]> git.donarmstrong.com Git - lilypond.git/blobdiff - lily/spacing-spanner.cc
''
[lilypond.git] / lily / spacing-spanner.cc
index de49d2c35bafa49b2b2c6be11f6d76265ef5b2f5..fd9585f1352e2b8dfe2af52a136b3cacbe2c7b0e 100644 (file)
 class Spacing_spanner
 {
 public:
+  static void standard_breakable_column_spacing (Grob * me, Item*l, Item*r,
+                                                Real * fixed, Real * space, Moment);
+  
+
   static Real default_bar_spacing (Grob*,Grob*,Grob*,Moment);
   static Real note_spacing (Grob*,Grob*,Grob*,Moment, bool*);
   static Real get_duration_space (Grob*,Moment dur, Rational shortest, bool*);
   static Rational find_shortest (Link_array<Grob> const &);  
-  static void breakable_column_spacing (Item* l, Item *r);
+  static void breakable_column_spacing (Grob*, Item* l, Item *r, Moment);
   static void find_loose_columns () {}
   static void prune_loose_colunms (Grob*,Link_array<Grob> *cols, Rational);
   static void find_loose_columns (Link_array<Grob> cols);
@@ -180,12 +184,31 @@ Spacing_spanner::prune_loose_colunms (Grob*me,Link_array<Grob> *cols, Rational s
 
                  Real space, fixed;
                  fixed = 0.0;
-                 bool expand_only;
-                 Real base = note_spacing (me, lc, rc, shortest, &expand_only);
-                 Note_spacing::get_spacing (sp, rc, base, increment, &space, &fixed);
-                 space -=base; 
+                 bool dummy;
+
+                 if (d == LEFT)
+                   {
+                     /*
+                       The note spacing should be taken from the musical
+                       columns.
+                   
+                     */
+                     Real base = note_spacing (me, lc, rc, shortest, &dummy);
+                     Note_spacing::get_spacing (sp, rc, base, increment, &space, &fixed);
+
+                     space -= increment; 
+                 
+                     dists[d] = dists[d] >? space;
+                   }
+                 else
+                   {
+                     Real space, fixed_space;
+                     Staff_spacing::get_spacing_params (sp,
+                                                        &space, &fixed_space);
+
+                     dists[d] = dists[d] >? fixed_space;
+                   }
                  
-                 dists[d] = dists[d] >? space;
                }
            }
          while (flip (&d) != LEFT);
@@ -430,6 +453,12 @@ Spacing_spanner::find_shortest (Link_array<Grob> const &cols)
   return d;
 }
 
+/*
+  Generate spacing for a single measure. We used to have code that did
+  per-measure spacing. Now we have piecewise spacing. We should fix
+  this to support "spacing-regions": some regions have different notes
+  (different time sigs) than others, and should be spaced differently.
+ */
 void
 Spacing_spanner::do_measure (Rational shortest, Grob*me, Link_array<Grob> *cols) 
 {
@@ -445,7 +474,7 @@ Spacing_spanner::do_measure (Rational shortest, Grob*me, Link_array<Grob> *cols)
 
       if (!Paper_column::musical_b (l))
        {
-         breakable_column_spacing (l, r);
+         breakable_column_spacing (me, l, r, shortest);
 
          /*
            
@@ -458,12 +487,12 @@ Spacing_spanner::do_measure (Rational shortest, Grob*me, Link_array<Grob> *cols)
          Item *rb = r->find_prebroken_piece (LEFT);
          
          if (lb)
-           breakable_column_spacing (lb,r);
+           breakable_column_spacing (me, lb,r, shortest);
 
          if (rb)
-           breakable_column_spacing (l, rb);
+           breakable_column_spacing (me, l, rb, shortest);
          if (lb && rb)
-           breakable_column_spacing (lb, rb);
+           breakable_column_spacing (me, lb, rb, shortest);
          
          continue ; 
        }
@@ -475,6 +504,10 @@ Spacing_spanner::do_measure (Rational shortest, Grob*me, Link_array<Grob> *cols)
     }    
 }
 
+
+/*
+  Generate the space between two musical columns LC and RC, given spacing parameters INCR and SHRTEST.
+ */
 void
 Spacing_spanner::musical_column_spacing (Grob *me, Item * lc, Item *rc, Real increment, Rational shortest)
 {
@@ -524,15 +557,47 @@ Spacing_spanner::musical_column_spacing (Grob *me, Item * lc, Item *rc, Real inc
   Spaceable_grob::add_spring (lc, rc, max_note_space,  1 / (max_note_space -max_fixed_note_space), expand_only);
 }
 
