On 3/30/2026 12:52 PM, Hraban Ramm wrote:
Hi,
in https://tug.ctan.org/info/drawing-with-metapost/Drawing-with-Metapost.pdf
I found this code to draw a spiral:
path S;
S = origin
for t=1 upto 90:
.. 1/12 t * dir 16t
endfor;
draw S;
I understand it starts at origin and adds a number of points – but where
are the points (pairs)? There’s a number (distance?) and a direction
(angle?). Could you explain this in layman’s terms?
"dir" produces a pair
\startMPpage
path S;
S := origin for t=1 upto 90 : .. 1/12 t * dir 16t endfor ;
S := S scaled 10 ;
draw S ;
drawpoints S withcolor red ;
\stopMPpage
If I try a different starting point than origin, the spiral still is
drawn around origin. I'd like to add it to another path and also
hm, if you replace origin by (10,10) it does looks different
> randomize the points a bit to make it look hand-drawn.
1/12 (t randomized .05t)
Hans
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