/*
  arpeggio.cc -- implement Arpeggio

  source file of the GNU LilyPond music typesetter

  (c) 2000--2007 Jan Nieuwenhuizen <janneke@gnu.org>
*/

#include "arpeggio.hh"

#include "bezier.hh"
#include "font-interface.hh"
#include "grob.hh"
#include "lookup.hh"
#include "output-def.hh"
#include "pointer-group-interface.hh"
#include "staff-symbol-referencer.hh"
#include "staff-symbol.hh"
#include "stem.hh"
#include "warn.hh"

Grob *
Arpeggio::get_common_y (Grob *me)
{
  Grob *common = me;

  extract_grob_set (me, "stems", stems);
  for (vsize i = 0; i < stems.size (); i++)
    {
      Grob *stem = stems[i];
      common = common->common_refpoint (Staff_symbol_referencer::get_staff_symbol (stem),
					Y_AXIS);
    }

  return common;
}

MAKE_SCHEME_CALLBACK(Arpeggio, calc_positions, 1);
SCM
Arpeggio::calc_positions (SCM grob)
{
  Grob *me = unsmob_grob (grob);
  Grob *common = get_common_y (me);
  
  /*
    TODO:

    Using stems here is not very convenient; should store noteheads
    instead, and also put them into the support. Now we will mess up
    in vicinity of a collision.
  */
  Interval heads;
  Real my_y = me->relative_coordinate (common, Y_AXIS);

  extract_grob_set (me, "stems", stems);
  for (vsize i = 0; i < stems.size (); i++)
    {
      Grob *stem = stems[i];
      Grob *ss = Staff_symbol_referencer::get_staff_symbol (stem);
      Interval iv = Stem::head_positions (stem);
      iv *= Staff_symbol::staff_space (ss) / 2.0;

      heads.unite (iv + ss->relative_coordinate (common, Y_AXIS)
		   - my_y);
    }

  heads *= 1/Staff_symbol_referencer::staff_space(me);

  return ly_interval2scm (heads);
}

MAKE_SCHEME_CALLBACK (Arpeggio, print, 1);
SCM
Arpeggio::print (SCM smob)
{
  Grob *me = unsmob_grob (smob);
  Interval heads = robust_scm2interval (me->get_property ("positions"),
					Interval())
    * Staff_symbol_referencer::staff_space (me);
  
  if (heads.is_empty () || heads.length () < 0.5)
    {
      if (!to_boolean (me->get_property ("transparent")))
	{
	  me->warning ("no heads for arpeggio found?");
	  me->suicide ();
	}
      return SCM_EOL;
    }

  SCM ad = me->get_property ("arpeggio-direction");
  Direction dir = CENTER;
  if (is_direction (ad))
    dir = to_dir (ad);

  Stencil mol;
  Font_metric *fm = Font_interface::get_default_font (me);
  Stencil squiggle = fm->find_by_name ("scripts.arpeggio");

  /*
    Compensate for rounding error which may occur when a chord
    reaches the center line, resulting in an extra squiggle
    being added to the arpeggio stencil.  This value is appreciably
    larger than the rounding error, which is in the region of 1e-16
    for a global-staff-size of 20, but small enough that it does not
    interfere with smaller staff sizes.
  */
  const Real epsilon = 1e-3;

  Stencil arrow;
  if (dir)
    {
      arrow = fm->find_by_name ("scripts.arpeggio.arrow." + to_string (dir));
      heads[dir] -= dir * arrow.extent (Y_AXIS).length ();
    }

  while (mol.extent (Y_AXIS).length () + epsilon < heads.length ())
    {
      mol.add_at_edge (Y_AXIS, UP, squiggle, 0.0);
    }

  mol.translate_axis (heads[LEFT], Y_AXIS);
  if (dir)
    mol.add_at_edge (Y_AXIS, dir, arrow, 0);

  return mol.smobbed_copy ();
}

/* Draws a vertical bracket to the left of a chord
   Chris Jackson <chris@fluffhouse.org.uk> */

MAKE_SCHEME_CALLBACK (Arpeggio, brew_chord_bracket, 1);
SCM
Arpeggio::brew_chord_bracket (SCM smob)
{
  Grob *me = unsmob_grob (smob);
  Interval heads = robust_scm2interval (me->get_property ("positions"),
					Interval())
    * Staff_symbol_referencer::staff_space (me);

  Real lt = me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
  Real sp = 1.5 * Staff_symbol_referencer::staff_space (me);
  Real dy = heads.length () + sp;
  Real x = 0.7;

  Stencil mol (Lookup::bracket (Y_AXIS, Interval (0, dy), lt, x, lt));
  mol.translate_axis (heads[LEFT] - sp / 2.0, Y_AXIS);
  return mol.smobbed_copy ();
}

MAKE_SCHEME_CALLBACK (Arpeggio, brew_chord_slur, 1);
SCM
Arpeggio::brew_chord_slur (SCM smob)
{
  Grob *me = unsmob_grob (smob);
  Interval heads = robust_scm2interval (me->get_property ("positions"),
					Interval())
    * Staff_symbol_referencer::staff_space (me);

  Real lt = me->layout ()->get_dimension (ly_symbol2scm ("line-thickness"));
  Real dy = heads.length ();

  Real height_limit = 1.5;
  Real ratio = .33;
  Bezier curve = slur_shape (dy, height_limit, ratio);
  curve.rotate (M_PI / 2);

  Stencil mol (Lookup::slur (curve, lt, lt));
  mol.translate_axis (heads[LEFT], Y_AXIS);
  return mol.smobbed_copy ();
}

/*
  We have to do a callback, because print () triggers a
  vertical alignment if it is cross-staff.
*/
MAKE_SCHEME_CALLBACK (Arpeggio, width, 1);
SCM
Arpeggio::width (SCM smob)
{
  Grob *me = unsmob_grob (smob);
  Stencil arpeggio = Font_interface::get_default_font (me)->find_by_name ("scripts.arpeggio");

  return ly_interval2scm (arpeggio.extent (X_AXIS));
}

MAKE_SCHEME_CALLBACK (Arpeggio, height, 1);
SCM
Arpeggio::height (SCM smob)
{
  return Grob::stencil_height (smob);
}

MAKE_SCHEME_CALLBACK (Arpeggio, pure_height, 3);
SCM
Arpeggio::pure_height (SCM smob, SCM, SCM)
{
  Grob *me = unsmob_grob (smob);
  if (to_boolean (me->get_property ("cross-staff")))
    return ly_interval2scm (Interval ());

  return height (smob);
}

ADD_INTERFACE (Arpeggio,
	       "Functions and settings for drawing an arpeggio symbol (a"
	       " wavy line left to noteheads.",

	       /* properties */
	       "arpeggio-direction "
	       "positions "
	       "script-priority " // TODO: make around-note-interface
	       "stems "
	       );

