(find_create_context): assign to lvalue.

[lilypond.git] / lily / stem.cc

diff --git a/lily/stem.cc b/lily/stem.cc
index 91fe78c888f2994e9d6b7d8ca6d6ce029d84e96c..cbf298745ba7b5c97e1ac7ef4d034e079c42a7f3 100644 (file)
--- a/lily/stem.cc
+++ b/lily/stem.cc
@@ -3,23 +3,27 @@
 
   source file of the GNU LilyPond music typesetter
 
 
   source file of the GNU LilyPond music typesetter
 

-  (c) 1996--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+  (c) 1996--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>

     Jan Nieuwenhuizen <janneke@gnu.org>
 
   TODO: This is way too hairy
     Jan Nieuwenhuizen <janneke@gnu.org>
 
   TODO: This is way too hairy

+
+  TODO: fix naming.
+
+  Stem-end, chord-start, etc. is all confusing naming.

 */
 
 */
 

-#include <math.h>              // m_pi
+#include <math.h>              // rint

 
 #include "lookup.hh"
 #include "directional-element-interface.hh"
 #include "note-head.hh"
 #include "stem.hh"
 
 #include "lookup.hh"
 #include "directional-element-interface.hh"
 #include "note-head.hh"
 #include "stem.hh"

-#include "debug.hh"
+#include "warn.hh"

 #include "paper-def.hh"
 #include "rhythmic-head.hh"
 #include "font-interface.hh"
 #include "paper-def.hh"
 #include "rhythmic-head.hh"
 #include "font-interface.hh"

-#include "molecule.hh"
+#include "stencil.hh"

 #include "paper-column.hh"
 #include "misc.hh"
 #include "beam.hh"
 #include "paper-column.hh"
 #include "misc.hh"
 #include "beam.hh"


@@ -28,34 +32,33 @@
 #include "staff-symbol-referencer.hh"
 #include "spanner.hh"
 #include "side-position-interface.hh"
 #include "staff-symbol-referencer.hh"
 #include "spanner.hh"
 #include "side-position-interface.hh"

+#include "dot-column.hh"
+#include "stem-tremolo.hh"

 
 void
 
 void

-Stem::set_beaming (Grob*me ,int i,  Direction d)
+Stem::set_beaming (Grob*me, int beam_count,  Direction d)

 {
 {

-  SCM pair = me->get_grob_property ("beaming");
+  SCM pair = me->get_property ("beaming");

   
   

-  if (!gh_pair_p (pair))
+  if (!ly_c_pair_p (pair))

     {
     {

-      pair = gh_cons (gh_int2scm (-1),gh_int2scm (-1));
-      me->      set_grob_property ("beaming", pair);
+      pair = scm_cons (SCM_EOL, SCM_EOL);
+      me->set_property ("beaming", pair);

     }
     }

-  index_set_cell (pair, d, gh_int2scm (i));
-}

 
 

-int
-Stem::beam_count (Grob*me,Direction d)
-{
-  SCM p=me->get_grob_property ("beaming");
-  if (gh_pair_p (p))
-    return gh_scm2int (index_cell (p,d));
-  else
-    return -1;
+  SCM l = index_get_cell (pair, d);
+  for (int i = 0; i<  beam_count; i++)
+    {
+      l = scm_cons (scm_int2num (i), l);
+    }
+  index_set_cell (pair, d, l);         

 }
 
 }
 

+

 Interval
 Stem::head_positions (Grob*me) 
 {
 Interval
 Stem::head_positions (Grob*me) 
 {

-  if (!heads_i (me))
+  if (!head_count (me))

     {
       Interval iv;
       return iv;
     {
       Interval iv;
       return iv;


@@ -63,13 +66,13 @@ Stem::head_positions (Grob*me)
 
   Drul_array<Grob*> e (extremal_heads (me));
 
 
   Drul_array<Grob*> e (extremal_heads (me));
 

-  return Interval (Staff_symbol_referencer::position_f (e[DOWN]),
-                  Staff_symbol_referencer::position_f (e[UP]));
+  return Interval (Staff_symbol_referencer::get_position (e[DOWN]),
+                  Staff_symbol_referencer::get_position (e[UP]));

 }
 
 
 Real
 }
 
 
 Real

-Stem::chord_start_f (Grob*me) 
+Stem::chord_start_y (Grob*me) 

 {
   return head_positions (me)[get_direction (me)]
     * Staff_symbol_referencer::staff_space (me)/2.0;
 {
   return head_positions (me)[get_direction (me)]
     * Staff_symbol_referencer::staff_space (me)/2.0;


@@ -78,15 +81,15 @@ Stem::chord_start_f (Grob*me)
 Real
 Stem::stem_end_position (Grob*me) 
 {
 Real
 Stem::stem_end_position (Grob*me) 
 {

-  SCM p =me->get_grob_property ("stem-end-position");
+  SCM p =me->get_property ("stem-end-position");

   Real pos;
   Real pos;

-  if (!gh_number_p (p))
+  if (!ly_c_number_p (p))

     {
       pos = get_default_stem_end_position (me);
     {
       pos = get_default_stem_end_position (me);

-      me->set_grob_property ("stem-end-position", gh_double2scm (pos));
+      me->set_property ("stem-end-position", scm_make_real (pos));

     }
   else
     }
   else

-    pos = gh_scm2double (p);
+    pos = ly_scm2double (p);

 
   return pos;
 }
 
   return pos;
 }


@@ -94,13 +97,13 @@ Stem::stem_end_position (Grob*me)
 Direction
 Stem::get_direction (Grob*me)
 {
 Direction
 Stem::get_direction (Grob*me)
 {

-  Direction d = Directional_element_interface::get (me);
+  Direction d = get_grob_direction (me);

 
   if (!d)
     {
        d = get_default_dir (me);
        // urg, AAARGH!
 
   if (!d)
     {
        d = get_default_dir (me);
        // urg, AAARGH!

