+/*
+ simple-spacer.cc -- implement Simple_spacer
+
+ source file of the GNU LilyPond music typesetter
+
+ (c) 1999--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
+
+ TODO:
+ - add support for different stretch/shrink constants?
+*/
+
+#include <cstdio>
+
+#include "column-x-positions.hh"
+#include "dimensions.hh"
+#include "international.hh"
+#include "libc-extension.hh" // isinf
+#include "paper-column.hh"
#include "simple-spacer.hh"
-#include "idealspacing.hh"
-// #include ""
+#include "spaceable-grob.hh"
+#include "spring.hh"
+#include "warn.hh"
+
+/*
+ A simple spacing constraint solver. The approach:
+
+ Stretch the line uniformly until none of the constraints (rods)
+ block. It then is very wide.
+
+ Compress until the next constraint blocks,
+
+ Mark the springs over the constrained part to be non-active.
+
+ Repeat with the smaller set of non-active constraints, until all
+ constraints blocked, or until the line is as short as desired.
+
+ This is much simpler, and much much faster than full scale
+ Constrained QP. On the other hand, a situation like this will not
+ be typeset as dense as possible, because
+
+ c4 c4 c4 c4
+ veryveryverylongsyllable2 veryveryverylongsyllable2
+ " "4 veryveryverylongsyllable2 syllable4
+
+
+ can be further compressed to
+
+
+ c4 c4 c4 c4
+ veryveryverylongsyllable2 veryveryverylongsyllable2
+ " "4 veryveryverylongsyllable2 syllable4
+
+ Perhaps this is not a bad thing, because the 1st looks better anyway. */
+
+/*
+ positive force = expanding, negative force = compressing.
+*/
+
+Simple_spacer::Simple_spacer ()
+{
+ line_len_ = 0.0;
+ force_ = 0.0;
+ fits_ = true;
+ ragged_ = true;
+}
+
+Real
+Simple_spacer::force () const
+{
+ return force_;
+}
+
+bool
+Simple_spacer::fits () const
+{
+ return fits_;
+}
+
+Real
+Simple_spacer::rod_force (int l, int r, Real dist)
+{
+ Real d = range_ideal_len (l, r);
+ Real c = range_stiffness (l, r, dist > d);
+ Real block_stretch = dist - d;
+
+ if (isinf (c) && block_stretch == 0) /* take care of the 0*infinity_f case */
+ return 0;
+ return c * block_stretch;
+}
void
-Spring_info::set(Idealspacing *i)
+Simple_spacer::add_rod (int l, int r, Real dist)
+{
+ if (isinf (dist) || isnan (dist))
+ {
+ programming_error ("ignoring weird minimum distance");
+ return;
+ }
+
+ Real block_force = rod_force (l, r, dist);
+
+ if (isinf (block_force))
+ {
+ Real spring_dist = range_ideal_len (l, r);
+ if (spring_dist < dist)
+ for (int i = l; i < r; i++)
+ {
+ if (spring_dist)
+ springs_[i].set_distance (springs_[i].distance () * dist / spring_dist);
+ else
+ springs_[i].set_distance (dist / (r - l));
+ }
+
+ return;
+ }
+ force_ = max (force_, block_force);
+ for (int i = l; i < r; i++)
+ springs_[i].set_blocking_force (max (block_force, springs_[i].blocking_force ()));
+}
+
+Real
+Simple_spacer::range_ideal_len (int l, int r) const
{
- space_f_ = i->space_f_;
- hooke_f_ = i->hooke_f_;
+ Real d = 0.;
+ for (int i = l; i < r; i++)
+ d += springs_[i].distance ();
+ return d;
}
-Spring_info::Spring_info()
+Real
+Simple_spacer::range_stiffness (int l, int r, bool stretch) const
{
- space_f_ = 0.0;
- hooke_f_ = 1.0;
