/*
- simple-spacer.hh -- declare
+ simple-spacer.hh -- declare Simple_spacer
source file of the GNU LilyPond music typesetter
- (c) 1998 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+ (c) 1999--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
*/
#ifndef SIMPLE_SPACER_HH
#define SIMPLE_SPACER_HH
-#include "real.hh"
-#include "array.hh"
+#include "parray.hh"
#include "lily-proto.hh"
-#include "list.hh"
-#include "drul-array.hh"
-struct Rod_info {
- Real distance_f_;
- Drul_array<int> cols_;
-};
-
-struct Spring_info {
- /// the ideal distance
- Real space_f_;
- /// Hooke's constant: how strong are the "springs" attached to columns
+struct Spring_description
+{
+ Real ideal_f_;
Real hooke_f_;
+ bool active_b_;
+
+ Real block_force_f_;
+
+ Real length (Real force) const;
+ Spring_description ();
- Real blocking_stretch_f_;
- Rod_info * blocking_rod_l_;
- void set (Idealspacing *);
- Spring_info();
+ bool sane_b () const;
};
+/**
+ 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
+
-class Simple_spring_spacer {
- Array<Spring_info> springs_;
- Pointer_list<Rod_info*> rods_;
+ Perhaps this is not a bad thing, because the 1st looks better anyway. */
+struct Simple_spacer
+{
+ Array<Spring_description> springs_;
+ Link_array<Grob> spaced_cols_;
+ Link_array<Grob> loose_cols_;
+ Real force_f_;
+ Real indent_f_;
+ Real line_len_f_;
+ Real default_space_f_;
+ int active_count_;
- void init ();
- Array<Real> solve ();
+ Simple_spacer ();
+ void solve (Column_x_positions *) const;
+ void add_columns (Link_array<Grob>);
+ void my_solve_linelen ();
+ void my_solve_natural_len ();
+ Real active_springs_stiffness () const;
+ Real range_stiffness (int, int) const;
+ void add_rod (int l, int r, Real dist);
+ Real range_ideal_len (int l, int r)const;
+ Real active_blocking_force ()const;
+ Real configuration_length ()const;
+ void set_active_states ();
+ bool active_b () const;
};
#endif /* SIMPLE_SPACER_HH */