-/*
-note-spacing.cc -- implement
+/*
+ note-spacing.cc -- implement Note_spacing
-source file of the GNU LilyPond music typesetter
+ source file of the GNU LilyPond music typesetter
-(c) 2001 Han-Wen Nienhuys <hanwen@cs.uu.nl>
-
- */
+ (c) 2001--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
+*/
#include "note-spacing.hh"
-#include "grob.hh"
-bool
-Note_spacing::has_interface (Grob* g)
+#include "bar-line.hh"
+#include "directional-element-interface.hh"
+#include "grob-array.hh"
+#include "paper-column.hh"
+#include "moment.hh"
+#include "note-column.hh"
+#include "warn.hh"
+#include "stem.hh"
+#include "separation-item.hh"
+#include "spacing-interface.hh"
+#include "staff-spacing.hh"
+#include "accidental-placement.hh"
+#include "output-def.hh"
+#include "pointer-group-interface.hh"
+
+static bool
+non_empty_barline (Grob *me)
+{
+ return Bar_line::has_interface (me) && !me->extent (me, X_AXIS).is_empty ();
+}
+
+/*
+ TODO: detect hshifts due to collisions, and account for them in
+ spacing?
+*/
+
+Spring
+Note_spacing::get_spacing (Grob *me, Item *right_col,
+ Real base_space, Real increment)
+{
+ vector<Item*> note_columns = Spacing_interface::left_note_columns (me);
+ Real left_head_end = 0;
+
+ for (vsize i = 0; i < note_columns.size (); i++)
+ {
+ SCM r = note_columns[i]->get_object ("rest");
+ Grob *g = unsmob_grob (r);
+ Grob *col = note_columns[i]->get_column ();
+
+ if (!g)
+ g = Note_column::first_head (note_columns[i]);
+
+ /*
+ Ugh. If Stem is switched off, we don't know what the
+ first note head will be.
+ */
+ if (g)
+ {
+ if (g->common_refpoint (col, X_AXIS) != col)
+ programming_error ("Note_spacing::get_spacing (): Common refpoint incorrect");
+ else
+ left_head_end = g->extent (col, X_AXIS)[RIGHT];
+ }
+ }
+
+ /*
+ The main factor that determines the amount of space is the width of the
+ note head (or the rest). For example, a quarter rest gets almost 0.5 ss
+ less horizontal space than a note.
+
+ The other parts of a note column (eg. flags, accidentals, etc.) don't get
+ the full amount of space. We give them half the amount of space, but then
+ adjust things so there are no collisions.
+ */
+ Drul_array<Skyline> skys = Spacing_interface::skylines (me, right_col);
+ Real distance = skys[LEFT].distance (skys[RIGHT]);
+ Real min_dist = max (0.0, distance);
+ Real min_desired_space = left_head_end + (min_dist - left_head_end + base_space - increment) / 2;
+ Real ideal = base_space - increment + left_head_end;
+
+ /* If we have a NonMusical column on the right, we measure the ideal distance
+ to the bar-line (if present), not the start of the column. */
+ if (!Paper_column::is_musical (right_col)
+ && !skys[RIGHT].is_empty ()
+ && to_boolean (me->get_property ("space-to-barline")))
+ {
+ Grob *bar = Pointer_group_interface::find_grob (right_col,
+ ly_symbol2scm ("elements"),
+ non_empty_barline);
+
+ if (bar)
+ {
+ Real shift = bar->extent (right_col, X_AXIS)[LEFT];
+ ideal -= shift;
+ min_desired_space -= max (shift, 0.0);
+ }
+ else
+ ideal -= right_col->extent (right_col, X_AXIS)[RIGHT];
+ }
+
+ ideal = max (ideal, min_desired_space);
+ stem_dir_correction (me, right_col, increment, &ideal, &min_desired_space);
+
+ /* TODO: grace notes look bad when things are stretched. Should we increase
+ their stretch strength? */
+ Spring ret (max (0.0, ideal), min_dist);
+ ret.set_inverse_compress_strength (max (0.0, ideal - min_desired_space));
+ ret.set_inverse_stretch_strength (max (0.1, base_space - increment));
+ return ret;
+}
+
+static Real
+knee_correction (Grob *note_spacing, Grob *right_stem, Real increment)
+{
+ Real note_head_width = increment;
+ Grob *head = right_stem ? Stem::support_head (right_stem) : 0;
+ Grob *rcolumn = dynamic_cast<Item*> (head)->get_column ();
+
+ Interval head_extent;
+ if (head)
+ {
+ head_extent = head->extent (rcolumn, X_AXIS);
+
+ if (!head_extent.is_empty ())
+ note_head_width = head_extent[RIGHT];
+
+ note_head_width -= Stem::thickness (right_stem);
+ }
+
+ return -note_head_width * get_grob_direction (right_stem)
+ * robust_scm2double (note_spacing->get_property ("knee-spacing-correction"), 0);
+}
+
+static Real
+different_directions_correction (Grob *note_spacing,
+ Drul_array<Interval> stem_posns,
+ Direction left_stem_dir)
+{
+ Real ret = 0.0;
+ Interval intersect = stem_posns[LEFT];
+ intersect.intersect (stem_posns[RIGHT]);
+
+ if (!intersect.is_empty ())
+ {
+ ret = abs (intersect.length ());
+
+ /*
+ Ugh. 7 is hardcoded.