- blocking_stretch_f_ = infinity_f;
- blocking_rod_l_ = 0;
+ Real den = 0.0;
+ for (int i = l; i < r; i++)
+ den += stretch ? springs_[i].inverse_stretch_strength ()
+ : springs_[i].inverse_compress_strength ();
+
+ return 1 / den;
}
-
+Real
+Simple_spacer::configuration_length (Real force) const
+{
+ Real l = 0.;
+ for (vsize i = 0; i < springs_.size (); i++)
+ l += springs_[i].length (force);
+
+ return l;
+}
void
-Simple_spring_spacer::init ()
+Simple_spacer::solve (Real line_len, bool ragged)
+{
+ Real conf = configuration_length (force_);
+
+ ragged_ = ragged;
+ line_len_ = line_len;
+ if (conf < line_len_)
+ force_ = expand_line ();
+ else if (conf > line_len_)
+ force_ = compress_line ();
+
+ if (ragged && force_ < 0)
+ fits_ = false;
+}
+
+Real
+Simple_spacer::expand_line ()
{
- for (PCursor<Rod_info*> i(rods_.top()); i.ok (); i++)
+ double inv_hooke = 0;
+ double cur_len = configuration_length (force_);
+
+ fits_ = true;
+ for (vsize i=0; i < springs_.size (); i++)
+ inv_hooke += springs_[i].inverse_stretch_strength ();
+
+ if (inv_hooke == 0.0) /* avoid division by zero. If springs are infinitely stiff */
+ return 0.0; /* anyway, then it makes no difference what the force is */
+
+ assert (cur_len <= line_len_);
+ return (line_len_ - cur_len) / inv_hooke + force_;
+}
+
+Real
+Simple_spacer::compress_line ()
+{
+ double inv_hooke = 0;
+ double cur_len = configuration_length (force_);
+ double cur_force = force_;
+ bool compressed = false;
+
+ /* just because we are in compress_line () doesn't mean that the line
+ will actually be compressed (as in, a negative force) because
+ we start out with a stretched line. Here, we check whether we
+ will be compressed or stretched (so we know which spring constant to use) */
+ if (configuration_length (0.0) > line_len_)
{
- Real hooke=0.0;
- Real dist= i->distance_f_;
+ cur_force = 0.0;
+ cur_len = configuration_length (0.0);
+ compressed = true;
+ }
- hooke =0.0;
-
- for (int j = i->cols_[LEFT]; j < i->cols_[RIGHT]; j++)
- {
- hooke += 1/springs_[j].hooke_f_;
- dist -= springs_[j].space_f_;
- }
-
- hooke = 1/hooke;
+ fits_ = true;
+ for (vsize i=0; i < springs_.size (); i++)
+ inv_hooke += compressed
+ ? springs_[i].inverse_compress_strength ()
+ : springs_[i].inverse_stretch_strength ();
+
+ assert (line_len_ <= cur_len);
+
+ vector<Spring> sorted_springs = springs_;
+ sort (sorted_springs.begin (), sorted_springs.end (), greater<Spring> ());
+
+ for (vsize i = 0; i < sorted_springs.size (); i++)
+ {
+ Spring sp = sorted_springs[i];
+
+ assert (sp.blocking_force () <= cur_force);
+ if (isinf (sp.blocking_force ()))
+ break;
- for (int j = i->cols_[LEFT]; j < i->cols_[RIGHT]; j++)
+ double block_dist = (cur_force - sp.blocking_force ()) * inv_hooke;
+ if (cur_len - block_dist < line_len_)
{
- Real block_stretch = hooke * dist / (springs_[j].space_f_ *
- springs_[j].hooke_f_ );
+ cur_force += (line_len_ - cur_len) / inv_hooke;
+ cur_len = line_len_;
- if (block_stretch < springs_[j].blocking_stretch_f_)
- {
- springs_[j].blocking_stretch_f_ = block_stretch;
- springs_[j].blocking_rod_l_ = i.ptr ();
- }
+ /*
+ Paranoia check.
