2 stem.cc -- implement Stem
4 source file of the GNU LilyPond music typesetter
6 (c) 1996--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
7 Jan Nieuwenhuizen <janneke@gnu.org>
9 TODO: This is way too hairy
13 Stem-end, chord-start, etc. is all confusing naming.
16 #include <math.h> // rint
19 #include "directional-element-interface.hh"
20 #include "note-head.hh"
23 #include "paper-def.hh"
24 #include "rhythmic-head.hh"
25 #include "font-interface.hh"
26 #include "molecule.hh"
27 #include "paper-column.hh"
31 #include "group-interface.hh"
32 #include "staff-symbol-referencer.hh"
34 #include "side-position-interface.hh"
35 #include "dot-column.hh"
36 #include "stem-tremolo.hh"
39 Stem::set_beaming (Grob*me, int beam_count, Direction d)
41 SCM pair = me->get_grob_property ("beaming");
43 if (!gh_pair_p (pair))
45 pair = gh_cons (SCM_EOL, SCM_EOL);
46 me->set_grob_property ("beaming", pair);
49 SCM l = index_get_cell (pair, d);
50 for( int i = 0; i< beam_count; i++)
52 l = gh_cons (gh_int2scm (i), l);
54 index_set_cell (pair, d, l);
59 Stem::head_positions (Grob*me)
67 Drul_array<Grob*> e (extremal_heads (me));
69 return Interval (Staff_symbol_referencer::get_position (e[DOWN]),
70 Staff_symbol_referencer::get_position (e[UP]));
75 Stem::chord_start_y (Grob*me)
77 return head_positions (me)[get_direction (me)]
78 * Staff_symbol_referencer::staff_space (me)/2.0;
82 Stem::stem_end_position (Grob*me)
84 SCM p =me->get_grob_property ("stem-end-position");
88 pos = get_default_stem_end_position (me);
89 me->set_grob_property ("stem-end-position", gh_double2scm (pos));
92 pos = gh_scm2double (p);
98 Stem::get_direction (Grob*me)
100 Direction d = get_grob_direction (me);
104 d = get_default_dir (me);
106 set_grob_direction (me, d);
113 Stem::set_stemend (Grob*me, Real se)
116 Direction d= get_direction (me);
118 if (d && d * head_positions (me)[get_direction (me)] >= se*d)
119 me->warning (_ ("Weird stem size; check for narrow beams"));
121 me->set_grob_property ("stem-end-position", gh_double2scm (se));
126 Note head that determines hshift for upstems
128 WARNING: triggers direction
131 Stem::support_head (Grob*me)
133 if (head_count (me) == 1)
139 return unsmob_grob (ly_car (me->get_grob_property ("note-heads")));
142 return first_head (me);
147 Stem::head_count (Grob*me)
149 return Pointer_group_interface::count (me, "note-heads");
153 The note head which forms one end of the stem.
155 WARNING: triggers direction
158 Stem::first_head (Grob*me)
160 Direction d = get_direction (me);
163 return extremal_heads (me)[-d];
167 The note head opposite to the first head.
170 Stem::last_head (Grob*me)
172 Direction d = get_direction (me);
175 return extremal_heads (me)[d];
179 START is part where stem reaches `last' head.
182 Stem::extremal_heads (Grob*me)
184 const int inf = 1000000;
185 Drul_array<int> extpos;
189 Drul_array<Grob *> exthead;
190 exthead[LEFT] = exthead[RIGHT] =0;
192 for (SCM s = me->get_grob_property ("note-heads"); gh_pair_p (s); s = ly_cdr (s))
194 Grob * n = unsmob_grob (ly_car (s));
197 int p = int (Staff_symbol_referencer::get_position (n));
201 if (d* p > d* extpos[d])
206 } while (flip (&d) != DOWN);
213 icmp (int const &a, int const &b)
219 Stem::note_head_positions (Grob *me)
222 for (SCM s = me->get_grob_property ("note-heads"); gh_pair_p (s); s = ly_cdr (s))
224 Grob * n = unsmob_grob (ly_car (s));
225 int p = int (Staff_symbol_referencer::get_position (n));
236 Stem::add_head (Grob*me, Grob *n)
238 n->set_grob_property ("stem", me->self_scm ());
239 n->add_dependency (me);
