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

P times(const P& arg1, const P& arg2)
{
  return P(arg1.x1()*arg2.x1() - arg1.x2()*arg2.x1(),
	   arg1.x1()*arg2.x2() + arg1.x2()*arg2.x1());
}

void mytri(const P& p1, const P& p2, const P& p3)
{
  line(p1, p2);
  line(p2, p3);
  line(p3, p1);
}

int main()
{
  picture(P(0,0), P(2,1.33), "2 x 1.33in");

  begin();

  P ptA(1.25, 0.6), ptC(0.5, 0.5), ptP(times(ptA, ptC)), X(xmax());
  P O(0,0), ptU(1);
  double dp(2);

  bold();
  line(O, X);

  mytri(O, ptU, ptA);
  mytri(O, ptC, ptP);

  label(X, P(0,-dp), "$X$", b);
  label(ptU, P(0,-dp), "$U$", b);
  label(O, P(-dp,0), "$O$", l);

  label(ptA, P(dp,0), "$A$", r);
  label(ptC, P(dp,0), "$C$", r);

  label(ptP, P(-dp,dp), "$P$", tl);

  label(P(0.5*xmax(), ymin()), P(0,-18), "\\textsc{Fig.~4}", b);

  tikz_format();
  end();
}