PlugAlgo : Add array[1] -> scalar conversion

This conversion is available in the various query nodes, and is particularly useful when querying attributes and primitive variables from certain DCCs which like to write everything as arrays, even if they make more sense as scalars.

Changes.md

@@ -1,7 +1,15 @@
 1.4.x.x (relative to 1.4.1.0)
 =======
 
+Improvements
+------------
+
+- AttributeQuery, PrimitiveVariableQuery, ContextQuery, OptionQuery, ShaderQuery : Added support for querying arrays of length 1 as their equivalent scalar types.
+
+API
+---
 
+- PlugAlgo : `setValueFromData()` and `canSetValueFromData()` now support conversion of arrays of length 1 to their equivalent scalar types.
 
 1.4.1.0 (relative to 1.4.0.0)
 =======

python/GafferSceneTest/PrimitiveVariableQueryTest.py

@@ -689,5 +689,36 @@ def testSerialisation( self ) :
 			self.assertEqual( output["type"].getValue(), dataType.staticTypeName() )
 			self.assertEqual( output["value"].getValue(), value )
 
+	def testArrayScalarConversion( self ) :
+
+		cube = GafferScene.Cube()
+
+		cubeFilter = GafferScene.PathFilter()
+		cubeFilter["paths"].setValue( IECore.StringVectorData( [ "/cube" ] ) )
+
+		primitiveVariables = GafferScene.PrimitiveVariables()
+		primitiveVariables["in"].setInput( cube["out"] )
+		primitiveVariables["filter"].setInput( cubeFilter["out"] )
+
+		primitiveVariables["primitiveVariables"].addChild( Gaffer.NameValuePlug( "testLengthZero", IECore.IntVectorData() ) )
+		primitiveVariables["primitiveVariables"].addChild( Gaffer.NameValuePlug( "testLengthOne", IECore.IntVectorData( [ 2 ] ) ) )
+		primitiveVariables["primitiveVariables"].addChild( Gaffer.NameValuePlug( "testLengthTwo", IECore.IntVectorData( [ 3, 3 ] ) ) )
+
+		query = GafferScene.PrimitiveVariableQuery()
+		query["scene"].setInput( primitiveVariables["out"] )
+		query["location"].setValue( "/cube" )
+		query.addQuery( Gaffer.IntPlug( defaultValue = -1 ), "testLengthZero" )
+
+		self.assertEqual( query["out"][0]["exists"].getValue(), True )
+		self.assertTrue( query["out"][0]["value"].getValue(), -1 )
+
+		query["queries"][0]["name"].setValue( "testLengthOne" )
+		self.assertEqual( query["out"][0]["exists"].getValue(), True )
+		self.assertTrue( query["out"][0]["value"].getValue(), 2 )
+
+		query["queries"][0]["name"].setValue( "testLengthTwo" )
+		self.assertEqual( query["out"][0]["exists"].getValue(), True )
+		self.assertTrue( query["out"][0]["value"].getValue(), -1 )
+
 if __name__ == "__main__":
-	unittest.main()
+	unittest.main()

python/GafferTest/PlugAlgoTest.py

@@ -961,6 +961,43 @@ def testDataConversionsForAllTypes( self ) :
 					self.assertEqual( plug.getValue(), data.value )
 				self.assertEqual( Gaffer.PlugAlgo.getValueAsData( plug ), data )
 
