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 = scm_to_double (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 && scm_to_int (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 = scm_to_double (scm_len);
278 s = me->get_property ("lengths");
280 length = 2 * scm_to_double (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)) ? scm_to_int (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)scm_to_int (ax);
499 Grob *me = unsmob_grob (smob);
500 assert (a == Y_AXIS);
503 ugh. - this dependency should be automatic.
505 Grob *beam= get_beam (me);
508 Beam::after_line_breaking (beam->self_scm ());
512 SCM mol = me->get_uncached_stencil ();
515 iv = unsmob_stencil (mol)->extent (a);
516 if (Grob *b =get_beam (me))
518 Direction d = get_direction (me);
519 iv[d] += d * Beam::get_thickness (b) * 0.5 ;
522 return ly_interval2scm (iv);
527 Stem::flag (Grob *me)
529 /* TODO: maybe property stroke-style should take different values,
530 e.g. "" (i.e. no stroke), "single" and "double" (currently, it's
534 SCM flag_style_scm = me->get_property ("flag-style");
535 if (ly_c_symbol_p (flag_style_scm))
536 flag_style = ly_symbol2string (flag_style_scm);
538 if (flag_style == "no-flag")
543 String staffline_offs;
544 if (String::compare (flag_style, "mensural") == 0)
545 /* Mensural notation: For notes on staff lines, use different
546 flags than for notes between staff lines. The idea is that
547 flags are always vertically aligned with the staff lines,
548 regardless if the note head is on a staff line or between two
549 staff lines. In other words, the inner end of a flag always
550 touches a staff line.
555 int p = (int)(rint (stem_end_position (me)));
557 Staff_symbol_referencer::on_staffline (me, p) ? "0" : "1";
561 staffline_offs = "2";
569 char dir = (get_direction (me) == UP) ? 'u' : 'd';
570 String font_char = flag_style
571 + to_string (dir) + staffline_offs + to_string (duration_log (me));
572 Font_metric *fm = Font_interface::get_default_font (me);
573 Stencil flag = fm->find_by_name ("flags-" + font_char);
574 if (flag.is_empty ())
575 me->warning (_f ("flag `%s' not found", font_char));
577 SCM stroke_style_scm = me->get_property ("stroke-style");
578 if (scm_is_string (stroke_style_scm))
580 String stroke_style = ly_scm2string (stroke_style_scm);
581 if (!stroke_style.is_empty ())
583 String font_char = to_string (dir) + stroke_style;
584 Stencil stroke = fm->find_by_name ("flags-" + font_char);
585 if (stroke.is_empty ())
586 me->warning (_f ("flag stroke `%s' not found", font_char));
588 flag.add_stencil (stroke);
595 MAKE_SCHEME_CALLBACK (Stem,dim_callback,2);
597 Stem::dim_callback (SCM e, SCM ax)
599 Axis a = (Axis) scm_to_int (ax);
600 assert (a == X_AXIS);
601 Grob *me = unsmob_grob (e);
605 if (is_invisible (me))
609 else if (unsmob_grob (me->get_property ("beam")) || abs (duration_log (me)) <= 2)
612 r *= thickness (me)/2;
616 r = flag (me).extent (X_AXIS)
619 return ly_interval2scm (r);
623 Stem::thickness (Grob *me)
625 return scm_to_double (me->get_property ("thickness"))
626 * Staff_symbol_referencer::line_thickness (me);
629 MAKE_SCHEME_CALLBACK (Stem, print, 1);
631 Stem::print (SCM smob)
633 Grob *me = unsmob_grob (smob);
635 Direction d = get_direction (me);
637 /* TODO: make the stem start a direction ?
638 This is required to avoid stems passing in tablature chords. */
639 Grob *lh = to_boolean (me->get_property ("avoid-note-head"))
640 ? last_head (me) : lh = first_head (me);
645 if (is_invisible (me))
648 Real y1 = Staff_symbol_referencer::get_position (lh);
649 Real y2 = stem_end_position (me);
651 Interval stem_y (y1 <? y2,y2 >? y1);
654 Real dy = Staff_symbol_referencer::staff_space (me) * 0.5;
656 if (Grob *hed = support_head (me))
659 must not take ledgers into account.
661 Interval head_height = Note_head::head_extent (hed,Y_AXIS);
662 Real y_attach = Note_head::stem_attachment_coordinate (hed, Y_AXIS);
664 y_attach = head_height.linear_combination (y_attach);
665 stem_y[Direction (-d)] += d * y_attach/dy;
670 Real stem_width = thickness (me);
672 me->get_paper ()->get_dimension (ly_symbol2scm ("blotdiameter"));
674 Box b = Box (Interval (-stem_width/2, stem_width/2),
675 Interval (stem_y[DOWN]*dy, stem_y[UP]*dy));
677 Stencil ss = Lookup::round_filled_box (b, blot);
678 mol.add_stencil (ss);
680 if (!get_beam (me) && abs (duration_log (me)) > 2)
682 Stencil fl = flag (me);
683 fl.translate_axis (stem_y[d]*dy - d * blot/2, Y_AXIS);
684 fl.translate_axis (stem_width/2, X_AXIS);
685 mol.add_stencil (fl);
688 return mol.smobbed_copy ();
692 move the stem to right of the notehead if it is up.