-       Directional_element_interface::set (me, d);
+       set_grob_direction (me, d);

     }
   return d ;
 }
     }
   return d ;
 }


@@ -115,32 +118,25 @@ Stem::set_stemend (Grob*me, Real se)
   if (d && d * head_positions (me)[get_direction (me)] >= se*d)
     me->warning (_ ("Weird stem size; check for narrow beams"));
 
   if (d && d * head_positions (me)[get_direction (me)] >= se*d)
     me->warning (_ ("Weird stem size; check for narrow beams"));
 

-  me->set_grob_property ("stem-end-position", gh_double2scm (se));
+  me->set_property ("stem-end-position", scm_make_real (se));

 }
 
 }
 

-int
-Stem::type_i (Grob*me) 
-{
-  return first_head (me) ?  Rhythmic_head::balltype_i (first_head (me)) : 2;
-}

 
 /*
   Note head that determines hshift for upstems
 
 /*
   Note head that determines hshift for upstems

- */ 
+
+  WARNING: triggers direction
+*/ 

 Grob*
 Stem::support_head (Grob*me)
 {
 Grob*
 Stem::support_head (Grob*me)
 {

-  SCM h = me->get_grob_property ("support-head");
-  Grob * nh = unsmob_grob (h);
-  if (nh)
-    return nh;
-  else if (heads_i (me) == 1)
+  if (head_count (me) == 1)

     {
       /*
        UGH.
        */
       
     {
       /*
        UGH.
        */
       

-      return unsmob_grob (ly_car (me->get_grob_property ("heads")));
+      return unsmob_grob (ly_car (me->get_property ("note-heads")));

     }
   else
     return first_head (me);
     }
   else
     return first_head (me);


@@ -148,18 +144,35 @@ Stem::support_head (Grob*me)
 
 
 int
 
 
 int

-Stem::heads_i (Grob*me)
+Stem::head_count (Grob*me)

 {
 {

-  return  Pointer_group_interface::count (me, "heads");
+  return  Pointer_group_interface::count (me, "note-heads");

 }
 
 /*
   The note head which forms one end of the stem.  
 }
 
 /*
   The note head which forms one end of the stem.  

- */
+
+  WARNING: triggers direction
+*/

 Grob*
 Stem::first_head (Grob*me)
 {
 Grob*
 Stem::first_head (Grob*me)
 {

-  return extremal_heads (me)[-get_direction (me)];
+  Direction d = get_direction (me);
+  if (!d)
+    return 0;
+  return extremal_heads (me)[-d];
+}
+
+/*
+  The note head opposite to the first head.
+ */
+Grob*
+Stem::last_head (Grob*me)
+{
+  Direction d = get_direction (me);
+  if (!d)
+    return 0;
+  return extremal_heads (me)[d];

 }
 
 /*
 }
 
 /*


@@ -176,12 +189,12 @@ Stem::extremal_heads (Grob*me)
   Drul_array<Grob *> exthead;
   exthead[LEFT] = exthead[RIGHT] =0;
   
   Drul_array<Grob *> exthead;
   exthead[LEFT] = exthead[RIGHT] =0;
   

-  for (SCM s = me->get_grob_property ("heads"); gh_pair_p (s); s = ly_cdr (s))
+  for (SCM s = me->get_property ("note-heads"); ly_c_pair_p (s); s = ly_cdr (s))

     {
       Grob * n = unsmob_grob (ly_car (s));
 
       
     {
       Grob * n = unsmob_grob (ly_car (s));
 
       

-      int p = int (Staff_symbol_referencer::position_f (n));
+      int p = Staff_symbol_referencer::get_rounded_position (n);

 
       Direction d = LEFT;
       do {
 
       Direction d = LEFT;
       do {


@@ -202,18 +215,21 @@ icmp (int const &a, int const &b)
   return a-b;
 }
 
   return a-b;
 }
 

+/*
+  The positions, in ascending order.
+ */

 Array<int>
 Stem::note_head_positions (Grob *me)
 {
   Array<int> ps ;
 Array<int>
 Stem::note_head_positions (Grob *me)
 {
   Array<int> ps ;

-  for (SCM s = me->get_grob_property ("heads"); gh_pair_p (s); s = ly_cdr (s))
+  for (SCM s = me->get_property ("note-heads"); ly_c_pair_p (s); s = ly_cdr (s))

     {
       Grob * n = unsmob_grob (ly_car (s));
     {
       Grob * n = unsmob_grob (ly_car (s));

-      int p = int (Staff_symbol_referencer::position_f (n));
+      int p = Staff_symbol_referencer::get_rounded_position (n);

 
       ps.push (p);
     }
 
       ps.push (p);
     }

-
+  

   ps.sort (icmp);
   return ps; 
 }
   ps.sort (icmp);
   return ps; 
 }


@@ -222,89 +238,70 @@ Stem::note_head_positions (Grob *me)
 void
 Stem::add_head (Grob*me, Grob *n)
 {
 void
 Stem::add_head (Grob*me, Grob *n)
 {

-  n->set_grob_property ("stem", me->self_scm ());
+  n->set_property ("stem", me->self_scm ());

   n->add_dependency (me);
 
   n->add_dependency (me);
 

+  /*
+    TODO: why not store Rest pointers? 
+  */

   if (Note_head::has_interface (n))
     {
   if (Note_head::has_interface (n))
     {

-      Pointer_group_interface::add_grob (me, ly_symbol2scm ("heads"), n);
-    }
-  else
-    {
-      /*
-       Apparently, this is never used.
-       */
-#if 0
-      me->set_grob_property ("rest", n->self_scm ());
-#endif
+      Pointer_group_interface::add_grob (me, ly_symbol2scm ("note-heads"), n);

     }
 }
 
 bool
     }
 }
 
 bool

-Stem::invisible_b (Grob*me)
+Stem::is_invisible (Grob*me)

 {
 {

-  return ! (heads_i (me) && Rhythmic_head::balltype_i (support_head (me)) >= 1);
-}
-
-int
-Stem::get_center_distance (Grob*me, Direction d)
-{
-  int staff_center = 0;
-  int distance = (int) (d* (head_positions (me)[d] - staff_center));
-  return distance >? 0;
+  return ! (head_count (me)
+           && ly_scm2int (me->get_property ("duration-log")) >= 1);

