---------- Forwarded message ---------
De: Jairo A. del Rio <jairoadelrio6@gmail.com>
Date: mié, 12 de may. de 2021 a la(s) 14:08
Subject: Re: [NTG-context] Fuzzy lines
To: mailing list for ConTeXt users <ntg-context@ntg.nl>




El mié, 12 de may. de 2021 a la(s) 13:03, Henning Hraban Ramm (texml@fiee.net) escribió:
Hi Jairo,

thank you for the suggestion.

> Am 11.05.2021 um 14:56 schrieb Jairo A. del Rio <jairoadelrio6@gmail.com>:
>
> For simple pens, you may define your own (section 9.7 of MetaPost manual).

Unfortunately, pens don’t work as patterns but only as outlines.

> For complicated strokes, something along these lines could be useful as a starting point (I'm not taking cyclic paths in consideration, btw). I did something similar with duck footprints some weeks ago:
>
> %Sorry for the ugly code...
> \starttext
> \startMPpage
> %Unit size
> numeric u; u := 1mm;
>
> %In a picture you are able to include everything, kinda
> picture Pluma;
> Pluma := image(
>       for i = 1 upto 5:
>               for j = 1 upto 5:
>                       draw (i,j) randomized 1;
>               endfor
>       endfor
> );

Unfortunately, that’s the same pattern over and over.
The randomization is only applied once.
Good for footprints, bad for fuzzy patterns.

You only need to move "randomized" at the drawing stage:

\starttext

\startMPpage

numeric u; u := 1mm;

picture Pluma;

Pluma := image(

for i = 1 upto 5:

for j = 1 upto 5:

draw (i,j);

endfor

endfor

);

path Camino;

Camino := origin for i = 1 upto 30: .. (u*i, u*sind (12i mod 360)) endfor;

for i = 0 step 1/2 until length Camino:

draw Pluma randomized 1 rotated (90 + angle direction i of Camino)

shifted point i of Camino;

endfor

\stopMPpage

\stoptext


But "randomized" will deform paths. Maybe you want something like this?

\starttext

\startMPpage[align=]

begingroup;

save Rnd; let Rnd = uniformdeviate;


numeric u; u := 3mm;

picture Pluma;

Pluma := image(

for i = 1 upto 5:

for j = 1 upto 5:

fill fullcircle shifted (i,j); %try fulltriangle or another shape

endfor

endfor

);

path Camino;

Camino := origin for i = 1 upto 30: .. u*i*left endfor;

for i = 0 step 1/2 until length Camino:

draw image(

for x within Pluma:

fill pathpart x %Assuming our image only contains cyclic paths

scaled (1+Rnd 1)

shifted (1/2dir Rnd 360)

withcolor hsvtorgb(6round(Rnd 60),9/10,1); %Colors just because they look cute

endfor

) rotated (90 + angle direction i of Camino)

shifted point i of Camino;

endfor

endgroup;

\stopMPpage

\stoptext


> %Simple curve
> path Camino;
> Camino := origin for i = 1 upto 30: .. (u*i, u*sind (12i mod 360)) endfor;
>
> %Strokes
> for i = 0 step 1/2 until length Camino:
>       draw Pluma rotated (90 + angle direction i of Camino)
>               shifted point i of Camino;
> endfor

Since I have more or less straight lines but of different length, the "one pattern per 1/n path segment" doesn’t work for me. I could try to construct my paths differently.

You only need to use fractions, i.e., "for 0 step 1/n until 1: ... endfor" if you work with straight lines defined using only two points. In the example above I made one from more than two points just for ease of manipulation. With examples and feedback from the mailing list, you might define your own function using the new Metafun interface for LMTX.
 

Hraban

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Jairo