+/*
+ simple-spacer.cc -- implement Simple_spacer
+
+ source file of the GNU LilyPond music typesetter
+
+ (c) 1999--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+
+ TODO:
+ - add support for different stretch/shrink constants?
+
+*/
+
#include "simple-spacer.hh"
-#include "idealspacing.hh"
-// #include ""
+#include <cstdio>
+#include <math.h>
+
+#include <libc-extension.hh> // isinf
+
+#include "paper-column.hh"
+#include "spring.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 ()
+{
+ /*
+ 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
-Spring_info::set(Idealspacing *i)
+Simple_spacer::add_rod (int l, int r, Real dist)
{
- space_f_ = i->space_f_;
- hooke_f_ = i->hooke_f_;
+ 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_ = force_ >? block_force;
+
+ for (int i = l; i < r; i++)
+ springs_[i].block_force_ = block_force >?
+ springs_[i].block_force_ ;
}
-Spring_info::Spring_info()
+Real
+Simple_spacer::range_ideal_len (int l, int r) const
{
- space_f_ = 0.0;
- hooke_f_ = 1.0;
- blocking_stretch_f_ = infinity_f;
- blocking_rod_l_ = 0;
+ 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++)
+ {
+ if (springs_[i].is_active_)
+ den += 1 / springs_[i].hooke_;
+ }
-void
-Simple_spring_spacer::init ()
+ return 1 / den;
+}
+
+Real
+Simple_spacer::active_blocking_force () const
{
- for (PCursor<Rod_info*> i(rods_.top()); i.ok (); i++)
+ Real bf = - infinity_f;
+ for (int i = 0; i < springs_.size (); i++)
+ if (springs_[i].is_active_)
+ {
+ bf = bf >? springs_[i].block_force_;
+ }
+ return bf;
+}
+
+Real
+Simple_spacer::active_springs_stiffness () const
+{
+ Real stiff = range_stiffness (0, springs_.size ());
+ if (isinf (stiff))
{
- Real hooke=0.0;
- Real dist= i->distance_f_;
+ /*
+ all springs are inactive. Take the stiffness of the
+ latest spring to block.
+ */
- hooke =0.0;
-
- for (int j = i->cols_[LEFT]; j < i->cols_[RIGHT]; j++)
+ Real max_block_force = -infinity_f;
+ int max_i = -1;
+ for (int i = 0; i < springs_.size (); i++)
{
- hooke += 1/springs_[j].hooke_f_;
- dist -= springs_[j].space_f_;
+ if (springs_[i].block_force_ > max_block_force)
+ {
+ max_i = i;
+ max_block_force = springs_[i].block_force_;
+ }
}
-
- hooke = 1/hooke;
- for (int j = i->cols_[LEFT]; j < i->cols_[RIGHT]; j++)
+ stiff = springs_[max_i].hooke_;
+ }
+ return stiff;
+}
+
+void
+Simple_spacer::set_active_states ()
+{
+ /* 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_);
+
+ return l;
+}
+
+bool
+Simple_spacer::is_active () const
+{
+ return active_count_;
+}
+
+void
+Simple_spacer::my_solve_linelen ()
+{
+ while (is_active ())
+ {
+ force_ = active_blocking_force ();
+ Real conf = configuration_length ();
+
+ if (conf < line_len_)
{
- Real block_stretch = hooke * dist / (springs_[j].space_f_ *
- springs_[j].hooke_f_ );
+ force_ += (line_len_ - conf) * active_springs_stiffness ();
+ break;
+ }
+ else
+ set_active_states ();
+ }
+}
- if (block_stretch < springs_[j].blocking_stretch_f_)
- {
- springs_[j].blocking_stretch_f_ = block_stretch;
- springs_[j].blocking_rod_l_ = i.ptr ();
- }
+
+void
+Simple_spacer::my_solve_natural_len ()
+{
+ Real line_len_force = 0.0;
+
+ while (is_active ())
+ {
+ force_ = active_blocking_force () >? 0.0;
+ Real conf = configuration_length ();
+
+ 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;
+}
+
+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. "
+ )
+{
+ 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))
+ {
+ Real ideal = scm_to_double (scm_caar (s));
+ Real hooke = scm_to_double (scm_cadar (s));
+
+ spacer.add_spring (ideal, hooke);
+ }
+
+ 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);
+ }
+
+ spacer.line_len_ = scm_to_double (length);
+
+ 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);
}
+
+
+
+ SCM force_return = SCM_BOOL_F;
+ if (!isinf (spacer.force_)
+ && (spacer.is_active () || is_ragged))
+ {
