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

int main()
{
  picture(P(0,0), P(1,3), "1 x 3in");

  begin();
  bold();
  arrow_inset(0.5);
  arrow_ratio(2);
  arrow_width(2);
  double rad(0.125);

  P dir(0.25, 1), perp(-rad*J(dir)), sun(dir), earth(perp), bend(sun + 3*perp),
    D1a(earth + 0.6*dir), D2(0.3*earth + 0.7*bend), D1b(bend + 1.7*dir);

  double th(Atan2(perp.x2(), perp.x1()));

  line(sun, sun + 3*perp);

  dashed();
  dash_size(12);
  line(earth, earth + 1.8*dir);
  line(earth, bend);
  line(bend, bend + 1.8*dir);

  arrow(D1a, D1a + 0.01*dir);
  arrow(D2, D2 + 0.01*(bend - earth));
  arrow(D1b, D1b + 0.01*dir);

  pen(2);
  circle(sun, rad);

  label(sun - P(rad, 0), P(-2,0), "$S$", l);
  dot(earth, P(-2,-2), "$E$", bl);

  label(D1a, P(-4,0), "$D_{1}$", l);
  label(D2, P( 4,0), "$D_{2}$", r);
  label(D1b, P( 4,0), "$D_{1}$", r);

  label_angle(th);
  label(sun + 0.15*dir + 1.5*perp,
	"$\\overbrace{\\rule{0.35in}{0pt}}^{\\mbox{\\;$\\Delta$}}$");

  tikz_format();
  end();
}