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 "simple-spacer.hh"
+
+#include <cstdio>
#include <math.h>
-#include "simple-spacer.hh"
+#include <libc-extension.hh> // isinf
+
#include "paper-column.hh"
#include "spring.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. */
+
+
+/*
+
+ positive force = expanding, negative force = compressing.
+
+*/
+
Simple_spacer::Simple_spacer ()
{
- force_f_ = 0.;
- indent_f_ =0.0;
- default_space_f_ = 20 PT;
- compression_energy_factor_f_ = 3.0;
+ /*
+ Give an extra penalty for compression. Needed to avoid compressing
+ tightly spaced lines.
+ */
+ active_count_ = 0;
+ force_ = 0.;
+ indent_ = 0.0;
+ default_space_ = 20 PT;
}
void
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_ ;
+ for (int i = l; i < r; i++)
+ springs_[i].block_force_ = block_force >?
+ springs_[i].block_force_ ;
}
Real
Simple_spacer::range_ideal_len (int l, int r) const
{
- Real d =0.;
- for (int i=l; i < r; i++)
- d += springs_[i].ideal_f_;
+ Real d = 0.;
+ for (int i = l; i < r; i++)
+ d += springs_[i].ideal_;
return d;
}
Real
Simple_spacer::range_stiffness (int l, int r) const
{
- Real den =0.0;
- for (int i=l; i < r; i++)
- den += 1 / springs_[i].hooke_f_;
+ Real den = 0.0;
+ for (int i = l; i < r; i++)
+ {
+ if (springs_[i].is_active_)
+ den += 1 / springs_[i].hooke_;
+ }
return 1 / den;
}
Simple_spacer::active_blocking_force () const
{
Real bf = - infinity_f;
- for (int i=0; i < springs_.size (); i++)
- if (springs_[i].active_b_)
+ for (int i = 0; i < springs_.size (); i++)
+ if (springs_[i].is_active_)
{
- 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;
+ Real stiff = range_stiffness (0, springs_.size ());
+ if (isinf (stiff))
+ {
+ /*
+ all springs are inactive. Take the stiffness of the
+ latest spring to block.
+ */
+
+ Real max_block_force = -infinity_f;
+ int max_i = -1;
+ for (int i = 0; i < springs_.size (); i++)
+ {
+ if (springs_[i].block_force_ > max_block_force)
+ {
+ max_i = i;
+ max_block_force = springs_[i].block_force_;
+ }
+ }
+
+ stiff = springs_[max_i].hooke_;
+ }
+ return stiff;
}
void
Simple_spacer::set_active_states ()
{
- // 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;
+ /* float comparison is safe, since force is only copied. */
+ for (int i = 0 ; i <springs_.size (); i++)
+ if (springs_[i].is_active_
+ && springs_[i].block_force_ >= force_)
+ {
+ springs_[i].is_active_ = false;
+ active_count_ --;
+ }
}
Real
Simple_spacer::configuration_length () const
{
- Real l =0.;
- for (int i=0; i < springs_.size (); i++)
- l += springs_[i].length (force_f_);
+ Real l = 0.;
+ for (int i = 0; i < springs_.size (); i++)
+ 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
+Simple_spacer::is_active () const
{
- for (int i=0; i < springs_.size (); i++)
- if (springs_[i].active_b_)
- return true;
- return false;
+ return active_count_;
}
void
Simple_spacer::my_solve_linelen ()
{
- while (active_b ())
+ while (is_active ())
{
- 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
void
Simple_spacer::my_solve_natural_len ()
{
- while (active_b ())
+ Real line_len_force = 0.0;
+
+ while (is_active ())
{
- force_f_ = active_blocking_force () >? 0.0;
+ force_ = active_blocking_force () >? 0.0;
+ Real conf = configuration_length ();
- if (force_f_ < 1e-8) // ugh.,
+ if (conf < line_len_)
+ {
+ line_len_force = force_
+ + (line_len_ - conf)
+ * active_springs_stiffness();
+ }
+
+ if (force_ < 1e-8) // ugh.,
break;
set_active_states ();
}
+
+ force_ = line_len_force;
}
-void
-Simple_spacer::add_columns (Link_array<Paper_column> cols)
+LY_DEFINE(ly_solve_spring_rod_problem, "ly:solve-spring-rod-problem",
+ 4, 1, 0, (SCM springs, SCM rods, SCM length, SCM ragged),
+ "Solve a spring and rod problem for @var{count} objects, that "
+ "are connected by @var{count-1} springs, and an arbitrary number of rods "
+ "Springs have the format (ideal, hooke) and rods (idx1, idx2, distance) "
+ "@var{length} is a number, @var{ragged} a boolean "
+ "Return: a list containing the force (positive for stretching, "