 }
 
 Direction
 Stem::get_default_dir (Grob*me) 
 {
 }
 
 Direction
 Stem::get_default_dir (Grob*me) 
 {

-  int du = get_center_distance (me,UP);
-  int dd = get_center_distance (me,DOWN);
-
-  if (sign (dd - du))
-    return Direction (sign (dd -du));
+  int staff_center = 0;
+  Interval hp = head_positions (me);
+  if (hp.is_empty ())
+    {
+      return CENTER;
+    }
+  
+  int udistance = (int) (UP * hp[UP] - staff_center);
+  int ddistance = (int) (DOWN* hp[DOWN] - staff_center);  
+  
+  if (sign (ddistance - udistance))
+    return Direction (sign (ddistance -udistance));

 
 

-  return to_dir (me->get_grob_property ("neutral-direction"));
+  return to_dir (me->get_property ("neutral-direction"));

 }
 
 Real
 Stem::get_default_stem_end_position (Grob*me) 
 {
 }
 
 Real
 Stem::get_default_stem_end_position (Grob*me) 
 {

-  bool grace_b = to_boolean (me->get_grob_property ("grace"));
+  Real ss = Staff_symbol_referencer::staff_space (me); 
+
+  int durlog = duration_log (me);
+    

   SCM s;
   Array<Real> a;
 
   SCM s;
   Array<Real> a;
 

-  Real length_f = 0.;
-  SCM scm_len = me->get_grob_property ("length");
-  if (gh_number_p (scm_len))
+  
+  Real length = 7;             // WARNING: IN HALF SPACES
+  SCM scm_len = me->get_property ("length");
+  if (ly_c_number_p (scm_len))

     {
     {

-      length_f = gh_scm2double (scm_len);
+      length = ly_scm2double (scm_len);

     }
   else
     {
     }
   else
     {

-      s = me->get_grob_property ("lengths");
-      for (SCM q = s; q != SCM_EOL; q = ly_cdr (q))
-       a.push (gh_scm2double (ly_car (q)));
-               
-      // stem uses half-spaces
-      length_f = a[ ((flag_i (me) - 2) >? 0) <? (a.size () - 1)] * 2;
+      s = me->get_property ("lengths");
+      if (ly_c_pair_p (s))
+       {
+         length = 2* ly_scm2double (robust_list_ref (durlog -2, s));
+       }

     }
 
     }
 

-
-  a.clear ();
-  s = me->get_grob_property ("stem-shorten");
-  for (SCM q = s; gh_pair_p (q); q = ly_cdr (q))
-    a.push (gh_scm2double (ly_car (q)));
-
-
-  // stem uses half-spaces
-
-  // fixme: use scm_list_n_ref () iso. array[]
-  Real shorten_f = a[ ((flag_i (me) - 2) >? 0) <? (a.size () - 1)] * 2;
-
-  /* On boundary: shorten only half */
-  if (abs (chord_start_f (me)) == 0.5)
-    shorten_f *= 0.5;
-

   /* URGURGURG
      'set-default-stemlen' sets direction too
    */
   /* URGURGURG
      'set-default-stemlen' sets direction too
    */


@@ -312,81 +309,137 @@ Stem::get_default_stem_end_position (Grob*me)
   if (!dir)
     {
       dir = get_default_dir (me);
   if (!dir)
     {
       dir = get_default_dir (me);

-      Directional_element_interface::set (me, dir);
+      set_grob_direction (me, dir);

     }
     }

-  
+

   /* stems in unnatural (forced) direction should be shortened, 
     according to [Roush & Gourlay] */
   /* stems in unnatural (forced) direction should be shortened, 
     according to [Roush & Gourlay] */

-  if (chord_start_f (me)
-      && (get_direction (me) != get_default_dir (me)))
-    length_f -= shorten_f;
+  if (dir * head_positions (me)[dir] >= 0)
+    {
+      SCM sshorten = me->get_property ("stem-shorten");
+      SCM scm_shorten = ly_c_pair_p (sshorten) ?
+       robust_list_ref ((duration_log (me) - 2) >? 0, sshorten): SCM_EOL;
+      Real shorten = 2* robust_scm2double (scm_shorten,0);
+      
+  
+      /* On boundary: shorten only half */
+      if (abs (head_positions (me)[dir]) <= 1)
+       shorten *= 0.5;
+  
+      length -= shorten;
+    }

 
 

-  Interval hp = head_positions (me);  
-  Real st = hp[dir] + dir * length_f;
+  /*
+    Tremolo stuff: 
+  */
+  Grob * trem = unsmob_grob (me->get_property ("tremolo-flag"));
+  if (trem &&  !unsmob_grob (me->get_property ("beam")))
+    {
+      /*
+       Crude hack: add extra space if tremolo flag is there.

 
 

+       We can't do this for the beam, since we get into a loop
+       (Stem_tremolo::raw_stencil () looks at the beam.)
+       
+        --hwn 
+      */
+      
+      Real minlen =
+       1.0 + 2 * Stem_tremolo::raw_stencil (trem).extent (Y_AXIS).length  () / ss;
+      
+      if (durlog >= 3)
+       {
+         Interval flag_ext = flag (me).extent (Y_AXIS) ;
+         if (!flag_ext.is_empty ())
+           minlen += 2 * flag_ext.length () / ss ;

 
 

-  
+         /*
+           The clash is smaller for down stems (since the tremolo is
+           angled up.)
+          */
+         if (dir == DOWN)
+           minlen -= 1.0;
+       }
+      
+      length = length >? (minlen + 1.0);
+    }
+   
+  Interval hp = head_positions (me);  
+  Real st = hp[dir] + dir * length;

 
   /*
 
   /*

-    Make a little room if we have a flag and there is a dot.
-
-    TODO:
+    TODO: change name  to extend-stems to staff/center/'()
+  */
+  bool no_extend_b = to_boolean (me->get_property ("no-stem-extend"));
+  if (!no_extend_b && dir * st < 0) // junkme?
+    st = 0.0;

 
 

-    maybe  we should consider moving the dot to the right?
+  /*
+    Make a little room if we have a upflag and there is a dot.
+    previous approach was to lengthen the stem. This is not
+    good typesetting practice. 
+    

   */
   */

-  if (!beam_l (me)
-      && flag_i (me))
+  if (!get_beam (me) && dir == UP
+      && durlog > 2)

     {
       Grob * closest_to_flag = extremal_heads (me)[dir];
       Grob * dots = closest_to_flag
     {
       Grob * closest_to_flag = extremal_heads (me)[dir];
       Grob * dots = closest_to_flag

