#include "direction.hh"
#include "directional-element-interface.hh"
#include "grob.hh"
+#include "grob-array.hh"
+#include "item.hh"
#include "international.hh"
+#include "least-squares.hh"
#include "libc-extension.hh"
#include "main.hh"
+#include "note-head.hh"
#include "output-def.hh"
#include "pointer-group-interface.hh"
+#include "rhythmic-head.hh"
#include "staff-symbol-referencer.hh"
#include "stencil.hh"
#include "stem.hh"
init_stems ();
}
+// Assuming V is not empty, pick a 'reasonable' point inside V.
+static Real
+point_in_interval (Interval v, Real dist)
+{
+ if (isinf (v[DOWN]))
+ return v[UP] - dist;
+ else if (isinf (v[UP]))
+ return v[DOWN] + dist;
+ else
+ return v.center ();
+}
+
+/* Set stem's shorten property if unset.
+
+TODO:
+take some y-position (chord/beam/nearest?) into account
+scmify forced-fraction
+
+This is done in beam because the shorten has to be uniform over the
+entire beam.
+*/
+
+void
+set_minimum_dy (Grob *me, Real *dy)
+{
+ if (*dy)
+ {
+ /*
+ If dy is smaller than the smallest quant, we
+ get absurd direction-sign penalties.
+ */
+
+ Real ss = Staff_symbol_referencer::staff_space (me);
+ Real beam_thickness = Beam::get_beam_thickness (me) / ss;
+ Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
+ Real sit = (beam_thickness - slt) / 2;
+ Real inter = 0.5;
+ Real hang = 1.0 - (beam_thickness - slt) / 2;
+
+ *dy = sign (*dy) * max (fabs (*dy),
+ min (min (sit, inter), hang));
+ }
+}
+
+Interval
+Beam::no_visible_stem_positions (Grob *me, Interval default_value)
+{
+ extract_grob_set (me, "stems", stems);
+ if (stems.empty ())
+ return default_value;
+
+ Interval head_positions;
+ Slice multiplicity;
+ for (vsize i = 0; i < stems.size (); i++)
+ {
+ head_positions.unite (Stem::head_positions (stems[i]));
+ multiplicity.unite (Stem::beam_multiplicity (stems[i]));
+ }
+
+ Direction dir = get_grob_direction (me);
+
+ if (!dir)
+ programming_error ("The beam should have a direction by now.");
+
+ Real y = head_positions.linear_combination (dir)
+ * 0.5 * Staff_symbol_referencer::staff_space (me)
+ + dir * get_beam_translation (me) * (multiplicity.length () + 1);
+
+ y /= Staff_symbol_referencer::staff_space (me);
+ return Interval (y, y);
+}
+
+/*
+ Compute a first approximation to the beam slope.
+*/
+MAKE_SCHEME_CALLBACK (Beam, calc_least_squares_positions, 2);
+SCM
+Beam::calc_least_squares_positions (SCM smob, SCM /* posns */)
+{
+ Grob *me = unsmob_grob (smob);
+
+ int count = normal_stem_count (me);
+ Interval pos (0, 0);
+ if (count < 1)
+ return ly_interval2scm (no_visible_stem_positions (me, pos));
+
+ vector<Real> x_posns;
+ extract_grob_set (me, "normal-stems", stems);
+ Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
+ Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
+
+ Real my_y = me->relative_coordinate (commony, Y_AXIS);
+
+ Grob *fvs = first_normal_stem (me);
+ Grob *lvs = last_normal_stem (me);
+
+ Interval ideal (Stem::get_stem_info (fvs).ideal_y_
+ + fvs->relative_coordinate (commony, Y_AXIS) - my_y,
+ Stem::get_stem_info (lvs).ideal_y_
+ + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
+
+ Real x0 = first_normal_stem (me)->relative_coordinate (commonx, X_AXIS);
+ for (vsize i = 0; i < stems.size (); i++)
+ {
+ Grob *s = stems[i];
+
+ Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
+ x_posns.push_back (x);
+ }
+ Real dx = last_normal_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
+
+ Real y = 0;
+ Real slope = 0;
+ Real dy = 0;
+ Real ldy = 0.0;
+ if (!ideal.delta ())
+ {
+ Interval chord (Stem::chord_start_y (stems[0]),
+ Stem::chord_start_y (stems.back ()));
+
+ /* Simple beams (2 stems) on middle line should be allowed to be
+ slightly sloped.
