(set_spacing_rods): rewrite to O(n)

algorithm.

diff --git a/ChangeLog b/ChangeLog
index 1e79238bcf1a03b2ed9c2a951d97476b044e7922..182a19c60bcc883e5073a3db9063713b491d9866 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2005-03-11  Han-Wen Nienhuys  <hanwen@xs4all.nl>
 
+       * lily/ledger-line-spanner.cc (set_spacing_rods): rewrite to O(n)
+       algorithm.
+
        * stepmake/stepmake/metafont-rules.make ($(outdir)/%.pfb
        $(outdir)/%.svg $(outdir)/%.pfa): add --simplify.
 

diff --git a/lily/ledger-line-spanner.cc b/lily/ledger-line-spanner.cc
index 7fc5cec3482c49c24757c3bc94b7732c2fae4c50..ab591ac4c11b7229dcdba739b31c9f3868578dce 100644 (file)
--- a/lily/ledger-line-spanner.cc
+++ b/lily/ledger-line-spanner.cc
@@ -76,6 +76,42 @@ Ledger_line_spanner::brew_ledger_lines (Grob *staff,
   return stencil;
 }
 
+
+static void
+set_rods (Drul_array<Interval> const &current_extents,
+         Drul_array<Interval> const &previous_extents,
+         Item *current_column,
+         Item *previous_column,
+         Real min_length_fraction)
+{
+  Direction d = UP;
+  do
+    {
+      if (!current_extents[d].is_empty ()
+         && !previous_extents[d].is_empty ())
+       {
+         Real total_head_length = previous_extents[d].length ()
+           + current_extents[d].length ();
+
+         Rod rod;
+         rod.distance_ = total_head_length
+           * (3/2 * min_length_fraction)
+           /*
+             we go from right to left.
+           */
+           - previous_extents[d][LEFT]
+           + current_extents[d][RIGHT];
+
+         rod.item_drul_[LEFT] = current_column;
+         rod.item_drul_[RIGHT] = previous_column;
+         rod.add_to_cols ();
+       }
+
+    }
+  while (flip (&d) != DOWN);
+}
+
+
 MAKE_SCHEME_CALLBACK (Ledger_line_spanner, set_spacing_rods, 1);
 SCM
 Ledger_line_spanner::set_spacing_rods (SCM smob)
@@ -101,7 +137,7 @@ Ledger_line_spanner::set_spacing_rods (SCM smob)
 
   /*
     Run through heads using a loop. Since Legder_line_spanner can
-    contain a lot of noteheads, we don't use an STL map or set.
+    contain a lot of noteheads, superlinear performance is too slow.
   */
   int interspaces = Staff_symbol::line_count (staff) - 1;
   for (SCM hp = heads; scm_is_pair (hp); hp = scm_cdr (hp))
@@ -115,31 +151,10 @@ Ledger_line_spanner::set_spacing_rods (SCM smob)
       Item *column = h->get_column ();
       if (current_column != column)
        {
-         Direction d = UP;
-         do
-           {
-             if (!current_extents[d].is_empty ()
-                 && !previous_extents[d].is_empty ())
-               {
-                 Real total_head_length = previous_extents[d].length ()
-                   + current_extents[d].length ();
-
-                 Rod rod;
-                 rod.distance_ = total_head_length
-                   * (3/2 * min_length_fraction)
-                   /*
-                     we go from right to left.
-                    */
-                   - previous_extents[d][LEFT]
-                   + current_extents[d][RIGHT];
-
-                 rod.item_drul_[LEFT] = current_column;
-                 rod.item_drul_[RIGHT] = previous_column;
-                 rod.add_to_cols ();
-               }
-           }
-         while (flip (&d) != DOWN);
-
+         set_rods (current_extents, previous_extents,
+                   current_column, previous_column,
+                   min_length_fraction);
+         
          previous_column = current_column;
          current_column = column;
          previous_extents = current_extents;
@@ -156,6 +171,13 @@ Ledger_line_spanner::set_spacing_rods (SCM smob)
 
       current_extents[vdir].unite (head_extent);
     }
+
+  if (previous_column && current_column)
+    set_rods (current_extents, previous_extents,
+             current_column, previous_column,
+             min_length_fraction);
+
+  
   
   return SCM_UNSPECIFIED;
 }

diff --git a/scm/define-grobs.scm b/scm/define-grobs.scm
index 7973045b7b9e65329d4f96892d572c5140775760..d2b46405b20099904f6fd617426e38eec2b6af9f 100644 (file)
--- a/scm/define-grobs.scm
+++ b/scm/define-grobs.scm
@@ -572,7 +572,7 @@
        (print-function . ,Ledger_line_spanner::print)
        (X-extent-callback . #f)
        (Y-extent-callback . #f)
-       (minimum-length-fraction . 0.15)
+       (minimum-length-fraction . 0.25)
        (length-fraction . 0.25)
        (spacing-procedure . ,Ledger_line_spanner::set_spacing_rods)
        (print-function . ,Ledger_line_spanner::print)