-/*
+/*
simple-spacer.cc -- implement Simple_spacer
-
+
source file of the GNU LilyPond music typesetter
-
- (c) 1999--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+
+ (c) 1999--2006 Han-Wen Nienhuys <hanwen@xs4all.nl>
TODO:
- add support for different stretch/shrink constants?
-
*/
-#include <stdio.h>
-#include <math.h>
-#include <libc-extension.hh> // isinf
-#include "simple-spacer.hh"
+#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 "spaceable-grob.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:
+ A simple spacing constraint solver. The approach:
- Stretch the line uniformly until none of the constraints (rods)
- block. It then is very wide.
+ Stretch the line uniformly until none of the constraints (rods)
+ block. It then is very wide.
- Compress until the next constraint blocks,
+ 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.
+ 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
+ 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
+ c4 c4 c4 c4
+ veryveryverylongsyllable2 veryveryverylongsyllable2
+ " "4 veryveryverylongsyllable2 syllable4
- can be further compressed to
+ can be further compressed to
- c4 c4 c4 c4
- veryveryverylongsyllable2 veryveryverylongsyllable2
- " "4 veryveryverylongsyllable2 syllable4
+ c4 c4 c4 c4
+ veryveryverylongsyllable2 veryveryverylongsyllable2
+ " "4 veryveryverylongsyllable2 syllable4
- Perhaps this is not a bad thing, because the 1st looks better anyway. */
+ 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.
- */
- compression_penalty_b_ = false;
- active_count_ = 0;
- force_ = 0.;
- indent_ =0.0;
- default_space_ = 20 PT;
+ 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 c = range_stiffness (l, r);
+ Real d = range_ideal_len (l, r);
+ Real block_stretch = dist - d;
+ return c * block_stretch;
}
void
{
if (isinf (dist) || isnan (dist))
{
- programming_error ("Weird minimum distance. Ignoring");
+ programming_error ("ignoring weird minimum distance");
return;
}
- Real c = range_stiffness (l,r);
- if (isinf (c))
+ Real block_force = rod_force (l, r, dist);
+
+ if (isinf (block_force))
{
- /*
- 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;
+ Real spring_dist = range_ideal_len (l, r);
+ if (spring_dist < dist)
+ for (int i = l; i < r; i++)
+ springs_[i].ideal_ *= dist / spring_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_ ;
+ force_ = max (force_, block_force);
+ for (int i = l; i < r; i++)
+ springs_[i].block_force_ = max (block_force, springs_[i].block_force_);
}
Real
-Simple_spacer::range_ideal_len (int l, int r) const
+Simple_spacer::range_ideal_len (int l, int r) const
{
- Real d =0.;
- for (int i=l; i < r; i++)
+ 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_;
- }
+ Real den = 0.0;
+ for (int i = l; i < r; i++)
+ den += springs_[i].inverse_hooke_;
return 1 / den;
}
Real
-Simple_spacer::is_activelocking_force () const
+Simple_spacer::configuration_length (Real force) const
{
- 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 l = 0.;
+ for (vsize i = 0; i < springs_.size (); i++)
+ l += springs_[i].length (force);
-Real
-Simple_spacer::active_springs_stiffness () const
-{
- return range_stiffness (0, springs_.size ());
+ return l;
}
void
-Simple_spacer::set_active_states ()
+Simple_spacer::solve (Real line_len, bool ragged)
{
- /* 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 conf = configuration_length (force_);
-Real
-Simple_spacer::configuration_length () const
-{
- Real l =0.;
- for (int i=0; i < springs_.size (); i++)
- l += springs_[i].length (force_);
+ ragged_ = ragged;
+ line_len_ = line_len;
+ if (conf < line_len_)
+ force_ = expand_line ();
+ else if (conf > line_len_)
+ force_ = compress_line ();
- return l;
+ if (ragged && force_ < 0)
+ fits_ = false;
}
-bool
-Simple_spacer::is_active () const
+Real
+Simple_spacer::expand_line ()
{
- return active_count_;
+ 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_hooke_;
+
+ assert (cur_len <= line_len_);
+ return (line_len_ - cur_len) / inv_hooke + force_;