+
+ However, if both stems reach middle line,
+ ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
+
+ For that case, we apply artificial slope */
+ if (!ideal[LEFT] && chord.delta () && count == 2)
+ {
+ /* FIXME. -> UP */
+ Direction d = (Direction) (sign (chord.delta ()) * UP);
+ pos[d] = get_beam_thickness (me) / 2;
+ pos[-d] = -pos[d];
+ }
+ else
+ pos = ideal;
+
+ /*
+ For broken beams this doesn't work well. In this case, the
+ slope esp. of the first part of a broken beam should predict
+ where the second part goes.
+ */
+ ldy = pos[RIGHT] - pos[LEFT];
+ }
+ else
+ {
+ vector<Offset> ideals;
+ for (vsize i = 0; i < stems.size (); i++)
+ {
+ Grob *s = stems[i];
+ ideals.push_back (Offset (x_posns[i],
+ Stem::get_stem_info (s).ideal_y_
+ + s->relative_coordinate (commony, Y_AXIS)
+ - my_y));
+ }
+
+ minimise_least_squares (&slope, &y, ideals);
+
+ dy = slope * dx;
+
+ set_minimum_dy (me, &dy);
+
+ ldy = dy;
+ pos = Interval (y, (y + dy));
+ }
+
+ /*
+ "position" is relative to the staff.
+ */
+ scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
+
+ me->set_property ("least-squares-dy", scm_from_double (ldy));
+ return ly_interval2scm (pos);
+}
+
+/* This neat trick is by Werner Lemberg,
+ damped = tanh (slope)
+ corresponds with some tables in [Wanske] CHECKME */
+MAKE_SCHEME_CALLBACK (Beam, slope_damping, 2);
+SCM
+Beam::slope_damping (SCM smob, SCM posns)
+{
+ Grob *me = unsmob_grob (smob);
+ Drul_array<Real> pos = ly_scm2interval (posns);
+
+ if (normal_stem_count (me) <= 1)
+ return posns;
+
+ SCM s = me->get_property ("damping");
+ Real damping = scm_to_double (s);
+ Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
+ if (concaveness >= 10000)
+ {
+ pos[LEFT] = pos[RIGHT];
+ me->set_property ("least-squares-dy", scm_from_double (0));
+ damping = 0;
+ }
+
+ if (damping)
+ {
+ scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
+
+ Real dy = pos[RIGHT] - pos[LEFT];
+
+ Grob *fvs = first_normal_stem (me);
+ Grob *lvs = last_normal_stem (me);
+
+ Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
+
+ Real dx = last_normal_stem (me)->relative_coordinate (commonx, X_AXIS)
+ - first_normal_stem (me)->relative_coordinate (commonx, X_AXIS);
+
+ Real slope = dy && dx ? dy / dx : 0;
+
+ slope = 0.6 * tanh (slope) / (damping + concaveness);
+
+ Real damped_dy = slope * dx;
+
+ set_minimum_dy (me, &damped_dy);
+
+ pos[LEFT] += (dy - damped_dy) / 2;
+ pos[RIGHT] -= (dy - damped_dy) / 2;
+
+ scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
+ }
+
+ return ly_interval2scm (pos);
+}
+
+/*
+ We can't combine with previous function, since check concave and
+ slope damping comes first.
+
+ TODO: we should use the concaveness to control the amount of damping
+ applied.
+*/
+MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 2);
+SCM
+Beam::shift_region_to_valid (SCM grob, SCM posns)
+{
+ Grob *me = unsmob_grob (grob);
+
+ /*
+ Code dup.
