# HG changeset patch
# User j.forth <j.forth@gold.ac.uk>
# Date 1265969720 0
# Node ID a85c59bcd88b40140044d4388fa0f176239cffb4
# Parent  d70ff27b1968d654517da40becfb59ed03415e22
add some time-related generic functions to base

Ignore-this: 8ad91dcfa5c8a0301c29dda7d2f27802

darcs-hash:20100212101520-16a00-6821cd98b78bf27be148e3e7e4b46c8f0b80928b.gz

diff -r d70ff27b1968 -r a85c59bcd88b base/generics.lisp
--- a/base/generics.lisp	Sun Apr 04 22:05:37 2010 +0100
+++ b/base/generics.lisp	Fri Feb 12 10:15:20 2010 +0000
@@ -451,15 +451,22 @@
   bar which contains moment"))
 
 (defgeneric beat-period (moment time-signature implementation-object)
-  (:documentation "Takes a moment, time signature object and crotchet and returns
-  an <anchored-period> for the containing beat containing moment. This
-  is more useful when there's a complex time signature (not currently
-  possible) in which tactus is different in different parts of the
-  bar (e.g. 3+3+2/8)"))
+  (:documentation "Takes a moment, time signature object and crotchet
+  and returns an <anchored-period> for the containing beat containing
+  moment. This is more useful when there's a complex time
+  signature (not currently possible) in which tactus is different in
+  different parts of the bar (e.g. 3+3+2/8)"))
 (defgeneric current-beat (moment composition)
   (:documentation "Returns an <anchored-period> representing the
   tactus unit which contains moment"))
 
+(defgeneric ioi-from-bar (moment)
+  (:documentation "Returns the IOI of moment (i.e. an event) from the
+  bar line."))
+
+(defgeneric onset-in-bar (moment)
+  (:documentation "The position of moment in the bar, measured in
+  beats."))
 
 ;;;;;;;;;;;;;;
 ;;
diff -r d70ff27b1968 -r a85c59bcd88b base/methods.lisp
--- a/base/methods.lisp	Sun Apr 04 22:05:37 2010 +0100
+++ b/base/methods.lisp	Fri Feb 12 10:15:20 2010 +0000
@@ -542,6 +542,17 @@
           (make-standard-anchored-period (timepoint start)
                                          (duration bar-duration))))))
 
+(defmethod ioi-from-bar ((event event))
+  (- (timepoint (onset event))
+     (timepoint (current-bar event (composition event)))))
+
+(defmethod ioi-from-bar ((constituent constituent))
+  (- (timepoint (onset constituent))
+     (timepoint (current-bar constituent constituent))))
+
+(defmethod onset-in-bar ((o moment))
+  (1+ (ioi-from-bar o)))
+
 (defmethod beat-period ((moment standard-moment)
                         (time-signature standard-time-signature)
                         (composition composition))
diff -r d70ff27b1968 -r a85c59bcd88b base/package.lisp
--- a/base/package.lisp	Sun Apr 04 22:05:37 2010 +0100
+++ b/base/package.lisp	Fri Feb 12 10:15:20 2010 +0000
@@ -155,6 +155,8 @@
            #:diatonic-pitch-mp
 	   #:current-beat
 	   #:current-bar
+	   #:ioi-from-bar
+	   #:onset-in-bar
 	   ;; condition restart options
 	   #:use-whole-bar
 	   #:use-crotchet-beat