lily/stem-info.cc

   1 /*
   2   stem-info.cc -- implement Stem_info
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--1999 Jan Nieuwenhuizen <janneke@gnu.org>
   7
   8 */
   9
  10 #include "proto.hh"
  11 #include "misc.hh"
  12 #include "cross-staff.hh"
  13 #include "debug.hh"
  14 #include "stem.hh"
  15 #include "paper-def.hh"
  16 #include "lookup.hh"
  17 #include "stem-info.hh"
  18 #include "beam.hh"
  19
  20
  21 Stem_info::Stem_info ()
  22 {
  23 }
  24
  25
  26 /*
  27   FIXME: y dims should not be in internote.
  28
  29
  30   GURG UGRGINRG INA UG R
  31
  32   JUNKME -> this should set elt properties of STEM.
  33 */
  34 Stem_info::Stem_info (Stem*s, int mult)
  35 {
  36   mult_i_ =mult;
  37   stem_l_ = s;
  38   Beam* beam_l = stem_l_->beam_l ();
  39
  40   x_ = stem_l_->hpos_f ();
  41   set_direction (stem_l_->get_direction ());
  42   SCM bd = stem_l_->remove_elt_property ("beam-dir");
  43
  44   if (gh_number_p (bd))
  45     {
  46       beam_dir_ = gh_scm2int (bd);
  47     }
  48   else
  49     {
  50       programming_error ("Beam direction not set.");
  51       beam_dir_ = UP;           //  GURAUGRNAGURAGU! urg !
  52     }
  53
  54   Paper_def* paper_l = stem_l_->paper_l ();
  55   Real internote_f = stem_l_->staff_line_leading_f ()/2;
  56   Real interbeam_f = paper_l->interbeam_f (mult_i_);
  57   Real beam_f = gh_scm2double (beam_l->get_elt_property ("beam-thickness"));
  58
  59
  60   // strangely enough, dim(chord_start_f) == pt (and not internote!)
  61   idealy_f_ = stem_l_->chord_start_f () / internote_f;
  62
  63   // calculate using dim(y) == pt
  64   idealy_f_ *= internote_f;
  65
  66   // for simplicity, we calculate as if dir == UP
  67   idealy_f_ *= beam_dir_;
  68
  69   bool grace_b = stem_l_->get_elt_property ("grace") != SCM_UNDEFINED;
  70   bool no_extend_b = stem_l_->get_elt_property ("no-stem-extend")
  71     != SCM_UNDEFINED;
  72
  73   int stem_max = (int)rint(paper_l->get_var ("stem_max"));
  74   String type_str = grace_b ? "grace_" : "";
  75   Real min_stem_f = paper_l->get_var (type_str + "minimum_stem_length"
  76                                       + to_str (mult_i_ <? stem_max)) * internote_f;
  77   Real stem_f = paper_l->get_var (type_str + "stem_length"
  78                                   + to_str (mult_i_ <? stem_max))* internote_f;
  79
  80   if (!beam_dir_ || (beam_dir_ == get_direction ()))
  81     /* normal beamed stem */
  82     {
  83       if (mult_i_)
  84         {
  85           idealy_f_ += beam_f;
  86           idealy_f_ += (mult_i_ - 1) * interbeam_f;
  87         }
  88       miny_f_ = idealy_f_;
  89       maxy_f_ = INT_MAX;
  90
  91       idealy_f_ += stem_f;
  92       miny_f_ += min_stem_f;
  93
  94       /*
  95         lowest beam of (UP) beam must never be lower than second staffline
  96
  97         Hmm, reference (Wanske?)
  98
  99         Although this (additional) rule is probably correct,
 100         I expect that highest beam (UP) should also never be lower
 101         than middle staffline, just as normal stems.
 102
 103       */
 104       if (!grace_b && !no_extend_b)
 105         {
 106           //highest beam of (UP) beam must never be lower than middle staffline
 107           miny_f_ = miny_f_ >? 0;
 108           //lowest beam of (UP) beam must never be lower than second staffline
 109           miny_f_ = miny_f_ >? (- 2 * internote_f - beam_f
 110                                 + (mult_i_ > 0) * beam_f + interbeam_f * (mult_i_ - 1));
 111         }
 112     }
 113   else
 114     /* knee */
 115     {
 116       idealy_f_ -= beam_f;
 117       maxy_f_ = idealy_f_;
 118       miny_f_ = -INT_MAX;
 119
 120       idealy_f_ -= stem_f;
 121       maxy_f_ -= min_stem_f;
 122     }
 123
 124   // set dim(y) == internote
 125   idealy_f_ /= internote_f;
 126   miny_f_ /= internote_f;
 127   maxy_f_ /= internote_f;
 128
 129   idealy_f_ = maxy_f_ <? idealy_f_;
 130   idealy_f_ = miny_f_ >? idealy_f_;
 131
 132   interstaff_f_ = calc_interstaff_dist (stem_l_, beam_l) / internote_f;
 133   idealy_f_ += interstaff_f_* beam_dir_;
 134   miny_f_   += interstaff_f_ * beam_dir_;
 135   maxy_f_   += interstaff_f_ * beam_dir_;
 136 }
 137
 138