-       ? Rhythmic_head::dots_l (closest_to_flag ) : 0;
+       ? Rhythmic_head::get_dots (closest_to_flag ) : 0;

 
       if (dots)
        {
 
       if (dots)
        {

-         Real dp = Staff_symbol_referencer::position_f  (dots);
-         Real flagy =  flag (me).extent (Y_AXIS)[-dir] * 2; // should divide by staffspace
+         Real dp = Staff_symbol_referencer::get_position (dots);
+         Real flagy =  flag (me).extent (Y_AXIS)[-dir] * 2
+           / ss;

 
          /*
            Very gory: add myself to the X-support of the parent,
            which should be a dot-column.
           */
          if (dir * (st + flagy -  dp) < 0.5)
 
          /*
            Very gory: add myself to the X-support of the parent,
            which should be a dot-column.
           */
          if (dir * (st + flagy -  dp) < 0.5)

-           Side_position_interface::add_support (dots->get_parent (X_AXIS), me);
-
-         /*
-           previous approach was to lengthen the stem. This is not
-           good typesetting practice.  */
+           {
+             Grob *par = dots->get_parent (X_AXIS);
+
+             if (Dot_column::has_interface (par))
+               {
+                 Side_position_interface::add_support (par, me);
+
+                 /*
+                   TODO: apply some better logic here. The flag is
+                   curved inwards, so this will typically be too
+                   much.
+                 */
+               }
+           }

        }
     }
 
 
        }
     }
 
 

-  bool no_extend_b = to_boolean (me->get_grob_property ("no-stem-extend"));
-  if (!grace_b && !no_extend_b && dir * st < 0) // junkme?
-    st = 0.0;
-

   return st;
 }
 
 
 
 /*
   return st;
 }
 
 
 
 /*

-  Number of hooks on the flag, ie. the log of the duration.
+  
+  the log of the duration (Number of hooks on the flag minus two)

  */
 int
  */
 int

-Stem::flag_i (Grob*me) 
+Stem::duration_log (Grob*me) 

 {
 {

-  SCM s = me->get_grob_property ("duration-log");
-  return (gh_number_p (s)) ? gh_scm2int (s) : 2;
+  SCM s = me->get_property ("duration-log");
+  return (ly_c_number_p (s)) ? ly_scm2int (s) : 2;

 }
 
 void
 Stem::position_noteheads (Grob*me)
 {
 }
 
 void
 Stem::position_noteheads (Grob*me)
 {

-  if (!heads_i (me))
+  if (!head_count (me))

     return;
   
   Link_array<Grob> heads =
     return;
   
   Link_array<Grob> heads =

-    Pointer_group_interface__extract_grobs (me, (Grob*)0, "heads");
+    Pointer_group_interface__extract_grobs (me, (Grob*)0, "note-heads");

 
   heads.sort (compare_position);
   Direction dir =get_direction (me);
 
   heads.sort (compare_position);
   Direction dir =get_direction (me);


@@ -395,6 +448,8 @@ Stem::position_noteheads (Grob*me)
     heads.reverse ();
 
 
     heads.reverse ();
 
 

+  Real thick = thickness (me);
+      

   Grob *hed = support_head (me);
   Real w = Note_head::head_extent (hed,X_AXIS)[dir];
   for (int i=0; i < heads.size (); i++)
   Grob *hed = support_head (me);
   Real w = Note_head::head_extent (hed,X_AXIS)[dir];
   for (int i=0; i < heads.size (); i++)


@@ -403,20 +458,54 @@ Stem::position_noteheads (Grob*me)
                                X_AXIS);
     }
   
                                X_AXIS);
     }
   

-  bool parity= true;           // todo: make me settable.
-  int lastpos = int (Staff_symbol_referencer::position_f (heads[0]));
+  bool parity= true;
+  Real lastpos = Real (Staff_symbol_referencer::get_position (heads[0]));

   for (int i=1; i < heads.size (); i ++)
     {
   for (int i=1; i < heads.size (); i ++)
     {

-      Real p = Staff_symbol_referencer::position_f (heads[i]);
-      int dy =abs (lastpos- (int)p);
+      Real p = Staff_symbol_referencer::get_position (heads[i]);
+      Real dy =fabs (lastpos- p);

 
 

-      if (dy <= 1)
+      /*
+       dy should always be 0.5, 0.0, 1.0, but provide safety margin
+       for rounding errors.
+      */
+      if (dy < 1.1)            

        {
          if (parity)
            {
              Real l = Note_head::head_extent (heads[i], X_AXIS).length ();
 
        {
          if (parity)
            {
              Real l = Note_head::head_extent (heads[i], X_AXIS).length ();
 

-             heads[i]->translate_axis (l * get_direction (me), X_AXIS);
+             Direction d = get_direction (me);
+             /*
+               Reversed head should be shifted l-thickness, but this
+               looks too crowded, so we only shift l-0.5*thickness.
+
+               This leads to assymetry: Normal heads overlap the
+               stem 100% whereas reversed heads only overlaps the
+               stem 50%
+
+             */
+
+             Real reverse_overlap =0.5;
+             heads[i]->translate_axis ((l-thick*reverse_overlap) * d, X_AXIS);
+
+             if (is_invisible (me))
+               heads[i]->translate_axis (-thick*(2 - reverse_overlap) * d , X_AXIS);
+
+             
+            /* TODO:
+                
+             For some cases we should kern some more: when the
+             distance between the next or prev note is too large, we'd 
+             get large white gaps, eg.
+             
+               |
+              X|
+              |X  <- kern this.
+              |
+             X
+             
+             */

            }
          parity = !parity;
        }
            }
          parity = !parity;
        }


@@ -432,13 +521,20 @@ SCM
 Stem::before_line_breaking (SCM smob)
 {
   Grob*me = unsmob_grob (smob);
 Stem::before_line_breaking (SCM smob)
 {
   Grob*me = unsmob_grob (smob);

-  stem_end_position (me);      // ugh. Trigger direction calc.
-  position_noteheads (me);

 
 

