kicad-developers team mailing list archive

[jean-pierre charras <jp.charras@xxxxxxxxxx>]

Le 18/04/2012 20:25, Dick Hollenbeck a écrit :
> > I am working on this today.
> >
> > My gut says this:
> >
> >
> > Basically it comes down to the fact that we cannot describe an area larger than about 12
> > feet with the nanometer internal units.
>
>
> Jean-Pierre,
>
> Can you first look over the attached patch, then play with it.
>
> This basically fixes the crash, but I think there's more finishing touches that need to be
> done.
>
> I need to get back to work now.
>
>
> Thank you very much,
>
> Dick

I'll work on that tomorrow.

I also make some tests.
Under Windows I did now have crashes, but I had other issues.

my opinion is with 32 bits integers we cannot handle more than something like 50 to 70 cm,
with nanometers units.

I noticed there are a lot of issues when calculating distance between 2 points.

Assuming calculations are using integers, with 32 bits we can handle 2 meters distances only.
if Xmax and Ymax are Y and Y difference between 2 points,
only Y or Y max <= 1.4 meter, if sqrt( Xmax*Xmax + Ymax*Ymax) always < 2m.

Because a distance is always >= 0, this means X and Y coordinates must have absolute coordinates < 70 cm.
With margins around work area, and because Pcbnew and Gerbview use a page only with positive coordinates,
the active area has a size < 50cm, roughly 20 inches, or A3 or B page size.


--
Jean-Pierre CHARRAS