Hello everyone,
for three days I have been immersed in the documentation written by Mr.
Samra, on how to define a new grob, a new event and a new engraver that
takes care of engraving the new grob, following a specific command.
Attached is the first result of my studies, available to everyone. Clearly
the built grob is completely useless, but it helped me to make some
attempts and understand the logic.
I hope it could be a script that shows the various stages of defining new
components, rather than modifying some existing ones. At present it needs a
revision, so:
to the more experienced, I would ask for an evaluation of what has been
done (i'm not a programmer!), above all given the non-functioning of some
overrides, which modify the properties of certain interfaces which are
however included in the grob definition.
Greetings to everyone
Rip_mus
\version "2.24.0"
%-----------------------------------------------------------------
% Pippo è un oggetto post evento che, una volta chiamato (\pippo), stampa la stringa "pippo" di un proprio colore
% (rosso di default) e rende la testa della nota relativa dello stesso colore.
% Di seguito:
% - le dichiarazioni delle funzioni di base per definire un grob e un evento (grazie a Jean Abou Samra!);
% - definizione di una nuova interfaccia, un nuovo stencil, un nuovo grob (con relativa dichiarazione #all-grob-descriptions);
% - definizione della classe di eventi, dell'evento stesso, di una funzione di creazione e di un comando Lilypond;
% - definizione dell'engraver, con relativo inserimento nel contesto Voice.
% Infine un esempio.
% [le intestazioni delle varie sezioni sono in italiano]
% Questo script è a puro scopo di studio e chiaramente non serve a nulla!
% Può essere uno spunto per costruire degli oggetti personalizzati ed estendere le funzionalità di Lilypond
%-----------------------------------------------------------------
% Pippo (Foo) is a post-event object which, once called (\pippo), prints the string "pippo" in its own color (red by default)
% and makes the relative note head of the same color.
% Right away:
% - the basic function declarations to define a grob and an event (thanks to Jean Abou Samra!);
% - definition of a new interface, a new stencil, a new grob (with relative declaration #all-grob-descriptions);
% - definition of the event class, the event itself, a create function and a Lilypond command;
% - definition of the engraver, with relative insertion in the Voice context.
% Finally an example.
% [the headings of the various sections are in Italian]
% This script is for study purposes only and is clearly useless!
% It can be a starting point for building custom objects and extending the functionality of Lilypond
%-----------------------------------------------------------------
%--------------FUNZIONI DI BASE-----------------------------------
#(define (define-grob! grob-name grob-entry)
(set! all-grob-descriptions
(cons ((@@ (lily) completize-grob-entry)
(cons grob-name grob-entry))
all-grob-descriptions)))
#(define (define-event! type properties)
(set-object-property! type
'music-description
(cdr (assq 'description properties)))
(set! properties (assoc-set! properties 'name type))
(set! properties (assq-remove! properties 'description))
(hashq-set! music-name-to-property-table type properties)
(set! music-descriptions
(sort (cons (cons type properties)
music-descriptions)
alist<?)))
%--------------DEFINIZIONE DEL GROB--------------------------------
#(ly:add-interface
'pippo-interface
"Just a markup with pippo"
'()
)
#(define (pippo-stencil grob) (grob-interpret-markup grob (ly:grob-property grob 'text)))
#(define-grob!
'PippoText
`(
(stencil . ,pippo-stencil)
(X-extent . ,empty-interval)
(Y-extent . ,empty-interval)
;(parent-alignment-X . 1) ;NOT WORKING
;(self-alignment-X . #f) ;NOT WORKING
;(padding . 0) ;NOT WORKING
(text . "pippo")
(color . ,red)
(layer . 0)
(font-size . 0)
(font-series . bold)
(transparent . #f)
(outside-staff-priority . 100)
(direction . ,UP)
(meta . (
(class . Item)
(interfaces . (
pippo-interface
text-interface
text-script-interface
font-interface
self-alignment-interface
item-interface
grob-interface
)
)
)
)
)
)
\layout {
\context {
\Global
\grobdescriptions #all-grob-descriptions
}
}
%--------------DEFINIZIONE E CREAZIONE DEL NUOVO EVENTO------------
%------------------------------------------------------------------
#(define-event-class 'pippo-event 'music-event)
#(define-event!
'PippoEvent
'(
(description . "Used to trigger pippo")
(types . (post-event pippo-event event))
)
)
#(define (make-pippo-script)
(make-music 'PippoEvent 'direction UP 'padding 100))
pippo = #(make-pippo-script)
%--------------DEFINIZIONE DELL'ENGRAVER---------------------------
#(define (Pippo_engraver context)
(let
(
(pippo-event #f)
(note-heads '())
(glob-col '())
)
(make-engraver
(listeners
(
(pippo-event engraver event)
(set! pippo-event event)
)
)
(
(process-music engraver)
(if pippo-event
(let*
(
(grob (ly:engraver-make-grob engraver 'PippoText pippo-event))
(t (ly:grob-property grob 'text))
(stil (grob-interpret-markup grob t))
(x-extent (ly:stencil-extent stil X))
(y-extent (ly:stencil-extent stil Y))
(y-offset (ly:grob-property grob 'Y-offset))
(dir (ly:event-property pippo-event 'direction))
(PCgrob (ly:context-property context 'currentMusicalColumn))
)
(set! glob-col (ly:grob-property grob 'color))
(ly:grob-set-property! grob 'X-extent x-extent)
(ly:grob-set-property! grob 'Y-extent y-extent)
(ly:grob-set-property! grob 'direction (if dir dir UP))
grob
)
)
)
(acknowledgers
(
(note-head-interface engraver grob source-engraver)
(set! note-heads (cons grob note-heads))
)
)
(
(process-acknowledged engraver)
(for-each
(lambda (note-head)
(if (and note-head pippo-event)
(begin
;---
(ly:grob-set-property! note-head 'color glob-col)
)
)
)
note-heads)
(set! note-heads '())
)
(
(stop-translation-timestep engraver)
(set! pippo-event #f)
(set! glob-col '())
)
)
)
)
\layout {
\context {
\Voice
\consists #Pippo_engraver
}
}
%----------------------------------------------------------------------------
\relative {
\once \override PippoText.font-size = 3
%\once \override PippoText.padding = 10 %NOT WORKING
a8_\pippo b4 e8 f2 r
\once \override PippoText.direction = #DOWN
\once \override PippoText.color = #blue
\once \override PippoText.whiteout = ##t
\once \override PippoText.layer = 2
\once \override PippoText.extra-offset = #'(0 . -2)
<g, d' a'>8\pippo a r e' g2
\once \override PippoText.parenthesized = ##t
\once \override PippoText.show-vertical-skylines = ##t
\once \override PippoText.show-horizontal-skylines = ##t
a2_\pippo
}