-  if (invisible_b (me))
+
+  /*
+    Do the calculations for visible stems, but also for invisible stems
+    with note heads (i.e. half notes.)
+   */
+  if (head_count (me))
+    {
+      stem_end_position (me);  // ugh. Trigger direction calc.
+      position_noteheads (me);
+    }
+  else

     {
     {

-      me->remove_grob_property ("molecule-callback");
-      // suicide ();
+      me->set_property ("print-function", SCM_EOL);

     }
   
   return SCM_UNSPECIFIED;
     }
   
   return SCM_UNSPECIFIED;


@@ -453,44 +549,47 @@ MAKE_SCHEME_CALLBACK (Stem, height, 2);
 SCM
 Stem::height (SCM smob, SCM ax)
 {
 SCM
 Stem::height (SCM smob, SCM ax)
 {

-  Axis a = (Axis)gh_scm2int (ax);
+  Axis a = (Axis)ly_scm2int (ax);

   Grob * me = unsmob_grob (smob);
   assert (a == Y_AXIS);
 
   Grob * me = unsmob_grob (smob);
   assert (a == Y_AXIS);
 

-  SCM mol = me->get_uncached_molecule ();
+  SCM mol = me->get_uncached_stencil ();

   Interval iv;
   if (mol != SCM_EOL)
   Interval iv;
   if (mol != SCM_EOL)

-    iv = unsmob_molecule (mol)->extent (a);
+    iv = unsmob_stencil (mol)->extent (a);
+  if (Grob *b =get_beam (me))
+    {
+      Direction d = get_direction (me);
+      iv[d] += d * Beam::get_thickness (b) /2.0 ;
+    }
+

   return ly_interval2scm (iv);
 }
 
 
   return ly_interval2scm (iv);
 }
 
 

-Molecule
+Stencil

 Stem::flag (Grob*me)
 {
 Stem::flag (Grob*me)
 {

-  /* TODO: rename flag-style into something more appropriate,
-   e.g. "stroke-style", maybe with values "" (i.e. no stroke),
-   "single" and "double".  Needs more discussion.
-  */
-  String style, fstyle, staffline_offs;
-  SCM fst = me->get_grob_property ("flag-style");
-  if (gh_string_p (fst))
+  /* TODO: maybe property stroke-style should take different values,
+     e.g. "" (i.e. no stroke), "single" and "double" (currently, it's
+     '() or "grace").  */
+  String flag_style;
+  
+  SCM flag_style_scm = me->get_property ("flag-style");
+  if (ly_c_symbol_p (flag_style_scm))

     {
     {

-      fstyle = ly_scm2string (fst);
+      flag_style = ly_symbol2string (flag_style_scm);

     }
 
     }
 

-  SCM st = me->get_grob_property ("style");
-  if (gh_symbol_p (st))
-    {
-      style = (ly_scm2string (scm_symbol_to_string (st)));
-    }
-  else
+  if (flag_style == "no-flag")

     {
     {

-      style = "";
+      return Stencil ();

     }
     }

-  bool adjust = to_boolean (me->get_grob_property ("adjust-if-on-staffline"));

 
 

-  if (String::compare_i (style, "mensural") == 0)
+  bool adjust = true;
+
+  String staffline_offs;
+  if (String::compare (flag_style, "mensural") == 0)

     /* Mensural notation: For notes on staff lines, use different
        flags than for notes between staff lines.  The idea is that
        flags are always vertically aligned with the staff lines,
     /* Mensural notation: For notes on staff lines, use different
        flags than for notes between staff lines.  The idea is that
        flags are always vertically aligned with the staff lines,


@@ -503,7 +602,7 @@ Stem::flag (Grob*me)
         {
          /* Urrgh!  We have to detect wether this stem ends on a staff
             line or between two staff lines.  But we can not call
         {
          /* Urrgh!  We have to detect wether this stem ends on a staff
             line or between two staff lines.  But we can not call

-            stem_end_position(me) or get_default_stem_end_position(me),
+            stem_end_position (me) or get_default_stem_end_position (me),

             since this encounters the flag and hence results in an
             infinite recursion.  However, in pure mensural notation,
             there are no multiple note heads attached to a single stem,
             since this encounters the flag and hence results in an
             infinite recursion.  However, in pure mensural notation,
             there are no multiple note heads attached to a single stem,


@@ -516,11 +615,18 @@ Stem::flag (Grob*me)
             flag's shape accordingly.  In the worst case, the shape
             looks slightly misplaced, but that will usually be the
             programmer's fault (e.g. when trying to attach multiple
             flag's shape accordingly.  In the worst case, the shape
             looks slightly misplaced, but that will usually be the
             programmer's fault (e.g. when trying to attach multiple

-            note heads to a single stem in mensural notation).  */
-         Grob *first = first_head(me);
-         int sz = Staff_symbol_referencer::line_count (me)-1;
-         int p = (int)rint (Staff_symbol_referencer::position_f (first));
-         staffline_offs = (((p ^ sz) & 0x1) == 0) ? "1" : "0";
+            note heads to a single stem in mensural notation).
+         */
+
+         /*
+           perhaps the detection whether this correction is needed should
+           happen in a different place  to avoid the recursion.
+           
+           --hwn.
+         */
+         int p = Staff_symbol_referencer::get_rounded_position (me);
+         staffline_offs = Staff_symbol_referencer::on_staffline (me, p) ?
+           "1" : "0";

        }
       else
         {
        }
       else
         {


@@ -531,50 +637,92 @@ Stem::flag (Grob*me)
     {
       staffline_offs = "";
     }
     {
       staffline_offs = "";
     }

