/*
  hyphen-spanner.cc -- implement Hyphen_spanner

  source file of the GNU LilyPond music typesetter

  (c) 2003--2004 Han-Wen Nienhuys <hanwen@xs4all.nl>
*/

#include <math.h>

#include "box.hh"
#include "lookup.hh"
#include "stencil.hh"
#include "output-def.hh"
#include "paper-column.hh"
#include "spanner.hh"
#include "item.hh"
#include "lyric-hyphen.hh"
#include "moment.hh"

MAKE_SCHEME_CALLBACK (Hyphen_spanner,print,1)
SCM 
Hyphen_spanner::print (SCM smob)
{
  Spanner * me = unsmob_spanner (smob);
  Drul_array<Item*> bounds (me->get_bound (LEFT),
			    me->get_bound (RIGHT));

  if (bounds[LEFT]->break_status_dir ()
      && Paper_column::when_mom (bounds[LEFT]) == Paper_column::when_mom (bounds[RIGHT]->get_column ()))
    return SCM_EOL;
  
  Grob * common = bounds[LEFT]->common_refpoint (bounds[RIGHT], X_AXIS);

  Interval span_points;
  Direction d = LEFT;
  do
    {
      Interval iv = bounds[d]->extent (common, X_AXIS);

      span_points[d] = iv.is_empty ()
	? bounds[d]->relative_coordinate (common, X_AXIS)
	: iv[-d];
    }
  while (flip (&d) != LEFT);
  
  Real lt = me->get_layout ()->get_dimension (ly_symbol2scm ("linethickness"));
  Real th = robust_scm2double (me->get_property ("thickness"), 1) * lt ;
  Real h = robust_scm2double (me->get_property ("height"), 0.5);

  // interval?
  
  Real dp = robust_scm2double (me->get_property ("dash-period"), 1.0);
  Real dl = robust_scm2double (me->get_property ("length"), .5 );

  if (dp < dl)
    dp = 1.5 * dl;

  Real l = span_points.length ();
  int n = int (ceil (l/dp - 0.5));
  if (n <= 0)
    n = 1;

  Real space_left = l - dl - (n-1)* dp;

  /*
    If there is not enough space, the hyphen should disappear, but not
    at the end of the line.
   */
  if (space_left < 0.0
      && !bounds[RIGHT]->break_status_dir ())
    return SCM_EOL;

  space_left = space_left >? 0.0;
  
  Box b (Interval (0, dl), Interval (h,h+th));
  Stencil dash_mol (Lookup::round_filled_box (b, 0.8 * lt));

  Stencil total;
  for (int i = 0; i < n; i++)
    {
      Stencil m (dash_mol);
      m.translate_axis (span_points[LEFT] + i * dp + space_left / 2, X_AXIS);
      total.add_stencil (m);
    }

  total.translate_axis ( -me->relative_coordinate (common, X_AXIS), X_AXIS);
  return total.smobbed_copy ();
}


MAKE_SCHEME_CALLBACK (Hyphen_spanner,set_spacing_rods,1);
SCM
Hyphen_spanner::set_spacing_rods (SCM smob)
{
  Grob*me = unsmob_grob (smob);

  Rod r;
  Spanner*sp = dynamic_cast<Spanner*> (me);
  r.distance_ =
    robust_scm2double (me->get_property ("minimum-length"), 0);

  Direction d=LEFT;
  do
    {
      r.item_l_drul_[d] = sp->get_bound (d);
      if (r.item_l_drul_[d])
	r.distance_ += r.item_l_drul_[d]->extent (r.item_l_drul_[d], X_AXIS)[-d];
    }
  while (flip (&d) != LEFT);

  if (r.item_l_drul_[LEFT]
      && r.item_l_drul_[RIGHT])
    r.add_to_cols ();
  
  return SCM_UNSPECIFIED;
}

ADD_INTERFACE (Hyphen_spanner, "lyric-hyphen-interface",
	       "A centred hyphen is a simple line between lyrics used to divide syllables",
	       "thickness height dash-period minimum-length length");


