kicad-developers team mailing list archive

[Jeff Young <jeff@xxxxxxxxx>]

Hi Seth,

I looked at that bug report, and all the Eagle zones have rounded corners, not square.  So I don’t think you were actually getting anything out of the mitering, but that was being masked by the fact that we do in fact stroke the outer zone boundary (therefore giving you rounded corners).

Just to be clear, we stroke with the zone-min-width stroke, rather than the zone boundary’s linewidth.  We first deflate the zone by 1/2-min-width (which drops out all the min-width features), and then stroke it with min-width which expands it back to size and gives us some corner rounding as a bonus.

JP has recently introduced a new mode where we don’t stroke the boundary anymore (I think primarily for performance, but I’m not 100% sure).  Under this algorithm we still deflate the zones by 1/2-min-width, but we then inflate them again to bring them back to size.  My changes are largely to add corner rounding to this case.

Cheers,
Jeff.


> On 14 Jul 2019, at 18:53, Seth Hillbrand <seth@xxxxxxxxxxxxx> wrote:
> 
> Please be super careful here.  I was using that implicit fallback in the Eagle import to get a square inflation that is needed to mimic the Eagle zones.  I didn't think we were using that type of inflation anywhere else (but that could have changed).  If we are using that elsewhere, can you verify that the change to clipper doesn't re-introduce https://bugs.launchpad.net/kicad/+bug/1817312 ?
> 
> Thanks-
> Seth
> 
> On 2019-07-14 13:17, Jeff Young wrote:
>> Hi Seth,
>> We weren’t calling it directly anywhere.  But jtMiter has a
>> MiterLimit, after which it falls back to square.  I’ve changed that
>> fallback to round (and enforced a much lower MiterLimit so that it
>> mimics the smoothing we used to get by drawing the border with a
>> 1/2-min-width thick stroke).
>> Cheers,
>> Jeff.
>>> On 14 Jul 2019, at 17:50, Seth Hillbrand <seth@xxxxxxxxxxxxx> wrote:
>>> On 2019-07-14 05:31, Jeff Young wrote:
>>>> I made another optimisation, this time within the Clipper library.
>>>> When the offset exceeds the MiterLimit it will perform jtRound instead
>>>> of jtSquare.  I *think* this makes the zero-width-border algorithm
>>>> materially indistinguishable from the old algorithm (well, except that
>>>> several bugs are fixed in the new one and it’s faster).
>>> Hi Jeff-
>>> Were we using jtSquare somewhere?  I had added an option to inflate using jtMiter but this was for Eagle import only.  I thought all other inflations were using jtRound.
>>> Best-
>>> Seth