}
-void
-Simple_spacer::my_solve_linelen ()
+Real
+Simple_spacer::compress_line ()
{
- while (is_active ())
- {
- force_ = is_activelocking_force ();
- Real conf = configuration_length ();
+ double inv_hooke = 0;
+ double cur_len = configuration_length (force_);
+ double cur_force = force_;
- if (conf < line_len_)
- {
- force_ += (line_len_ - conf) * active_springs_stiffness ();
- break;
- }
- else
- set_active_states ();
- }
-}
+ fits_ = true;
+ for (vsize i=0; i < springs_.size (); i++)
+ inv_hooke += springs_[i].inverse_hooke_;
+ assert (line_len_ <= cur_len);
-void
-Simple_spacer::my_solve_natural_len ()
-{
- while (is_active ())
+ vector<Spring_description> sorted_springs = springs_;
+ sort (sorted_springs.begin (), sorted_springs.end (), greater<Spring_description> ());
+ for (vsize i = 0; i < sorted_springs.size (); i++)
{
- force_ = is_activelocking_force () >? 0.0;
+ Spring_description sp = sorted_springs[i];
- if (force_ < 1e-8) // ugh.,
+ assert (sp.block_force_ <= cur_force);
+ if (isinf (sp.block_force_))
break;
+
+ double block_dist = (cur_force - sp.block_force_) * inv_hooke;
+ if (cur_len - block_dist < line_len_)
+ {
+ cur_force += (line_len_ - cur_len) / inv_hooke;
+ cur_len = line_len_;
+
+ /*
+ Paranoia check.
+ */
+ assert (fabs (configuration_length (cur_force) - cur_len) < 1e-6);
+ return cur_force;
+ }
- set_active_states ();
+ cur_len -= block_dist;
+ inv_hooke -= sp.inverse_hooke_;
+ cur_force = sp.block_force_;
}
+
+ fits_ = false;
+ return cur_force;
}
void
-Simple_spacer::add_columns (Link_array<Grob> const &icols)
+Simple_spacer::add_spring (Real ideal, Real inverse_hooke)
{
- Link_array<Grob> cols (icols);
-
- for (int i = cols.size (); i--;)
- if (ly_c_pair_p (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_description description;
+
+ description.ideal_ = ideal;
+ description.inverse_hooke_ = inverse_hooke;
+ if (!description.is_sane ())
{
- Spring_smob *spring = 0;
+ programming_error ("insane spring found, setting to unit");
- for (SCM s = cols[i]->get_property ("ideal-distances");
- !spring && ly_c_pair_p (s);
- s = ly_cdr (s))
- {
- Spring_smob *sp = unsmob_spring (ly_car (s));
-
-
- if (sp->other_ == cols[i+1])
- spring = sp;
- }
+ description.inverse_hooke_ = 1.0;
+ description.ideal_ = 1.0;
+ }
- Spring_description desc;
- if (spring)
- {
- desc.ideal_ = spring->distance_;
- desc.hooke_ = spring->strength_;
- }
- else
- {
- 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_;
+ description.block_force_ = -description.ideal_ / description.inverse_hooke_;
+ // block at distance 0
- continue;
- }
+ springs_.push_back (description);
+}
- if (!desc.is_sane ())
- {
- programming_error ("Insane spring found. Setting to unit spring.");
+vector<Real>
+Simple_spacer::spring_positions () const
+{
+ vector<Real> ret;
+ ret.push_back (0.);
- desc.hooke_ = 1.0;
- desc.ideal_ = 1.0;
- }
+ for (vsize i = 0; i < springs_.size (); i++)
+ ret.push_back (ret.back () + springs_[i].length (ragged_ && force_ > 0 ? 0.0 : force_));
+ return ret;
+}
- if (isinf (desc.hooke_))
- {
- desc.is_active_ = 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++)
- {
- for (SCM s = Spaceable_grob::get_minimum_distances (cols[i]);
- ly_c_pair_p (s); s = ly_cdr (s))
- {
- Grob * other = unsmob_grob (ly_caar (s));
- int oi = cols.find_index (other);
- if (oi >= 0)
- {
- add_rod (i, oi, ly_scm2double (ly_cdar (s)));
- }
- }
- }
+Spring_description::Spring_description ()
+{
+ ideal_ = 0.0;
+ inverse_hooke_ = 0.0;
+ block_force_ = 0.0;
}
+bool
+Spring_description::is_sane () const
+{
+ return (inverse_hooke_ >= 0)
+ && ideal_ > 0
+ && !isinf (ideal_) && !isnan (ideal_)
+ && (inverse_hooke_ == 0.0 || fabs (inverse_hooke_) > 1e-8)
+ ;
+}
+
+Real
+Spring_description::length (Real f) const
+{
+ return ideal_ + max (f, block_force_) * inverse_hooke_;
+}
+
+/****************************************************************/
+
/*
-
TODO: should a add penalty for widely varying spring forces (caused
by constraints, eg.
