§Abstract base class for all Aec streams
§Numerous signatures accept a wide variety of
geometric input
§Decompose geometric input into more
elemental forms
§Eventual result is simple vectors
(startpoint, endpoint)
§Derived stream classes override some
geometry signatures
§Each stream can use that to produce optimal
output
§Derived streams may be used for collections,
filters, calculations,
summations, and interfaces into other systems
§A stream contains several stacks for storing
the current color, linetype,
lineweight, layer, gsmarker, transformation, linetype scale, rendermode, fill type, entity, view
information, etc.
§Properties pushed onto the stack have a
corresponding pop after
the necessary geometry has been streamed through
§