From f542a0188fa0fc160b5580c119c64eb1966f196a Mon Sep 17 00:00:00 2001
From: Rune Zedeler <rune@lilypond.org>
Date: Tue, 19 Dec 2006 11:53:04 +0100
Subject: [PATCH] Fix #94. Added support for extraNatural.

Now key signature naturals are placed at the same location as the
accidental that they cancels.
---
 ...ey-signature-cancellation-extra-natural.ly | 23 +++++++++++++++++++
 lily/key-engraver.cc                          | 13 +++++++----
 lily/key-signature-interface.cc               | 13 +++++++++--
 3 files changed, 43 insertions(+), 6 deletions(-)
 create mode 100644 input/regression/key-signature-cancellation-extra-natural.ly

diff --git a/input/regression/key-signature-cancellation-extra-natural.ly b/input/regression/key-signature-cancellation-extra-natural.ly
new file mode 100644
index 0000000000..a103f4ed50
--- /dev/null
+++ b/input/regression/key-signature-cancellation-extra-natural.ly
@@ -0,0 +1,23 @@
+\header {
+
+  texidoc = "If @code{extraNatural} is set then keys that are not
+  altered farther away (eg from sharp to double sharp) are
+  cancelled. Otherwise only keys that does not accur in the new key
+  signature are cancelled."  }
+
+
+\version "2.11.2"
+
+\paper {
+  ragged-right = ##t
+}
+{
+  \set Staff.extraNatural = ##f
+  \key fes \major r1
+  \key as \major r1_"No B-natural (#f)"
+  \set Staff.extraNatural = ##t
+  \key gis \major r1
+  \key b \major r1_"with F-natural (#t)"
+
+}
+
diff --git a/lily/key-engraver.cc b/lily/key-engraver.cc
index 26b3985e4e..41cb7aed50 100644
--- a/lily/key-engraver.cc
+++ b/lily/key-engraver.cc
@@ -72,6 +72,7 @@ Key_engraver::create_key (bool is_default)
 
       SCM last = get_property ("lastKeySignature");
       SCM key = get_property ("keySignature");
+      bool extranatural = to_boolean(get_property("extraNatural"));
 
       if ((to_boolean (get_property ("printKeyCancellation"))
 	   || key == SCM_EOL)
@@ -81,10 +82,13 @@ Key_engraver::create_key (bool is_default)
 	  SCM *tail = &restore;
 	  for (SCM s = last; scm_is_pair (s); s = scm_cdr (s))
 	    {
-	      if (scm_assoc (scm_caar (s), key) == SCM_BOOL_F)
+	      SCM new_alter_pair = scm_assoc (scm_caar (s), key);
+	      int old_alter = scm_to_int (scm_cdar (s));
+	      if (new_alter_pair == SCM_BOOL_F
+		  || extranatural
+		     && (scm_to_int(scm_cdr(new_alter_pair))-old_alter)*old_alter < 0)
 		{
-		  *tail = scm_acons (scm_caar (s),
-				     scm_from_int (0), *tail);
+		  *tail = scm_cons (scm_car (s), *tail);
 		  tail = SCM_CDRLOC (*tail);
 		}
 	    }
@@ -94,7 +98,7 @@ Key_engraver::create_key (bool is_default)
 	      cancellation_ = make_item ("KeyCancellation",
 					 key_event_
 					 ? key_event_->self_scm () : SCM_EOL);
-	  
+	      
 	      cancellation_->set_property ("alteration-alist", restore);
 	      cancellation_->set_property ("c0-position",
 					   get_property ("middleCPosition"));
@@ -203,6 +207,7 @@ ADD_TRANSLATOR (Key_engraver,
 		/* read */
 		"createKeyOnClefChange "
 		"explicitKeySignatureVisibility "
+		"extraNatural "
 		"keyAlterationOrder "
 		"keySignature "
 		"keySignature "
diff --git a/lily/key-signature-interface.cc b/lily/key-signature-interface.cc
index 5705b46ccf..4c8d28f510 100644
--- a/lily/key-signature-interface.cc
+++ b/lily/key-signature-interface.cc
@@ -31,6 +31,9 @@ const int SHARP_TOP_PITCH = 4; /*  ais and bis typeset in lower octave */
 
 /*
   TODO: look this up. I'm not sure where the naturals ought to go.
+
+  COMMENT: Current implementation does not use the NATURAL_TOP_PITCH for anything,
+           always typesets naturals in the same place as the thing they cancel. -rz
 */
 const int NATURAL_TOP_PITCH = 4;
 
@@ -106,6 +109,9 @@ Key_signature_interface::print (SCM smob)
   if (scm_is_number (c0s))
     c0p = scm_to_int (c0s);
 
+  /* Is this the correct way to determine this? -rz */
+  bool is_cancellation = me->name()=="KeyCancellation";
+
   /*
     SCM lists are stacks, so we work from right to left, ending with
     the cancellation signature.
@@ -117,7 +123,10 @@ Key_signature_interface::print (SCM smob)
     {
       int alteration = scm_to_int (scm_cdar (s));
       string font_char
-	= Accidental_interface::get_fontcharname (style, alteration);
+	= Accidental_interface::get_fontcharname (style,
+						  is_cancellation
+						  ? 0
+						  : alteration);
       Stencil acc (fm->find_by_name ("accidentals." + font_char));
 
       if (acc.is_empty ())
@@ -134,7 +143,7 @@ Key_signature_interface::print (SCM smob)
 	    needed to prevent collisions.
 	  */
 	  Real padding = 0.0;
-	  if (alteration == 0
+	  if (is_cancellation
 	      && last_pos < pos + 2
 	      && last_pos > pos - 6)
 	    padding = 0.3;
-- 
2.39.2