694 MAKE_SCHEME_CALLBACK (Stem, off_callback, 2);
696 Stem::off_callback (SCM element_smob, SCM)
698 Grob *me = unsmob_grob (element_smob);
702 if (Grob *f = first_head (me))
704 Interval head_wid = Note_head::head_extent (f, X_AXIS);
707 if (is_invisible (me))
710 attach = Note_head::stem_attachment_coordinate (f, X_AXIS);
712 Direction d = get_direction (me);
713 Real real_attach = head_wid.linear_combination (d * attach);
716 /* If not centered: correct for stem thickness. */
719 Real rule_thick = thickness (me);
720 r += - d * rule_thick * 0.5;
723 return scm_make_real (r);
727 Stem::get_beam (Grob *me)
729 SCM b = me->get_property ("beam");
730 return dynamic_cast<Spanner*> (unsmob_grob (b));
734 Stem::get_stem_info (Grob *me)
736 /* Return cached info if available */
737 SCM scm_info = me->get_property ("stem-info");
738 if (!ly_c_pair_p (scm_info))
741 scm_info = me->get_property ("stem-info");
745 si.dir_ = get_grob_direction (me);
746 si.ideal_y_ = scm_to_double (ly_car (scm_info));
747 si.shortest_y_ = scm_to_double (ly_cadr (scm_info));
752 /* TODO: add extra space for tremolos! */
754 Stem::calc_stem_info (Grob *me)
756 Direction my_dir = get_grob_direction (me);
760 programming_error ("No stem dir set?");
764 Real staff_space = Staff_symbol_referencer::staff_space (me);
765 Grob *beam = get_beam (me);
766 Real beam_translation = Beam::get_beam_translation (beam);
767 Real beam_thickness = Beam::get_thickness (beam);
768 int beam_count = Beam::get_direction_beam_count (beam, my_dir);
771 /* Simple standard stem length */
772 SCM lengths = me->get_property ("beamed-lengths");
774 scm_to_double (robust_list_ref (beam_count - 1,lengths))
777 /* stem only extends to center of beam
779 - 0.5 * beam_thickness
782 /* Condition: sane minimum free stem length (chord to beams) */
783 lengths = me->get_property ("beamed-minimum-free-lengths");
784 Real ideal_minimum_free =
785 scm_to_double (robust_list_ref (beam_count - 1, lengths))
790 It seems that also for ideal minimum length, we must use
791 the maximum beam count (for this direction):
793 \score{ \notes\relative c''{ [a8 a32] }}
795 must be horizontal. */
796 Real height_of_my_beams = beam_thickness
797 + (beam_count - 1) * beam_translation;
799 Real ideal_minimum_length = ideal_minimum_free
801 /* stem only extends to center of beam */
802 - 0.5 * beam_thickness;
804 ideal_length = ideal_length >? ideal_minimum_length;
806 /* Convert to Y position, calculate for dir == UP */
808 /* staff positions */
809 head_positions (me)[my_dir] * 0.5
810 * my_dir * staff_space;
811 Real ideal_y = note_start + ideal_length;
814 /* Conditions for Y position */
816 /* Lowest beam of (UP) beam must never be lower than second staffline
820 Although this (additional) rule is probably correct,
821 I expect that highest beam (UP) should also never be lower
822 than middle staffline, just as normal stems.
826 Obviously not for grace beams.
828 Also, not for knees. Seems to be a good thing. */
829 bool no_extend_b = to_boolean (me->get_property ("no-stem-extend"));
830 bool is_knee = to_boolean (beam->get_property ("knee"));
831 if (!no_extend_b && !is_knee)
833 /* Highest beam of (UP) beam must never be lower than middle
835 ideal_y = ideal_y >? 0;
836 /* Lowest beam of (UP) beam must never be lower than second staffline */
837 ideal_y = ideal_y >? (-staff_space
838 - beam_thickness + height_of_my_beams);
842 ideal_y -= robust_scm2double (beam->get_property ("shorten"), 0);
845 scm_to_double (robust_list_ref
848 ("beamed-extreme-minimum-free-lengths")))
851 Real minimum_length = minimum_free
853 /* stem only extends to center of beam */
854 - 0.5 * beam_thickness;
857 Real minimum_y = note_start + minimum_length;
858 Real shortest_y = minimum_y * my_dir;
860 me->set_property ("stem-info",
861 scm_list_2 (scm_make_real (ideal_y),
862 scm_make_real (shortest_y)));
866 Stem::beam_multiplicity (Grob *stem)
868 SCM beaming= stem->get_property ("beaming");
869 Slice le = int_list_to_slice (ly_car (beaming));
870 Slice ri = int_list_to_slice (ly_cdr (beaming));
876 /* FIXME: Too many properties */
877 ADD_INTERFACE (Stem, "stem-interface",
878 "The stem represent the graphical stem. "
879 "In addition, it internally connects note heads, beams and"
881 "Rests and whole notes have invisible stems.",
882 "tremolo-flag french-beaming "
883 "avoid-note-head thickness "
884 "stem-info beamed-lengths beamed-minimum-free-lengths "
885 "beamed-extreme-minimum-free-lengths lengths beam stem-shorten "
886 "duration-log beaming neutral-direction stem-end-position "
887 "note-heads direction length flag-style "
888 "no-stem-extend stroke-style");
890 /****************************************************************/
892 Stem_info::Stem_info ()
894 ideal_y_ = shortest_y_ = 0;
899 Stem_info::scale (Real x)