- =====
- | |
- o|o| x ##x
-
+ . =====
+ . | |
+ .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, bool ragged)
+*/
+
+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 */
+ Real ideal_;
+ Real inverse_hooke_;
+ Real end_ideal_;
+ Real end_inverse_hooke_;
+ SCM break_permission_;
+ Interval keep_inside_line_;
+
+ Column_description ()
+ {
+ ideal_ = 0;
+ inverse_hooke_ = 0;
+ end_ideal_ = 0;
+ end_inverse_hooke_ = 0;
+ 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)
{
- if (ragged)
- my_solve_natural_len ();
- else
- my_solve_linelen ();
+ Grob *ret = dynamic_cast<Item*> (g)->find_prebroken_piece (d);
+ if (ret)
+ return ret;
+ return g;
+}
+
+static Grob*
+next_spaceable_column (vector<Grob*> const &list, vsize starting)
+{
+ for (vsize i = starting+1; i < list.size (); i++)
+ if (!is_loose (list[i]))
+ return list[i];
+ return 0;
+}
+
+static void
+get_column_spring (Grob *this_col, Grob *next_col, Real *ideal, Real *inv_hooke)
+{
+ Spring_smob *spring = 0;
+
+ for (SCM s = this_col->get_object ("ideal-distances");
+ !spring && scm_is_pair (s);
+ s = scm_cdr (s))
+ {
+ Spring_smob *sp = unsmob_spring (scm_car (s));
+
+ if (sp->other_ == next_col)
+ spring = sp;
+ }
+
+ if (!spring)
+ programming_error (_f ("No spring between column %d and next one",
+ Paper_column::get_rank (this_col)));
- positions->force_ = force_;
+ *ideal = (spring) ? spring->distance_ : 5.0;
+ *inv_hooke = (spring) ? spring->inverse_strength_ : 1.0;
+}
+
+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)
+ get_column_spring (col, next_col, &description.ideal_, &description.inverse_hooke_);
+ Grob *end_col = dynamic_cast<Item*> (cols[col_index+1])->find_prebroken_piece (LEFT);
+ if (end_col)
+ get_column_spring (col, end_col, &description.end_ideal_, &description.end_inverse_hooke_);
+
+ for (SCM s = Spaceable_grob::get_minimum_distances (col);
+ scm_is_pair (s); s = scm_cdr (s))
+ {
+ 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))));
+ }
+ }
- /*
- 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++)
+ 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;
+}
+
+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 < non_loose.size () - 1; i++)
{
- 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
- */
+ 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);
- /*
- 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)
+ for (vsize b = 0; b < breaks.size () - 1; b++)
{
- Real len = positions->config_.top ();
- if (line_len_ - len >= 0)
- positions->force_ = ((line_len_ - len) * active_springs_stiffness ());
- else
+ cols[breaks[b]] = get_column_description (non_loose, breaks[b], true);
+ vsize st = breaks[b];
+
+ for (vsize c = b+1; c < breaks.size (); c++)
{
- positions->force_ = 0.0;
- /*
- Don't go past end-of-line in ragged right.
