+/*
+ spacing-spanner.cc -- implement Spacing_spanner
+
+ source file of the GNU LilyPond music typesetter
+
+ (c) 1999--2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+
+ */
+
+#include "spacing-spanner.hh"
+#include "paper-column.hh"
+#include "dimensions.hh"
+#include "paper-def.hh"
+#include "warn.hh"
+#include "paper-score.hh"
+#include "line-of-score.hh"
+#include "misc.hh"
+
+void
+Spacing_spanner::set_interface (Grob*me)
+{
+ me->set_extent_callback (SCM_EOL, X_AXIS);
+ me->set_extent_callback (SCM_EOL, Y_AXIS) ;
+}
+
+#if 0
+struct Note_run
+{
+ Array<int> idxes;
+ int start, end;
+ Moment duration;
+ int count;
+};
+
+int
+column_compare (Grob *const &t1, Grob *const &t2)
+{
+ return Moment::compare (Paper_column::when_mom (t1),
+ Paper_column::when_mom (t2));
+}
+
+
+Note_run
+run_length (Moment dt, int i, Array<Moment> const &moms,
+ Link_array<Note_run> runs)
+{
+ int k = 0;
+ Array<int> idxes;
+
+ idxes.push (i);
+ while (1)
+ {
+ Moment next = moms[i] + dt;
+ while (i < moms.size () && moms[i] < next)
+ i++;
+ if (i == moms.size () || moms[i] != next)
+ break;
+
+ idxes.push (i);
+ k++;
+ }
+
+ Moment dur = idxes.size ()
+}
+
+void
+find_runs (Grob*me, Link_array<Grob> cols)
+{
+ Link_array<Grob> filter_cols;
+ Array<Moment> col_moments;
+ for (int i = 0; i < cols.size (); i++)
+ {
+ Moment w = Paper_column::when_mom (cols[i]);
+
+ if (!w.grace_part_ && Paper_column::musical_b (cols[i]))
+ {
+ filter_cols.push (cols[i]);
+ col_moments.push (w);
+ }
+ }
+
+ Moment end_mom = col_moments.top ();
+ for (int i = 0; i < col_moments.size () ; i++)
+ {
+ for (int j = i+1; j < col_moments.size (); j++)
+ {
+ Moment dt = Paper_column::col_momentsfilter_cols
+ }
+ }
+}
+#endif
+
+/*
+
+ The algorithm is partly taken from :
+
+ John S. Gourlay. ``Spacing a Line of Music,'' Technical Report
+ OSU-CISRC-10/87-TR35, Department of Computer and Information
+ Science, The Ohio State University, 1987.
+
+ TOO HAIRY.
+
+ TODO: write comments
+
+ */
+void
+Spacing_spanner::do_measure (Grob*me, Link_array<Grob> const & cols)
+{
+ Moment shortest;
+ Moment mean_shortest;
+
+ /*
+ space as if this duration is present.
+ */
+ Moment base_shortest_duration = *unsmob_moment (me->get_grob_property ("maximum-duration-for-spacing"));
+ shortest.set_infinite (1);
+
+ int n = 0;
+ for (int i =0 ; i < cols.size (); i++)
+ {
+ if (Paper_column::musical_b (cols[i]))
+ {
+ Moment *when = unsmob_moment (cols[i]->get_grob_property ("when"));
+
+ /*
+ ignore grace notes for shortest notes.
