Method isPrimitiveVariableValid

src/IECoreScene/Primitive.cpp:517–573

} // namespace

bool Primitive::isPrimitiveVariableValid( const PrimitiveVariable &pv ) const
{
	if( !pv.data || pv.interpolation==PrimitiveVariable::Invalid )
	{
		return false;
	}

	if( !pv.indices && pv.interpolation == PrimitiveVariable::Constant )
	{
		// any data is reasonable for constant interpolation
		// provided there are no indices. if there are indices
		// we still need to validate their range below.
		return true;
	}

	// All other interpolations require an array of data or an array of indices
	// of the correct length. It could be argued that SimpleTypedData should be
	// accepted in the rare case that variableSize==1, but we're rejecting that
	// argument on the grounds that it makes for a whole bunch of special cases
	// with no gain - the general cases require arrays. Note that variableSize
	// of 0 is a special case for empty data, which we must allow to pass here.
	size_t sz = variableSize( pv.interpolation );
	size_t dataSize = despatchTypedData<TypedDataSize, TypeTraits::IsVectorTypedData, ReturnZeroErrorHandler>( pv.data.get() );
	if( !dataSize && sz )
	{
		return false;
	}

	/// without indices, the data must match exactly
	/// \todo This is not correct in the case of CurvesPrimitives, where uniform
	/// interpolation should be treated the same as constant.
	if( !pv.indices )
	{
		return dataSize == sz;
	}

	// if there are indices, we must ensure they're within the range of data
	// and that they match the expected variable size. the exception for
	// constant variables, since size is irrelevant as the entire array
	// is considered the variable value
	if( pv.indices->readable().size() != sz && pv.interpolation != PrimitiveVariable::Constant )
	{
		return false;
	}

	for( const auto &index : pv.indices->readable() )
	{
		if( index >= (int)dataSize )
		{
			return false;
		}
	}

	// the data doesn't need further validation since we know its
	// VectorTypedData and the indices are in the correct range.
	return true;
}