CashFlow, A Visualization Framework for 3D Flow - Studierstube ...

Software Design3.7. DataAccess Node3.7 DataAccess NodeThe functions of the DataAccess node are:⋄ providing information on how to access the virtual array⋄ dispatching the reference to the MultiData node, where the raw data is stored.⋄ supplying suitable iterators for accessing the virtual array.It is a level of indirection between the MultiData node holding the data and theDataConsumer node accessing the data. The DataAccess node is a filter evaluated atruntime. This node enables the user to select parts of the data and change the selectionon the fly.It consists of the following components:• unique keyused to identify this node. All DataConsumer nodes use this unique key to getaccess to this node.• key to MultiData nodedefine the MultiData node this node is bound to. The definition of the virtualarray is based on the real data stored in the MultiData node.• offsetform the first element of the real array to the first element of the virtual array.• lengthnumber of values in the virtual array.• type of virtual arrayThe information is needed to define the corresponding type of virtual array iterator.Based on the type of virtual array special attributes are required like:* incrementused for Multiple Block Virtual Array* repeatused for Multiple Block Virtual Array* random access lookup tableused for Random Virtual Array53