C++ Plug::children方法代码示例

void OSLShader::loadShader( const std::string &shaderName, bool keepExistingValues )
{
	Plug *existingOut = outPlug();
	if( shaderName.empty() )
	{
		parametersPlug()->clearChildren();
		namePlug()->setValue( "" );
		typePlug()->setValue( "" );
		if( existingOut )
		{
			existingOut->clearChildren();
		}
		return;
	}

	const char *searchPath = getenv( "OSL_SHADER_PATHS" );

	OSLQuery query;
	if( !query.open( shaderName, searchPath ? searchPath : "" ) )
	{
		throw Exception( query.geterror() );
	}

	const bool outPlugHadChildren = existingOut ? existingOut->children().size() : false;
	if( !keepExistingValues )
	{
		// If we're not preserving existing values then remove all existing
		// parameter plugs - the various plug creators above know that if a
		// plug exists then they should preserve its values.
		parametersPlug()->clearChildren();
		if( existingOut )
		{
			existingOut->clearChildren();
		}
	}

	m_metadata = NULL;
	namePlug()->setValue( shaderName );
	typePlug()->setValue( std::string( "osl:" ) + query.shadertype().c_str() );

	const IECore::CompoundData *metadata = OSLShader::metadata();
	const IECore::CompoundData *parameterMetadata = NULL;
	if( metadata )
	{
		parameterMetadata = metadata->member<IECore::CompoundData>( "parameter" );
	}


	loadShaderParameters( query, parametersPlug(), parameterMetadata );

	if( !existingOut || existingOut->typeId() != Plug::staticTypeId() )
	{
		PlugPtr outPlug = new Plug( "out", Plug::Out, Plug::Default | Plug::Dynamic );
		if( existingOut )
		{
			// We had an out plug but it was the wrong type (we used
			// to use a CompoundPlug before that was deprecated). Move
			// over any existing child plugs onto our replacement.
			for( PlugIterator it( existingOut ); !it.done(); ++it )
			{
				outPlug->addChild( *it );
			}
		}
		setChild( "out", outPlug );
	}

	if( query.shadertype() == "shader" )
	{
		loadShaderParameters( query, outPlug(), parameterMetadata );
	}
	else
	{
		outPlug()->clearChildren();
	}

	if( static_cast<bool>( outPlug()->children().size() ) != outPlugHadChildren )
	{
		// OSLShaderUI registers a dynamic metadata entry which depends on whether or
		// not the plug has children, so we must notify the world that the value will
		// have changed.
		Metadata::plugValueChangedSignal()( staticTypeId(), "out", "nodule:type", outPlug() );
	}
}