-  char c = (get_direction (me) == UP) ? 'u' : 'd';
-  String index_str
-    = String ("flags-") + style + to_str (c) + staffline_offs + to_str (flag_i (me));
-  Molecule m
-    = Font_interface::get_default_font (me)->find_by_name (index_str);
-  if (!fstyle.empty_b ())
-    m.add_molecule (Font_interface::get_default_font (me)->find_by_name (String ("flags-") + to_str (c) + fstyle));
-  return m;
+
+  char dir = (get_direction (me) == UP) ? 'u' : 'd';
+  String font_char =
+    flag_style + to_string (dir) + staffline_offs + to_string (duration_log (me));
+  Font_metric *fm = Font_interface::get_default_font (me);
+  Stencil flag = fm->find_by_name ("flags-" + font_char);
+  if (flag.is_empty ())
+    {
+      me->warning (_f ("flag `%s' not found", font_char));
+    }
+
+  SCM stroke_style_scm = me->get_property ("stroke-style");
+  if (ly_c_string_p (stroke_style_scm))
+    {
+      String stroke_style = ly_scm2string (stroke_style_scm);
+      if (!stroke_style.is_empty ())
+       {
+         String font_char = to_string (dir) + stroke_style;
+         Stencil stroke = fm->find_by_name ("flags-" + font_char);
+         if (stroke.is_empty ())
+           {
+             me->warning (_f ("flag stroke `%s' not found", font_char));
+           }
+         else
+           {
+             flag.add_stencil (stroke);
+           }
+       }
+    }
+
+  return flag;

 }
 
 MAKE_SCHEME_CALLBACK (Stem,dim_callback,2);
 SCM
 Stem::dim_callback (SCM e, SCM ax)
 {
 }
 
 MAKE_SCHEME_CALLBACK (Stem,dim_callback,2);
 SCM
 Stem::dim_callback (SCM e, SCM ax)
 {

-  Axis a = (Axis) gh_scm2int (ax);
+  Axis a = (Axis) ly_scm2int (ax);

   assert (a == X_AXIS);
   assert (a == X_AXIS);

-  Grob *se = unsmob_grob (e);
+  Grob *me = unsmob_grob (e);

   Interval r (0, 0);
   Interval r (0, 0);

-  if (unsmob_grob (se->get_grob_property ("beam")) || abs (flag_i (se)) <= 2)
+  if (unsmob_grob (me->get_property ("beam")) || abs (duration_log (me)) <= 2)

     ;  // TODO!
   else
     {
     ;  // TODO!
   else
     {

-      r = flag (se).extent (X_AXIS);
+      r = flag (me).extent (X_AXIS)
+       + thickness (me)/2;

     }
   return ly_interval2scm (r);
 }
  
     }
   return ly_interval2scm (r);
 }
  

+Real
+Stem::thickness (Grob* me)
+{
+  return ly_scm2double (me->get_property ("thickness"))
+    * Staff_symbol_referencer::line_thickness (me);
+}

 
 

-
-MAKE_SCHEME_CALLBACK (Stem,brew_molecule,1);
+MAKE_SCHEME_CALLBACK (Stem,print,1);

 
 SCM
 
 SCM

-Stem::brew_molecule (SCM smob) 
+Stem::print (SCM smob) 

 {
   Grob*me = unsmob_grob (smob);
 {
   Grob*me = unsmob_grob (smob);

-  Molecule mol;
+  Stencil mol;

   Direction d = get_direction (me);
   Direction d = get_direction (me);

+     
+  /*
+    TODO: make the stem start a direction ?
+
+    This is required to avoid stems passing in tablature chords...
+  */
+  Grob *lh = to_boolean (me->get_property ("avoid-note-head")) 
+    ? last_head (me) :  lh = first_head (me);
+
+  if (!lh)
+    return SCM_EOL;
+
+  if (is_invisible (me))
+    return SCM_EOL;

   
   

-  
-  Real y1 = Staff_symbol_referencer::position_f (first_head (me));
+  Real y1 = Staff_symbol_referencer::get_position (lh);

   Real y2 = stem_end_position (me);
   
   Interval stem_y (y1 <? y2,y2 >? y1);
   Real y2 = stem_end_position (me);
   
   Interval stem_y (y1 <? y2,y2 >? y1);

-
+ 

 
   // dy?
   Real dy = Staff_symbol_referencer::staff_space (me) * 0.5;
 
   // dy?
   Real dy = Staff_symbol_referencer::staff_space (me) * 0.5;


@@ -585,28 +733,30 @@ Stem::brew_molecule (SCM smob)
        must not take ledgers into account.
        */
       Interval head_height = Note_head::head_extent (hed,Y_AXIS);
        must not take ledgers into account.
        */
       Interval head_height = Note_head::head_extent (hed,Y_AXIS);

-      Real y_attach = Note_head::stem_attachment_coordinate ( hed, Y_AXIS);
+      Real y_attach = Note_head::stem_attachment_coordinate (hed, Y_AXIS);

 
       y_attach = head_height.linear_combination (y_attach);
       stem_y[Direction (-d)] += d * y_attach/dy;
     }
 
       y_attach = head_height.linear_combination (y_attach);
       stem_y[Direction (-d)] += d * y_attach/dy;
     }

+

   
   

-  if (!invisible_b (me))
-    {
-      Real stem_width = gh_scm2double (me->get_grob_property ("thickness"))
-       // URG
-       * me->paper_l ()->get_var ("stafflinethickness");
-      
-      Molecule ss =Lookup::filledbox (Box (Interval (-stem_width/2, stem_width/2),
-                                          Interval (stem_y[DOWN]*dy, stem_y[UP]*dy)));
-      mol.add_molecule (ss);
-    }
+  // URG
+  Real stem_width = thickness (me);
+  Real blot = 
+       me->get_paper ()->get_dimension (ly_symbol2scm ("blotdiameter"));
+  
+  Box b = Box (Interval (-stem_width/2, stem_width/2),
+              Interval (stem_y[DOWN]*dy, stem_y[UP]*dy));
+
+  Stencil ss = Lookup::round_filled_box (b, blot);
+  mol.add_stencil (ss);

 
 

-  if (!beam_l (me) && abs (flag_i (me)) > 2)
+  if (!get_beam (me) && abs (duration_log (me)) > 2)

     {
     {

-      Molecule fl = flag (me);
-      fl.translate_axis (stem_y[d]*dy, Y_AXIS);
-      mol.add_molecule (fl);
+      Stencil fl = flag (me);
+      fl.translate_axis (stem_y[d]*dy - d * blot/2, Y_AXIS);
+      fl.translate_axis (stem_width/2, X_AXIS);
+      mol.add_stencil (fl);

     }
 
   return mol.smobbed_copy ();
     }
 
   return mol.smobbed_copy ();


@@ -622,12 +772,24 @@ Stem::off_callback (SCM element_smob, SCM)
   Grob *me = unsmob_grob (element_smob);
   
