-/*
-staff-spacing.cc -- implement
+/*
+ staff-spacing.cc -- implement Staff_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--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
+*/
#include "staff-spacing.hh"
-#include "grob.hh"
-bool
-Staff_spacing::has_interface (Grob* g)
+#include <cstdio>
+using namespace std;
+
+#include "international.hh"
+#include "paper-column.hh"
+#include "separation-item.hh"
+#include "warn.hh"
+#include "bar-line.hh"
+#include "staff-symbol-referencer.hh"
+#include "note-column.hh"
+#include "stem.hh"
+#include "spacing-interface.hh"
+#include "accidental-placement.hh"
+#include "pointer-group-interface.hh"
+#include "directional-element-interface.hh"
+
+/* A stem following a bar-line creates an optical illusion similar to the
+ one mentioned in note-spacing.cc. We correct for it here.
+
+ TODO: should we still correct if there are accidentals/arpeggios before
+ the stem?
+*/
+
+Real
+Staff_spacing::optical_correction (Grob *me, Grob *g, Interval bar_height)
+{
+ if (!g || !Note_column::has_interface (g))
+ return 0;
+
+ Grob *stem = Note_column::get_stem (g);
+ Real ret = 0.0;
+
+ if (!bar_height.is_empty () && stem)
+ {
+ Direction d = get_grob_direction (stem);
+ if (Stem::is_normal_stem (stem) && d == DOWN)
+ {
+
+ /*
+ can't look at stem-end-position, since that triggers
+ beam slope computations.
+ */
+ Real stem_start = Stem::head_positions (stem) [d];
+ Real stem_end = stem_start +
+ d * robust_scm2double (stem->get_property ("length"), 7);
+
+ Interval stem_posns (min (stem_start, stem_end),
+ max (stem_end, stem_start));
+
+ stem_posns.intersect (bar_height);
+
+ ret = min (abs (stem_posns.length () / 7.0), 1.0);
+ ret *= robust_scm2double (me->get_property ("stem-spacing-correction"), 1);
+ }
+ }
+ return ret;
+}
+
+/*
+ Y-positions that are covered by BAR_GROB, in the case that it is a
+ barline. */
+Interval
+Staff_spacing::bar_y_positions (Grob *bar_grob)
+{
+ Interval bar_size;
+ bar_size.set_empty ();
+ if (Bar_line::has_interface (bar_grob))
+ {
+ SCM glyph = bar_grob->get_property ("glyph-name");
+ Grob *staff_sym = Staff_symbol_referencer::get_staff_symbol (bar_grob);
+
+ string glyph_string = scm_is_string (glyph) ? ly_scm2string (glyph) : "";
+ if (glyph_string.substr (0, 1) == "|"
+ || glyph_string.substr (0, 1) == ".")
+ {
+ Grob *common = bar_grob->common_refpoint (staff_sym, Y_AXIS);
+ bar_size = bar_grob->extent (common, Y_AXIS);
+ bar_size *= 1.0 / Staff_symbol_referencer::staff_space (bar_grob);
+ }
+ }
+ return bar_size;
+}
+
+Real
+Staff_spacing::next_notes_correction (Grob *me,
+ Grob *last_grob)
{
- return g && g->has_interface (ly_symbol2scm ("staff-spacing-interface"));
+ Interval bar_size = bar_y_positions (last_grob);
+ Grob *orig = me->original () ? me->original () : me;
+ vector<Item*> note_columns = Spacing_interface::right_note_columns (orig);
+
+ Real max_optical = 0.0;
+
+ for (vsize i = 0; i < note_columns.size (); i++)
+ max_optical = max (max_optical, optical_correction (me, note_columns[i], bar_size));
+
+ return max_optical;
}
+
+/* We calculate three things here: the ideal distance, the minimum distance
+ (which is the distance at which collisions will occur) and the "fixed"
+ distance, which is the distance at which things start to look really bad.
+ We arrange things so that the fixed distance will be attained when the
+ line is compressed with a force of 1.0 */
+Spring
+Staff_spacing::get_spacing (Grob *me, Grob *right_col)
+{
+ Item *me_item = dynamic_cast<Item *> (me);
+ Grob *left_col = me_item->get_column ();
+
+ Interval last_ext;
+ Direction break_dir = me_item->break_status_dir ();
+ Grob *last_grob = Spacing_interface::extremal_break_aligned_grob (me, LEFT,
+ break_dir,
+ &last_ext);
+ if (!last_grob)
+ {
+ /*
+ TODO:
+
+ Should insert a adjustable space here? For excercises, you might want to
+ use a staff without a clef in the beginning.
+ */
+
+ /*
+ we used to have a warning here, but it generates a lot of
+ spurious error messages.
+ */
+ return Spring ();
+ }
+
+ SCM alist = last_grob->get_property ("space-alist");
+ if (!scm_list_p (alist))
+ return Spring ();
+
+ SCM space_def = scm_sloppy_assq (ly_symbol2scm ("first-note"), alist);
+ if (me_item->break_status_dir () == CENTER)
+ {
+ SCM nndef = scm_sloppy_assq (ly_symbol2scm ("next-note"), alist);
+ if (scm_is_pair (nndef))
+ space_def = nndef;
+ }
+
+ if (!scm_is_pair (space_def))
+ {
+ programming_error ("unknown prefatory spacing");
+ return Spring ();
+ }
+
+ space_def = scm_cdr (space_def);
+ Real distance = scm_to_double (scm_cdr (space_def));
+ SCM type = scm_car (space_def);
+
+ Real fixed = last_ext[RIGHT];
+ Real ideal = fixed + 1.0;
+
+ if (type == ly_symbol2scm ("fixed-space"))
+ {
+ fixed += distance;
+ ideal = fixed;
+ }
+ else if (type == ly_symbol2scm ("extra-space"))
+ ideal = fixed + distance;
+ else if (type == ly_symbol2scm ("semi-fixed-space"))
+ {
+ fixed += distance / 2;
+ ideal = fixed + distance / 2;
+ }
+ else if (type == ly_symbol2scm ("minimum-space"))
+ ideal = last_ext[LEFT] + max (last_ext.length (), distance);
+ else if (type == ly_symbol2scm ("minimum-fixed-space"))
+ {
+ fixed = last_ext[LEFT] + max (last_ext.length (), distance);
+ ideal = fixed;
+ }
+
+
+ Real optical_correction = next_notes_correction (me, last_grob);
+ Real min_dist = Paper_column::minimum_distance (left_col, right_col);
+
+ /* ensure that the "fixed" distance will leave a gap of at least 0.3 ss. */
+ Real min_dist_correction = max (0.0, 0.3 + min_dist - fixed);
+ Real correction = max (optical_correction, min_dist_correction);
+
+ fixed += correction;
+ ideal += correction;
+
+ Spring ret (ideal, min_dist);
+ ret.set_inverse_stretch_strength (max (0.0, ideal - fixed));
+ return ret;
+}
+
+ADD_INTERFACE (Staff_spacing,
+ "This object calculates spacing details from a breakable"
+ " symbol (left) to another object. For example, it takes care"
+ " of optical spacing from a bar line to a note.",
+
+ /* properties */
+ "stem-spacing-correction "
+ );
projects / lilypond.git / blobdiff