ShaderLang: Add support for length intrinsic

include/Nazara/Shader/Ast/Enums.hpp

@@ -54,9 +54,10 @@ namespace Nz::ShaderAst
 
 	enum class IntrinsicType
 	{
-		CrossProduct,
+		CrossProduct = 0,
-		DotProduct,
+		DotProduct = 1,
-		SampleTexture
+		Length = 3,
+		SampleTexture = 2,
 	};
 
 	enum class MemoryLayout

include/Nazara/Shader/SpirvWriter.hpp

@@ -57,6 +57,7 @@ namespace Nz
 			SpirvConstantCache::TypePtr BuildFunctionType(const ShaderAst::DeclareFunctionStatement& functionNode);
 
 			UInt32 GetConstantId(const ShaderAst::ConstantValue& value) const;
+			UInt32 GetExtendedInstructionSet(const std::string& instructionSetName) const;
 			UInt32 GetExtVarPointerId(std::size_t varIndex) const;
 			UInt32 GetFunctionTypeId(const ShaderAst::DeclareFunctionStatement& functionNode);
 			UInt32 GetPointerTypeId(const ShaderAst::ExpressionType& type, SpirvStorageClass storageClass) const;

src/Nazara/Shader/Ast/SanitizeVisitor.cpp

@@ -466,6 +466,21 @@ namespace Nz::ShaderAst
 				break;
 			}
 
+			case IntrinsicType::Length:
+			{
+				if (clone->parameters.size() != 1)
+					throw AstError{ "Expected only one parameters" };
+
+				for (auto& param : clone->parameters)
+					MandatoryExpr(param);
+
+				const ExpressionType& type = GetExpressionType(*clone->parameters.front());
+				if (!IsVectorType(type))
+					throw AstError{ "Expected a vector" };
+
+				break;
+			}
+
 			case IntrinsicType::SampleTexture:
 			{
 				if (clone->parameters.size() != 2)
@@ -479,6 +494,8 @@ namespace Nz::ShaderAst
 
 				if (!IsVectorType(GetExpressionType(*clone->parameters[1])))
 					throw AstError{ "Second parameter must be a vector" };
+
+				break;
 			}
 		}
 
@@ -496,6 +513,7 @@ namespace Nz::ShaderAst
 			}
 
 			case IntrinsicType::DotProduct:
+			case IntrinsicType::Length:
 			{
 				ExpressionType type = GetExpressionType(*clone->parameters.front());
 				if (!IsVectorType(type))

src/Nazara/Shader/GlslWriter.cpp

@@ -806,6 +806,10 @@ namespace Nz
 				Append("dot");
 				break;
 
+			case ShaderAst::IntrinsicType::Length:
+				Append("length");
+				break;
+
 			case ShaderAst::IntrinsicType::SampleTexture:
 				Append("texture");
 				break;

src/Nazara/Shader/LangWriter.cpp

@@ -654,6 +654,10 @@ namespace Nz
 				Append("dot");
 				break;
 
+			case ShaderAst::IntrinsicType::Length:
+				Append("length");
+				break;
+
 			case ShaderAst::IntrinsicType::SampleTexture:
 				Append("texture");
 				break;

src/Nazara/Shader/ShaderLangParser.cpp

@@ -22,6 +22,7 @@ namespace Nz::ShaderLang
 		std::unordered_map<std::string, ShaderAst::IntrinsicType> s_identifierToIntrinsic = {
 			{ "cross", ShaderAst::IntrinsicType::CrossProduct },
 			{ "dot", ShaderAst::IntrinsicType::DotProduct },
+			{ "length", ShaderAst::IntrinsicType::Length },
 		};
 
 		std::unordered_map<std::string, ShaderAst::AttributeType> s_identifierToAttributeType = {

src/Nazara/Shader/SpirvAstVisitor.cpp

@@ -9,6 +9,7 @@
 #include <Nazara/Shader/SpirvExpressionLoad.hpp>
 #include <Nazara/Shader/SpirvExpressionStore.hpp>
 #include <Nazara/Shader/SpirvWriter.hpp>
+#include <SpirV/GLSL.std.450.h>
 #include <Nazara/Shader/Debug.hpp>
 
 namespace Nz
@@ -600,7 +601,7 @@ namespace Nz
 		m_instructions.Append(SpirvOp::OpFunctionEnd);
 	}
 
