X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fstaff-spacing.cc;h=ff064b5c0f6a83455b4b9fd43de4f33046c17b89;hb=941dff9d2a67080e0dd8474f1e70f0c72ace6424;hp=b9fd874b9e9aba08e11cd6223ef701961e6fd19a;hpb=d903c7971c00e582b88ef6b76b97573186d3eb76;p=lilypond.git

diff --git a/lily/staff-spacing.cc b/lily/staff-spacing.cc
index b9fd874b9e..ff064b5c0f 100644
--- a/lily/staff-spacing.cc
+++ b/lily/staff-spacing.cc
@@ -1,9 +1,20 @@
 /*
-  staff-spacing.cc -- implement Staff_spacing
+  This file is part of LilyPond, the GNU music typesetter.
 
-  source file of the GNU LilyPond music typesetter
+  Copyright (C) 2001--2011  Han-Wen Nienhuys <hanwen@xs4all.nl>
 
-  (c) 2001--2007  Han-Wen Nienhuys <hanwen@xs4all.nl>
+  LilyPond is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  LilyPond is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "staff-spacing.hh"
@@ -24,6 +35,13 @@ using namespace std;
 #include "pointer-group-interface.hh"
 #include "directional-element-interface.hh"
 
+/* A stem following a bar-line creates an optical illusion similar to the
+   one mentioned in note-spacing.cc. We correct for it here.
+
+   TODO: should we still correct if there are accidentals/arpeggios before
+   the stem?
+*/
+
 Real
 Staff_spacing::optical_correction (Grob *me, Grob *g, Interval bar_height)
 {
@@ -100,36 +118,22 @@ Staff_spacing::next_notes_correction (Grob *me,
   return max_optical;
 }
 
-/* This routine does not impose any minimum distances between columns; it only
-   affects springs. As such, the FIXED variable does not refer to a minimum
-   distance between columns, but instead to a minimum desired distance between
-   columns -- this ends up affecting the stiffness of a spring. In fact, FIXED
-   will be the distance between columns if there is a compression force of 1.0
-   applied to the line. */
+/* We calculate three things here: the ideal distance, the minimum distance
+   (which is the distance at which collisions will occur) and the "fixed"
+   distance, which is the distance at which things start to look really bad.
+   We arrange things so that the fixed distance will be attained when the
+   line is compressed with a force of 1.0 */
 Spring
-Staff_spacing::get_spacing (Grob *me)
+Staff_spacing::get_spacing (Grob *me, Grob *right_col)
 {
-  Grob *separation_item = 0;
   Item *me_item = dynamic_cast<Item *> (me);
-
-  extract_grob_set (me, "left-items", items);
-  for (vsize i = items.size (); i--;)
-    {
-      Grob *cand = items[i];
-      if (cand && Separation_item::has_interface (cand))
-	separation_item = cand;
-    }
-
-  //  printf ("doing col %d\n" , Paper_column::get_rank (left_col));
-  if (!separation_item)
-    {
-      programming_error ("no sep item");
-      return Spring ();
-    }
+  Grob *left_col = me_item->get_column ();
 
   Interval last_ext;
-  Grob *last_grob = Separation_item::extremal_break_aligned_grob (separation_item, RIGHT,
-								  &last_ext);
+  Direction break_dir = me_item->break_status_dir ();
+  Grob *last_grob = Spacing_interface::extremal_break_aligned_grob (me, LEFT,
+								    break_dir,
+								    &last_ext);
   if (!last_grob)
     {
       /*
@@ -191,8 +195,11 @@ Staff_spacing::get_spacing (Grob *me)
       ideal = fixed;
     }
 
+
   Real optical_correction = next_notes_correction (me, last_grob);
-  Real min_dist = Spacing_interface::minimum_distance (me);
+  Real min_dist = Paper_column::minimum_distance (left_col, right_col);
+
+  /* ensure that the "fixed" distance will leave a gap of at least 0.3 ss. */
   Real min_dist_correction = max (0.0, 0.3 + min_dist - fixed);
   Real correction = max (optical_correction, min_dist_correction);
 
@@ -200,14 +207,14 @@ Staff_spacing::get_spacing (Grob *me)
   ideal += correction;
 
   Spring ret (ideal, min_dist);
-  ret.set_inverse_stretch_strength (ideal - fixed);
+  ret.set_inverse_stretch_strength (max (0.0, ideal - fixed));
   return ret;
 }
 
 ADD_INTERFACE (Staff_spacing,
-	       "This object calculates spacing details from a "
-	       " breakable symbol (left) to another object. For example, it takes care "
-	       " of  optical spacing from  a bar lines to a note.",
+	       "This object calculates spacing details from a breakable"
+	       " symbol (left) to another object.  For example, it takes care"
+	       " of optical spacing from a bar line to a note.",
 
 	       /* properties */
 	       "stem-spacing-correction "