+ */
+ vector<Real> x_posns;
+ extract_grob_set (me, "stems", stems);
+ extract_grob_set (me, "covered-grobs", covered);
+
+ Grob *common[NO_AXES] = { me, me };
+ for (Axis a = X_AXIS; a < NO_AXES; incr (a))
+ {
+ common[a] = common_refpoint_of_array (stems, me, a);
+ common[a] = common_refpoint_of_array (covered, common[a], a);
+ }
+ Grob *fvs = first_normal_stem (me);
+
+ if (!fvs)
+ return posns;
+ Interval x_span;
+ x_span[LEFT] = fvs->relative_coordinate (common[X_AXIS], X_AXIS);
+ for (vsize i = 0; i < stems.size (); i++)
+ {
+ Grob *s = stems[i];
+
+ Real x = s->relative_coordinate (common[X_AXIS], X_AXIS) - x_span[LEFT];
+ x_posns.push_back (x);
+ }
+
+ Grob *lvs = last_normal_stem (me);
+ x_span[RIGHT] = lvs->relative_coordinate (common[X_AXIS], X_AXIS);
+
+ Drul_array<Real> pos = ly_scm2interval (posns);
+
+ scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
+
+ Real beam_dy = pos[RIGHT] - pos[LEFT];
+ Real beam_left_y = pos[LEFT];
+ Real slope = x_span.delta () ? (beam_dy / x_span.delta ()) : 0.0;
+
+ /*
+ Shift the positions so that we have a chance of finding good
+ quants (i.e. no short stem failures.)
+ */
+ Interval feasible_left_point;
+ feasible_left_point.set_full ();
+
+ for (vsize i = 0; i < stems.size (); i++)
+ {
+ Grob *s = stems[i];
+ if (Stem::is_invisible (s))
+ continue;
+
+ Direction d = get_grob_direction (s);
+ Real left_y
+ = Stem::get_stem_info (s).shortest_y_
+ - slope * x_posns [i];
+
+ /*
+ left_y is now relative to the stem S. We want relative to
+ ourselves, so translate:
+ */
+ left_y
+ += + s->relative_coordinate (common[Y_AXIS], Y_AXIS)
+ - me->relative_coordinate (common[Y_AXIS], Y_AXIS);
+
+ Interval flp;
+ flp.set_full ();
+ flp[-d] = left_y;
+
+ feasible_left_point.intersect (flp);
+ }
+
+ vector<Grob *> filtered;
+ /*
+ We only update these for objects that are too large for quanting
+ to find a workaround. Typically, these are notes with
+ stems, and timesig/keysig/clef, which take out the entire area
+ inside the staff as feasible.
+
+ The code below disregards the thickness and multiplicity of the
+ beam. This should not be a problem, as the beam quanting will
+ take care of computing the impact those exactly.
+ */
+ Real min_y_size = 2.0;
+
+ // A list of intervals into which beams may not fall
+ vector<Interval> forbidden_intervals;
+
+ for (vsize i = 0; i < covered.size (); i++)
+ {
+ if (!covered[i]->is_live ())
+ continue;
+
+ if (Beam::has_interface (covered[i]) && is_cross_staff (covered[i]))
+ continue;
+
+ Box b;
+ for (Axis a = X_AXIS; a < NO_AXES; incr (a))
+ b[a] = covered[i]->extent (common[a], a);
+
+ if (b[X_AXIS].is_empty () || b[Y_AXIS].is_empty ())
+ continue;
+
+ if (intersection (b[X_AXIS], x_span).is_empty ())
+ continue;
+
+ filtered.push_back (covered[i]);
+ Grob *head_stem = Rhythmic_head::get_stem (covered[i]);
+ if (head_stem && Stem::is_normal_stem (head_stem)
+ && Note_head::has_interface (covered[i]))
+ {
+ if (Stem::get_beam (head_stem))
+ {
+ /*
+ We must assume that stems are infinitely long in this
+ case, as asking for the length of the stem typically
+ leads to circular dependencies.
+
+ This strategy assumes that we don't want to handle the
+ collision of beams in opposite non-forced directions
+ with this code, where shortening the stems of both
+ would resolve the problem, eg.
