Fix 1252 by compressing page (issue3422041)

[Carl . D . Sorensen]

Reviewers: ,

Message:
Here's a patch to fix issue 1252 (music overflows page) by compressing
music together.  It may cause collisions, but it should solve the
critical overflow error.


Description:
Fix 1252 by compressing page

Please review this at http://codereview.appspot.com/3422041/

Affected files:
  M lily/page-layout-problem.cc


Index: lily/page-layout-problem.cc
diff --git a/lily/page-layout-problem.cc b/lily/page-layout-problem.cc
index  
1a39ad51e8c21f681d1d345424b1c30931820e57..aef52e2bfb5ac8a3d360fc24c77901cceac7ea6c  
100644
--- a/lily/page-layout-problem.cc
+++ b/lily/page-layout-problem.cc
@@ -309,8 +309,16 @@ Page_layout_problem::solve_rod_spring_problem (bool  
ragged)
   solution_ = spacer.spring_positions ();

   if (!spacer.fits ())
-    warning (_f ("couldn't fit music on page: overflow is %f",
-                spacer.configuration_length(spacer.force()) - page_height_));
+    {
+      double overflow = spacer.configuration_length (spacer.force ()) -
+                         page_height_;
+      vsize space_count = solution_.size ();
+      for (vsize i = 0; i < space_count; i++)
+       solution_[i] -= (i + 1) * overflow / space_count;
+      warning (_f ("couldn't fit music on page: overflow is %f",
+                   overflow));
+      warning (_f ("compressing music to fit"));
+    }
 }

 // The solution_ vector stores the position of every live VerticalAxisGroup