+ */
+ assert (fabs (configuration_length (cur_force) - cur_len) < 1e-6);
+ return cur_force;
}
+
+ cur_len -= block_dist;
+ inv_hooke -= sp.inverse_compress_strength ();
+ cur_force = sp.blocking_force ();
}
+
+ fits_ = false;
+ return cur_force;
+}
+
+void
+Simple_spacer::add_spring (Spring const &sp)
+{
+ force_ = max (force_, sp.blocking_force ());
+ springs_.push_back (sp);
+}
+
+vector<Real>
+Simple_spacer::spring_positions () const
+{
+ vector<Real> ret;
+ ret.push_back (0.);
+
+ for (vsize i = 0; i < springs_.size (); i++)
+ ret.push_back (ret.back () + springs_[i].length (ragged_ && force_ > 0 ? 0.0 : force_));
+ return ret;
+}
+
+Real
+Simple_spacer::force_penalty (bool ragged) const
+{
+ /* If we are ragged-right, we don't want to penalise according to the force,
+ but according to the amount of whitespace that is present after the end
+ of the line. */
+ if (ragged)
+ return max (0.0, line_len_ - configuration_length (0.0));
+
+ /* Use a convex compression penalty. */
+ Real f = force_;
+ return f - (f < 0 ? f*f*f*f*2 : 0);
+}
+
+/****************************************************************/
+
+struct Rod_description
+{
+ vsize r_;
+ Real dist_;
+
+ bool operator< (const Rod_description r)
+ {
+ return r_ < r.r_;
+ }
+
+ Rod_description ()
+ {
+ r_ = 0;
+ dist_ = 0;
+ }
+
+ Rod_description (vsize r, Real d)
+ {
+ r_ = r;
+ dist_ = d;
+ }
+};
+
+struct Column_description
+{
+ vector<Rod_description> rods_;
+ vector<Rod_description> end_rods_; /* use these if they end at the last column of the line */
+ Spring spring_;
+ Spring end_spring_;
+
+ SCM break_permission_;
+ Interval keep_inside_line_;
+
+ Column_description ()
+ {
+ break_permission_ = SCM_EOL;
+ }
+};
+
+static bool
+is_loose (Grob *g)
+{
+ return (scm_is_pair (g->get_object ("between-cols")));
+}
+
+static Grob*
+maybe_find_prebroken_piece (Grob *g, Direction d)
+{
+ Grob *ret = dynamic_cast<Item*> (g)->find_prebroken_piece (d);
+ if (ret)
+ return ret;
+ return g;
}
-Array<Real>
-Simple_spring_spacer::solve ()
+static Grob*
+next_spaceable_column (vector<Grob*> const &list, vsize starting)
{
- Real start_force = 0.0;
+ for (vsize i = starting+1; i < list.size (); i++)
+ if (!is_loose (list[i]))
+ return list[i];
+ return 0;
+}
- for (int i=0; i< springs_.size (); i++)
+static Column_description
+get_column_description (vector<Grob*> const &cols, vsize col_index, bool line_starter)
+{
+ Grob *col = cols[col_index];
+ if (line_starter)
+ col = maybe_find_prebroken_piece (col, RIGHT);
+
+ Column_description description;
+ Grob *next_col = next_spaceable_column (cols, col_index);
+ if (next_col)
+ description.spring_ = Spaceable_grob::get_spring (col, next_col);
+
+ Grob *end_col = dynamic_cast<Item*> (cols[col_index+1])->find_prebroken_piece (LEFT);
+ if (end_col)
+ description.end_spring_ = Spaceable_grob::get_spring (col, end_col);
+
+ for (SCM s = Spaceable_grob::get_minimum_distances (col);
+ scm_is_pair (s); s = scm_cdr (s))
{
- start_force = start_force >?