+
+ x x
+ | |
+ =====
+
+ =====
+ | |
+ x x
+
+ Such beams would need a coordinating grob to resolve
+ the collision, since both will likely want to occupy
+ the centerline.
+ */
+ Direction stemdir = get_grob_direction (head_stem);
+ b[Y_AXIS][stemdir] = stemdir * infinity_f;
+ }
+ else
+ {
+ // TODO - should we include the extent of the stem here?
+ }
+ }
+
+ if (b[Y_AXIS].length () < min_y_size)
+ continue;
+
+ Direction d = LEFT;
+ do
+ {
+ Real x = b[X_AXIS][d] - x_span[LEFT];
+ Real dy = slope * x;
+
+ Direction yd = DOWN;
+ Interval disallowed;
+ do
+ {
+ Real left_y = b[Y_AXIS][yd];
+
+ left_y -= dy;
+
+ // Translate back to beam as ref point.
+ left_y -= me->relative_coordinate (common[Y_AXIS], Y_AXIS);
+
+ disallowed[yd] = left_y;
+ }
+ while (flip (&yd) != DOWN);
+
+ forbidden_intervals.push_back (disallowed);
+ }
+ while (flip (&d) != LEFT);
+ }
+
+ Grob_array *arr
+ = Pointer_group_interface::get_grob_array (me,
+ ly_symbol2scm ("covered-grobs"));
+ arr->set_array (filtered);
+
+ vector_sort (forbidden_intervals, Interval::left_less);
+ Real epsilon = 1.0e-10;
+ Interval feasible_beam_placements (beam_left_y, beam_left_y);
+
+ /*
+ forbidden_intervals contains a vector of intervals in which
+ the beam cannot start. it iterates through these intervals,
+ pushing feasible_beam_placements epsilon over or epsilon under a
+ collision. when this type of change happens, the loop is marked
+ as "dirty" and re-iterated.
+
+ TODO: figure out a faster ways that this loop can happen via
+ a better search algorithm and/or OOP.
+ */
+
+ bool dirty = false;
+ do
+ {
+ dirty = false;
+ for (vsize i = 0; i < forbidden_intervals.size (); i++)
+ {
+ Direction d = DOWN;
+ do
+ {
+ if (forbidden_intervals[i][d] == d * infinity_f)
+ feasible_beam_placements[d] = d * infinity_f;
+ else if (forbidden_intervals[i].contains (feasible_beam_placements[d]))
+ {
+ feasible_beam_placements[d] = d * epsilon + forbidden_intervals[i][d];
+ dirty = true;
+ }
+ }
+ while (flip (&d) != DOWN);
+ }
+ }
+ while (dirty);
+
+ // if the beam placement falls out of the feasible region, we push it
+ // to infinity so that it can never be a feasible candidate below
+ Direction d = DOWN;
+ do
+ {
+ if (!feasible_left_point.contains (feasible_beam_placements[d]))
+ feasible_beam_placements[d] = d * infinity_f;
+ }
+ while (flip (&d) != DOWN);
+
+ if ((feasible_beam_placements[UP] == infinity_f && feasible_beam_placements[DOWN] == -infinity_f) && !feasible_left_point.is_empty ())
+ {
+ // We are somewhat screwed: we have a collision, but at least
+ // there is a way to satisfy stem length constraints.
+ beam_left_y = point_in_interval (feasible_left_point, 2.0);
+ }
+ else if (!feasible_left_point.is_empty ())
+ {
+ // Only one of them offers is feasible solution. Pick that one.
+ if (abs (beam_left_y - feasible_beam_placements[DOWN]) > abs (beam_left_y - feasible_beam_placements[UP]))
+ beam_left_y = feasible_beam_placements[UP];
+ else
+ beam_left_y = feasible_beam_placements[DOWN];
+ }
+ else
+ {
+ // We are completely screwed.
+ me->warning (_ ("no viable initial configuration found: may not find good beam slope"));
+ }
+
+ pos = Drul_array<Real> (beam_left_y, (beam_left_y + beam_dy));
+ scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
+
+ return ly_interval2scm (pos);
+}
+
void
Beam_scoring_problem::generate_quants (vector<Beam_configuration *> *scores) const
{
#include "international.hh"
#include "interval-set.hh"
#include "item.hh"
-#include "least-squares.hh"
#include "lookup.hh"
#include "main.hh"
#include "misc.hh"
}
}
-/* Set stem's shorten property if unset.