+ */
+ if (when && when->grace_part_)
+ continue;
+
+ SCM st = cols[i]->get_grob_property ("shortest-starter-duration");
+ Moment this_shortest = *unsmob_moment (st);
+ shortest = shortest <? this_shortest;
+ if (!mean_shortest.main_part_.infty_b ())
+ {
+ n++;
+ mean_shortest += this_shortest;
+ }
+ }
+ }
+ mean_shortest /= n;
+
+ Array<Spring> springs;
+ for (int i= 0; i < cols.size () - 1; i++)
+ {
+ Item * l = dynamic_cast<Item*> (cols[i]);
+ Item * r = dynamic_cast<Item*> (cols[i+1]);
+ Item * lb = dynamic_cast<Item*> (l->find_prebroken_piece (RIGHT));
+ Item * rb = dynamic_cast<Item*> (r->find_prebroken_piece (LEFT));
+
+ Item* combinations[4][2]={{l,r}, {lb,r}, {l,rb},{lb,rb}};
+
+
+ /*
+ left refers to the space that is associated with items of the left column, so you have
+
+ LC <- left_space -><- right_space -> RC
+ <- total space ->
+
+
+ typically, right_space is non-zero when there are
+ accidentals in RC
+
+ */
+ for (int j=0; j < 4; j++)
+ {
+ Paper_column * lc = dynamic_cast<Paper_column*> (combinations[j][0]);
+ Paper_column *rc = dynamic_cast<Paper_column*> (combinations[j][1]);
+ if (!lc || !rc)
+ continue;
+
+ Spring s;
+ s.item_l_drul_[LEFT] = lc;
+ s.item_l_drul_[RIGHT] = rc;
+
+ SCM hint = lc->get_grob_property ("extra-space");
+ SCM next_hint = rc->get_grob_property ("extra-space");
+ SCM stretch_hint = lc->get_grob_property ("stretch-distance");
+ SCM next_stretch_hint = rc->get_grob_property ("stretch-distance");
+
+ Real left_distance = 0;
+ if (gh_pair_p (hint))
+ {
+ left_distance = gh_scm2double (gh_cdr (hint));
+ }
+ // 2nd condition should be (i+1 < col_count ()), ie. not the last column in score. FIXME
+ else if (!Paper_column::musical_b (lc) && i+1 < cols.size ())
+ {
+ left_distance= default_bar_spacing (me,lc,rc,shortest <? base_shortest_duration);
+ }
+ else if (Paper_column::musical_b ( lc))
+ {
+ left_distance = note_spacing (me,lc, rc, shortest <? base_shortest_duration);
+ }
+ else
+ programming_error ("uninitialised left_distance");
+
+ s.distance_f_ = left_distance;
+
+ /*
+ Only do tight spaces *after* barlines (breakable columns),
+ not before.
+
+ We want the space before barline to be like the note
+ spacing in the measure.
+ */
+ SCM sfac =lc->get_grob_property ("space-factor");
+ if (gh_number_p (lc->get_grob_property ("column-space-strength"))
+ && (Item::breakable_b (lc) || lc->original_l_))
+ {
+ s.strength_f_ =
+ gh_scm2double (lc->get_grob_property ("column-space-strength"));
+ }
+ else if (gh_number_p (sfac))
+ left_distance *= gh_scm2double (sfac);
+
+
+ Real right_dist = 0.0;
+ if (gh_pair_p (next_hint))
+ {
+ right_dist += - gh_scm2double (gh_car (next_hint));
+ }
+ else
+ {
+ Interval ext (rc->extent (rc, X_AXIS));
+ right_dist = ext.empty_b () ? 0.0 : - ext [LEFT];
+ }
+
+ /*
+ don't want to create too much extra space for accidentals
+ */
+ if (Paper_column::musical_b (rc))
+ {
+ if (to_boolean (rc->get_grob_property ("contains-grace")))
+ right_dist *= gh_scm2double (rc->get_grob_property ("before-grace-spacing-factor")); // fixme.
+ else
+ right_dist *= gh_scm2double (lc->get_grob_property ("before-musical-spacing-factor"));
+ }
+
+ s.distance_f_ = left_distance + right_dist;
+
+ Real stretch_dist = 0.;
+ if (gh_number_p (stretch_hint))
+ stretch_dist += gh_scm2double (stretch_hint);
+ else
+ stretch_dist += left_distance;
+
+ if (gh_pair_p (next_stretch_hint))
+ // see regtest spacing-tight
+ stretch_dist += - gh_scm2double (gh_car (next_stretch_hint));
+ else
+ stretch_dist += right_dist;
+
+ if (s.distance_f_ <0)
+ {
+ programming_error ("Negative dist, setting to 1.0 PT");
+ s.distance_f_ = 1.0;
+ }
+ if (stretch_dist == 0.0)
+ {
+ /*
+ \bar "". We give it 0 space, with high strength.
