On Oct 9, 2010, at 4:30 AM, Karl Hammar wrote: >> >> but scaled integers are a bit easier to use and understand, > > Yes (but we are talking about internal values, the user don't have to > "see" them, only the developers, think of todays "1mm").
In an open source toolkit, the distinction between "developer" and "user" is blurry. This is a good thing, as far as I'm concerned. In any case, the developers have to understand the geometry calculations. There are subtle problems with carrying real number analytic geometry into a discrete domain. These are easier to deal with if the granularity is fixed, so if scaled integers have adequate dynamic range, they are to be preferred. I am surprised by the efficiency debate. I would think that for pcb, the vast bulk of calculation involves rendering graphics in device coordinates, not board geometry in board coordinates. Board coordinates are extremely important as *anchors* for rendering, so precise calculations are important here, but rendering itself is a different thing. John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ [email protected] _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
