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

int main()
{
  picture(P(0,-1), P(4,4), "3.6 x 4.5in");

  begin();
  degrees();
  //  arrow_init();

  double t1(0.9), t2(2), t3(2.25), t4(3.25), th(-15);

  P O(0,0), ptc(4.5,4.5);
  P p1a(t1,t1), p2a(t2,t2), p3a(t2,t1);

  P b1(polar(t3, th)), b2(polar(t4, th));
  Segment L1(O, ptc), L2(b1, b1 + cis(th + 90)), L3(b2, b2 + cis(th + 90));
  P p1b(L1*L2), p2b(L1*L3), p3b(p1b + polar(t4 - t3, th));

  bold();

  line(O, P(xmax(),0));
  line(O, P(0,ymax()));

  dashed();
  line(O, polar(xmax(), th)); 
  line(O, polar(ymax(), th + 90)); 

  label(polar(xmax(), th), polar(4, th), "$X'$", br);
  label(polar(ymax(), th + 90), P(-2,-2), "$T'$", bl);

  dash_size(6);
  line(P(t1,0), p1a);
  line(P(t2,0), p2a);
  line(p1a, p3a);

  label(0.5*(p1a + p3a), P(0,-4), "$\\Delta x$", b);
  label(0.5*(p2a + p3a), P(4, 0), "$\\Delta t$", r);

  line(polar(t3, th), p1b);
  line(polar(t4, th), p2b);
  line(p1b, p3b);

  line_style("-   ----------   -");
  line(O, 1.1*p2b);

  label_angle(th);

  label(1.1*p2b, P(2,-2), "$c$", br);

  label(0.5*(p1b + p3b), P(0,-4), "$\\Delta x'$", b);
  label(0.5*(p2b + p3b), P(4, 0), "$\\Delta t'$", r);

  label_angle(0);
  label(P(0,0), P(-2,-2), "$O$", l);
  label(P(xmax(),0), P(2,0), "$X$", r);
  label(P(0,ymax()), P(-2,0), "$T$", bl);

  font_face("sc");
  label(P(0.5*(xmin() + xmax()),ymin()), P(0,-12), "Fig.~17.", b);
  tikz_format();
  end();
}