lily/measure-grouping-spanner.cc

   1 /*
   2 measure-grouping-spanner.cc --  implement Measure_grouping
   3
   4 source file of the GNU LilyPond music typesetter
   5
   6 (c) 2002--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9 #include "paper-def.hh"
  10 #include "spanner.hh"
  11 #include "measure-grouping-spanner.hh"
  12 #include "lookup.hh"
  13 #include "item.hh"
  14
  15 MAKE_SCHEME_CALLBACK (Measure_grouping, brew_molecule, 1);
  16 SCM
  17 Measure_grouping::brew_molecule (SCM grob)
  18 {
  19   Spanner * me = dynamic_cast<Spanner*> (unsmob_grob (grob));
  20
  21   /*
  22     TODO: robustify.
  23    */
  24   SCM which = me->get_grob_property ("style");
  25   SCM thick = me->get_grob_property ("thickness");
  26   SCM height = me->get_grob_property ("height");
  27
  28   Real t = me->get_paper ()->get_realvar (ly_symbol2scm ("linethickness")) *   gh_scm2double (thick);
  29   Grob *common = me->get_bound(LEFT)->common_refpoint (me->get_bound (RIGHT),
  30                                                        X_AXIS);
  31
  32   Interval rext = me->get_bound (RIGHT)->extent (common, X_AXIS);
  33
  34
  35   Real w =(rext.empty_b()
  36            ? me->get_bound (RIGHT)->relative_coordinate (common, X_AXIS)
  37            : rext[RIGHT])
  38     - me->get_bound (LEFT)->relative_coordinate (common, X_AXIS);
  39
  40   Interval iv (0,w);
  41
  42   Molecule m;
  43   if (which == ly_symbol2scm ("bracket"))
  44     {
  45       m = Lookup::bracket (X_AXIS, iv, t,-gh_scm2double (height));
  46     }
  47   else if (which == ly_symbol2scm ("triangle"))
  48     {
  49       m = Lookup::triangle (iv, t, gh_scm2double (height));
  50     }
  51
  52   m.align_to (Y_AXIS, DOWN);
  53   return m.smobbed_copy();
  54 }
  55
  56 ADD_INTERFACE (Measure_grouping,"measure-grouping-interface",
  57                "indicate groups of beats. Valid choices for 'type are 'bracket and 'triangle.",
  58                "thickness style height");
  59
  60