2 melody-spanner.cc -- implement Melody_spanner
4 source file of the GNU LilyPond music typesetter
6 (c) 2005--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
10 #include "melody-spanner.hh"
12 #include "pointer-group-interface.hh"
15 TODO: this could be either item or spanner. For efficiency reasons,
16 let's take item for now.
21 Interpolate stem directions for neutral stems.
23 MAKE_SCHEME_CALLBACK(Melody_spanner,calc_neutral_stem_direction, 1);
25 Melody_spanner::calc_neutral_stem_direction (SCM smob)
27 Grob *stem = unsmob_grob (smob);
28 Grob *me = unsmob_grob (stem->get_object ("melody-spanner"));
29 if (!me || !me->is_live ())
30 return SCM_UNSPECIFIED;
32 extract_grob_set (me, "stems", stems);
34 std::vector<Direction> dirs;
35 for (vsize i = 0; i < stems.size (); i++)
36 dirs.push_back (to_dir (stems[i]->get_property ("default-direction")));
38 vsize last_nonneutral = VPOS;
39 vsize next_nonneutral = 0;
40 while (next_nonneutral != VPOS && next_nonneutral < dirs.size ()
41 && !dirs[next_nonneutral])
44 while (last_nonneutral == VPOS || last_nonneutral < dirs.size () - 1)
46 Direction d1 = CENTER;
47 Direction d2 = CENTER;
48 if (last_nonneutral != VPOS)
49 d1 = dirs[last_nonneutral];
50 if (next_nonneutral < dirs.size ())
51 d2 = dirs[next_nonneutral];
53 Direction total = CENTER;
61 total = to_dir (me->get_property ("neutral-direction"));
63 for (vsize i = last_nonneutral + 1; i < next_nonneutral; i++)
64 stems[i]->set_property ("neutral-direction", scm_from_int (total));
67 last_nonneutral = next_nonneutral;
68 while (last_nonneutral < dirs.size ()
69 && dirs[last_nonneutral])
71 next_nonneutral = last_nonneutral;
74 while (next_nonneutral < dirs.size ()
75 && !dirs[next_nonneutral])
80 return SCM_UNSPECIFIED;
84 Melody_spanner::add_stem (Grob *me, Grob *stem)
86 Pointer_group_interface::add_grob (me, ly_symbol2scm ("stems"), stem);
87 stem->set_object ("melody-spanner", me->self_scm ());
88 stem->set_property ("neutral-direction", Melody_spanner::calc_neutral_stem_direction_proc);
91 ADD_INTERFACE (Melody_spanner, "melody-spanner-interface",
92 "Context dependent typesetting decisions.",
95 "neutral-direction ");