in Snippets - LilyPond

Contexts and engravers 371
#(define-class ()
(ambitus-group #:accessor ambitus-group)
(ambitus-line #:accessor ambitus-line)
(ambitus-up-note #:getter ambitus-up-note
#:init-form (make ))
(ambitus-down-note #:getter ambitus-down-note
#:init-form (make ))
(start-c0 #:accessor ambitus-start-c0
#:init-value #f)
(start-key-sig #:accessor ambitus-start-key-sig
#:init-value '()))
%%% Accessor for the lower and upper note data of an ambitus
#(define-method (ambitus-note (ambitus ) direction)
"If @var{direction} is @code{UP}, then return the upper ambitus note
of @var{ambitus}, otherwise return the lower ambitus note."
(if (= direction UP)
(ambitus-up-note ambitus)
(ambitus-down-note ambitus)))
%%% The class holds the grobs that are specific to ambitus
%%% (lower and upper) notes:
%%% - head: an AmbitusNoteHead grob;
%%% - accidental: an AmbitusAccidental grob, to be possibly printed next
%%% to the ambitus note head.
%%% Moreover:
%%% - pitch is the absolute pitch of the note
%%% - cause is the note event that causes this ambitus note, i.e. the lower
%%% or upper note of the considered music sequence.
#(define-class ()
(head #:accessor ambitus-note-head
#:init-value #f)
(accidental #:accessor ambitus-note-accidental
#:init-value #f)
(cause #:accessor ambitus-note-cause
#:init-value #f)
(pitch #:accessor ambitus-note-pitch
#:init-value #f))
%%%
%%% Ambitus engraving logics
%%%
%%% Rewrite of the code from @file{lily/ambitus-engraver.cc}.
#(define (make-ambitus translator)
"Build an ambitus object: initialize all the grobs and their relations.
The Ambitus grob contain all other grobs:
Ambitus
|- AmbitusLine