source file of the GNU LilyPond music typesetter
- (c) 1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+ (c) 1999--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
TODO:
- add support for different stretch/shrink constants?
- - Use force as a minimizing function, and use it to discourage mixes of
- wide and tight lines.
*/
-
+#include <stdio.h>
+#include <math.h>
+#include <libc-extension.hh> // isinf
#include "simple-spacer.hh"
#include "paper-column.hh"
#include "rod.hh"
#include "warn.hh"
#include "column-x-positions.hh"
+#include "spaceable-grob.hh"
+#include "dimensions.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. */
+
Simple_spacer::Simple_spacer ()
{
- force_f_ = 0.;
+ /*
+ Give an extra penalty for compression. Needed to avoid compressing
+ tightly spaced lines.
+ */
+ compression_penalty_b_ = false;
+ active_count_ = 0;
+ force_ = 0.;
+ indent_ =0.0;
+ default_space_ = 20 PT;
}
void
Simple_spacer::add_rod (int l, int r, Real dist)
{
+ if (isinf (dist) || isnan (dist))
+ {
+ programming_error ("Weird minimum distance. Ignoring");
+ return;
+ }
+
Real c = range_stiffness (l,r);
+ if (isinf (c))
+ {
+ /*
+ If a spring is fixed, we have to do something here:
+ we let the rod override the spring.
+ */
+ Real total_dist = 0.;
+ for (int i = l ; i < r; i++)
+ total_dist += springs_[i].ideal_;
+
+ if (total_dist < dist)
+ for (int i = l ; i < r; i++)
+ springs_[i].ideal_ *= dist/total_dist;
+
+ return;
+ }
+
Real d = range_ideal_len (l,r);
Real block_stretch = dist - d;
Real block_force = c * block_stretch;
- force_f_ = force_f_ >? block_force;
-
+ force_ = force_ >? block_force;
+
for (int i=l; i < r; i++)
- springs_[i].block_force_f_ = block_force >?
- springs_[i].block_force_f_ ;
+ springs_[i].block_force_ = block_force >?
+ springs_[i].block_force_ ;
}
Real
{
Real d =0.;
for (int i=l; i < r; i++)
- d += springs_[i].ideal_f_;
+ d += springs_[i].ideal_;
return d;
}
{
Real den =0.0;
for (int i=l; i < r; i++)
- den += 1 / springs_[i].hooke_f_;
+ {
+ if (springs_[i].active_b_)
+ den += 1 / springs_[i].hooke_;
+ }
return 1 / den;
}
for (int i=0; i < springs_.size (); i++)
if (springs_[i].active_b_)
{
- bf = bf >? springs_[i].block_force_f_;
+ bf = bf >? springs_[i].block_force_;
}
return bf;
}
Real
Simple_spacer::active_springs_stiffness () const
{
- Real den = 0.0;
- for (int i=0; i < springs_.size (); i++)
- if (springs_[i].active_b_)
- {
- den += 1 / springs_[i].hooke_f_;
- }
- return 1/den;
+ return range_stiffness (0, springs_.size ());
}
void
Simple_spacer::set_active_states ()
{
- // safe, since
- // force is only copied.