242 TODO: why not store Rest pointers?
244 if (Note_head::has_interface (n))
246 Pointer_group_interface::add_grob (me, ly_symbol2scm ("note-heads"), n);
251 Stem::invisible_b (Grob*me)
253 return ! (head_count (me)
254 && gh_scm2int (me->get_grob_property ("duration-log")) >= 1);
258 Stem::get_default_dir (Grob*me)
260 int staff_center = 0;
261 Interval hp = head_positions (me);
267 int udistance = (int) (UP * hp[UP] - staff_center);
268 int ddistance = (int) (DOWN* hp[DOWN] - staff_center);
270 if (sign (ddistance - udistance))
271 return Direction (sign (ddistance -udistance));
273 return to_dir (me->get_grob_property ("neutral-direction"));
277 Stem::get_default_stem_end_position (Grob*me)
279 Real ss = Staff_symbol_referencer::staff_space (me);
281 int durlog = duration_log (me);
287 Real length = 7; // WARNING: IN HALF SPACES
288 SCM scm_len = me->get_grob_property ("length");
289 if (gh_number_p (scm_len))
291 length = gh_scm2double (scm_len);
295 s = me->get_grob_property ("lengths");
298 length = 2* gh_scm2double (robust_list_ref (durlog -2, s));
305 'set-default-stemlen' sets direction too
307 Direction dir = get_direction (me);
310 dir = get_default_dir (me);
311 set_grob_direction (me, dir);
315 /* stems in unnatural (forced) direction should be shortened,
316 according to [Roush & Gourlay] */
317 if (!chord_start_y (me)
318 || (get_direction (me) != get_default_dir (me)))
323 SCM sshorten = me->get_grob_property ("stem-shorten");
324 SCM scm_shorten = gh_pair_p (sshorten) ?
325 robust_list_ref ((duration_log (me) - 2) >? 0, sshorten): SCM_EOL;
326 if (gh_number_p (scm_shorten))
328 shorten = 2* gh_scm2double (scm_shorten);
331 /* On boundary: shorten only half */
332 if (abs (head_positions (me)[get_direction (me)]) <= 1)
341 Grob * trem = unsmob_grob (me->get_grob_property ("tremolo-flag"));
342 if (trem && !unsmob_grob (me->get_grob_property ("beam")))
345 Crude hack: add extra space if tremolo flag is there.
347 We can't do this for the beam, since we get into a loop
348 (Stem_tremolo::raw_molecule() looks at the beam.)
354 1.0 + 2 * Stem_tremolo::raw_molecule (trem).extent (Y_AXIS).length () / ss;
358 Interval flag_ext = flag (me).extent (Y_AXIS) ;
359 if (!flag_ext.is_empty ())
360 minlen += 2 * flag_ext.length () / ss ;
363 The clash is smaller for down stems (since the tremolo is
370 length = length >? (minlen + 1.0);
373 Interval hp = head_positions (me);
374 Real st = hp[dir] + dir * length;
377 TODO: change name to extend-stems to staff/center/'()
379 bool no_extend_b = to_boolean (me->get_grob_property ("no-stem-extend"));
380 if (!no_extend_b && dir * st < 0) // junkme?
384 Make a little room if we have a upflag and there is a dot.
385 previous approach was to lengthen the stem. This is not
386 good typesetting practice.
389 if (!get_beam (me) && dir == UP
392 Grob * closest_to_flag = extremal_heads (me)[dir];
393 Grob * dots = closest_to_flag
394 ? Rhythmic_head::get_dots (closest_to_flag ) : 0;
398 Real dp = Staff_symbol_referencer::get_position (dots);
399 Real flagy = flag (me).extent (Y_AXIS)[-dir] * 2
403 Very gory: add myself to the X-support of the parent,
404 which should be a dot-column.
406 if (dir * (st + flagy - dp) < 0.5)
408 Grob *par = dots->get_parent (X_AXIS);
410 if (Dot_column::has_interface (par))
412 Side_position_interface::add_support (par, me);
415 TODO: apply some better logic here. The flag is
416 curved inwards, so this will typically be too
432 the log of the duration (Number of hooks on the flag minus two)
435 Stem::duration_log (Grob*me)
437 SCM s = me->get_grob_property ("duration-log");
438 return (gh_number_p (s)) ? gh_scm2int (s) : 2;
442 Stem::position_noteheads (Grob*me)
444 if (!head_count (me))
447 Link_array<Grob> heads =
448 Pointer_group_interface__extract_grobs (me, (Grob*)0, "note-heads");
450 heads.sort (compare_position);
451 Direction dir =get_direction (me);
457 Real thick = gh_scm2double (me->get_grob_property ("thickness"))
458 * me->get_paper ()->get_realvar (ly_symbol2scm ("linethickness"));
460 Grob *hed = support_head (me);
461 Real w = Note_head::head_extent (hed,X_AXIS)[dir];
462 for (int i=0; i < heads.size (); i++)
464 heads[i]->translate_axis (w - Note_head::head_extent (heads[i],X_AXIS)[dir],
469 int lastpos = int (Staff_symbol_referencer::get_position (heads[0]));
470 for (int i=1; i < heads.size (); i ++)
472 Real p = Staff_symbol_referencer::get_position (heads[i]);
473 int dy =abs (lastpos- (int)p);
479 Real l = Note_head::head_extent (heads[i], X_AXIS).length ();
481 Direction d = get_direction (me);
483 Reversed head should be shifted l-thickness, but this
484 looks too crowded, so we only shift l-0.5*thickness.
