FIX : ShaderNetworkAlgo : Prefer struct to tuple

Author: danieldresser-ie

src/IECoreScene/ShaderNetworkAlgo.cpp

@@ -1003,8 +1003,16 @@ const InternedString g_arrayOutputNames[maxArrayInputAdapterSize + 1] = {
 const boost::regex g_rampElementRegex( "^(.*)\\[(.*)\\]\\.y(.*)$" );
 const boost::regex g_splineAdapterInRegex( "^in([0-9]+)(\\..*)?$" );
 
+struct RampInputAdapterParameters
+{
+	InternedString adapterHandle;
+	size_t origSize;
+	size_t expandedSize;
+	int knotOffset;
+};
+
 template< typename TypedRamp >
-std::tuple< InternedString, size_t, size_t, size_t > createRampInputAdapter(
+RampInputAdapterParameters createRampInputAdapter(
 	ShaderNetwork *network, const TypedData<TypedRamp> *rampData,
 	const IECore::CompoundDataMap &newParameters, const IECore::InternedString &rampParameterName,
 	const ShaderNetwork::Parameter &destination
@@ -1052,7 +1060,7 @@ std::tuple< InternedString, size_t, size_t, size_t > createRampInputAdapter(
 		{ destination.shader, splineValuesName }
 	) );
 
-	return std::make_tuple( adapterHandle, rampData->readable().points.size(), splineValues.size(), rampData->readable().oslStartPointMultiplicity() );
+	return { adapterHandle, rampData->readable().points.size(), splineValues.size(), rampData->readable().oslStartPointMultiplicity() };
 }
 
 } // namespace
@@ -1238,7 +1246,7 @@ void ShaderNetworkAlgo::expandRamps( ShaderNetwork *network, std::string targetP
 		// parameter for the shader, and holds the name of the adapter shader, and the offset we
 		// need to use when accessing the knot vector.
 
-		std::map< IECore::InternedString, std::tuple< IECore::InternedString, size_t, size_t, size_t > > currentRampArrayAdapters;
+		std::map< IECore::InternedString, RampInputAdapterParameters > currentRampArrayAdapters;
 
 		std::vector< ShaderNetwork::Connection > connectionsToAdd;
 		ShaderNetwork::ConnectionRange inputConnections = network->inputConnections( s.first );
@@ -1271,7 +1279,7 @@ void ShaderNetworkAlgo::expandRamps( ShaderNetwork *network, std::string targetP
 			}
 
 			// Insert a conversion shader to handle connection to component
-			auto [ adapterIter, newlyInserted ] = currentRampArrayAdapters.insert( { parameterName, std::make_tuple( IECore::InternedString(), 0, 0, 0 ) } );
+			auto [ adapterIter, newlyInserted ] = currentRampArrayAdapters.insert( { parameterName, RampInputAdapterParameters() } );
 			if( newlyInserted )
 			{
 				if( colorRampData )
@@ -1288,7 +1296,7 @@ void ShaderNetworkAlgo::expandRamps( ShaderNetwork *network, std::string targetP
 				}
 			}
 
-			const auto [ adapterHandle, origSize, expandedSize, knotOffset ] = adapterIter->second;
+			const RampInputAdapterParameters &adapterParms = adapterIter->second;
 
 			int elementId;
 			std::string_view elementIdString( stringViewFromMatch( destName, rampElementMatch, 2 ) );
@@ -1301,9 +1309,9 @@ void ShaderNetworkAlgo::expandRamps( ShaderNetwork *network, std::string targetP
 				throw IECore::Exception( StringAlgo::concat( "Invalid ramp point index ", elementIdString ) );
 			}
 
-			if( elementId < 0 || elementId >= (int)origSize )
+			if( elementId < 0 || elementId >= (int)adapterParms.origSize )
 			{
-				throw IECore::Exception( "Connection to ramp index " + std::to_string( elementId ) + " is out of range in ramp with " + std::to_string( origSize ) + " points." );
+				throw IECore::Exception( "Connection to ramp index " + std::to_string( elementId ) + " is out of range in ramp with " + std::to_string( adapterParms.origSize ) + " points." );
 			}
 
 			// Map connections to the corresponding parameters of the expanded ramp. When mapping the
@@ -1321,16 +1329,16 @@ void ShaderNetworkAlgo::expandRamps( ShaderNetwork *network, std::string targetP
 			if( elementId == 0 )
 			{
 				outIndexMin = 0;
-				outIndexMax = knotOffset;
+				outIndexMax = adapterParms.knotOffset;
 			}
-			else if( elementId == (int)( origSize - 1 ) )
+			else if( elementId == (int)( adapterParms.origSize - 1 ) )
 			{
-				outIndexMin = elementId + knotOffset;
-				outIndexMax = expandedSize - 1;
+				outIndexMin = elementId + adapterParms.knotOffset;
+				outIndexMax = adapterParms.expandedSize - 1;
 			}
 			else
 			{
-				outIndexMin = outIndexMax = elementId + knotOffset;
+				outIndexMin = outIndexMax = elementId + adapterParms.knotOffset;
 			}
 
 			for( int i = outIndexMin; i <= outIndexMax; i++ )
@@ -1341,7 +1349,7 @@ void ShaderNetworkAlgo::expandRamps( ShaderNetwork *network, std::string targetP
 					destinationName = StringAlgo::concat( destinationName.string(), stringViewFromMatch( destName, rampElementMatch, 3 ) );
 				}
 
-				network->addConnection( { connection.source, { adapterHandle, destinationName } } );
+				network->addConnection( { connection.source, { adapterParms.adapterHandle, destinationName } } );
 			}
 		}