-	void SpirvAstVisitor::Visit(ShaderAst::DeclareOptionStatement& node)
+	void SpirvAstVisitor::Visit(ShaderAst::DeclareOptionStatement& /*node*/)
 	{
 		/* nothing to do */
 	}
@@ -666,6 +667,25 @@ namespace Nz
 				break;
 			}
 
+			case ShaderAst::IntrinsicType::Length:
+			{
+				UInt32 glslInstructionSet = m_writer.GetExtendedInstructionSet("GLSL.std.450");
+
+				const ShaderAst::ExpressionType& vecExprType = GetExpressionType(*node.parameters[0]);
+				assert(IsVectorType(vecExprType));
+
+				const ShaderAst::VectorType& vecType = std::get<ShaderAst::VectorType>(vecExprType);
+				UInt32 typeId = m_writer.GetTypeId(vecType.type);
+
+				UInt32 vec = EvaluateExpression(node.parameters[0]);
+
+				UInt32 resultId = m_writer.AllocateResultId();
+
+				m_currentBlock->Append(SpirvOp::OpExtInst, typeId, resultId, glslInstructionSet, GLSLstd450Length, vec);
+				PushResultId(resultId);
+				break;
+			}
+
 			case ShaderAst::IntrinsicType::SampleTexture:
 			{
 				UInt32 typeId = m_writer.GetTypeId(ShaderAst::VectorType{4, ShaderAst::PrimitiveType::Float32});

src/Nazara/Shader/SpirvWriter.cpp

@@ -274,6 +274,7 @@ namespace Nz
 					{
 						// Require GLSL.std.450
 						case ShaderAst::IntrinsicType::CrossProduct:
+						case ShaderAst::IntrinsicType::Length:
 							extInsts.emplace("GLSL.std.450");
 							break;
 
@@ -363,7 +364,7 @@ namespace Nz
 			UInt32 id;
 		};
 
-		std::unordered_map<std::string, UInt32> extensionInstructions;
+		std::unordered_map<std::string, UInt32> extensionInstructionSet;
 		std::unordered_map<std::string, UInt32> varToResult;
 		std::vector<SpirvAstVisitor::FuncData> funcs;
 		std::vector<UInt32> resultIds;
@@ -408,7 +409,7 @@ namespace Nz
 		m_currentState->preVisitor = &preVisitor;
 
 		for (const std::string& extInst : preVisitor.extInsts)
-			state.extensionInstructions[extInst] = AllocateResultId();
+			state.extensionInstructionSet[extInst] = AllocateResultId();
 
 		SpirvAstVisitor visitor(*this, state.instructions, state.funcs);
 		targetAst->Visit(visitor);
@@ -465,7 +466,7 @@ namespace Nz
 
 		m_currentState->header.Append(SpirvOp::OpCapability, SpirvCapability::Shader);
 
-		for (const auto& [extInst, resultId] : m_currentState->extensionInstructions)
+		for (const auto& [extInst, resultId] : m_currentState->extensionInstructionSet)
 			m_currentState->header.Append(SpirvOp::OpExtInstImport, resultId, extInst);
 
 		m_currentState->header.Append(SpirvOp::OpMemoryModel, SpirvAddressingModel::Logical, SpirvMemoryModel::GLSL450);
@@ -534,6 +535,14 @@ namespace Nz
 		return m_currentState->constantTypeCache.GetId(*m_currentState->constantTypeCache.BuildConstant(value));
 	}
 
+	UInt32 SpirvWriter::GetExtendedInstructionSet(const std::string& instructionSetName) const
+	{
+		auto it = m_currentState->extensionInstructionSet.find(instructionSetName);
+		assert(it != m_currentState->extensionInstructionSet.end());
+
+		return it->second;
+	}
+
 	UInt32 SpirvWriter::GetExtVarPointerId(std::size_t extVarIndex) const
 	{
 		auto it = m_currentState->preVisitor->extVars.find(extVarIndex);