486 This leads to assymetry: Normal heads overlap the
487 stem 100% whereas reversed heads only overlaps the
492 Real reverse_overlap =0.5;
493 heads[i]->translate_axis ((l-thick*reverse_overlap) * d, X_AXIS);
496 heads[i]->translate_axis (-thick*(2 - reverse_overlap) * d , X_AXIS);
501 For some cases we should kern some more: when the
502 distance between the next or prev note is too large, we'd
503 get large white gaps, eg.
522 MAKE_SCHEME_CALLBACK (Stem,before_line_breaking,1);
524 Stem::before_line_breaking (SCM smob)
526 Grob*me = unsmob_grob (smob);
530 Do the calculations for visible stems, but also for invisible stems
531 with note heads (i.e. half notes.)
535 stem_end_position (me); // ugh. Trigger direction calc.
536 position_noteheads (me);
540 me->set_grob_property ("molecule-callback", SCM_EOL);
543 return SCM_UNSPECIFIED;
548 When in a beam with tuplet brackets, brew_mol is called early,
549 caching a wrong value.
551 MAKE_SCHEME_CALLBACK (Stem, height, 2);
553 Stem::height (SCM smob, SCM ax)
555 Axis a = (Axis)gh_scm2int (ax);
556 Grob * me = unsmob_grob (smob);
557 assert (a == Y_AXIS);
559 SCM mol = me->get_uncached_molecule ();
562 iv = unsmob_molecule (mol)->extent (a);
563 if (Grob *b =get_beam (me))
565 Direction d = get_direction (me);
566 iv[d] += d * Beam::get_thickness (b) /2.0 ;
569 return ly_interval2scm (iv);
576 /* TODO: maybe property stroke-style should take different values,
577 e.g. "" (i.e. no stroke), "single" and "double" (currently, it's
581 SCM flag_style_scm = me->get_grob_property ("flag-style");
582 if (gh_symbol_p (flag_style_scm))
584 flag_style = ly_symbol2string (flag_style_scm);
587 if (flag_style == "no-flag")
592 bool adjust = to_boolean (me->get_grob_property ("adjust-if-on-staffline"));
594 String staffline_offs;
595 if (String::compare (flag_style, "mensural") == 0)
596 /* Mensural notation: For notes on staff lines, use different
597 flags than for notes between staff lines. The idea is that
598 flags are always vertically aligned with the staff lines,
599 regardless if the note head is on a staff line or between two
600 staff lines. In other words, the inner end of a flag always
601 touches a staff line.
606 /* Urrgh! We have to detect wether this stem ends on a staff
607 line or between two staff lines. But we can not call
608 stem_end_position(me) or get_default_stem_end_position(me),
609 since this encounters the flag and hence results in an
610 infinite recursion. However, in pure mensural notation,
611 there are no multiple note heads attached to a single stem,
612 neither is there usually need for using the stem_shorten
613 property (except for 32th and 64th notes, but that is not a
614 problem since the stem length in this case is augmented by
615 an integral multiple of staff_space). Hence, it should be
616 sufficient to just take the first note head, assume it's
617 the only one, look if it's on a staff line, and select the
618 flag's shape accordingly. In the worst case, the shape
619 looks slightly misplaced, but that will usually be the
620 programmer's fault (e.g. when trying to attach multiple
621 note heads to a single stem in mensural notation).
625 perhaps the detection whether this correction is needed should
626 happen in a different place to avoid the recursion.
630 int p = (int)rint (Staff_symbol_referencer::get_position (first_head (me)));
631 staffline_offs = Staff_symbol_referencer::on_staffline (me, p) ?