+ */
+ s.strength_f_ = 20.0;
+ }
+ else
+ s.strength_f_ /= stretch_dist;
+
+ springs.push (s);
+ }
+ }
+
+ Spacing_spanner::stretch_to_regularity (me, &springs, cols);
+ for (int i=springs.size (); i --;)
+ springs[i].add_to_cols ();
+}
+
+/*
+ Look at COLS, searching for columns that have 'regular-distance-to
+ set. A sequence of columns that have this property set should have
+ an equal distance (an equispaced run). Extract the projected
+ distance from SPRINGS, and scale SPRINGS for the equispaced run, to the
+ widest space necessary.
+
+
+ TODO:
+
+ -- inefficient code; maybe it is easier to twiddle with the springs
+ after they've become grob properties (ie. have their
+ minimum-distances set)
+
+ -- does not adjust strength field of the springs very well: result
+ awkward spacing at the start of a line. (?)
+
+ -- will be confused when there are multiple equispaced runs in a measure.
+
+ -- dealing with springs for line breaks is a little tricky; in any
+ case, we will only space per measure.
+
+ -- we scale to actual distances, not to optical effects. Eg. if the
+ equispaced run contains optical corrections, then the scaling will
+ cancel those.
+
+ -- Regular_spacing_engraver doesn't mark the first column of the
+ next bar, making the space before a barline too short, in this case
+
+
+ x<- 16ths--> x(8th)
+ x(8th) x(8th) <- equispaced run.
+
+*/
+
+void
+Spacing_spanner::stretch_to_regularity (Grob *me,
+ Array<Spring> * springs,
+ Link_array<Grob> const & cols)
+{
+ /*
+ Find the starting column of the run. REGULAR-DISTANCE-TO points
+ back to a previous column, so we look ahead to find a column
+ pointing back to the first one.
+
+ */
+ Grob * first_regular_spaced_col = 0;
+ for (int i = 0 ; i < cols.size () && !first_regular_spaced_col; i++)
+ {
+ SCM rdt = cols[i]->get_grob_property ("regular-distance-to");
+ if (cols.find_l (unsmob_grob (rdt)))
+ first_regular_spaced_col = unsmob_grob (rdt);
+ }
+ for (int i = springs->size (); i-- ;)
+ springs->elem (i).set_to_cols ();
+
+ int i;
+ for (i = 0; i < springs->size ()
+ && springs->elem (i).item_l_drul_[RIGHT] != first_regular_spaced_col;
+ i++)
+ ;
+
+
+ if (i==springs->size ())
+ return ;
+
+ Real maxdist = 0.0;
+ Real dist =0.0;
+ Grob *last_col = first_regular_spaced_col;
+ Grob *last_regular_spaced_col = first_regular_spaced_col;
+
+
+ /*
+ find the max distance for this run.
+ */
+ for (int j = i; j < springs->size (); j++)
+ {
+ Spring *s = &(springs->elem_ref (j));
+ if (s->item_l_drul_[LEFT] != last_col)
+ continue;
+
+ dist += s->distance_f_;
+
+ last_col = s->item_l_drul_[RIGHT];
+ SCM rdt = last_col->get_grob_property ("regular-distance-to");
+ if (unsmob_grob (rdt) == last_regular_spaced_col)
+ {
+ maxdist = maxdist >? dist;
+ dist = 0.0;
+ last_regular_spaced_col = last_col;
+ }
+
+ }
+
+ /*
+ Scale the springs
+ */
+ dist =0.0;
+ last_col = first_regular_spaced_col;
+ last_regular_spaced_col = first_regular_spaced_col;
+ for (int j = i; j < springs->size (); j++)
+ {
+ Spring *s = &springs->elem_ref (j);
+ if (s->item_l_drul_[LEFT] != last_col)
+ continue;
+ dist += s->distance_f_;
+
+ last_col = s->item_l_drul_[RIGHT];
+ SCM rdt = last_col->get_grob_property ("regular-distance-to");
+ if (unsmob_grob (rdt) == last_regular_spaced_col)
+ {
+ do {
+ springs->elem_ref (i).distance_f_ *= maxdist / dist;
+ springs->elem_ref (i).strength_f_ *= dist / maxdist;
+ } while (i++ < j);
+ last_regular_spaced_col = last_col;
+ dist =0.0;
+ }
+ }
+}
+
+/**
+ Do something if breakable column has no spacing hints set.