+ "negative for compressing and #f for non-satisfied constraints) "
+ "followed by the @var{spring-count}+1 positions of the objects. "
+ )
{
- for (int i=0; i < cols.size () - 1; i++)
+ int len = scm_ilength (springs);
+ if (len == 0)
+ return scm_list_2 (scm_from_double (0.0), scm_from_double (0.0));
+
+ SCM_ASSERT_TYPE (len >= 0, springs, SCM_ARG1, __FUNCTION__, "list of springs");
+ SCM_ASSERT_TYPE (scm_ilength (rods) >= 0, rods, SCM_ARG2, __FUNCTION__, "list of rods");
+ SCM_ASSERT_TYPE (scm_is_number (length) || length == SCM_BOOL_F,
+ length, SCM_ARG3, __FUNCTION__, "number or #f");
+
+
+ bool is_ragged = ragged == SCM_BOOL_T;
+ Simple_spacer spacer;
+ for (SCM s = springs; scm_is_pair (s); s = scm_cdr (s))
{
- 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;
+ Real ideal = scm_to_double (scm_caar (s));
+ Real hooke = scm_to_double (scm_cadar (s));
- to_next = &sp;
- }
+ spacer.add_spring (ideal, hooke);
+ }
- Spring_description desc;
- if (to_next)
- {
- desc.hooke_f_ = to_next->strength_f_;
- desc.ideal_f_ = to_next->distance_f_;
- }
- else
- {
- desc.hooke_f_ = 1.0;
- desc.ideal_f_ = default_space_f_;
- }
+ for (SCM s = rods; scm_is_pair (s); s = scm_cdr (s))
+ {
+ SCM entry = scm_car (s);
+ int l = scm_to_int (scm_car (entry));
+ int r = scm_to_int (scm_cadr (entry));
+ entry = scm_cddr (entry);
+
+ Real distance = scm_to_double (scm_car (entry));
+ spacer.add_rod (l, r, distance);
+ }
- if (!desc.sane_b ())
- {
- programming_error ("Insane spring.");
- continue;
- }
+ spacer.line_len_ = scm_to_double (length);
- desc.block_force_f_ = - desc.hooke_f_ * desc.ideal_f_; // block at distance 0
- springs_.push (desc);
+ if (is_ragged)
+ spacer.my_solve_natural_len ();
+ else
+ spacer.my_solve_linelen ();
+
+ Array<Real> posns;
+ posns.push (0.0);
+ for (int i = 0; i < spacer.springs_.size(); i++)
+ {
+ Real l = spacer.springs_[i].length ((is_ragged) ? 0.0 : spacer.force_);
+ posns.push (posns.top() + l);
}
-
- for (int i=0; i < cols.size () - 1; i++)
+
+
+
+ SCM force_return = SCM_BOOL_F;
+ if (!isinf (spacer.force_)
+ && (spacer.is_active () || is_ragged))
{
- Array<Column_rod> * rods = &cols [i]->minimal_dists_arr_drul_[RIGHT];
- for (int j =0; j < rods->size( ); j++)
- {
- int oi = cols.find_i (rods->elem (j).other_l_ );
- if (oi >= 0)
- {
- add_rod (i, oi, rods->elem (j).distance_f_);
- }
- }
+ force_return = scm_from_double (spacer.force_);
}
- if (line_len_f_ < 0)
- my_solve_natural_len ();
- else
- my_solve_linelen ();
-}
+ if (is_ragged
+ && posns.top () > spacer.line_len_)
+ {
+ force_return = SCM_BOOL_F;
+ }
-void
-Simple_spacer::solve (Column_x_positions *positions) const
-{
- positions->energy_f_ = energy_f (); // abs (force_f_);
- positions->force_f_ = force_f_;
-
- positions->config_.push (indent_f_);
- for (int i=0; i <springs_.size (); i++)
+ SCM retval = SCM_EOL;
+ for (int i = posns.size(); i--;)
{
- positions->config_.push (positions->config_.top () + springs_[i].length (force_f_));
+ retval = scm_cons (scm_from_double (posns[i]), retval);
}
- positions->satisfies_constraints_b_ = (line_len_f_ < 0) || active_b ();
+ retval = scm_cons (force_return, retval);
+ return retval;
}
+
+
+/****************************************************************/
+Spring_description::Spring_description ()
+{
+ ideal_ = 0.0;
+ hooke_ = 0.0;
+ is_active_ = true;
+ block_force_ = 0.0;
+}
-Spring_description::Spring_description( )
+bool
+Spring_description::is_sane () const
{
- ideal_f_ =0.0;
- hooke_f_ =0.0;
- active_b_ = true;
- block_force_f_ = 0.0;
+ return (hooke_ > 0)
+ && ideal_ > 0
+ && !isinf (ideal_) && !isnan (ideal_);
}
Real
-Spring_description::energy_f (Real force) const
+Spring_description::length (Real f) const
{
- Real stretch = (force >? block_force_f_) / hooke_f_;
- Real e = 0.5 * stretch * stretch * hooke_f_;
- return e;
+ if (!is_active_)
+ f = block_force_;
+ return ideal_ + f / hooke_ ;
}
+/****************************************************************/
-bool
