Figure Asymptote ccw -- 004

Posted on 2011-01-01 Edited on 2025-06-30 In EN , Tech , Programming , Asymptote , Surveys , Path Orientation

An Asymptote code and the generated picture ccw--004.

🔗This picture comes from the Asymptote gallery of topic ccw

Show ccw/fig0040.asy on Github.
Generated with Asymptote 3.00-0.
Categories : Surveys | Path Orientation

// Use of the windingnumber works also for CROSSED curves

size(8cm,10cm,false);

import math;

bool counterclockwise(path g)
{
  // Return "true" if "g" is counterclockwise
  // Retounre "true" si "g" est dans le sens contraire des aiguilles d'une montre
  return (windingnumber(g,inside(g)) > 0);
}

path counterclockdirected(path g)
{
  if (counterclockwise(g)) return g; else return reverse(g);
}

guide p=randompath(30)..cycle;
draw(counterclockdirected(reverse(p)),Arrow(10bp,Relative(0.025)), BeginBar);
draw(counterclockdirected(p),Arrow(10bp,FillDraw(red),Relative(.05)), BeginBar);