-
-TODO:
-take some y-position (chord/beam/nearest?) into account
-scmify forced-fraction
-
-This is done in beam because the shorten has to be uniform over the
-entire beam.
-*/
-
-void
-set_minimum_dy (Grob *me, Real *dy)
-{
- if (*dy)
- {
- /*
- If dy is smaller than the smallest quant, we
- get absurd direction-sign penalties.
- */
-
- Real ss = Staff_symbol_referencer::staff_space (me);
- Real beam_thickness = Beam::get_beam_thickness (me) / ss;
- Real slt = Staff_symbol_referencer::line_thickness (me) / ss;
- Real sit = (beam_thickness - slt) / 2;
- Real inter = 0.5;
- Real hang = 1.0 - (beam_thickness - slt) / 2;
-
- *dy = sign (*dy) * max (fabs (*dy),
- min (min (sit, inter), hang));
- }
-}
-
MAKE_SCHEME_CALLBACK (Beam, calc_stem_shorten, 1)
SCM
Beam::calc_stem_shorten (SCM smob)
return scm_from_double (0.0);
}
-Interval
-Beam::no_visible_stem_positions (Grob *me, Interval default_value)
-{
- extract_grob_set (me, "stems", stems);
- if (stems.empty ())
- return default_value;
-
- Interval head_positions;
- Slice multiplicity;
- for (vsize i = 0; i < stems.size (); i++)
- {
- head_positions.unite (Stem::head_positions (stems[i]));
- multiplicity.unite (Stem::beam_multiplicity (stems[i]));
- }
-
- Direction dir = get_grob_direction (me);
-
- if (!dir)
- programming_error ("The beam should have a direction by now.");
-
- Real y = head_positions.linear_combination (dir)
- * 0.5 * Staff_symbol_referencer::staff_space (me)
- + dir * get_beam_translation (me) * (multiplicity.length () + 1);
-
- y /= Staff_symbol_referencer::staff_space (me);
- return Interval (y, y);
-}
-
-/*
- Compute a first approximation to the beam slope.
-*/
-MAKE_SCHEME_CALLBACK (Beam, calc_least_squares_positions, 2);
-SCM
-Beam::calc_least_squares_positions (SCM smob, SCM /* posns */)
-{
- Grob *me = unsmob_grob (smob);
-
- int count = normal_stem_count (me);
- Interval pos (0, 0);
- if (count < 1)
- return ly_interval2scm (no_visible_stem_positions (me, pos));
-
- vector<Real> x_posns;
- extract_grob_set (me, "normal-stems", stems);
- Grob *commonx = common_refpoint_of_array (stems, me, X_AXIS);
- Grob *commony = common_refpoint_of_array (stems, me, Y_AXIS);
-
- Real my_y = me->relative_coordinate (commony, Y_AXIS);
-
- Grob *fvs = first_normal_stem (me);
- Grob *lvs = last_normal_stem (me);
-
- Interval ideal (Stem::get_stem_info (fvs).ideal_y_
- + fvs->relative_coordinate (commony, Y_AXIS) - my_y,
- Stem::get_stem_info (lvs).ideal_y_
- + lvs->relative_coordinate (commony, Y_AXIS) - my_y);
-
- Real x0 = first_normal_stem (me)->relative_coordinate (commonx, X_AXIS);
- for (vsize i = 0; i < stems.size (); i++)
- {
- Grob *s = stems[i];
-
- Real x = s->relative_coordinate (commonx, X_AXIS) - x0;
- x_posns.push_back (x);
- }
- Real dx = last_normal_stem (me)->relative_coordinate (commonx, X_AXIS) - x0;
-
- Real y = 0;
- Real slope = 0;
- Real dy = 0;
- Real ldy = 0.0;
- if (!ideal.delta ())
- {
- Interval chord (Stem::chord_start_y (stems[0]),
- Stem::chord_start_y (stems.back ()));
-
- /* Simple beams (2 stems) on middle line should be allowed to be
- slightly sloped.