-Spring_description::sane_b () const
+
+/*
+
+ 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_wrapper::solve (Column_x_positions *positions, bool ragged)
{
- return (hooke_f_ > 0) && ! isinf (ideal_f_) && !isnan (ideal_f_);
+ if (ragged)
+ spacer_->my_solve_natural_len ();
+ else
+ spacer_->my_solve_linelen ();
+
+ positions->force_ = spacer_->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 (spacer_->indent_);
+ for (int i = 0; i < spacer_->springs_.size (); i++)
+ {
+ Real l = spacer_->springs_[i].length ((ragged) ? 0.0 : spacer_->force_);
+ positions->config_.push (positions->config_.top () + l);
+ /*
+ we have l>= 0 here, up to rounding errors
+ */
+ }
+
+ /*
+ 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)
+ {
+ positions->satisfies_constraints_ =
+ positions->config_.top () < spacer_->line_len_ ;
+ }
+ else
+ positions->satisfies_constraints_ = spacer_->is_active ();
+
+ positions->cols_ = spaced_cols_;
+ positions->loose_cols_ = loose_cols_;
+
+ /*
+ 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_property ( "penalty");
+ if (scm_is_number (p))
+ {
+ if (scm_to_double (p) < -9999)
+ break_satisfy = break_satisfy && (i == 0 || i == sz -1);
+ if (scm_to_double (p) > 9999)
+ break_satisfy = break_satisfy && !(i == 0 || i == sz -1);
+ }
+
+ }
+
+ positions->satisfies_constraints_ =
+ positions->satisfies_constraints_ && break_satisfy;
}
+void
+Simple_spacer::add_spring (Real ideal, Real hooke)
+{
+ Spring_description desc;
+
+ desc.ideal_ = ideal;
+ desc.hooke_ = hooke;
+ if (!desc.is_sane ())
+ {
+ programming_error ("Insane spring found. Setting to unit spring.");
-Real
-Simple_spacer::energy_f () const
+ desc.hooke_ = 1.0;
+ desc.ideal_ = 1.0;
+ }
+
+ if (isinf (hooke))
+ {
+ desc.is_active_ = false;
+ }
+ else
+ {
+ /*
+ desc.is_active_ ?
+ */
+ desc.block_force_ = - desc.hooke_ * desc.ideal_; // block at distance 0
+
+ active_count_ ++;
+ }
+ springs_.push (desc);
+}
+
+static int
+compare_paper_column_rank (Grob *const &a,
+ Grob *const &b)
{
- Real e =0.;
+ return Paper_column::get_rank (a) - Paper_column::get_rank (b);
+}
+
+void
+Simple_spacer_wrapper::add_columns (Link_array<Grob> const &icols)
+{
+ Link_array<Grob> cols (icols);
+
+ for (int i = cols.size (); i--;)
+ if (scm_is_pair (cols[i]->get_property ("between-cols")))
+ {
+ loose_cols_.push (cols[i]);
+ cols.del (i);
+ }
+
+ spaced_cols_ = cols;
+ for (int i = 0; i < cols.size () - 1; i++)
+ {
+ Spring_smob *spring = 0;
+
+ for (SCM s = cols[i]->get_property ("ideal-distances");
+ !spring && scm_is_pair (s);
+ s = scm_cdr (s))
+ {
+ Spring_smob *sp = unsmob_spring (scm_car (s));
+
+
+ if (sp->other_ == cols[i+1])
+ spring = sp;
+ }
- for (int i=0; i <springs_.size (); i++)
+ if (!spring)
+ programming_error (_f ("No spring between column %d and next one",
+ Paper_column::get_rank (cols[i])
+ ));
+
+ Real ideal = (spring) ? spring->distance_ : spacer_->default_space_;
+ Real hooke = (spring) ? spring->strength_ : 1.0;
+
+ spacer_->add_spring (ideal, hooke);
+ }
+
+ for (int i = 0; i < cols.size () - 1; i++)
{
- e += springs_[i].energy_f (force_f_);
+ for (SCM s = Spaceable_grob::get_minimum_distances (cols[i]);
+ scm_is_pair (s); s = scm_cdr (s))
+ {
+ Grob * other = unsmob_grob (scm_caar (s));
+ int oi = binsearch_links (cols, other, &compare_paper_column_rank);
+ if (oi >= 0)
+ {
+ spacer_->add_rod (i, oi, scm_to_double (scm_cdar (s)));
+ }
+ }
+
+ if (i
+ && !to_boolean (cols[i]->get_property ("allow-outside-line")))
+ {
+ Interval e = cols[i]->extent (cols[i], X_AXIS);
+ if (!e.is_empty())
+ {
+ spacer_->add_rod (i, cols.size()-1, e[RIGHT]);
+ spacer_->add_rod (0, i, e[LEFT]);
+ }
+ }
}
+}
+
+Simple_spacer_wrapper::Simple_spacer_wrapper ()
+{
+ spacer_ = new Simple_spacer ();
+}
- if (force_f_ < 0)
- e *= compression_energy_factor_f_;
+Simple_spacer_wrapper::~Simple_spacer_wrapper ()
+{
+ delete spacer_;
+}
- return e;
+
+Simple_spacer_wrapper::Simple_spacer_wrapper (Simple_spacer_wrapper const&)
+{
}
projects / lilypond.git / blobdiff