release: 1.2.8

[lilypond.git] / lily / include / simple-spacer.hh

diff --git a/lily/include/simple-spacer.hh b/lily/include/simple-spacer.hh
index c122c64e2cc11445bc277a9c40f75c4caca5be23..80f7a32904e504633d5e8e80a4b18e742949fc48 100644 (file)
--- a/lily/include/simple-spacer.hh
+++ b/lily/include/simple-spacer.hh
@@ -10,8 +10,78 @@
 #ifndef SIMPLE_SPACER_HH
 #define SIMPLE_SPACER_HH
 
-class Simple_spacer {
+#include "parray.hh"
+#include "line-spacer.hh"
 
+
+struct Spring_description
+{
+  Real ideal_f_;
+  Real hooke_f_;
+  bool active_b_;
+
+  Real block_force_f_;
+
+  Real length (Real force) const;
+  Spring_description ();
+  Real energy_f (Real) 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
+
+
+   Perhaps this is not a bad thing, because the 1st looks better anyway.  */
+struct Simple_spacer: public Line_spacer
+{
+  Array<Spring_description> springs_;
+  Real force_f_;
+
+  Simple_spacer ();
+  
+  virtual void solve (Column_x_positions *) const;
+  virtual void lower_bound_solution (Column_x_positions *) const;
+  virtual void add_columns (Link_array<Paper_column>);
+    
+  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 ();
+  Real energy_f () const;
+
+  bool active_b () const;
 };
 
 #endif /* SIMPLE_SPACER_HH */