+ */
+ ret = min (ret / 7, 1.0)
+ * left_stem_dir
+ * robust_scm2double (note_spacing->get_property ("stem-spacing-correction"), 0);
+ }
+ return ret;
+}
+
+static Real
+same_direction_correction (Grob *note_spacing, Drul_array<Interval> head_posns)
{
- return g && g->has_interface (ly_symbol2scm ("note-spacing-interface"));
+ /*
+ Correct for the following situation:
+
+ X X
+ | |
+ | |
+ | X |
+ | | |
+ ========
+
+ ^ move the center one to the left.
+
+
+ this effect seems to be much more subtle than the
+ stem-direction stuff (why?), and also does not scale with the
+ difference in stem length.
+
+ */
+
+ Interval hp = head_posns[LEFT];
+ hp.intersect (head_posns[RIGHT]);
+ if (!hp.is_empty ())
+ return 0;
+
+ Direction lowest
+ = (head_posns[LEFT][DOWN] > head_posns[RIGHT][UP]) ? RIGHT : LEFT;
+
+ Real delta = head_posns[-lowest][DOWN] - head_posns[lowest][UP];
+ Real corr = robust_scm2double (note_spacing->get_property ("same-direction-correction"), 0);
+
+ return (delta > 1) ? -lowest * corr : 0;
+}
+
+
+/**
+ 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.
+
+ TODO: have to check whether the stems are in the same staff.
+*/
+void
+Note_spacing::stem_dir_correction (Grob *me, Item *rcolumn,
+ Real increment,
+ Real *space, Real *fixed)
+{
+ Drul_array<Direction> stem_dirs (CENTER, CENTER);
+ Drul_array<Interval> stem_posns;
+ Drul_array<Interval> head_posns;
+ Drul_array<SCM> props (me->get_object ("left-items"),
+ me->get_object ("right-items"));
+
+ Drul_array<Spanner *> beams_drul (0, 0);
+ Drul_array<Grob *> stems_drul (0, 0);
+
+ stem_dirs[LEFT] = stem_dirs[RIGHT] = CENTER;
+ Interval intersect;
+ Interval bar_xextent;
+ Interval bar_yextent;
+
+ Direction d = LEFT;
+
+ Grob *bar = Spacing_interface::extremal_break_aligned_grob (me, RIGHT,
+ rcolumn->break_status_dir (),
+ &bar_xextent);
+ if (bar && dynamic_cast<Item*> (bar)->get_column () == rcolumn)
+ bar_yextent = Staff_spacing::bar_y_positions (bar);
+
+ do
+ {
+ vector<Grob*> const &items (ly_scm2link_array (props [d]));
+ for (vsize i = 0; i < items.size (); i++)
+ {
+ Item *it = dynamic_cast<Item *> (items[i]);
+ if (!Note_column::has_interface (it))
+ continue;
+
+ /*
+ don't correct if accidentals are sticking out of the right side.
+ */
+ if (d == RIGHT && Note_column::accidentals (it))
+ return;
+
+ Grob *stem = Note_column::get_stem (it);
+
+ if (!stem || !stem->is_live () || Stem::is_invisible (stem))
+ return;
+
+ stems_drul[d] = stem;
+ beams_drul[d] = Stem::get_beam (stem);
+
+ Direction stem_dir = get_grob_direction (stem);
+ if (stem_dirs[d] && stem_dirs[d] != stem_dir)
+ return;
+
+ stem_dirs[d] = stem_dir;
+
+ /*
+ Correction doesn't seem appropriate when there is a large flag
+ hanging from the note.
+ */
+ if (d == LEFT
+ && Stem::duration_log (stem) > 2 && !Stem::get_beam (stem))
+ return;
+
+ Interval hp = Stem::head_positions (stem);
+ if (!hp.is_empty ())
+ {
+ Real chord_start = hp[stem_dir];
+
+ /*
+ can't look at stem-end-position, since that triggers
+ beam slope computations.
+ */
+ Real stem_end = hp[stem_dir] +
+ stem_dir * robust_scm2double (stem->get_property ("length"), 7);
+
+ stem_posns[d] = Interval (min (chord_start, stem_end),
+ max (chord_start, stem_end));
+ head_posns[d].unite (hp);
+ }
+ }
+ }
+ while (flip (&d) != LEFT);
+
+ Real correction = 0.0;
+
+ if (!bar_yextent.is_empty ())
+ {
+ stem_dirs[RIGHT] = -stem_dirs[LEFT];
+ stem_posns[RIGHT] = bar_yextent;
+ stem_posns[RIGHT] *= 2;
+ }
+
+ if (stem_dirs[LEFT] * stem_dirs[RIGHT] == -1)
+ {
+ if (beams_drul[LEFT] && beams_drul[LEFT] == beams_drul[RIGHT])
+ {
+ correction = knee_correction (me, stems_drul[RIGHT], increment);
+ *fixed += correction;
+ }
+ else
+ {
+ correction = different_directions_correction (me, stem_posns, stem_dirs[LEFT]);
+
+ if (!bar_yextent.is_empty ())
+ correction *= 0.5;
+ }
+ }
+ else if (stem_dirs[LEFT] * stem_dirs[RIGHT] == 1)
+ correction = same_direction_correction (me, head_posns);
+
+ *space += correction;
+
+ /* there used to be a correction for bar_xextent () here, but
+ it's unclear what that was good for ?
+ */
}
+
+ADD_INTERFACE (Note_spacing,
+ "This object calculates spacing wishes for individual voices.",
+
+ /* properties */
+ "knee-spacing-correction "
+ "left-items "
+ "right-items "
+ "same-direction-correction "
+ "stem-spacing-correction "
+ "space-to-barline "
+ );
+
projects / lilypond.git / blobdiff