# HG changeset patch
# User Marcus Pearce <m.pearce@gold.ac.uk>
# Date 1184691065 -3600
# Node ID 7a0ee88f1edb00f344998f91605b6994549eb4df
# Parent  c81375b9304f21991cead93a84b7a8bbda4e3338
base/: new generics DIATONIC-PITCH-ACCIDENTAL and OCTAVE

darcs-hash:20070717165105-c0ce4-9f6acb06961d3413ceca604ca0285ababcdda377.gz

diff -r c81375b9304f -r 7a0ee88f1edb base/generics.lisp
--- a/base/generics.lisp	Tue Jul 17 17:49:46 2007 +0100
+++ b/base/generics.lisp	Tue Jul 17 17:51:05 2007 +0100
@@ -39,6 +39,16 @@
 (defgeneric mips-pitch (pitch-designator))
 (defgeneric frequency (object)) ;?
 
+(defgeneric octave (pitch-designator)
+  (:documentation "Return an integer representing the octave of
+pitch-designator where middle c is defined to be the lowest pitch in
+octave 4."))
+
+(defgeneric diatonic-pitch-accidental (pitch-designator)
+  (:documentation "Return an integer representing the inflection of a
+diatonic pitch where where negative values indicate numbers of flats,
+0 indicates natural and positive values indicate numbers of sharps."))
+
 (defgeneric middle-c (pitch-designator) 
   (:documentation "Returns the value of middle C in the particular
 representation of pitch used by PITCH-DESIGNATOR."))
diff -r c81375b9304f -r 7a0ee88f1edb base/methods.lisp
--- a/base/methods.lisp	Tue Jul 17 17:49:46 2007 +0100
+++ b/base/methods.lisp	Tue Jul 17 17:51:05 2007 +0100
@@ -2,6 +2,12 @@
 
 ;;; diatonic pitch 
 
+(defmethod octave ((dp diatonic-pitch))
+  (%diatonic-pitch-octave dp))
+
+(defmethod diatonic-pitch-accidental ((dp diatonic-pitch))
+  (%diatonic-pitch-accidental dp))
+
 (defmethod pitch= ((p1 diatonic-pitch) (p2 diatonic-pitch))
   (let ((n1 (%diatonic-pitch-name p1))
         (a1 (%diatonic-pitch-accidental p1))
@@ -47,6 +53,12 @@
 
 ;;; MIPS pitch 
 
+(defmethod octave ((mp mips-pitch))
+  (octave (diatonic-pitch mp)))
+
+(defmethod diatonic-pitch-accidental ((mp mips-pitch))
+  (diatonic-pitch-accidental (diatonic-pitch mp)))
+
 (defmethod pitch= ((p1 mips-pitch) (p2 mips-pitch))
   (let ((c1 (meredith-chromatic-pitch-number p1))
         (m1 (meredith-morphetic-pitch-number p1))
@@ -95,6 +107,9 @@
 
 ;;; Chromatic pitch 
 
+(defmethod octave ((cp chromatic-pitch))
+  (1- (/ (%chromatic-pitch-number cp) 12)))
+
 (defmethod middle-c ((cp chromatic-pitch))
   (make-chromatic-pitch 60))
 
diff -r c81375b9304f -r 7a0ee88f1edb base/package.lisp
--- a/base/package.lisp	Tue Jul 17 17:49:46 2007 +0100
+++ b/base/package.lisp	Tue Jul 17 17:51:05 2007 +0100
@@ -118,4 +118,6 @@
            #:diatonic-pitch-name 
            #:middle-c 
            #:make-mips-pitch
+           #:octave 
+           #:diatonic-pitch-accidental
 	   ))