view classes.lisp @ 19:2f331bbdfab8

Added preliminary support for time- and key-signatures and for tempi

darcs-hash:20061213155334-f76cc-a1ece6adfd1e6292e1f67418ddb3f38a56ad2233.gz

(cl:in-package #:amuse) 

;; collections of more than one event

(defclass constituent () ())
(defclass composition (constituent) ())
(defclass monody (constituent) ())

;; types of information-specifiers

(defclass moment-designator () ())
(defclass period-designator () ())
(defclass anchored-period-designator (moment-designator period-designator) ())
(defclass pitch-designator () ())
(defclass pitch-interval-designator () ())

;; time-related classes

(defclass moment (moment-designator) 
  ((time :accessor %moment-time :initarg :time)))

(defclass period (period-designator) 
  ((interval :accessor %period-interval :initarg :interval)))

(defclass floating-period (period) ())
(defclass anchored-period (period moment anchored-period-designator) ())

;; pitch-related classes

(defclass frequency () ())

(defclass pitch (pitch-designator) ())
(defclass chromatic-pitch (pitch) 
  ((number :accessor %chromatic-pitch-number :initarg :number)))
(defclass diatonic-pitch (pitch) 
  ((name :accessor %diatonic-pitch-name :initarg :name)
   (accidental :accessor %diatonic-pitch-accidental :initarg :accidental)
   (octave :accessor %diatonic-pitch-octave :initarg :octave)))
  
(defclass pitch-interval (pitch-interval-designator) 
  ((span :accessor %pitch-interval-span :initarg :span)))

(defclass midi-message () ;?
  ((channel :accessor %midi-message-channel :initarg :channel)
   (track :accessor %midi-message-track :initarg :track)))

;; events

(defclass event (anchored-period) ())
(defclass pitched-event (event pitch-designator) ())
(defclass chromatic-pitched-event (pitched-event chromatic-pitch) ())
(defclass midi-pitched-event (chromatic-pitched-event midi-message)
  ((velocity :initarg :velocity)
   (patch :initarg :patch)))
(defclass percussive-event (event) ())
(defclass midi-percussive-event (percussive-event midi-message)
  ((velocity :initarg :velocity)
   (patch :initarg :patch)
   (sound :initarg :sound)))

;;; Range-based `constituents'
;; Whilst these are all constituents in the CHARM sense, their
;; properties apply to a timed range rather than to a set of
;; events. As such, they can be regarded as anchored-periods with
;; properties.

(defclass time-signature (anchored-period) ())

(defclass basic-time-signature (anchored-period)
  ;; N.B. Can only deal with numeric signatures
  ((numerator :accessor %basic-time-signature-numerator
	      :initarg :numerator)
   (denominator :accessor %basic-time-signature-denominator
		:initarg :denominator)))

(defclass key-signature (anchored-period) ())

(defclass basic-key-signature (key-signature)
  ;; Only has line-of-fifths distance from c, so custom signatures
  ;; won't work
  ((sharp-count :accessor %basic-key-signature-sharp-count
		:initarg sharp-count)))

(defclass midi-key-signature (basic-key-signature)
  ;; Is mode ever used in real life? Is it ever accurately used in
  ;; real life?
  ((mode :accessor %midi-key-signature-mode
	 :initarg mode)))

(defclass tempo (anchored-period)
  ;; accel and rit in symbolic encoding will need other structures, as
  ;; will textual tempo markings.
  ((bpm :accessor %tempo-bpm
	:initarg :bpm)))