Hello,
  I am going to create:
     - a list of graphics objects, starting from primitives like point, line, polyline etc. (TGrObj);
     - a list of objects that provide different device contests, like googleearth, autocad, glsceneviewers, bitmap canvas etc. (TGrDevice)
 and I would like to decide to which graphic device draw objects, independetly, something like: TGrObj.drawto(TGrDevice) or TGrDevice.drawlist(list of TGrObj)....

I would appreciate hints to do it efficiently and enough "independently".
(I should use interfaces? if yes.. how?)

thanks in advance,
Filippo
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Filippo Forlani
www.filippoforlani.org