+ */
+Real
+Spacing_spanner::default_bar_spacing (Grob*me, Grob *lc, Grob *rc,
+ Moment shortest)
+{
+ Real symbol_distance = lc->extent (lc,X_AXIS)[RIGHT] ;
+ Real durational_distance = 0;
+ Moment delta_t = Paper_column::when_mom (rc) - Paper_column::when_mom (lc);
+
+ /*
+ ugh should use shortest_playing distance
+ */
+ if (delta_t)
+ {
+ durational_distance = get_duration_space (me, delta_t, shortest);
+ }
+
+ return symbol_distance >? durational_distance;
+}
+
+
+/**
+ Get the measure wide ant for arithmetic spacing.
+
+ @see
+ John S. Gourlay. ``Spacing a Line of Music,'' Technical Report
+ OSU-CISRC-10/87-TR35, Department of Computer and Information Science,
+ The Ohio State University, 1987.
+
+ */
+Real
+Spacing_spanner::get_duration_space (Grob*me, Moment d, Moment shortest)
+{
+ Real log = log_2 (shortest);
+ Real k = gh_scm2double (me->get_grob_property ("arithmetic-basicspace"))
+ - log;
+
+ return (log_2 (d) + k) * gh_scm2double (me->get_grob_property ("arithmetic-multiplier"));
+}
+
+
+Real
+Spacing_spanner::note_spacing (Grob*me, Grob *lc, Grob *rc,
+ Moment shortest)
+{
+ Moment shortest_playing_len = 0;
+ SCM s = lc->get_grob_property ("shortest-playing-duration");
+
+ // SCM s = lc->get_grob_property ("mean-playing-duration");
+ if (unsmob_moment (s))
+ shortest_playing_len = *unsmob_moment (s);
+
+ if (! shortest_playing_len)
+ {
+ programming_error ("can't find a ruling note at " + Paper_column::when_mom (lc).str ());
+ shortest_playing_len = 1;
+ }
+
+ if (! shortest)
+ {
+ programming_error ("no minimum in measure at " + Paper_column::when_mom (lc).str ());
+ shortest = 1;
+ }
+ Moment delta_t = Paper_column::when_mom (rc) - Paper_column::when_mom (lc);
+ Real dist = get_duration_space (me, shortest_playing_len, shortest);
+
+
+ /*
+ ugh: 0.1 is an arbitrary distance.
+ */
+ dist *= (double) (delta_t.main_part_ / shortest_playing_len.main_part_)
+ + 0.1 * (double) (delta_t.grace_part_ / shortest_playing_len.main_part_);
+
+
+
+ /*
+ UGH: KLUDGE!
+ */
+
+ if (delta_t > Moment (1,32))
+ dist += stem_dir_correction (me, lc,rc);
+
+
+ Moment *lm = unsmob_moment (lc->get_grob_property ("when"));
+ Moment *rm = unsmob_moment (rc->get_grob_property ("when"));
+
+ if (lm && rm)
+ {
+ if (lm->grace_part_ && rm->grace_part_)
+ dist *= 0.5;
+ else if (!rm->grace_part_ && lm->grace_part_)
+ dist *= 0.7;
+ }
+
+
+ return dist;
+}
+
+
+/**
+ Correct for optical illusions. See [Wanske] p. 138. The combination
+ up-stem + down-stem should get extra space, the combination
+ down-stem + up-stem less.