+ force_return = scm_from_double (spacer.force_);
+ }
+
+ if (is_ragged
+ && posns.top () > spacer.line_len_)
+ {
+ force_return = SCM_BOOL_F;
+ }
+
+ SCM retval = SCM_EOL;
+ for (int i = posns.size(); i--;)
+ {
+ retval = scm_cons (scm_from_double (posns[i]), retval);
+ }
+
+ retval = scm_cons (force_return, retval);
+ return retval;
}
+
+
+/****************************************************************/
-Array<Real>
-Simple_spring_spacer::solve ()
+Spring_description::Spring_description ()
{
- Real start_force = 0.0;
+ ideal_ = 0.0;
+ hooke_ = 0.0;
+ is_active_ = true;
+ block_force_ = 0.0;
+}
+
+
+bool
+Spring_description::is_sane () const
+{
+ return (hooke_ > 0)
+ && ideal_ > 0
+ && !isinf (ideal_) && !isnan (ideal_);
+}
+
+Real
+Spring_description::length (Real f) const
+{
+ if (!is_active_)
+ f = block_force_;
+ return ideal_ + f / hooke_ ;
+}
+/****************************************************************/
+
+
+/*
+
+ TODO: should a add penalty for widely varying spring forces (caused
+ by constraints, eg.
- for (int i=0; i< springs_.size (); i++)
+
+ =====
+ | |
+ 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)
+{
+ 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++)
{
- start_force = start_force >?
- springs_[i].blocking_stretch_f_ * springs_[i].hooke_f_;
+ 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
+ */
}
- Array<Real> stretch_factors;
- Array<bool> blocked;
- int blocked_count=0;
- Real current_len =0.0;
- for (int i=0; i < springs_.size (); i++)
+ /*
+ 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)
{
- 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);
+ 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_;
-
- while (blocked_count < blocked.size ())
+ /*
+ Check if breaking constraints are met.
+ */
+ bool break_satisfy = true;
+ int sz = positions->cols_.size ();
+ for (int i = sz; i--; )
{
- Real next_stretch = -1.0;
- int block_index;
- for (int i=0; i< stretch_factors.size (); i++)
+ SCM p = positions->cols_[i]->get_property ( "penalty");
+ if (scm_is_number (p))
{
- if (!blocked[i])
- {
- next_stretch = next_stretch >? springs_[i].blocking_stretch_f_;
+ 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);
+ }
+
+ }
- if (next_stretch < springs_[i].blocking_stretch_f_)
- {
- next_stretch = springs_[i].blocking_stretch_f_;
- block_index = i;
- }
- }
+ 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.");
+
+ 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)
+{
+ 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;
}
- current_len = 0.0;
- Real force = next_stretch * (springs_[block_index].space_f_* springs_[block_index].hooke_f_);
- for (int i=0; i< stretch_factors.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++)
+ {
+ for (SCM s = Spaceable_grob::get_minimum_distances (cols[i]);
+ scm_is_pair (s); s = scm_cdr (s))
{
- if (!blocked[i])
+ Grob * other = unsmob_grob (scm_caar (s));
+ int oi = binsearch_links (cols, other, &compare_paper_column_rank);
+ if (oi >= 0)
{
- stretch_factors[i] = force / (springs_[i].space_f_ * springs_[i].hooke_f_);
+ spacer_->add_rod (i, oi, scm_to_double (scm_cdar (s)));
}
- current_len += (1.0 + stretch_factors[i]) * springs_[i].space_f_;
}
- Rod_info *blockrod = springs_[block_index].blocking_rod_l_;
- for (int j = blockrod->cols_ [LEFT]; j < blockrod->cols_ [RIGHT]; j++)
+ if (i
+ && !to_boolean (cols[i]->get_property ("allow-outside-line")))
{
- blocked[j] = true;
- blocked_count ++;
+ 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 ();
+}
- Array<Real> distances;
- for (int i=0; i < stretch_factors.size (); i++)
- {
- distances.push (stretch_factors[i] * springs_[i].space_f_);
- }
- return distances;
+Simple_spacer_wrapper::~Simple_spacer_wrapper ()
+{
+ delete spacer_;
}
+
+Simple_spacer_wrapper::Simple_spacer_wrapper (Simple_spacer_wrapper const&)
+{
+}
projects / lilypond.git / blobdiff