lily/paper-system-scheme.cc

   1 /*
   2   paper-system-scheme.cc -- implement Paper_system bindings.
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2008 Han-Wen Nienhuys <hanwen@lilypond.org>
   7
   8 */
   9
  10 #include "prob.hh"
  11
  12 #include "skyline-pair.hh"
  13
  14 LY_DEFINE (ly_paper_system_p, "ly:paper-system?",
  15           1, 0, 0, (SCM obj),
  16           "Type predicate.")
  17 {
  18   return ly_prob_type_p (obj, ly_symbol2scm ("paper-system"));
  19 }
  20
  21 LY_DEFINE (ly_paper_system_minimum_distance, "ly:paper-system-minimum-distance",
  22            2, 0, 0, (SCM sys1, SCM sys2),
  23            "Measure the minimum distance between these two paper-systems,"
  24            " using their stored skylines if possible and falling back to"
  25            " their extents otherwise.")
  26 {
  27   Real ret = 0;
  28   Prob *p1 = unsmob_prob (sys1);
  29   Prob *p2 = unsmob_prob (sys2);
  30   Skyline_pair *sky1 = Skyline_pair::unsmob (p1->get_property ("vertical-skylines"));
  31   Skyline_pair *sky2 = Skyline_pair::unsmob (p2->get_property ("vertical-skylines"));
  32
  33   if (sky1 && sky2)
  34     ret = (*sky1)[DOWN].distance ((*sky2)[UP]);
  35   else
  36     {
  37       Stencil *s1 = unsmob_stencil (p1->get_property ("stencil"));
  38       Stencil *s2 = unsmob_stencil (p2->get_property ("stencil"));
  39       Interval iv1 = s1->extent (Y_AXIS);
  40       Interval iv2 = s2->extent (Y_AXIS);
  41       ret = iv2[UP] - iv1[DOWN];
  42     }
  43   return scm_from_double (ret);
  44 }