[NTG-context] About filling paths, unfill, etc.

[Hans Hagen]

On 11/3/2020 12:59 PM, Jairo A. del Rio wrote:
> Hi everyone. I want to know if nowadays (2020) Metafun is able to do an 
> actual unfill, like above:
> 
> https://tex.stackexchange.com/questions/151068/how-can-i-fill-a-complex-path-with-metapost-metafun/218718#218718
> 
> Example of what I want to do:
> 
> \startMPpage
> 
> path A, B, C;
> 
> A := unitcircle shifted (-center unitcircle);
> 
> A := A scaled 4cm;
> 
> B := unitcircle shifted (-center unitcircle);
> 
> B := B scaled 1cm;
> 
> %C := (reverse B) shifted (left*1.4cm);
> 
> %It works for two paths
> 
> fill (reverse B)-- A -- cycle withcolor red;
> 
> %fill A -- (reverse B) -- C -- cycle withcolor red;
> 
> %When I try the same with three paths, a thin, unwanted line appears
> 
> \stopMPpage
> 
> I'm aware of unfill and I've read somewhere else about using pens 
> instead, but I want to know if a better solution is possible. Thank you 
> in advance.
     \startMPpage
         path A; A := (unitcircle shifted (-center unitcircle)) scaled 4cm;
         path B; B := (unitcircle shifted (-center unitcircle)) scaled 1cm;
         path C; C := B shifted (left*1.4cm);

         nofill A; nofill B; eofill C;
     \stopMPpage

to be wikified

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