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;
}
Real
-Simple_spacer::is_activelocking_force () const
+Simple_spacer::active_blocking_force () const
{
Real bf = - infinity_f;
for (int i=0; i < springs_.size (); i++)
Real
Simple_spacer::active_springs_stiffness () const
{
- return range_stiffness (0, springs_.size ());
+ 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
{
while (is_active ())
{
- force_ = is_activelocking_force ();
+ force_ = active_blocking_force ();
Real conf = configuration_length ();
if (conf < line_len_)
{
- force_ += (line_len_ - conf) * active_springs_stiffness ();
+ force_ += (line_len_ - conf) * active_springs_stiffness ();
break;
}
else
void
Simple_spacer::my_solve_natural_len ()
{
+ Real line_len_force = 0.0;
+
while (is_active ())
{
- force_ = is_activelocking_force () >? 0.0;
+ 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;
}
-void
-Simple_spacer::add_columns (Link_array<Grob> const &icols)
+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 (#f for non-satisfied constraints) "
+ "followed by the @var{spring-count}+1 positions of the objects. "
+ )
{
- Link_array<Grob> cols(icols);
+ int len = scm_ilength (springs);
+ if (len == 0)
+ return scm_list_2 (scm_from_double (0.0), scm_from_double (0.0));
- 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++)
+ 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))
{
- Spring_smob *spring = 0;
+ Real ideal = scm_to_double (scm_caar (s));
+ Real hooke = scm_to_double (scm_cadar (s));
- 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;
- }
+ spacer.add_spring (ideal, hooke);
+ }
- 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_;
+ 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);
+ }
- continue;
- }
+ spacer.line_len_ = scm_to_double (length);
+
+ if (is_ragged)
+ spacer.my_solve_natural_len ();
+ else
+ spacer.my_solve_linelen ();
- if (!desc.sane_b ())
- {
- programming_error ("Insane spring found. Setting to unit spring.");
+ 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);
+ }
- desc.hooke_ = 1.0;
- desc.ideal_ = 1.0;
- }
- 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_ ++;
- }
+
+ SCM force_return = SCM_BOOL_F;
+ if (!isinf (spacer.force_)
+ && spacer.is_active ())
+ {
+ force_return = scm_from_double (spacer.force_);
+ }
- if (spring->expand_only_b_)
- {
- compression_penalty_b_ = true;
- }
-
+ if (is_ragged
+ && posns.top () > spacer.line_len_)
+ {
+ force_return = SCM_BOOL_F;
}
-
- for (int i=0; i < cols.size () - 1; i++)
+
+ SCM retval= SCM_EOL;
+ for (int i = posns.size(); i--;)
{
- for (SCM s = Spaceable_grob::get_minimum_distances (cols[i]);
- gh_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, gh_scm2double (ly_cdar (s)));
- }
- }
+ retval = scm_cons (scm_from_double (posns[i]), retval);
}
+
+ 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;
+}
+
+
+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_ ;
+}
+/****************************************************************/
+
/*
*/
void
-Simple_spacer::solve (Column_x_positions *positions, bool ragged)
+Simple_spacer_wrapper::solve (Column_x_positions *positions, bool ragged)
{
if (ragged)
- my_solve_natural_len ();
+ spacer_->my_solve_natural_len ();
else
- my_solve_linelen ();
+ spacer_->my_solve_linelen ();
- positions->force_ = force_;
+ 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 (indent_);
- for (int i=0; i <springs_.size (); i++)
+ positions->config_.push (spacer_->indent_);
+ for (int i=0; i < spacer_->springs_.size (); i++)
{
- Real l = springs_[i].length ((ragged) ? 0.0 : force_);
+ 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
*/
if (ragged)
{
- Real len = positions->config_.top ();
- if (line_len_ - len >= 0)
- positions->force_ = ((line_len_ - len) * active_springs_stiffness ());
- else
- {
- positions->force_ = 0.0;
- /*
- Don't go past end-of-line in ragged right.
- */
- positions->satisfies_constraints_ = false;
- }
+ positions->satisfies_constraints_ =
+ positions->config_.top () < spacer_->line_len_ ;
}
positions->cols_ = spaced_cols_;
positions->loose_cols_ = loose_cols_;
positions->satisfies_constraints_ =
- positions->satisfies_constraints_ && is_active ();
+ positions->satisfies_constraints_ && spacer_->is_active ();
/*
Check if breaking constraints are met.
int sz = positions->cols_.size ();
for (int i = sz; i--; )
{
- SCM p = positions->cols_[i]->get_grob_property( "penalty");
- if (gh_number_p (p))
+ SCM p = positions->cols_[i]->get_property ( "penalty");
+ if (scm_is_number (p))
{
- if (gh_scm2double (p) < -9999)
+ if (scm_to_double (p) < -9999)
break_satisfy = break_satisfy && (i == 0 || i == sz -1);
- if (gh_scm2double (p) > 9999)
+ if (scm_to_double (p) > 9999)
break_satisfy = break_satisfy && !(i == 0 || i == sz -1);
}
positions->satisfies_constraints_ && break_satisfy;
}
-/****************************************************************/
+void
+Simple_spacer::add_spring (Real ideal, Real hooke)
+{
+ Spring_description desc;
-Spring_description::Spring_description ()
+ 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);
+}
+
+void
+Simple_spacer_wrapper::add_columns (Link_array<Grob> const &icols)
{
- ideal_ =0.0;
- hooke_ =0.0;
- is_active_ = true;
- block_force_ = 0.0;
+ 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;
+ }
+
+ 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))
+ {
+ Grob * other = unsmob_grob (scm_caar (s));
+ int oi = cols.find_index (other);
+ if (oi >= 0)
+ {
+ spacer_->add_rod (i, oi, scm_to_double (scm_cdar (s)));
+ }
+ }
+ }
}
+Simple_spacer_wrapper::Simple_spacer_wrapper ()
+{
+ spacer_ = new Simple_spacer ();
+}
-bool
-Spring_description::sane_b () const
+Simple_spacer_wrapper::~Simple_spacer_wrapper ()
{
- return (hooke_ > 0) && !isinf (ideal_) && !isnan (ideal_);
+ delete spacer_;
}
-Real
-Spring_description::length (Real f) const
+
+Simple_spacer_wrapper::Simple_spacer_wrapper (Simple_spacer_wrapper const&)
{
- if (!is_active_)
- f = block_force_;
- return ideal_ + f / hooke_ ;
}