2 stem.cc -- implement Stem
4 source file of the GNU LilyPond music typesetter
6 (c) 1996--2004 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 "output-def.hh"
24 #include "rhythmic-head.hh"
25 #include "font-interface.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_property ("beaming");
43 if (!ly_c_pair_p (pair))
45 pair = scm_cons (SCM_EOL, SCM_EOL);
46 me->set_property ("beaming", pair);
49 SCM lst = index_get_cell (pair, d);
50 for (int i = 0; i < beam_count; i++)
51 lst = scm_cons (scm_int2num (i), lst);
52 index_set_cell (pair, d, lst);
56 Stem::get_beaming (Grob *me, Direction d)
58 SCM pair = me->get_property ("beaming");
59 if (!ly_c_pair_p (pair))
62 SCM lst = index_get_cell (pair, d);
63 return scm_ilength (lst);
68 Stem::head_positions (Grob *me)
72 Drul_array<Grob*> e (extremal_heads (me));
73 return Interval (Staff_symbol_referencer::get_position (e[DOWN]),
74 Staff_symbol_referencer::get_position (e[UP]));
80 Stem::chord_start_y (Grob *me)
82 Interval hp = head_positions (me);
84 return hp[get_direction (me)] * Staff_symbol_referencer::staff_space (me)
90 Stem::stem_end_position (Grob *me)
92 SCM p = me->get_property ("stem-end-position");
94 if (!ly_c_number_p (p))
96 pos = get_default_stem_end_position (me);
97 me->set_property ("stem-end-position", scm_make_real (pos));
100 pos = ly_scm2double (p);
106 Stem::get_direction (Grob *me)
108 Direction d = get_grob_direction (me);
112 d = get_default_dir (me);
114 set_grob_direction (me, d);
120 Stem::set_stemend (Grob *me, Real se)
123 Direction d = get_direction (me);
125 if (d && d * head_positions (me)[get_direction (me)] >= se*d)
126 me->warning (_ ("Weird stem size; check for narrow beams"));
128 me->set_property ("stem-end-position", scm_make_real (se));
131 /* Note head that determines hshift for upstems
132 WARNING: triggers direction */
134 Stem::support_head (Grob *me)
136 if (head_count (me) == 1)
138 return unsmob_grob (ly_car (me->get_property ("note-heads")));
139 return first_head (me);
143 Stem::head_count (Grob *me)
145 return Pointer_group_interface::count (me, "note-heads");
148 /* The note head which forms one end of the stem.
149 WARNING: triggers direction */
151 Stem::first_head (Grob *me)
153 Direction d = get_direction (me);
155 return extremal_heads (me)[-d];
159 /* The note head opposite to the first head. */
161 Stem::last_head (Grob *me)
163 Direction d = get_direction (me);
165 return extremal_heads (me)[d];
169 /* START is part where stem reaches `last' head.
171 This function returns a drul with (bottom-head, top-head).
175 Stem::extremal_heads (Grob *me)
177 const int inf = 1000000;
178 Drul_array<int> extpos;
182 Drul_array<Grob *> exthead;
183 exthead[LEFT] = exthead[RIGHT] =0;
185 for (SCM s = me->get_property ("note-heads"); ly_c_pair_p (s);
188 Grob *n = unsmob_grob (ly_car (s));
189 int p = Staff_symbol_referencer::get_rounded_position (n);
194 if (d * p > d * extpos[d])
199 } while (flip (&d) != DOWN);
205 icmp (int const &a, int const &b)
210 /* The positions, in ascending order. */
212 Stem::note_head_positions (Grob *me)
215 for (SCM s = me->get_property ("note-heads"); ly_c_pair_p (s);
218 Grob *n = unsmob_grob (ly_car (s));
219 int p = Staff_symbol_referencer::get_rounded_position (n);
229 Stem::add_head (Grob *me, Grob *n)
231 n->set_property ("stem", me->self_scm ());
232 n->add_dependency (me);
234 /* TODO: why not store Rest pointers? */
235 if (Note_head::has_interface (n))
236 Pointer_group_interface::add_grob (me, ly_symbol2scm ("note-heads"), n);
240 Stem::is_invisible (Grob *me)
242 return !(head_count (me)
243 && ly_scm2int (me->get_property ("duration-log")) >= 1);
247 Stem::get_default_dir (Grob *me)
249 int staff_center = 0;
250 Interval hp = head_positions (me);
254 int udistance = (int) (UP * hp[UP] - staff_center);
255 int ddistance = (int) (DOWN * hp[DOWN] - staff_center);
257 if (sign (ddistance - udistance))
258 return Direction (sign (ddistance - udistance));