   Real r=0;
   Grob *me = unsmob_grob (element_smob);
   
   Real r=0;

+
+  if (head_count (me) == 0)
+    {
+      return scm_make_real (0.0);
+    }
+  

   if (Grob * f = first_head (me))
     {
   if (Grob * f = first_head (me))
     {

-      Interval head_wid = Note_head::head_extent(f, X_AXIS);
+      Interval head_wid = Note_head::head_extent (f, X_AXIS);
+      
+      Real attach =0.0;

 
 

-      Real attach =
-       Note_head::stem_attachment_coordinate(f, X_AXIS);
+      if (is_invisible (me))
+       {
+         attach = 0.0;
+       }
+      else
+       attach = Note_head::stem_attachment_coordinate (f, X_AXIS);

 
       Direction d = get_direction (me);
 
 
       Direction d = get_direction (me);
 


@@ -641,166 +803,201 @@ Stem::off_callback (SCM element_smob, SCM)
       if (attach)
        {
          Real rule_thick
       if (attach)
        {
          Real rule_thick

-           = gh_scm2double (me->get_grob_property ("thickness"))
-           * me->paper_l ()->get_var ("stafflinethickness");
-
+           = thickness (me);

          
          r += - d * rule_thick * 0.5;
        }
     }
          
          r += - d * rule_thick * 0.5;
        }
     }

-  return gh_double2scm (r);
+  return scm_make_real (r);

 }
 
 
 }
 
 

-

 Grob*
 Grob*

-Stem::beam_l (Grob*me)
+Stem::get_beam (Grob*me)

 {
 {

-  SCM b=  me->get_grob_property ("beam");
+  SCM b=  me->get_property ("beam");

   return unsmob_grob (b);
 }
 
   return unsmob_grob (b);
 }
 

-
-// ugh still very long.

 Stem_info
 Stem_info

-Stem::calc_stem_info (Grob*me) 
+Stem::get_stem_info (Grob *me)

 {
 {

-  SCM scm_info = me->get_grob_property ("stem-info");
-
-  if (gh_pair_p (scm_info ))
+  /* Return cached info if available */
+  SCM scm_info = me->get_property ("stem-info");
+  if (!ly_c_pair_p (scm_info))

     {
     {

-      Stem_info si ;
+      calc_stem_info (me);
+      scm_info = me->get_property ("stem-info");
+    }
+  
+  Stem_info si;
+  si.dir_ = get_grob_direction (me); 
+  si.ideal_y_ = ly_scm2double (ly_car (scm_info)); 
+  si.shortest_y_ = ly_scm2double (ly_cadr (scm_info));
+  return si;
+}

 
 

-      si.ideal_y = gh_scm2double (gh_car (scm_info)); 
-      si.max_y = gh_scm2double (gh_cadr (scm_info)); 
-      si.min_y = gh_scm2double (gh_caddr (scm_info));

 
 

-      return si;
-    }
-    
-  Grob * beam = beam_l (me);
+/*
+  TODO: add extra space for tremolos!
+ */
+void
+Stem::calc_stem_info (Grob *me)
+{
+  Direction my_dir = get_grob_direction (me);

 
 

-  Direction beam_dir = Directional_element_interface::get (beam);
-  if (!beam_dir)
+  if (!my_dir)

     {
     {

-      programming_error ("Beam dir not set.");
-      beam_dir = UP;
+      programming_error ("No stem dir set?");
+      my_dir  = UP;

     }
     }

-    
-
-  Real staff_space = Staff_symbol_referencer::staff_space (me);
-  Real half_space = staff_space / 2;

   
   

-  int multiplicity = Beam::get_multiplicity (beam);
-  Real interbeam_f = Beam::get_interbeam (beam);
-
-  Real thick = gh_scm2double (beam->get_grob_property ("thickness"));
-  Stem_info info; 
-  info.ideal_y = chord_start_f (me);
+  Real staff_space = Staff_symbol_referencer::staff_space (me);
+  Grob *beam = get_beam (me);
+  Real beam_translation = Beam::get_beam_translation (beam);
+  Real beam_thickness = Beam::get_thickness (beam);
+  int beam_count = Beam::get_direction_beam_count (beam, my_dir);

 
 

-  // for simplicity, we calculate as if dir == UP
-  info.ideal_y *= beam_dir;
-  SCM grace_prop = me->get_grob_property ("grace");

 
 

-  bool grace_b = to_boolean (grace_prop);
+  /* Simple standard stem length */
+  SCM lengths = me->get_property ("beamed-lengths");
+  Real ideal_length =
+    ly_scm2double (robust_list_ref (beam_count - 1,lengths))
+               
+    * staff_space
+    /* stem only extends to center of beam */
+    - 0.5 * beam_thickness;

   
   

-  Array<Real> a;
-  SCM s;
+  /* Condition: sane minimum free stem length (chord to beams) */
+  lengths = me->get_property ("beamed-minimum-free-lengths");
+  Real ideal_minimum_free =
+    ly_scm2double (robust_list_ref (beam_count - 1, lengths))
+    * staff_space;

   
   

-  s = me->get_grob_property ("beamed-minimum-lengths");
-  a.clear ();
-  for (SCM q = s; q != SCM_EOL; q = ly_cdr (q))
-    a.push (gh_scm2double (ly_car (q)));

 
 

+  /* UGH
+     It seems that also for ideal minimum length, we must use
+     the maximum beam count (for this direction):
+     
+     \score{ \notes\relative c''{ [a8 a32] }}
+     
+     must be horizontal. */
+  Real height_of_my_beams = beam_thickness
+    + (beam_count - 1) * beam_translation;

 
 

-  Real minimum_length = a[multiplicity <? (a.size () - 1)] * staff_space;
-  s = me->get_grob_property ("beamed-lengths");
+  Real ideal_minimum_length = ideal_minimum_free
+    + height_of_my_beams
+    /* stem only extends to center of beam */
+    - 0.5 * beam_thickness;

 
 

-  a.clear ();
-  for (SCM q = s; q != SCM_EOL; q = ly_cdr (q))
-    a.push (gh_scm2double (ly_car (q)));
+  ideal_length = ideal_length >? ideal_minimum_length;

 
 

