lily/hairpin.cc

   1 /*
   2   hairpin.cc -- implement Hairpin
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include "molecule.hh"
  10 #include "hairpin.hh"
  11 #include "spanner.hh"
  12 #include "font-interface.hh"
  13 #include "dimensions.hh"
  14 #include "paper-def.hh"
  15 #include "warn.hh"
  16 #include "paper-column.hh"
  17 #include "lookup.hh"
  18
  19 MAKE_SCHEME_CALLBACK (Hairpin, brew_molecule, 1);
  20
  21 SCM
  22 Hairpin::brew_molecule (SCM smob)
  23 {
  24   Grob *me= unsmob_grob (smob);
  25   Spanner *spanner = dynamic_cast<Spanner*> (me);
  26
  27   Real line = me->get_paper ()->get_realvar (ly_symbol2scm ("linethickness"));
  28
  29   SCM s = me->get_grob_property ("grow-direction");
  30   if (!is_direction (s))
  31     {
  32       me->suicide ();
  33       return SCM_EOL;
  34     }
  35
  36   Direction grow_dir = to_dir (s);
  37
  38
  39   /* Ugh, must be same as Text_spanner::brew_molecule.  */
  40
  41   /*
  42     Ugh. property name is not general.
  43    */
  44   Real padding = gh_scm2double (me->get_grob_property ("if-text-padding"));
  45
  46   Drul_array<bool> broken;
  47   Drul_array<Item*> bounds ;
  48   Direction d = LEFT;
  49   do
  50     {
  51       bounds[d] =spanner->get_bound (d);
  52       broken[d] = bounds[d]->break_status_dir () != CENTER;
  53     }
  54   while (flip (&d) != LEFT);
  55
  56   Grob *common = bounds[LEFT]->common_refpoint (bounds[RIGHT], X_AXIS);
  57   Drul_array<Real> x_points ;
  58
  59   do
  60     {
  61       Item *b = bounds[d];
  62       x_points[d]  = b->relative_coordinate (common, X_AXIS);
  63       if (broken [d])
  64         {
  65           if (d == LEFT)
  66             x_points[d] = b->extent (common,X_AXIS)[RIGHT] ;
  67         }
  68       else
  69         {
  70           if (dynamic_cast<Paper_column*> (b))
  71             {
  72               /*
  73                 If we're hung on a paper column, that means we're not
  74                 adjacent to a text-dynamic, and we may move closer. We
  75                 make the padding a little smaller, here.
  76               */
  77               Interval e =b->extent (common, X_AXIS);
  78               if (e.empty_b ())
  79                 e = Interval (0,0) + b->relative_coordinate (common, X_AXIS);
  80
  81               x_points[d] = e.center () - d  * padding /3; // ugh.
  82             }
  83           else
  84             {
  85               Interval e =b->extent (common, X_AXIS);
  86               if (!e.empty_b ())
  87                 x_points[d] = e[-d] - d*padding;
  88             }
  89         }
  90     }
  91   while (flip (&d) != LEFT);
  92
  93
  94   Real width = x_points[RIGHT] - x_points[LEFT];
  95
  96   if (width < 0)
  97     {
  98       me->warning (_ ((grow_dir < 0) ? "decrescendo too small"
  99                   : "crescendo too small"));
 100       width = 0;
 101     }
 102
 103   bool continued = broken[Direction (-grow_dir)];
 104   Real height = gh_scm2double (me->get_grob_property ("height"));
 105   Real thick = line * gh_scm2double (me->get_grob_property ("thickness"));
 106
 107   Real starth, endh;
 108   if (grow_dir < 0)
 109     {
 110       starth = height;
 111       endh = continued ? height/2 : 0.0;
 112     }
 113   else
 114     {
 115       starth = continued ? height/2 : 0.0;
 116       endh = height;
 117     }
 118
 119   /*
 120     should do relative to staff-symbol staff-space?
 121    */
 122
 123   Real period = 1.0;
 124   s = me->get_grob_property ("dash-period");
 125   if (gh_number_p (s))
 126     period = gh_scm2double (s);
 127
 128   Real fraction = 1.0;
 129   s = me->get_grob_property ("dash-fraction");
 130   if (gh_number_p (s))
 131     fraction = gh_scm2double (s);
 132
 133   /*
 134     TODO: set line style.
 135    */
 136   Molecule mol;
 137   if (fraction < 1.0)
 138     {
 139       mol  = Lookup::dashed_line (thick,
 140                                   Offset (0, starth),
 141                                   Offset (width, endh),
 142                                   period, fraction);
 143       mol.add_molecule (Lookup::dashed_line (thick,
 144                                              Offset (0, -starth),
 145                                              Offset (width, -endh),
 146                                              period, fraction));
 147     }
 148   else
 149     {
 150       mol  = Lookup::line (thick,
 151                            Offset (0, starth),
 152                            Offset (width, endh));
 153       mol.add_molecule (Lookup::line (thick,
 154                                       Offset (0, -starth),
 155                                       Offset (width, -endh)
 156                                       ));
 157     }
 158   mol.translate_axis (x_points[LEFT]
 159                       - bounds[LEFT]->relative_coordinate (common, X_AXIS),
 160                       X_AXIS);
 161   return mol.smobbed_copy ();
 162 }
 163
 164
 165
 166 ADD_INTERFACE (Hairpin, "hairpin-interface",
 167   "hairpin crescendo.",
 168   "dash-period dash-fraction grow-direction thickness height if-text-padding");
 169