+ /* float comparison is safe, since force is only copied. */
for (int i=0 ; i <springs_.size (); i++)
- if (springs_[i].block_force_f_ >= force_f_)
- springs_[i].active_b_ = false;
+ if (springs_[i].active_b_
+ && springs_[i].block_force_ >= force_)
+ {
+ springs_[i].active_b_ = false;
+ active_count_ --;
+ }
}
Real
{
Real l =0.;
for (int i=0; i < springs_.size (); i++)
- l += springs_[i].length (force_f_);
+ l += springs_[i].length (force_);
return l;
}
-Real
-Spring_description::length (Real f) const
-{
- if (!active_b_)
- f = block_force_f_;
- return ideal_f_ + f / hooke_f_ ;
-}
-
bool
Simple_spacer::active_b () const
{
- for (int i=0; i < springs_.size (); i++)
- if (springs_[i].active_b_)
- return true;
- return false;
+ return active_count_;
}
void
{
while (active_b ())
{
- force_f_ = active_blocking_force ();
+ force_ = active_blocking_force ();
Real conf = configuration_length ();
- if (conf < line_len_f_)
+ if (conf < line_len_)
{
- force_f_ += (line_len_f_ - conf) * active_springs_stiffness ();
+ force_ += (line_len_ - conf) * active_springs_stiffness ();
break;
}
else
{
while (active_b ())
{
- force_f_ = active_blocking_force () >? 0.0;
+ force_ = active_blocking_force () >? 0.0;
- if (force_f_ < 1e-8) // ugh.,
+ if (force_ < 1e-8) // ugh.,
break;
set_active_states ();
}
void
-Simple_spacer::add_columns (Link_array<Paper_column> cols)
+Simple_spacer::add_columns (Link_array<Grob> const &icols)
{
+ Link_array<Grob> cols(icols);
+
+ for (int i = cols.size (); i--;)
+ if (gh_pair_p (cols[i]->get_grob_property ("between-cols")))
+ {
+ loose_cols_.push (cols[i]);
+ cols.del (i);
+ }
+
+ spaced_cols_ = cols;
for (int i=0; i < cols.size () - 1; i++)
{
- Paper_column * c = cols [i];
- Column_spring *to_next = 0;
- for (int j =0; !to_next && j < c->spring_arr_drul_[RIGHT].size( ); j++)
- {
- Column_spring &sp = c->spring_arr_drul_[RIGHT] [j];
- if (sp.other_l_ != cols[i+1])
- continue;
+ Spring_smob *spring = 0;
- to_next = &sp;
+ for (SCM s = cols[i]->get_grob_property ("ideal-distances");
+ !spring && gh_pair_p (s);
+ s = ly_cdr (s))
+ {
+ Spring_smob *sp = unsmob_spring (ly_car (s));
+
+
+ if (sp->other_ == cols[i+1])
+ spring = sp;
}
Spring_description desc;
- if (to_next)
+ if (spring)
{
- desc.hooke_f_ = to_next->strength_f_;
- desc.ideal_f_ = to_next->distance_f_;
+ desc.ideal_ = spring->distance_;
+ desc.hooke_ = spring->strength_;
}
else
{
- desc.hooke_f_ = 1.0;
- desc.ideal_f_ = default_space_f_;
+ programming_error (_f("No spring between column %d and next one",
+ Paper_column::get_rank (cols[i])
+ ));
+ desc.hooke_ = 1.0;
+ desc.ideal_ = default_space_;
+
+ continue;
}
- desc.block_force_f_ = - desc.hooke_f_ * desc.ideal_f_; // block at distance 0
- springs_.push (desc);
+
+ if (!desc.sane_b ())
+ {
+ programming_error ("Insane spring found. Setting to unit spring.");
+
+ desc.hooke_ = 1.0;
+ desc.ideal_ = 1.0;
+ }
+
+ if (isinf (desc.hooke_))
+ {
+ desc.active_b_ = false;
+ springs_.push (desc);
+ }
+ else
+ {
+ desc.block_force_ = - desc.hooke_ * desc.ideal_; // block at distance 0
+ springs_.push (desc);
+
+ active_count_ ++;
+ }
+
+ if (spring->expand_only_b_)
+ {
+ compression_penalty_b_ = true;
+ }
+
}
for (int i=0; i < cols.size () - 1; i++)
{
- Array<Column_rod> * rods = &cols [i]->minimal_dists_arr_drul_[RIGHT];
- for (int j =0; j < rods->size( ); j++)
+ for (SCM s = Spaceable_grob::get_minimum_distances (cols[i]);
+ gh_pair_p (s); s = ly_cdr (s))
{
- int oi = cols.find_i (rods->elem (j).other_l_ );
+ Grob * other = unsmob_grob (ly_caar (s));
+ int oi = cols.find_index (other);
if (oi >= 0)
{
- add_rod (i, oi, rods->elem (j).distance_f_);
+ add_rod (i, oi, gh_scm2double (ly_cdar (s)));
}
}
}
- if (line_len_f_ < 0)
- my_solve_natural_len ();
- else
- my_solve_linelen ();
+
}
+/*
+
+ TODO: should a add penalty for widely varying spring forces (caused
+ by constraints, eg.