+
+ This should be more advanced, since relative heights of the note
+ heads also influence required correction.
+
+ Also might not work correctly in case of multi voices or staff
+ changing voices
+
+ TODO: lookup correction distances? More advanced correction?
+ Possibly turn this off?
+
+ TODO: have to check wether the stems are in the same staff.
+
+ This routine reads the DIR-LIST property of both its L and R arguments. */
+Real
+Spacing_spanner::stem_dir_correction (Grob*me, Grob*l, Grob*r)
+{
+ SCM dl = l->get_grob_property ("dir-list");
+ SCM dr = r->get_grob_property ("dir-list");
+
+ if (scm_ilength (dl) != 1 || scm_ilength (dr) != 1)
+ return 0.;
+
+ dl = gh_car (dl);
+ dr = gh_car (dr);
+
+ assert (gh_number_p (dl) && gh_number_p (dr));
+ int d1 = gh_scm2int (dl);
+ int d2 = gh_scm2int (dr);
+
+ if (d1 == d2)
+ return 0.0;
+
+
+ Real correction = 0.0;
+ Real ssc = gh_scm2double (me->get_grob_property ("stem-spacing-correction"));
+
+ if (d1 && d2 && d1 * d2 == -1)
+ {
+ correction = d1 * ssc;
+ }
+ else
+ programming_error ("Stem directions not set correctly for optical correction");
+ return correction;
+}
+
+
+MAKE_SCHEME_CALLBACK (Spacing_spanner, set_springs,1);
+SCM
+Spacing_spanner::set_springs (SCM smob)
+{
+ Grob *me = unsmob_grob (smob);
+ Link_array<Grob> all (me->pscore_l_->line_l_->column_l_arr ()) ;
+
+ int j = 0;
+
+ for (int i = 1; i < all.size (); i++)
+ {
+ Grob *sc = all[i];
+ if (Item::breakable_b (sc))
+ {
+ Link_array<Grob> measure (all.slice (j, i+1));
+ do_measure (me, measure);
+ j = i;
+ }
+ }
+
+ /*
+ farewell, cruel world
+ */
+ me->suicide ();
+ return SCM_UNSPECIFIED;
+}
+
+
+
+/*
+ maximum-duration-for-spacing
+From: bf250@freenet.carleton.ca (John Sankey)
+To: gnu-music-discuss@gnu.org
+Subject: note spacing suggestion
+Date: Mon, 10 Jul 2000 11:28:03 -0400 (EDT)
+
+Currently, Lily spaces notes by starting with a basic distance,
+arithmetic_multiplier, which it applies to the minimum duration note
+of the bar. Then she adds a logarithmic increment, scaled from
+arithmetic_basicspace, for longer notes. (Then, columns are aligned
+and justified.) Fundamentally, this matches visual spacing to musical
+weight and works well.
+
+A lot of the time in music, I see a section basically in melodic
+notes that occasionally has a rapid ornamental run (scale). So, there
+will be a section in 1/4 notes, then a brief passage in 1/32nds, then
+a return to long notes. Currently, Lily gives the same horizontal
+space to the 1/32nd notes in their bar (even if set in small size as
+is commonly done for cadenzii) as she gives to 1/4 notes in bars
+where 1/4 note is the minimum duration. The resulting visual weight
+does not match the musical weight over the page.
+
+Looking at the music I am typesetting, I feel that Lily's spacing
+could be significantly improved if, with no change in the basic
+method used, arithmetic_multiplier could be applied referred to the
+same duration throughout a piece. Of course, the current method
+should be retained for those who have already set music in it, so I
+suggest a property called something like arithmetic_base=16 to fix
+1/16 duration as the reference for arithmetic_multiplier; the default
+would be a dynamic base is it is now.
+
+Does anyone else feel that this would be a useful improvement for
+their music? (Of course, if arithmetic_multiplier became a regular
+property, this could be used to achieve a similar result by
+tweaking.)
+
+ */
projects / lilypond.git / commitdiff