Tue Oct 17 08:45:26 IST 2006  Joe Neeman <address@hidden>
  * Suggested patch for configurable compression-penalty
diff -rN -u old-lilypond/ChangeLog new-lilypond/ChangeLog
--- old-lilypond/ChangeLog	2006-10-17 08:48:36.000000000 +0200
+++ new-lilypond/ChangeLog	2006-10-17 08:48:37.000000000 +0200
@@ -1,3 +1,13 @@
+2006-10-17  Joe Neeman  <address@hidden>
+
+	* lily/page-turn-page-breaking.cc (Page_turn_page_breaking): set
+	a higher default for compression-penalty
+
+	* lily/simple-spacer.cc:
+	* lily/constrained-breaking.cc:
+	make get_line_forces and get_line_configuration take a
+	compression_penalty parameter.
+
 2006-10-17  Han-Wen Nienhuys  <address@hidden>
 
 	* lily/script-column.cc (row_before_line_breaking): also handle
diff -rN -u old-lilypond/lily/constrained-breaking.cc new-lilypond/lily/constrained-breaking.cc
--- old-lilypond/lily/constrained-breaking.cc	2006-10-17 08:48:36.000000000 +0200
+++ new-lilypond/lily/constrained-breaking.cc	2006-10-17 08:48:36.000000000 +0200
@@ -122,8 +122,10 @@
 Column_x_positions
 Constrained_breaking::space_line (vsize i, vsize j)
 {
-  bool ragged_right = to_boolean (pscore_->layout ()->c_variable ("ragged-right"));
-  bool ragged_last = to_boolean (pscore_->layout ()->c_variable ("ragged-last"));
+  Output_def *l = pscore_->layout ();
+  bool ragged_right = to_boolean (l->c_variable ("ragged-right"));
+  bool ragged_last = to_boolean (l->c_variable ("ragged-last"));
+  Real compression_penalty = robust_scm2double (l->c_variable ("compression-penalty"), 0.5);
   Column_x_positions col;
 
   vector<Grob*> line (all_.begin () + breaks_[i],
@@ -132,7 +134,11 @@
   bool last = j == breaks_.size () - 1;
   bool ragged = ragged_right || (last && ragged_last);
 
-  return get_line_configuration (line, line_dims[RIGHT] - line_dims[LEFT], line_dims[LEFT], ragged);
+  return get_line_configuration (line,
+				 line_dims[RIGHT] - line_dims[LEFT],
+				 line_dims[LEFT],
+				 compression_penalty,
+				 ragged);
 }
 
 void
@@ -324,6 +330,7 @@
   System *sys = pscore_->root_system ();
   Real padding = robust_scm2double (l->c_variable ("between-system-padding"), 0);
   Real space = robust_scm2double (l->c_variable ("ideal-system-space"), 0);
+  Real compression_penalty = robust_scm2double (l->c_variable ("compression-penalty"), 0.5);
 
   Interval first_line = line_dimensions_int (pscore_->layout (), 0);
   Interval other_lines = line_dimensions_int (pscore_->layout (), 1);
@@ -334,6 +341,7 @@
   vector<Real> forces = get_line_forces (all_,
 					 other_lines.length (),
 					 other_lines.length () - first_line.length (),
+					 compression_penalty,
 					 ragged_right_);
   for (vsize i = 0; i < breaks_.size () - 1; i++)
     {
diff -rN -u old-lilypond/lily/include/simple-spacer.hh new-lilypond/lily/include/simple-spacer.hh
--- old-lilypond/lily/include/simple-spacer.hh	2006-10-17 08:48:36.000000000 +0200
+++ new-lilypond/lily/include/simple-spacer.hh	2006-10-17 08:48:36.000000000 +0200
@@ -69,11 +69,13 @@
 vector<Real> get_line_forces (vector<Grob*> const &columns,
 			      Real line_len,
 			      Real indent,
+			      Real compression_penalty,
 			      bool ragged);
 
 Column_x_positions get_line_configuration (vector<Grob*> const &columns,
 					   Real line_len,
 					   Real indent,
+					   Real compression_penalty,
 					   bool ragged);
 
 #endif /* SIMPLE_SPACER_HH */
diff -rN -u old-lilypond/lily/page-turn-page-breaking.cc new-lilypond/lily/page-turn-page-breaking.cc
--- old-lilypond/lily/page-turn-page-breaking.cc	2006-10-17 08:48:36.000000000 +0200
+++ new-lilypond/lily/page-turn-page-breaking.cc	2006-10-17 08:48:36.000000000 +0200
@@ -27,6 +27,12 @@
 Page_turn_page_breaking::Page_turn_page_breaking (Paper_book *pb)
   : Page_breaking (pb, is_break)
 {
+  /* because the page-turn-page-breaker has to deal with more constraints,
+     we are likely to find worse line-breaking configurations and we set
+     the compression-penalty higher so that those line-breaking configurations
+     will be stretched rather than compressed. */
+  if (!scm_is_number (pb->paper_->c_variable ("compression-penalty")))
+    pb->paper_->set_variable (ly_symbol2scm ("compression-penalty"), scm_from_int (4));
 }
 
 Page_turn_page_breaking::~Page_turn_page_breaking ()
diff -rN -u old-lilypond/lily/simple-spacer.cc new-lilypond/lily/simple-spacer.cc
--- old-lilypond/lily/simple-spacer.cc	2006-10-17 08:48:36.000000000 +0200
+++ new-lilypond/lily/simple-spacer.cc	2006-10-17 08:48:36.000000000 +0200
@@ -415,7 +415,10 @@
 
 vector<Real>
 get_line_forces (vector<Grob*> const &columns,
-		 Real line_len, Real indent, bool ragged)
+		 Real line_len,
+		 Real indent,
+		 Real compression_penalty,
+		 bool ragged)
 {
   vector<vsize> breaks;
   vector<Real> force;
@@ -471,13 +474,9 @@
 	    }
 	  spacer.solve ((b == 0) ? line_len - indent : line_len, ragged);
 
-	  /* add a (convex) penalty for compression. We do this _only_ in get_line_forces,
-	     not get_line_configuration. This is temporary, for backwards compatibility;
-	     the old line/page-breaking stuff ignores page breaks when it calculates line
-	     breaks, so compression penalties can result in scores (eg. wtk-fugue) blowing
-	     up to too many pages. */
+	  /* add a (convex) penalty for compression */
 	  Real f = spacer.force ();
-	  force[b * breaks.size () + c] = f - (f < 0 ? f*f*f*f*4 : 0);
+	  force[b * breaks.size () + c] = f - (f < 0 ? f*f*f*f*compression_penalty : 0);
 
 	  if (end < cols.size () && cols[end].break_permission_ == force_break)
 	    break;
@@ -498,6 +497,7 @@
 get_line_configuration (vector<Grob*> const &columns,
 			Real line_len,
 			Real indent,
+			Real compression_penalty,
 			bool ragged)
 {
   vector<Column_description> cols;
@@ -534,7 +534,8 @@
     }
 
   spacer.solve (line_len, ragged);
-  ret.force_ = spacer.force ();
+  Real f = spacer.force ();
+  ret.force_ = f - (f < 0 ? f*f*f*f*compression_penalty : 0);
 
   /*
     We used to have a penalty for compression, no matter what, but that