X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Falign-interface.cc;h=cbc9443fc7ce4f1491492ecb745f2c1e26241717;hb=7f9360aeec613b5899ce74e092a797b1b5ccd723;hp=057e233f443d6522ddf4bddc5d74b7a515881dde;hpb=eeb973b4126dad28bd9f60ab2af772c919401e23;p=lilypond.git

diff --git a/lily/align-interface.cc b/lily/align-interface.cc
index 057e233f44..cbc9443fc7 100644
--- a/lily/align-interface.cc
+++ b/lily/align-interface.cc
@@ -3,7 +3,7 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c) 2000--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  (c) 2000--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
 */
 
 #include "align-interface.hh"
@@ -84,6 +84,8 @@ Align_interface::stretch_after_break (SCM grob)
    an empty extent, delete it from the list instead. If the extent is
    non-empty but there is no skyline available (or pure is true), just
    create a flat skyline from the bounding box */
+// TODO(jneem): the pure and non-pure parts seem to share very little
+// code. Split them into 2 functions, perhaps?
 static void
 get_skylines (Grob *me,
 	      vector<Grob*> *const elements,
@@ -91,37 +93,13 @@ get_skylines (Grob *me,
 	      bool pure, int start, int end,
 	      vector<Skyline_pair> *const ret)
 {
-  /* each child's skyline was calculated according to the common refpoint of its
-     elements. Here we need all the skylines to be positioned with respect to
-     a single refpoint, so we need the common refpoint of the common refpoints
-     of the elements of the children */
-  vector<Grob*> child_refpoints;
-  for (vsize i = 0; i < elements->size (); i++)
-    {
-      Grob *elt = (*elements)[i];
-      Grob *child_common = unsmob_grob ((a == Y_AXIS)
-					? elt->get_object ("X-common")
-					: elt->get_object ("Y-common"));
-      
-      if (!child_common)
-	{
-	  extract_grob_set (elt, "elements", child_elts);
-	  child_common = common_refpoint_of_array (child_elts, elt, other_axis (a));
-	}
-      
-      child_refpoints.push_back (child_common);
-    }
-
-  Grob *other_common = common_refpoint_of_array (child_refpoints, me, other_axis (a));
+  Grob *other_common = common_refpoint_of_array (*elements, me, other_axis (a));
   
   for (vsize i = elements->size (); i--;)
     {
       Grob *g = (*elements)[i];
       Skyline_pair skylines;
 
-      /* each skyline is calculated relative to (potentially) a different other_axis
-	 coordinate. In order to compare the skylines effectively, we need to shift them
-	 to some absolute reference point */
       if (!pure)
 	{
 	  Skyline_pair *skys = Skyline_pair::unsmob (g->get_property (a == Y_AXIS
@@ -147,7 +125,10 @@ get_skylines (Grob *me,
 		skylines.insert (b, 0, other_axis (a));
 	    }
 
-	  Real offset = child_refpoints[i]->relative_coordinate (other_common, other_axis (a));
+	  /* This skyline was calculated relative to the grob g. In order to compare it to
+	     skylines belonging to other grobs, we need to shift it so that it is relative
+	     to the common reference. */
+	  Real offset = g->relative_coordinate (other_common, other_axis (a));
 	  skylines.shift (offset);
 	}
       else
@@ -158,9 +139,32 @@ get_skylines (Grob *me,
 	    {
 	      Box b;
 	      b[a] = extent;
-	      b[other_axis (a)] = Interval (-infinity_f, infinity_f);
+	      b[other_axis (a)] = Interval (0, infinity_f);
 	      skylines.insert (b, 0, other_axis (a));
 	    }
+
+	  // This is a hack to get better accuracy on the pure-height of VerticalAlignment.
+	  // It's quite common for a treble clef to be the highest element of one system
+	  // and for a low note (or lyrics) to be the lowest note on another. The two will
+	  // never collide, but the pure-height stuff only works with bounding boxes, so it
+	  // doesn't know that. The result is a significant over-estimation of the pure-height,
+	  // especially on systems with many staves. To correct for this, we build a skyline
+	  // in two parts: the part we did above contains most of the grobs (note-heads, etc.)
+	  // while the bit we're about to do only contains the breakable grobs at the beginning
+	  // of the system. This way, the tall treble clefs are only compared with the treble
+	  // clefs of the other staff and they will be ignored if the staff above is, for example,
+	  // lyrics.
+	  if (Axis_group_interface::has_interface (g))
+	    {
+	      Interval begin_of_line_extent = Axis_group_interface::begin_of_line_pure_height (g, start);
+	      if (!begin_of_line_extent.is_empty ())
+		{
+		  Box b;
+		  b[a] = begin_of_line_extent;
+		  b[other_axis (a)] = Interval (-infinity_f, -1);
+		  skylines.insert (b, 0, other_axis (a));
+		}
+	    }
 	}
 
       if (skylines.is_empty ())
@@ -245,8 +249,10 @@ Align_interface::get_extents_aligned_translates (Grob *me,
 	}
     }
 
+  // So far, we've computed the translates for all the non-empty elements.
+  // Here, we set the translates for the empty elements: an empty element
+  // gets the same translation as the last non-empty element before it.
   vector<Real> all_translates;
-
   if (!translates.empty ())
     {
       Real w = translates[0];
@@ -403,7 +409,7 @@ ADD_INTERFACE (Align_interface,
 	       "Order grobs from top to bottom, left to right, right to left"
 	       " or bottom to top.  For vertical alignments of staves, the"
 	       " @code{break-system-details} of the left"
-	       " @internalsref{NonMusicalPaperColumn} may be set to tune"
+	       " @rinternals{NonMusicalPaperColumn} may be set to tune"
 	       " vertical spacing.  Set @code{alignment-extra-space} to add"
 	       " extra space for staves.  Set"
 	       " @code{fixed-alignment-extra-space} to force staves in"