260 return to_dir (me->get_property ("neutral-direction"));
264 Stem::get_default_stem_end_position (Grob *me)
266 Real ss = Staff_symbol_referencer::staff_space (me);
267 int durlog = duration_log (me);
271 /* WARNING: IN HALF SPACES */
273 SCM scm_len = me->get_property ("length");
274 if (ly_c_number_p (scm_len))
275 length = ly_scm2double (scm_len);
278 s = me->get_property ("lengths");
280 length = 2 * ly_scm2double (robust_list_ref (durlog - 2, s));
284 'set-default-stemlen' sets direction too. */
285 Direction dir = get_direction (me);
288 dir = get_default_dir (me);
289 set_grob_direction (me, dir);
292 /* Stems in unnatural (forced) direction should be shortened,
293 according to [Roush & Gourlay] */
294 Interval hp = head_positions (me);
295 if (dir && dir * hp[dir] >= 0)
297 SCM sshorten = me->get_property ("stem-shorten");
298 SCM scm_shorten = ly_c_pair_p (sshorten) ?
299 robust_list_ref ((duration_log (me) - 2) >? 0, sshorten): SCM_EOL;
300 Real shorten = 2* robust_scm2double (scm_shorten,0);
302 /* On boundary: shorten only half */
303 if (abs (head_positions (me)[dir]) <= 1)
310 Grob *t_flag = unsmob_grob (me->get_property ("tremolo-flag"));
311 if (t_flag && !unsmob_grob (me->get_property ("beam")))
313 /* Crude hack: add extra space if tremolo flag is there.
315 We can't do this for the beam, since we get into a loop
316 (Stem_tremolo::raw_stencil () looks at the beam.) --hwn */
319 + 2 * Stem_tremolo::raw_stencil (t_flag).extent (Y_AXIS).length ()
324 Interval flag_ext = flag (me).extent (Y_AXIS);
325 if (!flag_ext.is_empty ())
326 minlen += 2 * flag_ext.length () / ss;
328 /* The clash is smaller for down stems (since the tremolo is
333 length = length >? (minlen + 1.0);
336 Real st = dir ? hp[dir] + dir * length : 0;
338 /* TODO: change name to extend-stems to staff/center/'() */
339 bool no_extend_b = to_boolean (me->get_property ("no-stem-extend"));
340 if (!no_extend_b && dir * st < 0)
343 /* Make a little room if we have a upflag and there is a dot.
344 previous approach was to lengthen the stem. This is not
345 good typesetting practice. */
346 if (!get_beam (me) && dir == UP
349 Grob * closest_to_flag = extremal_heads (me)[dir];
350 Grob * dots = closest_to_flag
351 ? Rhythmic_head::get_dots (closest_to_flag ) : 0;
355 Real dp = Staff_symbol_referencer::get_position (dots);
356 Real flagy = flag (me).extent (Y_AXIS)[-dir] * 2 / ss;
358 /* Very gory: add myself to the X-support of the parent,
359 which should be a dot-column. */
360 if (dir * (st + flagy - dp) < 0.5)
362 Grob *par = dots->get_parent (X_AXIS);
364 if (Dot_column::has_interface (par))
366 Side_position_interface::add_support (par, me);
368 /* TODO: apply some better logic here. The flag is
369 curved inwards, so this will typically be too
378 /* The log of the duration (Number of hooks on the flag minus two) */
380 Stem::duration_log (Grob *me)
382 SCM s = me->get_property ("duration-log");
383 return (ly_c_number_p (s)) ? ly_scm2int (s) : 2;
387 Stem::position_noteheads (Grob *me)
389 if (!head_count (me))
392 Link_array<Grob> heads =
393 Pointer_group_interface__extract_grobs (me, (Grob*) 0, "note-heads");
395 heads.sort (compare_position);
396 Direction dir =get_direction (me);
401 Real thick = thickness (me);
403 Grob *hed = support_head (me);
404 Real w = Note_head::head_extent (hed,X_AXIS)[dir];
405 for (int i = 0; i < heads.size (); i++)
406 heads[i]->translate_axis (w - Note_head::head_extent (heads[i],
411 Real lastpos = Real (Staff_symbol_referencer::get_position (heads[0]));
412 for (int i = 1; i < heads.size (); i ++)
414 Real p = Staff_symbol_referencer::get_position (heads[i]);
415 Real dy =fabs (lastpos- p);
418 dy should always be 0.5, 0.0, 1.0, but provide safety margin
425 Real ell = Note_head::head_extent (heads[i], X_AXIS).length ();
427 Direction d = get_direction (me);
429 Reversed head should be shifted ell-thickness, but this
430 looks too crowded, so we only shift ell-0.5*thickness.
