Ban complex fresnels from BTDFs, add CSpectralVariable getters for the ParameterSet stuff

Author: devsh

examples_tests

@@ -289,16 +289,19 @@ class CFrontendIR : public CNodePool
 
 				enum class Semantics : uint8_t
 				{
+					NoneUndefined = 0,
 					// 3 knots, their wavelengths are implied and fixed at color primaries
-					Fixed3_SRGB = 0,
-					Fixed3_DCI_P3 = 1,
-					Fixed3_BT2020 = 2,
-					Fixed3_AdobeRGB = 3,
-					Fixed3_AcesCG = 4,
+					Fixed3_SRGB = 1,
+					Fixed3_DCI_P3 = 2,
+					Fixed3_BT2020 = 3,
+					Fixed3_AdobeRGB = 4,
+					Fixed3_AcesCG = 5,
 					// Ideas: each node is described by (wavelength,value) pair
 					// PairsLinear = 5, // linear interpolation
 					// PairsLogLinear = 5, // linear interpolation in wavelenght log space
 				};
+
+				//
 				template<uint8_t Count>
 				struct SCreationParams
 				{
@@ -312,46 +315,74 @@ class CFrontendIR : public CNodePool
 					template<bool Enable=true> requires (Enable==(Count>1))
 					const Semantics& getSemantics() const {return const_cast<const Semantics&>(const_cast<SCreationParams<Count>*>(this)->getSemantics());}
 				};
+				//
 				template<uint8_t Count>
-				static inline uint32_t calc_size(const SCreationParams<Count>&)
+				inline CSpectralVariable(SCreationParams<Count>&& params)
 				{
-					return sizeof(CSpectralVariable)+sizeof(SCreationParams<Count>);
+					// back up the count
+					params.knots.params[0].padding[1] = Count;
+					// set it correctly for monochrome
+					if constexpr (Count==1)
+						params.knots.params[0].padding[2] = static_cast<uint8_t>(Semantics::NoneUndefined);
+					else
+					{
+						assert(params.getSemantics()!=Semantics::NoneUndefined);
+					}
+					std::construct_at(reinterpret_cast<SCreationParams<Count>*>(this+1),std::move(params));
 				}
-				
+
+				// encapsulation due to padding abuse
+				inline uint8_t& uvSlot() {return pWonky()->knots.uvSlot();}
+				inline const uint8_t& uvSlot() const {return pWonky()->knots.uvSlot();}
+
+				// these getters are immutable
 				inline uint8_t getKnotCount() const
 				{
 					static_assert(sizeof(SParameter::padding)>1);
 					return paramsBeginPadding()[1];
 				}
-				inline uint32_t getSize() const override
+				inline Semantics getSemantics() const
 				{
-					return sizeof(CSpectralVariable)+sizeof(SCreationParams<1>)+(getKnotCount()-1)*sizeof(SParameter);
+					static_assert(sizeof(SParameter::padding)>2);
+					const auto retval = static_cast<Semantics>(paramsBeginPadding()[2]);
+					assert((getKnotCount()==1)==(retval==Semantics::NoneUndefined));
+					return retval;
+				}
+
+				//
+				inline SParameter* getParam(const uint8_t i)
+				{
+					if (i<getKnotCount())
+						return &pWonky()->knots.params[i];
+					return nullptr;
 				}
+				inline const SParameter* getParam(const uint8_t i) const {return const_cast<const SParameter*>(const_cast<CSpectralVariable*>(this)->getParam(i));}
 
+				//
 				template<uint8_t Count>
-				inline CSpectralVariable(SCreationParams<Count>&& params)
+				static inline uint32_t calc_size(const SCreationParams<Count>&)
 				{
-					// back up the count
-					params.knots.params[0].padding[1] = Count;
-					std::construct_at(reinterpret_cast<SCreationParams<Count>*>(this+1),std::move(params));
+					return sizeof(CSpectralVariable)+sizeof(SCreationParams<Count>);
+				}
+				inline uint32_t getSize() const override
+				{
+					return sizeof(CSpectralVariable)+sizeof(SCreationParams<1>)+(getKnotCount()-1)*sizeof(SParameter);
 				}
 
 				inline operator bool() const {return !invalid(SInvalidCheckArgs{.pool=nullptr,.logger=nullptr});}
 
 			protected:
 				inline ~CSpectralVariable()
 				{
-					auto pWonky = reinterpret_cast<SCreationParams<1>*>(this+1);
-					std::destroy_n(pWonky->knots.params,getKnotCount());
+					std::destroy_n(pWonky()->knots.params,getKnotCount());
 				}
 
 				inline _TypedHandle<IExprNode> getChildHandle_impl(const uint8_t ix) const override {return {};}
 				inline bool invalid(const SInvalidCheckArgs& args) const override
 				{
 					const auto knotCount = getKnotCount();
-					auto pWonky = reinterpret_cast<const SCreationParams<2>*>(this+1);
 					// non-monochrome spectral variable 
-					if (const auto semantic=pWonky->getSemantics(); knotCount>1)
+					if (const auto semantic=getSemantics(); knotCount>1)
 					switch (semantic)
 					{
 						case Semantics::Fixed3_SRGB: [[fallthrough]];
@@ -370,7 +401,7 @@ class CFrontendIR : public CNodePool
 							return true;
 					}
 					for (auto i=0u; i<knotCount; i++)
-					if (!pWonky->knots.params[i])
+					if (!*getParam(i))
 					{
 						args.logger.log("Knot %u parameters invalid",system::ILogger::ELL_ERROR,i);
 						return true;
@@ -382,7 +413,9 @@ class CFrontendIR : public CNodePool
 				NBL_API void printDot(std::ostringstream& sstr, const core::string& selfID) const override;
 
 			private:
-				const uint8_t* paramsBeginPadding() const {return reinterpret_cast<const SCreationParams<1>*>(this+1)->knots.params[0].padding;}
+				SCreationParams<1>* pWonky() {return reinterpret_cast<SCreationParams<1>*>(this+1);}
+				const SCreationParams<1>* pWonky() const {return reinterpret_cast<const SCreationParams<1>*>(this+1);}
+				const uint8_t* paramsBeginPadding() const {return pWonky()->knots.params[0].padding; }
 		};
 		//
 		class IUnaryOp : public IExprNode

include/nbl/asset/material_compiler3/CFrontendIR.h

@@ -47,7 +47,14 @@ bool CFrontendIR::CFresnel::invalid(const SInvalidCheckArgs& args) const
 		if (args.isBTDF)
 		{
 			const auto knotCount = imagEta->getKnotCount();
-			// TODO: check all knots have a scale of 0
+			for (uint8_t i=0; i<knotCount; i++)
+			{
+				const auto& param = *imagEta->getParam(i);
+				if (param.scale==0.f)
+					continue;
+				args.logger.log("Fresnels used for BTDFs cannot have Imaginary Eta, scale must be 0.f for all knots, is %.*e at knot %u",ELL_ERROR,param.scale,i);
+				return true;
+			}
 		}
 	}
 	else
@@ -235,6 +242,7 @@ void CFrontendIR::printDotGraph(std::ostringstream& str) const
 			const auto childCount = node->getChildCount();
 			if (childCount)
 			{
+				// TODO: print with child link names
 				str << "\n\t" << nodeID << " -> {";
 				for (auto childIx=0; childIx<childCount; childIx++)
 				{