source file of the GNU LilyPond music typesetter
- (c) 1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+ (c) 1999--2000 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 <math.h>
+#include <libc-extension.hh>
#include "simple-spacer.hh"
#include "paper-column.hh"
#include "rod.hh"
#include "warn.hh"
#include "column-x-positions.hh"
+#include "spaceable-element.hh"
+#include "dimensions.hh"
Simple_spacer::Simple_spacer ()
{
force_f_ = 0.;
+ indent_f_ =0.0;
+ default_space_f_ = 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);
Real d = range_ideal_len (l,r);
Real block_stretch = dist - d;
Real block_force = c * block_stretch;
force_f_ = force_f_ >? block_force;
-
+
for (int i=l; i < r; i++)
springs_[i].block_force_f_ = block_force >?
springs_[i].block_force_f_ ;
}
void
-Simple_spacer::add_columns (Link_array<Paper_column> cols)
+Simple_spacer::add_columns (Link_array<Score_element> 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++)
+ SCM spring_params = SCM_UNDEFINED;
+ for (SCM s = Spaceable_element::get_ideal_distances (cols[i]);
+ spring_params == SCM_UNDEFINED && gh_pair_p (s);
+ s = gh_cdr (s))
{
- Column_spring &sp = c->spring_arr_drul_[RIGHT] [j];
- if (sp.other_l_ != cols[i+1])
+ Score_element *other = unsmob_element (gh_caar (s));
+ if (other != cols[i+1])
continue;
- to_next = &sp;
+ spring_params = gh_cdar (s);
}
Spring_description desc;
- if (to_next)
+ if (spring_params != SCM_UNDEFINED)
{
- desc.hooke_f_ = to_next->strength_f_;
- desc.ideal_f_ = to_next->distance_f_;
+ desc.ideal_f_ = gh_scm2double (gh_car (spring_params));
+ desc.hooke_f_ = gh_scm2double (gh_cdr (spring_params));
}
else
{
+ programming_error ("No spring between adjacent columns");
desc.hooke_f_ = 1.0;
desc.ideal_f_ = default_space_f_;
}
+
+ if (!desc.sane_b ())
+ {
+ programming_error ("Insane spring found. Setting to unit spring.");
+ desc.hooke_f_ = 1.0;
+ desc.ideal_f_ = 1.0;
+ }
+
desc.block_force_f_ = - desc.hooke_f_ * desc.ideal_f_; // block at distance 0
springs_.push (desc);
}
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_element::get_minimum_distances (cols[i]);
+ gh_pair_p (s); s = gh_cdr (s))
{
- int oi = cols.find_i (rods->elem (j).other_l_ );
+ Score_element * other = unsmob_element (gh_caar (s));
+ int oi = cols.find_i (other);
if (oi >= 0)
{
- add_rod (i, oi, rods->elem (j).distance_f_);
+ add_rod (i, oi, gh_scm2double (gh_cdar (s)));
}
}
}
+ /*
+ TODO: should support natural length on only the last line.
+ */
if (line_len_f_ < 0)
my_solve_natural_len ();
else
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++)
{
positions->config_.push (positions->config_.top () + springs_[i].length (force_f_));
}
- positions->satisfies_constraints_b_ = active_b ();
+ positions->satisfies_constraints_b_ = (line_len_f_ < 0) || active_b ();
}
-void
-Simple_spacer::lower_bound_solution (Column_x_positions * posns) const
-{
- solve (posns);
-}
Spring_description::Spring_description( )
block_force_f_ = 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_f_ > 0) && ! isinf (ideal_f_) && !isnan (ideal_f_);
}
-Real
-Simple_spacer::energy_f () const
-{
- Real e =0.;
- for (int i=0; i <springs_.size (); i++)
- e += springs_[i].energy_f (force_f_);
-
- return e;
-}