Doc-es: Oops; fix bad xref.

[lilypond.git] / lily / note-collision.cc

diff --git a/lily/note-collision.cc b/lily/note-collision.cc
index c0391f5015d4a51e72f40ecd266ec1d79d243482..aad09a95a99ee64069f3fdca24441b06b096d709 100644 (file)
--- a/lily/note-collision.cc
+++ b/lily/note-collision.cc
@@ -56,6 +56,9 @@ check_meshing_chords (Grob *me,
   Grob *head_up = Note_column::first_head (clash_up);
   Grob *head_down = Note_column::first_head (clash_down);
 
+  Interval extent_up = head_up->extent (head_up, X_AXIS);
+  Interval extent_down = head_down->extent (head_down, X_AXIS);
+
   /* Staff-positions of all noteheads on each stem */
   vector<int> ups = Stem::note_head_positions (stems[UP]);
   vector<int> dps = Stem::note_head_positions (stems[DOWN]);
@@ -173,7 +176,9 @@ check_meshing_chords (Grob *me,
     }
 
   full_collide = full_collide || (close_half_collide
-                                  && distant_half_collide);
+                                  && distant_half_collide)
+                 || ( distant_half_collide // like full_ for wholes and longer
+                      && (up_ball_type <= 0 || down_ball_type <= 0));
 
   /* Determine which chord goes on the left, and which goes right.
      Up-stem usually goes on the right, but if chords just 'touch' we can put
@@ -226,7 +231,8 @@ check_meshing_chords (Grob *me,
 
       /* If possible, don't wipe any heads.  Else, wipe shortest head,
          or head with smallest amount of dots.  Note: when merging
-         different heads, dots on the smaller one disappear. */
+         different heads, dots on the smaller one disappear; and when
+         merging identical heads, dots on the down-stem head disappear */
       Grob *wipe_ball = 0;
       Grob *dot_wipe_head = head_up;
 
@@ -243,7 +249,7 @@ check_meshing_chords (Grob *me,
               wipe_ball = head_up;
             }
           else
-            dot_wipe_head = head_up;
+            dot_wipe_head = head_down;
         }
       else if (down_ball_type > up_ball_type)
         {
@@ -261,8 +267,7 @@ check_meshing_chords (Grob *me,
           */
           if (Stem::duration_log (stems[DOWN]) == 1
               && Stem::duration_log (stems[UP]) >= 3)
-            shift_amount = (1 - head_up->extent (head_up, X_AXIS).length ()
-                            / head_down->extent (head_down, X_AXIS).length ()) * 0.5;
+            shift_amount = (1 - extent_up[RIGHT] / extent_down[RIGHT]) * 0.5;
         }
 
       if (dot_wipe_head)
@@ -293,20 +298,14 @@ check_meshing_chords (Grob *me,
   else
     shift_amount *= 0.17;
 
-  /*
-  */
-  if (full_collide
-      && down_ball_type *up_ball_type == 0)
-    {
-      if (up_ball_type == 0 && down_ball_type == 1)
-        shift_amount *= 1.25;
-      else if (up_ball_type == 0 && down_ball_type == 2)
-        shift_amount *= 1.35;
-      else if (down_ball_type == 0 && up_ball_type == 1)
-        shift_amount *= 0.7;
-      else if (down_ball_type == 0 && up_ball_type == 2)
-        shift_amount *= 0.75;
-    }
+  /* The offsets computed in this routine are multiplied,
+     in calc_positioning_done(), by the width of the downstem note.
+     The shift required to clear collisions, however, depends on the extents
+     of the note heads on the sides that interfere. */
+  if (shift_amount < 0.0) // Down-stem shifts right.
+    shift_amount *= (extent_up[RIGHT] - extent_down[LEFT]) / extent_down.length ();
+  else // Up-stem shifts right.
+    shift_amount *= (extent_down[RIGHT] - extent_up[LEFT]) / extent_down.length ();
 
   /* If any dotted notes ended up on the left,
      tell the Dot_Columnn to avoid the note heads on the right.
@@ -355,8 +354,8 @@ check_meshing_chords (Grob *me,
           Grob *stem = unsmob_grob (head_down->get_object ("stem"));
           extract_grob_set (stem, "note-heads", heads);
           for (vsize i = 0; i < heads.size (); i++)
-            unsmob_grob (heads[i]->get_object ("dot"))
-            ->set_property ("direction", scm_from_int (dir));
+            if (Grob *dot = unsmob_grob (heads[i]->get_object ("dot")))
+              dot->set_property ("direction", scm_from_int (dir));
         }
     }
 
@@ -595,6 +594,22 @@ Note_collision_interface::add_column (Grob *me, Grob *ncol)
   Axis_group_interface::add_element (me, ncol);
 }
 
+vector<int>
+Note_collision_interface::note_head_positions (Grob *me)
+{
+  vector<int> out;
+  extract_grob_set (me, "elements", elts);
+  for (vsize i = 0; i < elts.size (); i++)
+    if (Grob *stem = unsmob_grob (elts[i]->get_object ("stem")))
+      {
+        vector<int> nhp = Stem::note_head_positions (stem);
+        out.insert (out.end (), nhp.begin (), nhp.end ());
+      }
+
+  vector_sort (out, less<int> ());
+  return out;
+}
+
 ADD_INTERFACE (Note_collision_interface,
                "An object that handles collisions between notes with"
                " different stem directions and horizontal shifts.  Most of"