X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fstaff-symbol.cc;h=c00c2338d407f3572096805cf78e6b1ad050ed4f;hb=5b4b0d6e9a197e8f9eb085b7c2ad78b8be3e5cfc;hp=a6ab40d9093fcc1f58d4120be8a2f92da0a12783;hpb=570d70e5094bbc73de291d1016394ef70b1d96fb;p=lilypond.git

diff --git a/lily/staff-symbol.cc b/lily/staff-symbol.cc
index a6ab40d909..c00c2338d4 100644
--- a/lily/staff-symbol.cc
+++ b/lily/staff-symbol.cc
@@ -3,7 +3,7 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c) 1997--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  (c) 1997--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
 */
 
 #include "staff-symbol.hh"
@@ -167,17 +167,43 @@ Staff_symbol::height  (SCM smob)
   return ly_interval2scm (y_ext);
 }
 
+bool
+Staff_symbol::on_line (Grob *me, int pos)
+{
+  SCM line_positions = me->get_property ("line-positions");
+  if (scm_is_pair (line_positions))
+    {
+      Real min_line = HUGE_VAL;
+      Real max_line = -HUGE_VAL;
+      for (SCM s = line_positions; scm_is_pair (s); s = scm_cdr (s))
+	{
+	  Real current_line = scm_to_double (scm_car (s));
+	  if (pos == current_line)
+	    return true;
+	  if (current_line > max_line)
+	    max_line = current_line;
+	  if (current_line < min_line)
+	    min_line = current_line;
+	
+	}
+      if (pos < min_line)
+	return (( (int) (rint (pos - min_line)) % 2) == 0);
+      if (pos > max_line)
+	return (( (int) (rint (pos - max_line)) % 2) == 0);
 
-
+      return false;
+    }
+  else
+    return ((abs (pos + line_count (me)) % 2) == 1);
+}
 
 ADD_INTERFACE (Staff_symbol,
-	       "This spanner draws the lines of a staff. "
-	       "A staff symbol definines a vertical unit, the staff space. "
-	       "Quantities that go by a half staff space are called positions "
-	       "The center (i.e. middle line "
-	       "or space) is position 0. The length of the symbol may be set by hand "
-	       "through the @code{width} property. ",
-
+	       "This spanner draws the lines of a staff.  A staff symbol"
+	       " defines a vertical unit, the @emph{staff space}.  Quantities"
+	       " that go by a half staff space are called @emph{positions}."
+	       "  The center (i.e., middle line or space) is position@tie{}0."
+	       " The length of the symbol may be set by hand through the"
+	       " @code{width} property.",
 
 	       /* properties */
 	       "ledger-line-thickness "