Re: [NTG-context] Check if two paths intersect in Metafun

Hi,

Le 25 déc. 2020 à 08:48, Jairo A. del Rio a écrit :

Hi, list. I've got a question about paths and intersections. The following:

\starttext \startMPpage path p[];

p[1] = fullcircle scaled 2cm; p[2] = unitsquare shifted (4cm,6cm);

if (known (p[1] intersectionpoint p[2])):

draw textext("yes");

else:

draw textext("no"); fi;

\stopMPpage \stoptext

yields an error message: "The paths don't intersect". Is there a way to intercept this error message and trigger an action instead? Thank you in advance.

Instead of using « intersectionpoint » use « Intersectiontimes », this will give you the « time » of the intersection of the two paths. If the paths do not intersect, than the value is (-1,-1). So you could do something like: pair checkintersec ; checkintersec := p[1] intersectiontimes p[2] ; If xpart(checkintersec) <> -1 : draw textext("yes »); else: draw textext(« non »); fi; Fabrice.

Best regards,

Jairo ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki!

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