Hi Taco, thanks, from your observation and the way I build the paths, I found out that I can avoid the problem by shortening the paths I join just slightly:
cl := (fullcircle scaled 4u) shifted z0; cl := cl cutbefore point (1/6+epsilon) along cl cutafter point (2/6-epsilon) along cl; cs := (fullcircle scaled 16u) shifted z1; cs := cs cutafter point (1/6-epsilon) along cs; and indeed, it works here now, with different values of the scale u, and it seems more stable. /Mikael PS I found out that eps and epsilon both worked, and I do not see in the metafun manual if there is a difference. On Fri, Feb 12, 2021 at 9:35 AM Taco Hoekwater <t...@bittext.nl> wrote: > > Hi, > > > On 11 Feb 2021, at 17:41, Mikael Sundqvist <mic...@gmail.com> wrote: > > > > Thanks for your investigation and extended example! > > > > So, if I understand it correctly, the problem occurs where the > > different circles are glued together with the .. construction. > > Took me a while to get it, but the problem is the definition of p0: > > p[0] := cs .. cl .. (cs rotated 120) .. (cl rotated 120) .. (cs rotated 240) > .. (cl rotated 240) .. cycle; > > Here are cs and cl after your earlier definition: > > cs := (141.73224999999996,-49.097491614210789) > ..(75.312386775380347,111.25424516116959) > ..(28.347427842053655,147.2925755432174); > > cl := (28.346108531095332,147.29283827977969) > ..(0,154.88788322842163) > ..(-28.346108531095332,147.29283827977969); > > Note how the last point of cs and the first point of cl are nearly the same. > When you combine these bits into p0, p0 becomes a cyclic path with 18 points > (where you really want/need only 12 points). > > The micro-segments between these nearly-identical paths are the problem. At > smaller u values the differences between the points become zero, and the > directionpoint of a path of length zero is mathematically undefined. > > I do not know a quick generic solution off hand, but that is what the issue > is. > > Best wishes, > Taco > > > ___________________________________________________________________________________ > If your question is of interest to others as well, please add an entry to the > Wiki! > > maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context > webpage : http://www.pragma-ade.nl / http://context.aanhet.net > archive : https://bitbucket.org/phg/context-mirror/commits/ > wiki : http://contextgarden.net > ___________________________________________________________________________________ ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________
