Adding support for array parameters

include/Gaffer/PlugAlgo.h

@@ -50,6 +50,7 @@ namespace Gaffer
 
 IE_CORE_FORWARDDECLARE( GraphComponent )
 IE_CORE_FORWARDDECLARE( ValuePlug )
+IE_CORE_FORWARDDECLARE( ArrayPlug )
 
 namespace PlugAlgo
 {
@@ -86,6 +87,9 @@ GAFFER_API ValuePlugPtr createPlugFromData( const std::string &name, Plug::Direc
 /// Returns a Data value from a plug.
 GAFFER_API IECore::DataPtr getValueAsData( const ValuePlug *plug );
 
+/// Returns a VectorData value from an array plug.
+GAFFER_API IECore::DataPtr getArrayAsVectorData( const ArrayPlug *plug );
+
 /// Sets the value of an existing plug to the specified data.
 /// Returns `true` on success and `false` on failure.
 GAFFER_API bool setValueFromData( ValuePlug *plug, const IECore::Data *value );

src/Gaffer/PlugAlgo.cpp

@@ -48,6 +48,7 @@
 #include "Gaffer/TransformPlug.h"
 #include "Gaffer/TypedObjectPlug.h"
 #include "Gaffer/ValuePlug.h"
+#include "Gaffer/ArrayPlug.h"
 
 #include "IECore/SplineData.h"
 
@@ -532,6 +533,66 @@ IECore::DataPtr getValueAsData( const ValuePlug *plug )
 
 }
 
+IECore::DataPtr getArrayAsVectorData( const ArrayPlug *plug )
+{
+	size_t size = plug->children().size();
+	if ( !size )
+	{
+		return nullptr;
+	}
+	auto *childPlug = plug->getChild( 0 );
+	int i = 0;
+	switch(static_cast<Gaffer::TypeId>(childPlug->typeId()))
+	{
+		case FloatPlugTypeId :
+		{
+			FloatVectorDataPtr data = new FloatVectorData();
+			data->writable().resize( size );
+			for( Plug::InputIterator it( plug ); !it.done(); ++it, ++i )
+			{
+				data->writable()[i] = static_cast<const FloatPlug *>( it->get() )->getValue();
+			}
+			return data;
+		}
+		case IntPlugTypeId :
+		{
+			IntVectorDataPtr data = new IntVectorData();
+			data->writable().resize( size );
+			for( Plug::InputIterator it( plug ); !it.done(); ++it, ++i )
+			{
+				data->writable()[i] = static_cast<const IntPlug *>( it->get() )->getValue();
+			}
+			return data;
+		}
+		case Color3fPlugTypeId :
+		{
+			Color3fVectorDataPtr data = new Color3fVectorData();
+			data->writable().resize( size );
+			for( Plug::InputIterator it( plug ); !it.done(); ++it, ++i )
+			{
+				data->writable()[i] = static_cast<const Color3fPlug *>( it->get() )->getValue();
+			}
+			return data;
+		}
+		case Color4fPlugTypeId :
+		{
+			Color4fVectorDataPtr data = new Color4fVectorData();
+			data->writable().resize( size );
+			for( Plug::InputIterator it( plug ); !it.done(); ++it, ++i )
+			{
+				data->writable()[i] = static_cast<const Color4fPlug *>( it->get() )->getValue();
+			}
+			return data;
+		}
+		default :
+			throw IECore::Exception(
+				fmt::format( "Plug \"{}\" has unsupported type \"{}\"", childPlug->getName().string(), childPlug->typeName() )
+			);
+	}
+
+}
+
+
 IECore::DataPtr extractDataFromPlug( const ValuePlug *plug )
 {
 	return getValueAsData( plug );

src/GafferArnold/ParameterHandler.cpp

@@ -45,6 +45,7 @@
 #include "Gaffer/ScriptNode.h"
 #include "Gaffer/StringPlug.h"
 #include "Gaffer/TypedPlug.h"
+#include "Gaffer/ArrayPlug.h"
 
 #include "IECore/MessageHandler.h"
 
@@ -146,6 +147,26 @@ Gaffer::Plug *setupNumericPlug( const AtNodeEntry *node, const AtParamEntry *par
 	return plug.get();
 }
 
+template<typename PlugType>
+Gaffer::Plug *setupArrayPlug( const IECore::InternedString &parameterName, Gaffer::GraphComponent *plugParent, Gaffer::Plug::Direction direction )
+{
+    PlugType *existingPlug = plugParent->getChild<PlugType>( parameterName );
+
+    if(
+        existingPlug &&
+        existingPlug->direction() == direction
+    )
+    {
+        existingPlug->setFlags( Gaffer::Plug::Dynamic, false );
+        return existingPlug;
+    }
+
+    typename PlugType::Ptr plug = new PlugType( parameterName, direction, nullptr, 1, std::numeric_limits<size_t>::max(), Plug::Flags::Default, false );
+    PlugAlgo::replacePlug( plugParent, plug );
+
+    return plug.get();
+}
+
 Gaffer::Plug *setupPlug( const IECore::InternedString &parameterName, Gaffer::GraphComponent *plugParent, Gaffer::Plug::Direction direction )
 {
 	Plug *existingPlug = plugParent->getChild<Plug>( parameterName );
@@ -572,6 +593,10 @@ Gaffer::Plug *ParameterHandler::setupPlug( const AtNodeEntry *node, const AtPara
 			);
 			break;
 
+        case AI_TYPE_ARRAY :
+            plug = setupArrayPlug<ArrayPlug>( AiParamGetName( parameter ).c_str(), plugParent, direction);
+            break;
+
 	}
 
 	if( !plug )

src/GafferScene/Shader.cpp

@@ -430,12 +430,7 @@ class Shader::NetworkBuilder
 			}
 			else if( const Gaffer::ArrayPlug *array = IECore::runTimeCast<const Gaffer::ArrayPlug>( parameter ) )
 			{
-				int i = 0;
-				for( Plug::InputIterator it( array ); !it.done(); ++it, ++i )
-				{
-					IECore::InternedString childParameterName = parameterName.string() + "[" + std::to_string( i ) + "]";
-					addParameter( it->get(), childParameterName, shader, connections );
-				}
+				addParameter( parameter, parameterName, shader, connections );
 			}
 			else
 			{
@@ -617,6 +612,15 @@ class Shader::NetworkBuilder
 			{
 				addSplineParameterComponentConnections< SplinefColor4fPlug >( (const SplinefColor4fPlug*)parameter, parameterName, connections );
 			}
+			else if ( (Gaffer::TypeId)parameter->typeId() == ArrayPlugTypeId )
+			{
+				int i = 0; 
+				for ( Plug::InputIterator it( parameter ); !it.done(); ++it, ++i )
+				{
+					IECore::InternedString inputName = parameterName.string() + "[" + std::to_string( i ) + "]";
+					addParameterComponentConnections( it->get(), inputName, connections );
+				}
+			}
 		}
 
 		template< typename T >
@@ -1059,6 +1063,10 @@ IECore::DataPtr Shader::parameterValue( const Gaffer::Plug *parameterPlug ) cons
 	{
 		return Gaffer::PlugAlgo::getValueAsData( valuePlug );
 	}
+	else if( auto arrayPlug = IECore::runTimeCast<const Gaffer::ArrayPlug>( parameterPlug ) )
+	{
+		return Gaffer::PlugAlgo::getArrayAsVectorData( arrayPlug );
+	}
 
 	return nullptr;
 }