/* -*-ePiX-*- */
#include "epix.h"
using namespace ePiX;

int main()
{
  picture(P(0,-1), P(9,1), "4.5 x 1in");

  begin();

  double phi(1);

  const P omega1(2.5,0);
  const P omega2(polar(1.25,phi));
  const P O2(6,0);

  double rad(0.5);
  arrow_width(2);
  arc_arrow(P(0,0), rad, 0, phi);
  arc_arrow(O2, rad, 0, M_PI+phi);

  arrow_width(3);
  arrow_inset(0.5);

  arrow(P(0,0), omega1);
  arrow(P(0,0), omega2);

  arrow(O2, O2 + omega1);
  arrow(O2, O2 - omega2);

  //  font_size("footnotesize");
  label(P(0,0), P(2,-4), "$O'$", b);
  label(O2, P(4,-4), "$O'$", b);

  //  font_size("scriptsize");
  label(omega1, P(2,-4), "$2\\omega_1$", b);
  label(O2+omega1, P(2,4), "$2\\omega_1$", t);

  label(omega2, P(2,4), "$2\\omega_2$", t);
  label(O2-omega2, P(2,-4), "$2\\omega_2$", b);

  label(polar(rad, 0.5*phi), polar(2, 0.5*phi), "$\\varphi$", tr);
  label(O2+polar(rad, M_PI_2+0.5*phi), polar(2, M_PI_2+0.5*phi), "$\\varphi$", tl);

  dashed();
  dash_size(6);
  line(omega1, omega1 + omega2);
  line(omega2, omega1 + omega2);

  line(O2 + omega1, O2 + omega1 - omega2);
  line(O2 - omega2, O2 + omega1 - omega2);

  tikz_format();
  end();
}