- springs_[i].blocking_stretch_f_ * springs_[i].hooke_f_;
+ Grob *other = unsmob_grob (scm_caar (s));
+ vsize j = binary_search (cols, other, Paper_column::less_than, col_index);
+ if (j != VPOS)
+ {
+ if (cols[j] == other)
+ description.rods_.push_back (Rod_description (j, scm_to_double (scm_cdar (s))));
+ else /* it must end at the LEFT prebroken_piece */
+ description.end_rods_.push_back (Rod_description (j, scm_to_double (scm_cdar (s))));
+ }
}
+
+ if (!line_starter && to_boolean (col->get_property ("keep-inside-line")))
+ description.keep_inside_line_ = col->extent (col, X_AXIS);
+
+ description.break_permission_ = col->get_property ("line-break-permission");
+ return description;
+}
- Array<Real> stretch_factors;
- Array<bool> blocked;
- int blocked_count=0;
- Real current_len =0.0;
- for (int i=0; i < springs_.size (); i++)
+vector<Real>
+get_line_forces (vector<Grob*> const &columns,
+ Real line_len, Real indent, bool ragged)
+{
+ vector<vsize> breaks;
+ vector<Real> force;
+ vector<Grob*> non_loose;
+ vector<Column_description> cols;
+ SCM force_break = ly_symbol2scm ("force");
+
+ for (vsize i = 0; i < columns.size (); i++)
+ if (!is_loose (columns[i]) || Paper_column::is_breakable (columns[i]))
+ non_loose.push_back (columns[i]);
+
+ breaks.clear ();
+ breaks.push_back (0);
+ cols.push_back (Column_description ());
+ for (vsize i = 1; i + 1 < non_loose.size (); i++)
{
- Real stretch = start_force / (springs_[i].hooke_f_ * springs_[i].space_f_);
- stretch_factors.push (stretch);
- current_len += (1 + stretch) * springs_[i].space_f_;
- blocked.push(false);
+ if (Paper_column::is_breakable (non_loose[i]))
+ breaks.push_back (cols.size ());
+
+ cols.push_back (get_column_description (non_loose, i, false));
}
+ breaks.push_back (cols.size ());
+ force.resize (breaks.size () * breaks.size (), infinity_f);
-
- while (blocked_count < blocked.size ())
+ for (vsize b = 0; b + 1 < breaks.size (); b++)
{
- Real next_stretch = -1.0;
- int block_index;
- for (int i=0; i< stretch_factors.size (); i++)
+ cols[breaks[b]] = get_column_description (non_loose, breaks[b], true);
+ vsize st = breaks[b];
+
+ for (vsize c = b+1; c < breaks.size (); c++)
{
- if (!blocked[i])
- {
- next_stretch = next_stretch >? springs_[i].blocking_stretch_f_;
+ vsize end = breaks[c];
+ Simple_spacer spacer;
+
+ for (vsize i = breaks[b]; i < end - 1; i++)
+ spacer.add_spring (cols[i].spring_);
+ spacer.add_spring (cols[end-1].end_spring_);
- if (next_stretch < springs_[i].blocking_stretch_f_)
+
+ for (vsize i = breaks[b]; i < end; i++)
+ {
+ for (vsize r = 0; r < cols[i].rods_.size (); r++)
+ if (cols[i].rods_[r].r_ < end)
+ spacer.add_rod (i - st, cols[i].rods_[r].r_ - st, cols[i].rods_[r].dist_);
+ for (vsize r = 0; r < cols[i].end_rods_.size (); r++)
+ if (cols[i].end_rods_[r].r_ == end)
+ spacer.add_rod (i - st, end - st, cols[i].end_rods_[r].dist_);
+ if (!cols[i].keep_inside_line_.is_empty ())
{
- next_stretch = springs_[i].blocking_stretch_f_;