+void
+Spacing_spanner::standard_breakable_column_spacing (Grob * me, Item*l, Item*r,
+                                  Real * fixed, Real * space,
+                                  Moment shortest)
+{
+  *fixed = l->extent (l, X_AXIS)[RIGHT] - r->extent (r, X_AXIS)[LEFT];
+      
+  if (l->breakable_b (l) && r->breakable_b(r))
+    {
+      Moment *dt = unsmob_moment (l->get_grob_property ("measure-length"));
+      Moment mlen (1);
+      if (dt)
+       mlen = *dt;
+      
+      Real incr = gh_scm2double (me->get_grob_property ("spacing-increment"));
+
+      *space =  *fixed + incr * double (mlen.main_part_ / shortest.main_part_) * 0.8;
+    }
+  else
+    {
+      Moment dt = Paper_column::when_mom (r) - Paper_column::when_mom (l);
+      bool dummy;
+
+      *space = *fixed + get_duration_space (me, dt, shortest.main_part_, &dummy);
+    }
+  
+  
+}
+
 
 /*
-  Read hints from L (todo: R) and generate springs.
+  Read hints from L and generate springs.
  */
 void
-Spacing_spanner::breakable_column_spacing (Item* l, Item *r)
+Spacing_spanner::breakable_column_spacing (Grob*me, Item* l, Item *r,Moment shortest)
 {
   Real max_fixed = -infinity_f;
   Real max_space = -infinity_f;
+
+  standard_breakable_column_spacing (me, l, r, &max_fixed, &max_space ,
+                                    shortest);
   
   for (SCM s = l->get_grob_property ("spacing-wishes");
        gh_pair_p (s); s = gh_cdr (s))
@@ -561,6 +626,9 @@ Spacing_spanner::breakable_column_spacing (Item* l, Item *r)
        }
     }
 
+  
+  
+
   if (isinf (max_space))
     {
       programming_error ("No pref spacing found");
@@ -632,11 +700,14 @@ Spacing_spanner::note_spacing (Grob*me, Grob *lc, Grob *rc,
       programming_error ("can't find a ruling note at " + Paper_column::when_mom (lc).str ());
       shortest_playing_len = 1;
     }
-  
-  Moment delta_t = Paper_column::when_mom (rc) - Paper_column::when_mom (lc);
+
+  Moment lwhen = Paper_column::when_mom (lc);
+  Moment rwhen =  Paper_column::when_mom (rc);
+
+  Moment delta_t = rwhen - lwhen;
   Real dist = 0.0;
 
-  if (delta_t.main_part_)
+  if (delta_t.main_part_ && !lwhen.grace_part_)
     {
       dist = get_duration_space (me, shortest_playing_len, shortest.main_part_, expand_only);
       dist *= (double) (delta_t.main_part_ / shortest_playing_len.main_part_);
@@ -660,3 +731,50 @@ Spacing_spanner::note_spacing (Grob*me, Grob *lc, Grob *rc,
   return dist;
 }
 
+
+
+ADD_INTERFACE (Spacing_spanner,"spacing-spanner-interface",
+  " SPACE = arithmetic_multiplier * ( C + log2 (TIME) ))
+The space taken by a note is determined by the formula 
+
+
+
+where TIME is the amount of time a note occupies.  The value of C is
+chosen such that the smallest space within a measure is
+arithmetic_basicspace:
+
+C = arithmetic_basicspace - log2 (mininum (SHORTEST, 1/8)) 
+
+The smallest space is the one following the shortest note in the
+measure, or the space following a hypothetical 1/8 note.  Typically
+arithmetic_basicspace is set to a value so that the shortest note
+takes about two noteheads of space (ie, is followed by a notehead of
+space):
+
+@example
+2*quartwidth = arithmetic_multiplier * ( C + log2 (SHORTEST) ))
+
+@{ using: C = arithmetic_basicspace - log2 (mininum (SHORTEST, 1/8)) @}
+@{ assuming: SHORTEST <= 1/8 @}
+
+= arithmetic_multiplier *
+( arithmetic_basicspace - log2 (SHORTEST) + log2 (SHORTEST) )
+
+= arithmetic_multiplier * arithmetic_basicspace
+
+@{ choose: arithmetic_multiplier = 1.0*quartwidth (why?) @}
+
+= quartwidth * arithmetic_basicspace
+
+=>            
+
+arithmetic_basicspace = 2/1 = 2
+
+
+If you want to space your music wider, use something like:
+
+arithmetic_basicspace = 4.;
+
+@end example",
+  "spacing-increment shortest-duration-space");
+