636 staffline_offs = "2";
644 char dir = (get_direction (me) == UP) ? 'u' : 'd';
646 flag_style + to_string (dir) + staffline_offs + to_string (duration_log (me));
647 Font_metric *fm = Font_interface::get_default_font (me);
648 Molecule flag = fm->find_by_name ("flags-" + font_char);
649 if (flag.is_empty ())
651 me->warning (_f ("flag `%s' not found", font_char));
654 SCM stroke_style_scm = me->get_grob_property ("stroke-style");
655 if (gh_string_p (stroke_style_scm))
657 String stroke_style = ly_scm2string (stroke_style_scm);
658 if (!stroke_style.is_empty ())
660 String font_char = to_string (dir) + stroke_style;
661 Molecule stroke = fm->find_by_name ("flags-" + font_char);
662 if (stroke.is_empty ())
664 me->warning (_f ("flag stroke `%s' not found", font_char));
668 flag.add_molecule (stroke);
676 MAKE_SCHEME_CALLBACK (Stem,dim_callback,2);
678 Stem::dim_callback (SCM e, SCM ax)
680 Axis a = (Axis) gh_scm2int (ax);
681 assert (a == X_AXIS);
682 Grob *me = unsmob_grob (e);
684 if (unsmob_grob (me->get_grob_property ("beam")) || abs (duration_log (me)) <= 2)
688 r = flag (me).extent (X_AXIS)
690 gh_scm2double (me->get_grob_property ("thickness"))
691 * me->get_paper ()->get_realvar (ly_symbol2scm ("linethickness"))/2;
693 return ly_interval2scm (r);
698 MAKE_SCHEME_CALLBACK (Stem,brew_molecule,1);
701 Stem::brew_molecule (SCM smob)
703 Grob*me = unsmob_grob (smob);
705 Direction d = get_direction (me);
710 TODO: make the stem start a direction ?
712 This is required to avoid stems passing in tablature chords...
714 Grob *lh = to_boolean (me->get_grob_property ("avoid-note-head"))
715 ? last_head (me) : lh = first_head (me);
720 if (invisible_b (me))
725 Real y1 = Staff_symbol_referencer::get_position (lh);
726 Real y2 = stem_end_position (me);
728 Interval stem_y (y1 <? y2,y2 >? y1);
732 Real dy = Staff_symbol_referencer::staff_space (me) * 0.5;
734 if (Grob *hed = support_head (me))
737 must not take ledgers into account.
739 Interval head_height = Note_head::head_extent (hed,Y_AXIS);
740 Real y_attach = Note_head::stem_attachment_coordinate (hed, Y_AXIS);
742 y_attach = head_height.linear_combination (y_attach);
743 stem_y[Direction (-d)] += d * y_attach/dy;
748 Real stem_width = gh_scm2double (me->get_grob_property ("thickness"))
749 * me->get_paper ()->get_realvar (ly_symbol2scm ("linethickness"));
751 me->get_paper ()->get_realvar (ly_symbol2scm ("blotdiameter"));
753 Box b = Box (Interval (-stem_width/2, stem_width/2),
754 Interval (stem_y[DOWN]*dy, stem_y[UP]*dy));
756 Molecule ss = Lookup::round_filled_box (b, blot);
757 mol.add_molecule (ss);
759 if (!get_beam (me) && abs (duration_log (me)) > 2)
761 Molecule fl = flag (me);
762 fl.translate_axis (stem_y[d]*dy - d * blot/2, Y_AXIS);
763 fl.translate_axis (stem_width/2, X_AXIS);
764 mol.add_molecule (fl);
767 return mol.smobbed_copy ();
771 move the stem to right of the notehead if it is up.
773 MAKE_SCHEME_CALLBACK (Stem,off_callback,2);
775 Stem::off_callback (SCM element_smob, SCM)
777 Grob *me = unsmob_grob (element_smob);
781 if (head_count (me) == 0)
783 return gh_double2scm (0.0);
786 if (Grob * f = first_head (me))
788 Interval head_wid = Note_head::head_extent(f, X_AXIS);
792 if (invisible_b (me))
797 attach = Note_head::stem_attachment_coordinate(f, X_AXIS);