432 This leads to assymetry: Normal heads overlap the
433 stem 100% whereas reversed heads only overlaps the
437 Real reverse_overlap = 0.5;
438 heads[i]->translate_axis ((ell - thick * reverse_overlap) * d,
441 if (is_invisible (me))
442 heads[i]->translate_axis (-thick * (2 - reverse_overlap) * d,
447 For some cases we should kern some more: when the
448 distance between the next or prev note is too large, we'd
449 get large white gaps, eg.
468 MAKE_SCHEME_CALLBACK (Stem,before_line_breaking,1);
470 Stem::before_line_breaking (SCM smob)
472 Grob *me = unsmob_grob (smob);
475 Do the calculations for visible stems, but also for invisible stems
476 with note heads (i.e. half notes.)
480 stem_end_position (me); // ugh. Trigger direction calc.
481 position_noteheads (me);
484 me->set_property ("print-function", SCM_EOL);
486 return SCM_UNSPECIFIED;
491 When in a beam with tuplet brackets, brew_mol is called early,
492 caching a wrong value.
494 MAKE_SCHEME_CALLBACK (Stem, height, 2);
496 Stem::height (SCM smob, SCM ax)
498 Axis a = (Axis)ly_scm2int (ax);
499 Grob *me = unsmob_grob (smob);
500 assert (a == Y_AXIS);
502 SCM mol = me->get_uncached_stencil ();
505 iv = unsmob_stencil (mol)->extent (a);
506 if (Grob *b =get_beam (me))
508 Direction d = get_direction (me);
509 iv[d] += d * Beam::get_thickness (b) * 0.5 ;
512 return ly_interval2scm (iv);
517 Stem::flag (Grob *me)
519 /* TODO: maybe property stroke-style should take different values,
520 e.g. "" (i.e. no stroke), "single" and "double" (currently, it's
524 SCM flag_style_scm = me->get_property ("flag-style");
525 if (ly_c_symbol_p (flag_style_scm))
526 flag_style = ly_symbol2string (flag_style_scm);
528 if (flag_style == "no-flag")
533 String staffline_offs;
534 if (String::compare (flag_style, "mensural") == 0)
535 /* Mensural notation: For notes on staff lines, use different
536 flags than for notes between staff lines. The idea is that
537 flags are always vertically aligned with the staff lines,
538 regardless if the note head is on a staff line or between two
539 staff lines. In other words, the inner end of a flag always
540 touches a staff line.
545 /* Urrgh! We have to detect wether this stem ends on a staff
546 line or between two staff lines. But we can not call
547 stem_end_position (me) or get_default_stem_end_position (me),
548 since this encounters the flag and hence results in an
549 infinite recursion. However, in pure mensural notation,
550 there are no multiple note heads attached to a single stem,
551 neither is there usually need for using the stem_shorten
552 property (except for 32th and 64th notes, but that is not a
553 problem since the stem length in this case is augmented by
554 an integral multiple of staff_space). Hence, it should be
555 sufficient to just take the first note head, assume it's
556 the only one, look if it's on a staff line, and select the
557 flag's shape accordingly. In the worst case, the shape
558 looks slightly misplaced, but that will usually be the
559 programmer's fault (e.g. when trying to attach multiple
560 note heads to a single stem in mensural notation).
564 perhaps the detection whether this correction is needed should
565 happen in a different place to avoid the recursion.