-
- However, if both stems reach middle line,
- ideal[LEFT] == ideal[RIGHT] and ideal.delta () == 0.
-
- For that case, we apply artificial slope */
- if (!ideal[LEFT] && chord.delta () && count == 2)
- {
- /* FIXME. -> UP */
- Direction d = (Direction) (sign (chord.delta ()) * UP);
- pos[d] = get_beam_thickness (me) / 2;
- pos[-d] = -pos[d];
- }
- else
- pos = ideal;
-
- /*
- For broken beams this doesn't work well. In this case, the
- slope esp. of the first part of a broken beam should predict
- where the second part goes.
- */
- ldy = pos[RIGHT] - pos[LEFT];
- }
- else
- {
- vector<Offset> ideals;
- for (vsize i = 0; i < stems.size (); i++)
- {
- Grob *s = stems[i];
- ideals.push_back (Offset (x_posns[i],
- Stem::get_stem_info (s).ideal_y_
- + s->relative_coordinate (commony, Y_AXIS)
- - my_y));
- }
-
- minimise_least_squares (&slope, &y, ideals);
-
- dy = slope * dx;
-
- set_minimum_dy (me, &dy);
-
- ldy = dy;
- pos = Interval (y, (y + dy));
- }
-
- /*
- "position" is relative to the staff.
- */
- scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
-
- me->set_property ("least-squares-dy", scm_from_double (ldy));
- return ly_interval2scm (pos);
-}
-
-// Assuming V is not empty, pick a 'reasonable' point inside V.
-static Real
-point_in_interval (Interval v, Real dist)
-{
- if (isinf (v[DOWN]))
- return v[UP] - dist;
- else if (isinf (v[UP]))
- return v[DOWN] + dist;
- else
- return v.center ();
-}
-
-/*
- We can't combine with previous function, since check concave and
- slope damping comes first.
-
- TODO: we should use the concaveness to control the amount of damping
- applied.
-*/
-MAKE_SCHEME_CALLBACK (Beam, shift_region_to_valid, 2);
-SCM
-Beam::shift_region_to_valid (SCM grob, SCM posns)
-{
- Grob *me = unsmob_grob (grob);
-
- /*
- Code dup.
- */
- vector<Real> x_posns;
- extract_grob_set (me, "stems", stems);
- extract_grob_set (me, "covered-grobs", covered);
-
- Grob *common[NO_AXES] = { me, me };
- for (Axis a = X_AXIS; a < NO_AXES; incr (a))
- {
- common[a] = common_refpoint_of_array (stems, me, a);
- common[a] = common_refpoint_of_array (covered, common[a], a);
- }
- Grob *fvs = first_normal_stem (me);
-
- if (!fvs)
- return posns;
- Interval x_span;
- x_span[LEFT] = fvs->relative_coordinate (common[X_AXIS], X_AXIS);
- for (vsize i = 0; i < stems.size (); i++)
- {
- Grob *s = stems[i];
-
- Real x = s->relative_coordinate (common[X_AXIS], X_AXIS) - x_span[LEFT];
- x_posns.push_back (x);
- }
-
- Grob *lvs = last_normal_stem (me);
- x_span[RIGHT] = lvs->relative_coordinate (common[X_AXIS], X_AXIS);
-
- Drul_array<Real> pos = ly_scm2interval (posns);
-
- scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
-
- Real beam_dy = pos[RIGHT] - pos[LEFT];
- Real beam_left_y = pos[LEFT];
- Real slope = x_span.delta () ? (beam_dy / x_span.delta ()) : 0.0;
-
- /*
- Shift the positions so that we have a chance of finding good
- quants (i.e. no short stem failures.)