- block_index = i;
+ spacer.add_rod (i - st, end - st, cols[i].keep_inside_line_[RIGHT]);
+ spacer.add_rod (0, i - st, -cols[i].keep_inside_line_[LEFT]);
}
}
- }
- current_len = 0.0;
+ spacer.solve ((b == 0) ? line_len - indent : line_len, ragged);
+ force[b * breaks.size () + c] = spacer.force_penalty (ragged);
- Real force = next_stretch * (springs_[block_index].space_f_* springs_[block_index].hooke_f_);
- for (int i=0; i< stretch_factors.size (); i++)
- {
- if (!blocked[i])
+ if (!spacer.fits ())
{
- stretch_factors[i] = force / (springs_[i].space_f_ * springs_[i].hooke_f_);
+ if (c == b + 1)
+ force[b * breaks.size () + c] = -200000;
+ else
+ force[b * breaks.size () + c] = infinity_f;
+ break;
}
- current_len += (1.0 + stretch_factors[i]) * springs_[i].space_f_;
+ if (end < cols.size () && cols[end].break_permission_ == force_break)
+ break;
}
+ }
+ return force;
+}
+
+Column_x_positions
+get_line_configuration (vector<Grob*> const &columns,
+ Real line_len,
+ Real indent,
+ bool ragged)
+{
+ vector<Column_description> cols;
+ Simple_spacer spacer;
+ Column_x_positions ret;
+
+ ret.cols_.push_back (dynamic_cast<Item*> (columns[0])->find_prebroken_piece (RIGHT));
+ for (vsize i = 1; i + 1 < columns.size (); i++)
+ {
+ if (is_loose (columns[i]))
+ ret.loose_cols_.push_back (columns[i]);
+ else
+ ret.cols_.push_back (columns[i]);
+ }
+ ret.cols_.push_back (dynamic_cast<Item*> (columns.back ())->find_prebroken_piece (LEFT));
+
+ /* since we've already put our line-ending column in the column list, we can ignore
+ the end_XXX_ fields of our column_description */
+ for (vsize i = 0; i + 1 < ret.cols_.size (); i++)
+ {
+ cols.push_back (get_column_description (ret.cols_, i, i == 0));
+ spacer.add_spring (cols[i].spring_);
+ }
+ for (vsize i = 0; i < cols.size (); i++)
+ {
+ for (vsize r = 0; r < cols[i].rods_.size (); r++)
+ spacer.add_rod (i, cols[i].rods_[r].r_, cols[i].rods_[r].dist_);
- Rod_info *blockrod = springs_[block_index].blocking_rod_l_;
- for (int j = blockrod->cols_ [LEFT]; j < blockrod->cols_ [RIGHT]; j++)
+ if (!cols[i].keep_inside_line_.is_empty ())
{
- blocked[j] = true;
- blocked_count ++;
+ spacer.add_rod (i, cols.size (), cols[i].keep_inside_line_[RIGHT]);
+ spacer.add_rod (0, i, -cols[i].keep_inside_line_[LEFT]);
}
}
+ spacer.solve (line_len, ragged);
+ ret.force_ = spacer.force_penalty (ragged);
+
+ ret.config_ = spacer.spring_positions ();
+ for (vsize i = 0; i < ret.config_.size (); i++)
+ ret.config_[i] += indent;
- Array<Real> distances;
- for (int i=0; i < stretch_factors.size (); i++)
+ ret.satisfies_constraints_ = spacer.fits ();
+
+ /*
+ Check if breaking constraints are met.
+ */
+ for (vsize i = 1; i + 1 < ret.cols_.size (); i++)
{
- distances.push (stretch_factors[i] * springs_[i].space_f_);
+ SCM p = ret.cols_[i]->get_property ("line-break-permission");
+ if (p == ly_symbol2scm ("force"))
+ ret.satisfies_constraints_ = false;
}
- return distances;
+
+ return ret;
}
projects / lilypond.git / blobdiff