- */
- positions->satisfies_constraints_ = false;
+ vsize end = breaks[c];
+ Simple_spacer spacer;
+
+ for (vsize i = breaks[b]; i < end - 1; i++)
+ spacer.add_spring (cols[i].ideal_, cols[i].inverse_hooke_);
+ spacer.add_spring (cols[end-1].end_ideal_, cols[end-1].end_inverse_hooke_);
+
+
+ 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 ())
+ {
+ 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]);
+ }
+ }
+ spacer.solve ((b == 0) ? line_len - indent : line_len, ragged);
+
+ /* add a (convex) penalty for compression. We do this _only_ in get_line_forces,
+ not get_line_configuration. This is temporary, for backwards compatibility;
+ the old line/page-breaking stuff ignores page breaks when it calculates line
+ breaks, so compression penalties can result in scores (eg. wtk-fugue) blowing
+ up to too many pages. */
+ Real f = spacer.force ();
+ force[b * breaks.size () + c] = f - (f < 0 ? f*f*f*f*4 : 0);
+
+ if (!spacer.fits ())
+ {
+ if (c == b + 1)
+ force[b * breaks.size () + c] = -200000;
+ else
+ force[b * breaks.size () + c] = infinity_f;
+ break;
+ }
+ 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;
- positions->cols_ = spaced_cols_;
- positions->loose_cols_ = loose_cols_;
- positions->satisfies_constraints_ =
- positions->satisfies_constraints_ && is_active ();
+ ret.cols_.push_back (dynamic_cast<Item*> (columns[0])->find_prebroken_piece (RIGHT));
+ for (vsize i = 1; i < columns.size () - 1; 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));
- /*
- Check if breaking constraints are met.
- */
- bool break_satisfy = true;
- int sz = positions->cols_.size ();
- for (int i = sz; i--; )
+ /* 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 < ret.cols_.size () - 1; i++)
+ {
+ cols.push_back (get_column_description (ret.cols_, i, i == 0));
+ spacer.add_spring (cols[i].ideal_, cols[i].inverse_hooke_);
+ }
+ for (vsize i = 0; i < cols.size (); i++)
{
- SCM p = positions->cols_[i]->get_property ( "penalty");
- if (ly_c_number_p (p))
+ for (vsize r = 0; r < cols[i].rods_.size (); r++)
+ spacer.add_rod (i, cols[i].rods_[r].r_, cols[i].rods_[r].dist_);
+
+ if (!cols[i].keep_inside_line_.is_empty ())
{
- if (ly_scm2double (p) < -9999)
- break_satisfy = break_satisfy && (i == 0 || i == sz -1);
- if (ly_scm2double (p) > 9999)
- break_satisfy = break_satisfy && !(i == 0 || i == sz -1);
+ spacer.add_rod (i, cols.size (), cols[i].keep_inside_line_[RIGHT]);
+ spacer.add_rod (0, i, -cols[i].keep_inside_line_[LEFT]);
}
-
}
- positions->satisfies_constraints_ =
- positions->satisfies_constraints_ && break_satisfy;
-}
+ spacer.solve (line_len, ragged);
+ ret.force_ = spacer.force ();
-/****************************************************************/
+ /*
+ We used to have a penalty for compression, no matter what, but that
+ fucked up wtk1-fugue2 (taking 3 full pages.)
+ */
+ ret.config_ = spacer.spring_positions ();
+ for (vsize i = 0; i < ret.config_.size (); i++)
+ ret.config_[i] += indent;
-Spring_description::Spring_description ()
-{
- ideal_ =0.0;
- hooke_ =0.0;
- is_active_ = true;
- block_force_ = 0.0;
-}
+ ret.satisfies_constraints_ = spacer.fits ();
+ /*
+ Check if breaking constraints are met.
+ */
+ for (vsize i = 1; i < ret.cols_.size () - 1; i++)
+ {
+ SCM p = ret.cols_[i]->get_property ("line-break-permission");
+ if (p == ly_symbol2scm ("force"))
+ ret.satisfies_constraints_ = false;
+ }
-bool
-Spring_description::is_sane () const
-{
- return (hooke_ > 0) && !isinf (ideal_) && !isnan (ideal_);
+ return ret;
}
-Real
-Spring_description::length (Real f) const
-{
- if (!is_active_)
- f = block_force_;
- return ideal_ + f / hooke_ ;
-}