Am Mittwoch, den 19.11.2008, 16:37 -0500 schrieb DJ Delorie: > > Important may be the correct mapping of user input to internal pcb > > coordinates. > > The problem is rounding - some grid points round up, some round down. > You end up with off-by-one bugs, no matter how "precise" you are, > unless you can avoid the need to round completely. >
I see that rounding can be a problem. I think that pcb program should always use its internal coordinates for calculation and for its grid. If each user input (mouse click) is mapped to this exact grid position (which is an integer multiple of pcbs internal units) it may work. Of course, if user input is first mapped to a mm grid, than rounded, rounding errors and problems may occur. If user select i.e. 0.25 mm grid, pcb program should use a 0.01 mil based grid which best fits a 0.25 mm look. Maybe I am wrong, I do not no internals of pcb program, and have not much experience in programming graphical software. Best regards Stefan _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
