@ class ShaderNode : public QtNodes::NodeDataModel
 		std::optional<QPixmap> m_pixmap;
 		std::string m_variableName;
 		ShaderGraph& m_graph;
-		bool m_forceVariable;
+		bool m_enableCustomVariableName;
 		bool m_isPreviewEnabled;
 };
 

src/ShaderNode/DataModels/ShaderNode.inl

@@ -24,3 +24,20 @@ inline void ShaderNode::SetPreviewSize(const Nz::Vector2i& size)
 		embeddedWidgetSizeUpdated();
 	}
 }
+
+inline void ShaderNode::SetVariableName(std::string variableName)
+{
+	m_variableName = std::move(variableName);
+}
+
+inline void ShaderNode::DisableCustomVariableName()
+{
+	return EnableCustomVariableName(false);
+}
+
+inline void ShaderNode::EnableCustomVariableName(bool enable)
+{
+	m_enableCustomVariableName = enable;
+	if (!m_enableCustomVariableName)
+		m_variableName.clear();
+}

src/ShaderNode/DataModels/TextureValue.cpp

@@ -22,6 +22,7 @@ ShaderNode(graph)
 		m_currentTextureText = firstInput.name;
 	}
 
+	DisableCustomVariableName();
 	EnablePreview(true);
 }
 

src/ShaderNode/ShaderGraph.cpp

@@ -16,6 +16,7 @@
 #include <nodes/FlowScene>
 #include <nodes/FlowView>
 #include <nodes/DataModelRegistry>
+#include <unordered_set>
 
 namespace
 {
@@ -105,8 +106,6 @@ Nz::ShaderAst::StatementPtr ShaderGraph::ToAst()
 	std::vector<Nz::ShaderAst::StatementPtr> statements;
 	QHash<QUuid, unsigned int> usageCount;
 
-	unsigned int varCount = 0;
-
 	std::function<void(QtNodes::Node*)> DetectVariables;
 	DetectVariables = [&](QtNodes::Node* node)
 	{
@@ -135,6 +134,9 @@ Nz::ShaderAst::StatementPtr ShaderGraph::ToAst()
 
 	QHash<QUuid, Nz::ShaderAst::ExpressionPtr> variableExpressions;
 
+	unsigned int varCount = 0;
+	std::unordered_set<std::string> usedVariableNames;
+
 	std::function<Nz::ShaderAst::ExpressionPtr(QtNodes::Node*)> HandleNode;
 	HandleNode = [&](QtNodes::Node* node) -> Nz::ShaderAst::ExpressionPtr
 	{
@@ -163,12 +165,24 @@ Nz::ShaderAst::StatementPtr ShaderGraph::ToAst()
 
 		auto expression = shaderNode->GetExpression(expressions.data(), expressions.size());
 
-		if (*it > 1)
+		const std::string& variableName = shaderNode->GetVariableName();
+		if (*it > 1 || !variableName.empty())
 		{
 			Nz::ShaderAst::ExpressionPtr varExpression;
 			if (expression->GetExpressionCategory() == Nz::ShaderAst::ExpressionCategory::RValue)
 			{
-				auto variable = Nz::ShaderBuilder::Variable("var" + std::to_string(varCount++), expression->GetExpressionType());
+				std::string name;
+				if (variableName.empty())
+					name = "var" + std::to_string(varCount++);
+				else
+					name = variableName;
+
+				if (usedVariableNames.find(name) != usedVariableNames.end())
+					throw std::runtime_error("duplicate variable found: " + name);
+
+				usedVariableNames.insert(name);
+
+				auto variable = Nz::ShaderBuilder::Variable(std::move(name), expression->GetExpressionType());
 				statements.emplace_back(Nz::ShaderBuilder::DeclareVariable(variable, expression));
 
 				varExpression = variable;