patch::: 1.3.151.jcn3

[lilypond.git] / lily / span-bar.cc

diff --git a/lily/span-bar.cc b/lily/span-bar.cc
index fddeb470fe339f9d0f1cf980bfc3cf9273acd1e2..d25fa7d5ba75b6e14877f7862cb392115e4b4fb6 100644 (file)
--- a/lily/span-bar.cc
+++ b/lily/span-bar.cc
@@ -25,6 +25,131 @@ Span_bar::add_bar (Grob*me, Grob*b)
   me->add_dependency (b);
 }
 
+MAKE_SCHEME_CALLBACK (Span_bar,brew_molecule,1);
+
+/**
+ * Limitations/Bugs:
+ *
+ * (1) Elements from 'me->get_grob_property ("elements")' must be
+ * ordered according to their y coordinates relative to their common
+ * axis group parent.  Otherwise, the computation goes mad.  (TODO:
+ * apply a sort algorithm that ensures this precondition.)  However,
+ * until now, I have seen no case where lily has not fulfilled this
+ * precondition.
+ *
+ * (2) This method depends on bar_engraver not being removed from
+ * staff context.  If bar_engraver is removed, the size of the staff
+ * lines is evaluated as 0, which results in a solid span bar line
+ * with faulty y coordinate.
+ *
+ */
+SCM
+Span_bar::brew_molecule (SCM smobbed_me) 
+{
+  Grob *me = unsmob_grob (smobbed_me);
+  Span_bar::evaluate_glyph(me);
+  SCM glyph = me->get_grob_property (ly_symbol2scm ("glyph"));
+  String glyph_str = ly_scm2string (glyph);
+  SCM first_elt = me->get_grob_property ("elements");
+
+  // first walk: compute axis_group parent via common_refpoint () on all bars
+  Grob *refpoint = 0;
+  int staff_bar_count = 0;
+  for (SCM elts = first_elt;
+       elts != SCM_EOL;
+       elts = gh_cdr (elts))
+  {
+    SCM smobbed_staff_bar = gh_car (elts);
+    Grob *staff_bar = unsmob_grob (smobbed_staff_bar);
+    refpoint = (staff_bar_count > 0) ?
+      staff_bar->common_refpoint (refpoint, Y_AXIS) :
+      staff_bar;
+    staff_bar_count++;
+  }
+  /* assert: refpoint is an axis-group object */
+  Grob *axis_group = refpoint;
+
+  // second walk: collect span bar components;
+  // compute extent of axis_group
+  Real last_staff_bar_length;
+  Real *interstaff_bar_length = new Real[staff_bar_count];
+  Real *interstaff_bar_yoffs = new Real[staff_bar_count];
+  Molecule *interstaff_bar_molecule = new Molecule[staff_bar_count];
+  Real axis_group_extent = 0.0;
+  staff_bar_count = 0;
+  for (SCM elts = first_elt;
+       elts != SCM_EOL;
+       elts = gh_cdr (elts))
+  {
+    SCM smobbed_staff_bar = gh_car (elts);
+    SCM smobbed_staff_bar_molecule =
+      Bar::brew_molecule (smobbed_staff_bar);
+    Grob *staff_bar = unsmob_grob (smobbed_staff_bar);
+    interstaff_bar_yoffs[staff_bar_count] =
+      staff_bar->relative_coordinate (axis_group, (Axis)Y_AXIS);
+    if (smobbed_staff_bar_molecule != SCM_EOL)
+    {
+      Real staff_bar_length =
+       unsmob_molecule (smobbed_staff_bar_molecule)->
+       extent (Y_AXIS).length ();
+      if (staff_bar_count > 0)
+      {
+       // clone bar_molecule and fix y extent
+       interstaff_bar_length[staff_bar_count] =
+         interstaff_bar_yoffs[staff_bar_count] -
+         interstaff_bar_yoffs[staff_bar_count - 1] -
+         last_staff_bar_length;
+       SCM smobbed_interstaff_bar_molecule = 
+         Bar::compound_barline (staff_bar, glyph_str,
+                                interstaff_bar_length[staff_bar_count]).
+         smobbed_copy ();
+       interstaff_bar_molecule[staff_bar_count] =
+         *unsmob_molecule (smobbed_interstaff_bar_molecule);
+      }
+      else
+      {
+       interstaff_bar_molecule[staff_bar_count] = Molecule::Molecule ();
+      }
+      last_staff_bar_length = staff_bar_length;
+    }
+    else
+    {
+      last_staff_bar_length = 0;
+      interstaff_bar_length[staff_bar_count] = 0;
+      interstaff_bar_molecule[staff_bar_count] = Molecule::Molecule ();
+    }
+    axis_group_extent += last_staff_bar_length;
+    axis_group_extent += interstaff_bar_length[staff_bar_count];
+    staff_bar_count++;
+  }
+  // assert(abs(axis_group_extent -
+  //           axis_group->extent (axis_group, Y_AXIS).length ()) < EPSILON);
+
+  // third walk: correct y axis on all span bar components;
+  // put all components into a single span bar molecule
+  Molecule span_bar_molecule = Molecule::Molecule ();
+  staff_bar_count = 0;
+  for (SCM elts = first_elt;
+       elts != SCM_EOL;
+       elts = gh_cdr (elts))
+  {
+    interstaff_bar_yoffs[staff_bar_count] +=
+      (axis_group_extent - interstaff_bar_length[staff_bar_count]) / 2;
+    interstaff_bar_molecule[staff_bar_count].//DEBUG
+      translate_axis (-1.0 PT, X_AXIS);//DEBUG
+    interstaff_bar_molecule[staff_bar_count].
+      translate_axis (interstaff_bar_yoffs[staff_bar_count], Y_AXIS);
+    span_bar_molecule.add_molecule (interstaff_bar_molecule[staff_bar_count]);
+    staff_bar_count++;
+  }
+
+  // clean-up & exit
+  delete interstaff_bar_length;
+  delete interstaff_bar_yoffs;
+  delete interstaff_bar_molecule;
+  return span_bar_molecule.smobbed_copy ();
+}
+
 MAKE_SCHEME_CALLBACK (Span_bar,width_callback,2);
 SCM
 Span_bar::width_callback (SCM element_smob, SCM scm_axis)