569 int p = Staff_symbol_referencer::get_rounded_position (me);
570 staffline_offs = Staff_symbol_referencer::on_staffline (me, p)
575 staffline_offs = "2";
583 char dir = (get_direction (me) == UP) ? 'u' : 'd';
584 String font_char = flag_style
585 + to_string (dir) + staffline_offs + to_string (duration_log (me));
586 Font_metric *fm = Font_interface::get_default_font (me);
587 Stencil flag = fm->find_by_name ("flags-" + font_char);
588 if (flag.is_empty ())
589 me->warning (_f ("flag `%s' not found", font_char));
591 SCM stroke_style_scm = me->get_property ("stroke-style");
592 if (ly_c_string_p (stroke_style_scm))
594 String stroke_style = ly_scm2string (stroke_style_scm);
595 if (!stroke_style.is_empty ())
597 String font_char = to_string (dir) + stroke_style;
598 Stencil stroke = fm->find_by_name ("flags-" + font_char);
599 if (stroke.is_empty ())
600 me->warning (_f ("flag stroke `%s' not found", font_char));
602 flag.add_stencil (stroke);
609 MAKE_SCHEME_CALLBACK (Stem,dim_callback,2);
611 Stem::dim_callback (SCM e, SCM ax)
613 Axis a = (Axis) ly_scm2int (ax);
614 assert (a == X_AXIS);
615 Grob *me = unsmob_grob (e);
617 if (unsmob_grob (me->get_property ("beam")) || abs (duration_log (me)) <= 2)
620 r = flag (me).extent (X_AXIS)
622 return ly_interval2scm (r);
626 Stem::thickness (Grob *me)
628 return ly_scm2double (me->get_property ("thickness"))
629 * Staff_symbol_referencer::line_thickness (me);
632 MAKE_SCHEME_CALLBACK (Stem, print, 1);
634 Stem::print (SCM smob)
636 Grob *me = unsmob_grob (smob);
638 Direction d = get_direction (me);
640 /* TODO: make the stem start a direction ?
641 This is required to avoid stems passing in tablature chords. */
642 Grob *lh = to_boolean (me->get_property ("avoid-note-head"))
643 ? last_head (me) : lh = first_head (me);
648 if (is_invisible (me))
651 Real y1 = Staff_symbol_referencer::get_position (lh);
652 Real y2 = stem_end_position (me);
654 Interval stem_y (y1 <? y2,y2 >? y1);
657 Real dy = Staff_symbol_referencer::staff_space (me) * 0.5;
659 if (Grob *hed = support_head (me))
662 must not take ledgers into account.
664 Interval head_height = Note_head::head_extent (hed,Y_AXIS);
665 Real y_attach = Note_head::stem_attachment_coordinate (hed, Y_AXIS);
667 y_attach = head_height.linear_combination (y_attach);
668 stem_y[Direction (-d)] += d * y_attach/dy;
673 Real stem_width = thickness (me);
675 me->get_paper ()->get_dimension (ly_symbol2scm ("blotdiameter"));
677 Box b = Box (Interval (-stem_width/2, stem_width/2),
678 Interval (stem_y[DOWN]*dy, stem_y[UP]*dy));
680 Stencil ss = Lookup::round_filled_box (b, blot);
681 mol.add_stencil (ss);
683 if (!get_beam (me) && abs (duration_log (me)) > 2)
685 Stencil fl = flag (me);
686 fl.translate_axis (stem_y[d]*dy - d * blot/2, Y_AXIS);
687 fl.translate_axis (stem_width/2, X_AXIS);
688 mol.add_stencil (fl);
691 return mol.smobbed_copy ();
695 move the stem to right of the notehead if it is up.