-  Real stem_length =  a[multiplicity <? (a.size () - 1)] * staff_space;
+  
+  /* Convert to Y position, calculate for dir == UP */
+  Real note_start =
+    /* staff positions */
+    head_positions (me)[my_dir] * 0.5
+    * my_dir * staff_space;
+  Real ideal_y = note_start + ideal_length;

 
 

-  if (!beam_dir || (beam_dir == Directional_element_interface::get (me)))
-    /* normal beamed stem */
-    {
-      if (multiplicity)
-       {
-         info.ideal_y += thick + (multiplicity - 1) * interbeam_f;
-       }
-      info.min_y = info.ideal_y;
-      info.max_y = 1000;  // INT_MAX;

 
 

-      info.ideal_y += stem_length;
-      info.min_y += minimum_length;
+  /* Conditions for Y position */

 
 

-      /*
-       lowest beam of (UP) beam must never be lower than second staffline
+  /* Lowest beam of (UP) beam must never be lower than second staffline
+ 
+     Reference?
+ 
+     Although this (additional) rule is probably correct,
+     I expect that highest beam (UP) should also never be lower
+     than middle staffline, just as normal stems.
+
+     Reference?
+
+     Obviously not for grace beams.
+     
+     Also, not for knees.  Seems to be a good thing. */
+  bool no_extend_b = to_boolean (me->get_property ("no-stem-extend"));
+  bool is_knee = to_boolean (beam->get_property ("knee"));
+  if (!no_extend_b && !is_knee)
+    {
+      /* Highest beam of (UP) beam must never be lower than middle
+        staffline */
+      ideal_y =        ideal_y >? 0;
+      /* Lowest beam of (UP) beam must never be lower than second staffline */
+      ideal_y =        ideal_y >? (-staff_space
+                           - beam_thickness + height_of_my_beams);
+    }

 
 

-       Hmm, reference (Wanske?)

 
 

-       Although this (additional) rule is probably correct,
-       I expect that highest beam (UP) should also never be lower
-       than middle staffline, just as normal stems.
-       
-      */
-      bool no_extend_b = to_boolean (me->get_grob_property ("no-stem-extend"));
-      if (!grace_b && !no_extend_b)
-       {
-         /* highest beam of (UP) beam must never be lower than middle
-            staffline
-            lowest beam of (UP) beam must never be lower than second staffline
-          */
-         info.min_y =
-           info.min_y >? 0
-           >? (- 2 * half_space - thick
-               + (multiplicity > 0) * thick
-               + interbeam_f * (multiplicity - 1));
-       }
-    }
-  else
-    /* knee */
-    {
-      info.ideal_y -= thick;
-      info.max_y = info.ideal_y;
-      info.min_y = - 1000 ; // INT_MAX;
+  ideal_y -= robust_scm2double (beam->get_property ("shorten"), 0);

 
 

-      info.ideal_y -= stem_length;
-      info.max_y -= minimum_length;
-    }
-  
-  info.ideal_y = (info.max_y <? info.ideal_y) >? info.min_y;
+  Real minimum_free =
+    ly_scm2double (robust_list_ref
+                  (beam_count - 1,
+                   me->get_property
+                   ("beamed-extreme-minimum-free-lengths")))
+    * staff_space;

 
 

-  s = beam->get_grob_property ("shorten");
-  if (gh_number_p (s))
-    info.ideal_y -= gh_scm2double (s);
+  Real minimum_length = minimum_free
+    + height_of_my_beams
+    /* stem only extends to center of beam */
+    - 0.5 * beam_thickness;

 
 

-  Grob *common = me->common_refpoint (beam, Y_AXIS);
-  Real interstaff_f = beam_dir *
-    (me->relative_coordinate (common, Y_AXIS)
-     - beam->relative_coordinate (common, Y_AXIS));
+  Real minimum_y = note_start + minimum_length;

   
   

-  info.ideal_y += interstaff_f;
-  info.min_y += interstaff_f;
-  info.max_y += interstaff_f ;
-
-  me->set_grob_property ("stem-info",
-                        scm_list_n (gh_double2scm (info.ideal_y),
-                                    gh_double2scm (info.max_y),
-                                    gh_double2scm (info.min_y),
-                                    SCM_UNDEFINED));

   
   

-  return info;
+  ideal_y *= my_dir;
+  Real shortest_y = minimum_y * my_dir; 
+  
+  me->set_property ("stem-info",
+                        scm_list_n (scm_make_real (ideal_y),
+                                    scm_make_real (shortest_y),
+                                    SCM_UNDEFINED));

 }
 
 }
 

-bool
-Stem::has_interface (Grob*m)
+Slice
+Stem::beam_multiplicity (Grob *stem)

 {
 {

-  return m && m->has_interface (ly_symbol2scm ("stem-interface"));
+  SCM beaming= stem->get_property ("beaming");
+  Slice l = int_list_to_slice (ly_car (beaming));
+  Slice r = int_list_to_slice (ly_cdr (beaming));
+  l.unite (r);
+
+  return l;

 }
 
 }
 

+
+/*
+  these are too many props.
+ */

 ADD_INTERFACE (Stem,"stem-interface",
 ADD_INTERFACE (Stem,"stem-interface",

-  "A stem",
-  "thickness stem-info beamed-lengths beamed-minimum-lengths lengths beam stem-shorten duration-log beaming neutral-direction stem-end-position support-head heads direction length style no-stem-extend flag-style dir-forced");
+              "The stem represent the graphical  stem. "
+              "  In addition, it internally connects note heads, beams, tremolos. Rests "
+              " and whole notes have invisible stems."
+
+,
+              
+              "tremolo-flag french-beaming "
+              "avoid-note-head thickness "
+              "stem-info beamed-lengths beamed-minimum-free-lengths "
+              "beamed-extreme-minimum-free-lengths lengths beam stem-shorten "
+              "duration-log beaming neutral-direction stem-end-position "
+              "note-heads direction length flag-style "
+              "no-stem-extend stroke-style");
+
+
+
+/****************************************************************/

 
 

+Stem_info::Stem_info ()
+{
+  ideal_y_ = shortest_y_ =0;
+  dir_ = CENTER;
+}
+
+void
+Stem_info::scale (Real x)
+{
+  ideal_y_ *= x;
+  shortest_y_ *= x;
+}