Method readAttribute

src/IECoreScene/NParticleReader.cpp:289–410

}

DataPtr NParticleReader::readAttribute( const std::string &name )
{
	if( !open() )
	{
		return nullptr;
	}

	int frameIndex = m_frameParameter->getNumericValue();
	int frame = m_frames->readable()[frameIndex];
	std::map<int, IFFFile::Chunk::ChunkIterator>::const_iterator frameIt = frameToRootChildren.find( frame );
	if( frameIt == frameToRootChildren.end() )
	{
		msg( Msg::Warning, "NParticleReader::readAttribute()", boost::format( "Frame '%d' (index '%d') does not exist in '%s'." ) % frame % frameIndex % m_iffFileName );
		return nullptr;
	}

	bool foundAttr = false;
	std::string channelName;
	IFFFile::Chunk::ChunkIterator attrIt;
	IFFFile::Chunk::ChunkIterator cache = frameIt->second;
	IFFFile::Chunk::ChunkIterator it = cache->childrenBegin();

	for ( ; it != cache->childrenEnd(); it++ )
	{
		if ( it->type().id() == kCHNM )
		{
			it->read( channelName );

			if ( name.compare( channelName ) == 0 )
			{
				attrIt = it;
				foundAttr = true;
				break;
			}
		}
	}

	if ( !foundAttr )
	{
		return nullptr;
	}

	for ( it++; it < attrIt+2 && it != cache->childrenEnd(); it++ )
	{
		int id = it->type().id();
		if ( id != kSIZE && id != kDBLA && id != kDVCA && id != kFVCA )
		{
			msg( Msg::Warning, "NParticleReader::readAttribute()", boost::format( "CHNM '%s' found, but was followed by invalid Tag '%s'." ) % name % it->type().name() );
			return nullptr;
		}
	}

	DataPtr result = nullptr;

	int numParticles = 0;
	(attrIt+1)->read( numParticles );

	switch( (attrIt+2)->type().id() )