Hi there,
Then what about saving the result: it could be as SVG, or maybe some other format (rendered as png or whatever?), so perhaps non-member writer functions would be best, along with accessor const-member functions in the vector_drawing type to allow the DOM to be enumerated? Presumable it would be possible to read in SVG as well, although maybe that would be a step too far for this project?
More questions than answers here maybe, but something for you to think about.
Since gil has been accepted into boost I could image using gil for writing an image. I'm creating an extension for gil using openCV for the drawing commands. It's very limited so far, but the basic commands are there, like line, polyline, circle, etc.. It's also very easy to extend the capabilities. So, why not use gil for saving the results of the SVG plotter? Christian