- */
- Interval feasible_left_point;
- feasible_left_point.set_full ();
-
- for (vsize i = 0; i < stems.size (); i++)
- {
- Grob *s = stems[i];
- if (Stem::is_invisible (s))
- continue;
-
- Direction d = get_grob_direction (s);
- Real left_y
- = Stem::get_stem_info (s).shortest_y_
- - slope * x_posns [i];
-
- /*
- left_y is now relative to the stem S. We want relative to
- ourselves, so translate:
- */
- left_y
- += + s->relative_coordinate (common[Y_AXIS], Y_AXIS)
- - me->relative_coordinate (common[Y_AXIS], Y_AXIS);
-
- Interval flp;
- flp.set_full ();
- flp[-d] = left_y;
-
- feasible_left_point.intersect (flp);
- }
-
- vector<Grob *> filtered;
- /*
- We only update these for objects that are too large for quanting
- to find a workaround. Typically, these are notes with
- stems, and timesig/keysig/clef, which take out the entire area
- inside the staff as feasible.
-
- The code below disregards the thickness and multiplicity of the
- beam. This should not be a problem, as the beam quanting will
- take care of computing the impact those exactly.
- */
- Real min_y_size = 2.0;
-
- // A list of intervals into which beams may not fall
- vector<Interval> forbidden_intervals;
-
- for (vsize i = 0; i < covered.size (); i++)
- {
- if (!covered[i]->is_live ())
- continue;
-
- if (Beam::has_interface (covered[i]) && is_cross_staff (covered[i]))
- continue;
-
- Box b;
- for (Axis a = X_AXIS; a < NO_AXES; incr (a))
- b[a] = covered[i]->extent (common[a], a);
-
- if (b[X_AXIS].is_empty () || b[Y_AXIS].is_empty ())
- continue;
-
- if (intersection (b[X_AXIS], x_span).is_empty ())
- continue;
-
- filtered.push_back (covered[i]);
- Grob *head_stem = Rhythmic_head::get_stem (covered[i]);
- if (head_stem && Stem::is_normal_stem (head_stem)
- && Note_head::has_interface (covered[i]))
- {
- if (Stem::get_beam (head_stem))
- {
- /*
- We must assume that stems are infinitely long in this
- case, as asking for the length of the stem typically
- leads to circular dependencies.
-
- This strategy assumes that we don't want to handle the
- collision of beams in opposite non-forced directions
- with this code, where shortening the stems of both
- would resolve the problem, eg.
-
- x x
- | |
- =====
-
- =====
- | |
- x x
-
- Such beams would need a coordinating grob to resolve
- the collision, since both will likely want to occupy
- the centerline.
- */
- Direction stemdir = get_grob_direction (head_stem);
- b[Y_AXIS][stemdir] = stemdir * infinity_f;
- }
- else
- {
- // TODO - should we include the extent of the stem here?
- }
- }
-
- if (b[Y_AXIS].length () < min_y_size)
- continue;
-
- Direction d = LEFT;
- do
- {
- Real x = b[X_AXIS][d] - x_span[LEFT];
- Real dy = slope * x;
-
- Direction yd = DOWN;
- Interval disallowed;
- do
- {
- Real left_y = b[Y_AXIS][yd];
-
- left_y -= dy;
-
- // Translate back to beam as ref point.
- left_y -= me->relative_coordinate (common[Y_AXIS], Y_AXIS);
-
- disallowed[yd] = left_y;
- }
- while (flip (&yd) != DOWN);
-
- forbidden_intervals.push_back (disallowed);
- }
- while (flip (&d) != LEFT);
- }
-
- Grob_array *arr
- = Pointer_group_interface::get_grob_array (me,
- ly_symbol2scm ("covered-grobs"));
- arr->set_array (filtered);
-
- vector_sort (forbidden_intervals, Interval::left_less);
- Real epsilon = 1.0e-10;
- Interval feasible_beam_placements (beam_left_y, beam_left_y);
-
- /*
- forbidden_intervals contains a vector of intervals in which
- the beam cannot start. it iterates through these intervals,
- pushing feasible_beam_placements epsilon over or epsilon under a
- collision. when this type of change happens, the loop is marked
- as "dirty" and re-iterated.
-
- TODO: figure out a faster ways that this loop can happen via
- a better search algorithm and/or OOP.