697 MAKE_SCHEME_CALLBACK (Stem, off_callback, 2);
699 Stem::off_callback (SCM element_smob, SCM)
701 Grob *me = unsmob_grob (element_smob);
705 if (Grob *f = first_head (me))
707 Interval head_wid = Note_head::head_extent (f, X_AXIS);
710 if (is_invisible (me))
713 attach = Note_head::stem_attachment_coordinate (f, X_AXIS);
715 Direction d = get_direction (me);
716 Real real_attach = head_wid.linear_combination (d * attach);
719 /* If not centered: correct for stem thickness. */
722 Real rule_thick = thickness (me);
723 r += - d * rule_thick * 0.5;
726 return scm_make_real (r);
730 Stem::get_beam (Grob *me)
732 SCM b = me->get_property ("beam");
733 return unsmob_grob (b);
737 Stem::get_stem_info (Grob *me)
739 /* Return cached info if available */
740 SCM scm_info = me->get_property ("stem-info");
741 if (!ly_c_pair_p (scm_info))
744 scm_info = me->get_property ("stem-info");
748 si.dir_ = get_grob_direction (me);
749 si.ideal_y_ = ly_scm2double (ly_car (scm_info));
750 si.shortest_y_ = ly_scm2double (ly_cadr (scm_info));
755 /* TODO: add extra space for tremolos! */
757 Stem::calc_stem_info (Grob *me)
759 Direction my_dir = get_grob_direction (me);
763 programming_error ("No stem dir set?");
767 Real staff_space = Staff_symbol_referencer::staff_space (me);
768 Grob *beam = get_beam (me);
769 Real beam_translation = Beam::get_beam_translation (beam);
770 Real beam_thickness = Beam::get_thickness (beam);
771 int beam_count = Beam::get_direction_beam_count (beam, my_dir);
774 /* Simple standard stem length */
775 SCM lengths = me->get_property ("beamed-lengths");
777 ly_scm2double (robust_list_ref (beam_count - 1,lengths))
780 /* stem only extends to center of beam */
781 - 0.5 * beam_thickness;
783 /* Condition: sane minimum free stem length (chord to beams) */
784 lengths = me->get_property ("beamed-minimum-free-lengths");
785 Real ideal_minimum_free =
786 ly_scm2double (robust_list_ref (beam_count - 1, lengths))
791 It seems that also for ideal minimum length, we must use
792 the maximum beam count (for this direction):
794 \score{ \notes\relative c''{ [a8 a32] }}
796 must be horizontal. */
797 Real height_of_my_beams = beam_thickness
798 + (beam_count - 1) * beam_translation;
800 Real ideal_minimum_length = ideal_minimum_free
802 /* stem only extends to center of beam */
803 - 0.5 * beam_thickness;
805 ideal_length = ideal_length >? ideal_minimum_length;
807 /* Convert to Y position, calculate for dir == UP */
809 /* staff positions */
810 head_positions (me)[my_dir] * 0.5
811 * my_dir * staff_space;
812 Real ideal_y = note_start + ideal_length;
815 /* Conditions for Y position */
817 /* Lowest beam of (UP) beam must never be lower than second staffline
821 Although this (additional) rule is probably correct,
822 I expect that highest beam (UP) should also never be lower
823 than middle staffline, just as normal stems.
827 Obviously not for grace beams.
829 Also, not for knees. Seems to be a good thing. */
830 bool no_extend_b = to_boolean (me->get_property ("no-stem-extend"));
831 bool is_knee = to_boolean (beam->get_property ("knee"));
832 if (!no_extend_b && !is_knee)
834 /* Highest beam of (UP) beam must never be lower than middle
836 ideal_y = ideal_y >? 0;
837 /* Lowest beam of (UP) beam must never be lower than second staffline */
838 ideal_y = ideal_y >? (-staff_space
839 - beam_thickness + height_of_my_beams);
843 ideal_y -= robust_scm2double (beam->get_property ("shorten"), 0);
846 ly_scm2double (robust_list_ref
849 ("beamed-extreme-minimum-free-lengths")))
852 Real minimum_length = minimum_free
854 /* stem only extends to center of beam */
855 - 0.5 * beam_thickness;
858 Real minimum_y = note_start + minimum_length;
859 Real shortest_y = minimum_y * my_dir;
861 me->set_property ("stem-info",
862 scm_list_2 (scm_make_real (ideal_y),
863 scm_make_real (shortest_y)));
867 Stem::beam_multiplicity (Grob *stem)
869 SCM beaming= stem->get_property ("beaming");
870 Slice le = int_list_to_slice (ly_car (beaming));
871 Slice ri = int_list_to_slice (ly_cdr (beaming));
877 /* FIXME: Too many properties */
878 ADD_INTERFACE (Stem, "stem-interface",
879 "The stem represent the graphical stem. "
880 "In addition, it internally connects note heads, beams and"
882 "Rests and whole notes have invisible stems.",
883 "tremolo-flag french-beaming "
884 "avoid-note-head thickness "
885 "stem-info beamed-lengths beamed-minimum-free-lengths "
886 "beamed-extreme-minimum-free-lengths lengths beam stem-shorten "
887 "duration-log beaming neutral-direction stem-end-position "
888 "note-heads direction length flag-style "
889 "no-stem-extend stroke-style");
891 /****************************************************************/
893 Stem_info::Stem_info ()
895 ideal_y_ = shortest_y_ = 0;
900 Stem_info::scale (Real x)