+	def testSetNumericValueFromVectorData( self ) :
+
+		for plugType in Gaffer.FloatPlug, Gaffer.IntPlug, Gaffer.BoolPlug :
+			plug = plugType()
+			for dataType in [
+				IECore.HalfVectorData,
+				IECore.FloatVectorData,
+				IECore.DoubleVectorData,
+				IECore.UCharVectorData,
+				IECore.ShortVectorData,
+				IECore.UShortVectorData,
+				IECore.IntVectorData,
+				IECore.UIntVectorData,
+				IECore.Int64VectorData,
+				IECore.UInt64VectorData,
+				IECore.BoolVectorData,
+			] :
+				with self.subTest( plugType = plugType, dataType = dataType ) :
+					for value in ( 0, 1 ) :
+						data = dataType()
+						# Array length 0, can't set.
+						self.assertFalse( Gaffer.PlugAlgo.canSetValueFromData( plug, data ) )
+						plug.setToDefault()
+						self.assertFalse( Gaffer.PlugAlgo.setValueFromData( plug, data ) )
+						self.assertTrue( plug.isSetToDefault() )
+						# Array length 1, can set.
+						data.append( value )
+						self.assertTrue( Gaffer.PlugAlgo.canSetValueFromData( plug, data ) )
+						self.assertTrue( Gaffer.PlugAlgo.setValueFromData( plug, data ) )
+						self.assertEqual( plug.getValue(), value )
+						# Array length > 1, can't set.
+						data.append( value )
+						self.assertFalse( Gaffer.PlugAlgo.canSetValueFromData( plug, data ) )
+						plug.setToDefault()
+						self.assertFalse( Gaffer.PlugAlgo.setValueFromData( plug, data ) )
+						self.assertTrue( plug.isSetToDefault() )
+
 	def testDependsOnCompute( self ) :
 
 		add = GafferTest.AddNode()

src/Gaffer/PlugAlgo.cpp

@@ -49,6 +49,7 @@
 #include "Gaffer/TypedObjectPlug.h"
 #include "Gaffer/ValuePlug.h"
 
+#include "IECore/DataAlgo.h"
 #include "IECore/SplineData.h"
 
 #include "boost/algorithm/string/predicate.hpp"
@@ -565,6 +566,17 @@ IECore::DataPtr extractDataFromPlug( const ValuePlug *plug )
 namespace
 {
 
+template<typename PlugType, typename DataType>
+bool setNumericPlugValueFromVectorData( PlugType *plug, const DataType *value )
+{
+	if( value->readable().size() == 1 )
+	{
+		plug->setValue( value->readable()[0] );
+		return true;
+	}
+	return false;
+}
+
 template<typename PlugType>
 bool setNumericPlugValue( PlugType *plug, const Data *value )
 {
@@ -606,6 +618,30 @@ bool setNumericPlugValue( PlugType *plug, const Data *value )
 		case BoolDataTypeId :
 			plug->setValue( static_cast<const BoolData *>( value )->readable() );
 			return true;
+		case HalfVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const HalfVectorData *>( value ) );
+		case FloatVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const FloatVectorData *>( value ) );
+		case DoubleVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const DoubleVectorData *>( value ) );
+		case CharVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const CharVectorData *>( value ) );
+		case UCharVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const UCharVectorData *>( value ) );
+		case ShortVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const ShortVectorData *>( value ) );
+		case UShortVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const UShortVectorData *>( value ) );
+		case IntVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const IntVectorData *>( value ) );
+		case UIntVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const UIntVectorData *>( value ) );
+		case Int64VectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const Int64VectorData *>( value ) );
+		case UInt64VectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const UInt64VectorData *>( value ) );
+		case BoolVectorDataTypeId :
+			return setNumericPlugValueFromVectorData( plug, static_cast<const BoolVectorData *>( value ) );
 		default :
 			return false;
 	}
@@ -774,6 +810,19 @@ bool canSetNumericPlugValue( const Data *value )
 		case UInt64DataTypeId :
 		case BoolDataTypeId :
 			return true;
+		case HalfVectorDataTypeId :
+		case FloatVectorDataTypeId :
+		case DoubleVectorDataTypeId :
+		case CharVectorDataTypeId :
+		case UCharVectorDataTypeId :
+		case ShortVectorDataTypeId :
+		case UShortVectorDataTypeId :
+		case IntVectorDataTypeId :
+		case UIntVectorDataTypeId :
+		case Int64VectorDataTypeId :
+		case UInt64VectorDataTypeId :
+		case BoolVectorDataTypeId :
+			return IECore::size( value ) == 1;
 		default :
 			return false;
 	}