- */
-
- bool dirty = false;
- do
- {
- dirty = false;
- for (vsize i = 0; i < forbidden_intervals.size (); i++)
- {
- Direction d = DOWN;
- do
- {
- if (forbidden_intervals[i][d] == d * infinity_f)
- feasible_beam_placements[d] = d * infinity_f;
- else if (forbidden_intervals[i].contains (feasible_beam_placements[d]))
- {
- feasible_beam_placements[d] = d * epsilon + forbidden_intervals[i][d];
- dirty = true;
- }
- }
- while (flip (&d) != DOWN);
- }
- }
- while (dirty);
-
- // if the beam placement falls out of the feasible region, we push it
- // to infinity so that it can never be a feasible candidate below
- Direction d = DOWN;
- do
- {
- if (!feasible_left_point.contains (feasible_beam_placements[d]))
- feasible_beam_placements[d] = d * infinity_f;
- }
- while (flip (&d) != DOWN);
-
- if ((feasible_beam_placements[UP] == infinity_f && feasible_beam_placements[DOWN] == -infinity_f) && !feasible_left_point.is_empty ())
- {
- // We are somewhat screwed: we have a collision, but at least
- // there is a way to satisfy stem length constraints.
- beam_left_y = point_in_interval (feasible_left_point, 2.0);
- }
- else if (!feasible_left_point.is_empty ())
- {
- // Only one of them offers is feasible solution. Pick that one.
- if (abs (beam_left_y - feasible_beam_placements[DOWN]) > abs (beam_left_y - feasible_beam_placements[UP]))
- beam_left_y = feasible_beam_placements[UP];
- else
- beam_left_y = feasible_beam_placements[DOWN];
- }
- else
- {
- // We are completely screwed.
- me->warning (_ ("no viable initial configuration found: may not find good beam slope"));
- }
-
- pos = Drul_array<Real> (beam_left_y, (beam_left_y + beam_dy));
- scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
-
- return ly_interval2scm (pos);
-}
-
-/* This neat trick is by Werner Lemberg,
- damped = tanh (slope)
- corresponds with some tables in [Wanske] CHECKME */
-MAKE_SCHEME_CALLBACK (Beam, slope_damping, 2);
-SCM
-Beam::slope_damping (SCM smob, SCM posns)
-{
- Grob *me = unsmob_grob (smob);
- Drul_array<Real> pos = ly_scm2interval (posns);
-
- if (normal_stem_count (me) <= 1)
- return posns;
-
- SCM s = me->get_property ("damping");
- Real damping = scm_to_double (s);
- Real concaveness = robust_scm2double (me->get_property ("concaveness"), 0.0);
- if (concaveness >= 10000)
- {
- pos[LEFT] = pos[RIGHT];
- me->set_property ("least-squares-dy", scm_from_double (0));
- damping = 0;
- }
-
- if (damping)
- {
- scale_drul (&pos, Staff_symbol_referencer::staff_space (me));
-
- Real dy = pos[RIGHT] - pos[LEFT];
-
- Grob *fvs = first_normal_stem (me);
- Grob *lvs = last_normal_stem (me);
-
- Grob *commonx = fvs->common_refpoint (lvs, X_AXIS);
-
- Real dx = last_normal_stem (me)->relative_coordinate (commonx, X_AXIS)
- - first_normal_stem (me)->relative_coordinate (commonx, X_AXIS);
-
- Real slope = dy && dx ? dy / dx : 0;
-
- slope = 0.6 * tanh (slope) / (damping + concaveness);
-
- Real damped_dy = slope * dx;
-
- set_minimum_dy (me, &damped_dy);
-
- pos[LEFT] += (dy - damped_dy) / 2;
- pos[RIGHT] -= (dy - damped_dy) / 2;
-
- scale_drul (&pos, 1 / Staff_symbol_referencer::staff_space (me));
- }
-
- return ly_interval2scm (pos);
-}
-
MAKE_SCHEME_CALLBACK (Beam, quanting, 2);
SCM
Beam::quanting (SCM smob, SCM posns)
projects / lilypond.git / commitdiff