799 Direction d = get_direction (me);
801 Real real_attach = head_wid.linear_combination (d * attach);
806 If not centered: correct for stem thickness.
811 = gh_scm2double (me->get_grob_property ("thickness"))
812 * me->get_paper ()->get_realvar (ly_symbol2scm ("linethickness"));
814 r += - d * rule_thick * 0.5;
817 return gh_double2scm (r);
822 Stem::get_beam (Grob*me)
824 SCM b= me->get_grob_property ("beam");
825 return unsmob_grob (b);
829 Stem::get_stem_info (Grob *me)
831 /* Return cached info if available */
832 SCM scm_info = me->get_grob_property ("stem-info");
833 if (!gh_pair_p (scm_info))
836 scm_info = me->get_grob_property ("stem-info");
840 si.dir_ = get_grob_direction (me);
841 si.ideal_y_ = gh_scm2double (gh_car (scm_info));
842 si.shortest_y_ = gh_scm2double (gh_cadr (scm_info));
848 TODO: add extra space for tremolos!
851 Stem::calc_stem_info (Grob *me)
853 Direction my_dir = get_grob_direction (me);
854 Real staff_space = Staff_symbol_referencer::staff_space (me);
855 Grob *beam = get_beam (me);
856 Real beam_translation = Beam::get_beam_translation (beam);
857 Real beam_thickness = gh_scm2double (beam->get_grob_property ("thickness"));
858 int beam_count = Beam::get_direction_beam_count (beam, my_dir);
861 /* Simple standard stem length */
862 SCM lengths = me->get_grob_property ("beamed-lengths");
864 gh_scm2double (robust_list_ref (beam_count - 1,lengths))
867 /* stem only extends to center of beam */
868 - 0.5 * beam_thickness;
870 /* Condition: sane minimum free stem length (chord to beams) */
871 lengths = me->get_grob_property ("beamed-minimum-free-lengths");
872 Real ideal_minimum_free =
873 gh_scm2double (robust_list_ref (beam_count - 1, lengths))
878 It seems that also for ideal minimum length, we must use
879 the maximum beam count (for this direction):
881 \score{ \notes\relative c''{ [a8 a32] }}
883 must be horizontal. */
884 Real height_of_my_beams = beam_thickness
885 + (beam_count - 1) * beam_translation;
887 Real ideal_minimum_length = ideal_minimum_free
889 /* stem only extends to center of beam */
890 - 0.5 * beam_thickness;
892 ideal_length = ideal_length >? ideal_minimum_length;
895 /* Convert to Y position, calculate for dir == UP */
897 /* staff positions */
898 head_positions (me)[my_dir] * 0.5
900 Real ideal_y = note_start + ideal_length;
903 /* Conditions for Y position */
905 /* Lowest beam of (UP) beam must never be lower than second staffline
909 Although this (additional) rule is probably correct,
910 I expect that highest beam (UP) should also never be lower
911 than middle staffline, just as normal stems.
915 Obviously not for grace beams.
917 Also, not for knees. Seems to be a good thing. */
918 bool no_extend_b = to_boolean (me->get_grob_property ("no-stem-extend"));
919 bool knee_b = to_boolean (beam->get_grob_property ("knee"));
920 if (!no_extend_b && !knee_b)
922 /* Highest beam of (UP) beam must never be lower than middle
924 ideal_y = ideal_y >? 0;
925 /* Lowest beam of (UP) beam must never be lower than second staffline */
926 ideal_y = ideal_y >? (-staff_space
927 - beam_thickness + height_of_my_beams);
931 SCM shorten = beam->get_grob_property ("shorten");
932 if (gh_number_p (shorten))
933 ideal_y -= gh_scm2double (shorten);
936 gh_scm2double (robust_list_ref
938 me->get_grob_property
939 ("beamed-extreme-minimum-free-lengths")))
942 Real minimum_length = minimum_free
944 /* stem only extends to center of beam */
945 - 0.5 * beam_thickness;
947 Real minimum_y = note_start + minimum_length;
951 Real shortest_y = minimum_y * my_dir;
953 me->set_grob_property ("stem-info",
954 scm_list_n (gh_double2scm (ideal_y),
955 gh_double2scm (shortest_y),
960 Stem::beam_multiplicity (Grob *stem)
962 SCM beaming= stem->get_grob_property ("beaming");
963 Slice l = int_list_to_slice (gh_car (beaming));
964 Slice r = int_list_to_slice (gh_cdr (beaming));
972 these are too many props.
974 ADD_INTERFACE (Stem,"stem-interface",
976 "tremolo-flag french-beaming "
977 "avoid-note-head adjust-if-on-staffline thickness "
978 "stem-info beamed-lengths beamed-minimum-free-lengths "
979 "beamed-extreme-minimum-free-lengths lengths beam stem-shorten "
980 "duration-log beaming neutral-direction stem-end-position "
981 "note-heads direction length flag-style "
982 "no-stem-extend stroke-style");