+
+
+ =====
+ | |
+ o|o| x ##x
+
+
+ The ## forces the notes apart; we shouldn't allow the O's to touch
+ this closely.
+
+ */
void
-Simple_spacer::solve (Column_x_positions *positions) const
+Simple_spacer::solve (Column_x_positions *positions, bool ragged)
{
- positions->energy_f_ = energy_f (); // abs (force_f_);
- positions->config_.push (indent_f_);
+ /*
+ TODO: should support natural length on only the last line.
+ */
+ ragged = ragged || (line_len_ < 0) ;
+ if (ragged)
+ my_solve_natural_len ();
+ else
+ my_solve_linelen ();
+
+ positions->force_ = force_;
+ /*
+ We used to have a penalty for compression, no matter what, but that
+ fucked up wtk1-fugue2 (taking 3 full pages.)
+ */
+
+ positions->config_.push (indent_);
for (int i=0; i <springs_.size (); i++)
{
- positions->config_.push (positions->config_.top () + springs_[i].length (force_f_));
+ Real l = springs_[i].length ((ragged) ? 0.0 : force_);
+ positions->config_.push (positions->config_.top () + l);
+ /*
+ we have l>= 0 here, up to rounding errors
+ */
}
- positions->satisfies_constraints_b_ = active_b ();
-}
+ /*
+ For raggedright, we must have a measure of music density: this is
+ to prevent lots of short lines (which all have force = 0).
+ */
+ if (ragged && line_len_ > 0)
+ {
+ Real len = positions->config_.top ();
+ positions->force_ = (line_len_ - len) * active_springs_stiffness ();
+ }
-void
-Simple_spacer::lower_bound_solution (Column_x_positions * posns) const
-{
- solve (posns);
+
+ positions->cols_ = spaced_cols_;
+ positions->loose_cols_ = loose_cols_;
+ positions->satisfies_constraints_b_ = (line_len_ < 0) || active_b ();
+
+ /*
+ Check if breaking constraints are met.
+ */
+ bool break_satisfy = true;
+ int sz = positions->cols_.size ();
+ for (int i = sz; i--; )
+ {
+ SCM p = positions->cols_[i]->get_grob_property( "penalty");
+ if (gh_number_p (p))
+ {
+ if (gh_scm2double (p) < -9999)
+ break_satisfy = break_satisfy && (i == 0 || i == sz -1);
+ if (gh_scm2double (p) > 9999)
+ break_satisfy = break_satisfy && !(i == 0 || i == sz -1);
+ }
+
+ }
+
+ positions->satisfies_constraints_b_ =
+ positions->satisfies_constraints_b_ && break_satisfy;
+
+ if (ragged && force_ < 0)
+ positions->satisfies_constraints_b_ = false;
}
+/****************************************************************/
-Spring_description::Spring_description( )
+Spring_description::Spring_description ()
{
- ideal_f_ =0.0;
- hooke_f_ =0.0;
+ ideal_ =0.0;
+ hooke_ =0.0;
active_b_ = true;
- block_force_f_ = 0.0;
+ block_force_ = 0.0;
}
-Real
-Spring_description::energy_f (Real force) const
-{
- Real stretch = (force >? block_force_f_) / hooke_f_;
- Real e = 0.5 * stretch * stretch * hooke_f_;
- /*
- be harder to compress.
- */
- if (stretch < 0)
- e *= 4;
-
- return e;
+bool
+Spring_description::sane_b () const
+{
+ return (hooke_ > 0) && !isinf (ideal_) && !isnan (ideal_);
}
Real
-Simple_spacer::energy_f () const
+Spring_description::length (Real f) const
{
- Real e =0.;
-
- for (int i=0; i <springs_.size (); i++)
- e += springs_[i].energy_f (force_f_);
-
- return e;
+ if (!active_b_)
+ f = block_force_;
+ return ideal_ + f / hooke_ ;
}
projects / lilypond.git / blobdiff