Re: how offsets and alignment works: an explanation

[Thomas Morley]

2013/3/25 Thomas Morley <address@hidden>:
> 2013/3/24 Janek Warchoł <address@hidden>:
>
>> On Sun, Mar 24, 2013 at 3:02 AM, Thomas Morley
>> <address@hidden> wrote:
>>> this is great!!
> [...]
>> Could i ask you to write a function that would print a red dot on top
>> of a grob's refpoint?  (the image i've attached was made with GIMP,
>> and it would be better to have it in lily code.  I'm sure this would
>> be simple for you.)
>
> Sometimes simple things are the most difficult. :)
>
> Will try the upcoming days.

Hi Janek,

functions below as desired. :)

Usage:
\printRefpoint <boolean> <arg>
<arg> may be a single grob-name-symbol or a list of grob-names or 'all-grobs
Setting <boolean> #t will result in an additional text, printing the
grob-name. Enabling it will result in possible
overlappings.
Due to issue 3255 the output will be strange, while using a newer devel-version.

I didn't manage to apply \printRefpoint only once. Hints?
Therefore I provide a second method.

More comments in code.


\version "2.16.2"

#(set-global-staff-size 20)

#(define (add-dot text?)
  (lambda (grob)
      (let* ((layout (ly:grob-layout grob))
             (props (layout-extract-page-properties layout))
             (font
               (ly:paper-get-font layout
                 (cons '((font-encoding . fetaMusic)) props)))
             ;; Get the stencil-procedure from ly:grob-basic-properties.
             ;; If any, use it to create the stencil.
             (function (assoc-get 'stencil (ly:grob-basic-properties grob)))
             (stencil (if function (function grob) point-stencil))
             ;; Get the grob-name and create a text-stencil.
             ;; Read out the y-length for later translate.
             (grob-name-proc
                (lambda (x) (assq-ref (ly:grob-property x 'meta) 'name)))
             (grob-name (grob-name-proc grob))
             (grob-string (if (symbol? grob-name)
                              (symbol->string grob-name)
                              "no name"))
             (ref-text-stil (grob-interpret-markup grob
                                  (markup
                                     #:with-color red
                                     #:normal-text
                                     #:abs-fontsize 6
                                     (string-append "   " grob-string))))
             (ref-text-stil-length
                (interval-length (ly:stencil-extent ref-text-stil Y)))
             (grob-string-stil (if text? (grob-interpret-markup grob
                                  (markup
                                     #:with-dimensions '(0 . 0) '(0 . 0)
                                     #:stencil
                                     ref-text-stil))
                                     point-stencil
                                     ))
             ;; Create a red-dot-stencil
             (dot (ly:font-get-glyph font "dots.dot"))
             (red-dot (ly:stencil-in-color dot 1 0 0))
             (red-dot-length
                (interval-length (ly:stencil-extent red-dot X)))
             (red-dot-stil
                (ly:stencil-translate-axis red-dot (/ red-dot-length -2) X)))

      ;; If there's a grob with stencil-procedure and a valid stencil is
      ;; created, add the red-dot-stil and an optional text-stencil.
      (if (and function (ly:stencil? stencil) (grob::is-live? grob))
          (ly:grob-set-property! grob 'stencil
            (ly:stencil-add
              stencil
              red-dot-stil
              (if text?
                (ly:stencil-translate-axis
                  (ly:stencil-rotate
                    grob-string-stil
                    90 0 0)
                    (/ ref-text-stil-length 2)
                    X)
                point-stencil)))))))

% needs to be here for 2.16.2
#(define-public (symbol-list-or-symbol? x)
  (if (list? x)
      (every symbol? x)
      (symbol? x)))

#(define (add-red-dot-to-grobs text? l)
 ;; possible values for l:
 ;;   'all-grobs (adds red-dots to all grobs, where possible)
 ;;          this will naturally cause collisions,
 ;;   a single grob-name, must be a symbol,
 ;;   a list of grob-names,
 ;;   anything else (returns the unchanged original stencil)
 ;;  TODO: How to apply it once?
  (let ((grobs-to-consider
          (cond ((eq? l 'all-grobs)
                  all-grob-descriptions)
                ((symbol? l)
                  (list (assoc l all-grob-descriptions)))
                ((list? l)
                  (map
                    (lambda (grob)
                      (assoc grob all-grob-descriptions))
                      l))
                (else '()))))
  (lambda (context)
   (let loop ((x grobs-to-consider))
    (if (not (null? x))
     (let ((grob-name (caar x)))
      (ly:context-pushpop-property
         context
         grob-name
         'after-line-breaking
         (add-dot text?))
      (loop (cdr x))))))))

printRefpoint =
#(define-music-function (parser location text? s-or-l)(boolean?
symbol-list-or-symbol?)
"
 Will add a red dot (and an optional text) to the stencil's ref-point of the
 specified grob(s).
 Valid input for s-or-l:
      @code{'all-grobs}, (adds red-dots to all grobs, where possible), this will
          naturally cause collisions
      a single grob-name, must be a symbol,
      a list of grob-names.
 The additional text may be activated by @code{##t}.
 To avoid bleeding-overs any context has to be initiated explicitly.
"
#{
        \applyContext #(add-red-dot-to-grobs text? s-or-l)
#})

%% For single use:

#(define addDot
  (lambda (grob)
      (let* ((function (assoc-get 'stencil (ly:grob-basic-properties grob)))
             (stencil (if function (function grob) point-stencil))
             (layout (ly:grob-layout grob))
             (props (layout-extract-page-properties layout))
             (font
               (ly:paper-get-font layout
                 (cons '((font-encoding . fetaMusic)) props)))
             (dot (ly:font-get-glyph font "dots.dot"))
             (red-dot (ly:stencil-in-color dot 1 0 0))
             (red-dot-length (interval-length (ly:stencil-extent red-dot X)))
             (red-dot-stil
                (ly:stencil-translate-axis red-dot (/ red-dot-length -2) X)))

      (if (and function (ly:stencil? stencil) (grob::is-live? grob))
          (ly:grob-set-property! grob 'stencil
            (ly:stencil-add
              stencil
              red-dot-stil))))))

%% Overriding grobs must be defined separately.
%% Don't forget to specify the context if necessary.
onceRedScript = \once \override Script #'after-line-breaking = #addDot

%%%%%%%%%%%%
%%% EXAMPLES
%%%%%%%%%%%%

mus =
{
        \override NoteHead #'style = #'altdefault
        g'2->
        % Testing if \printRefpoint works with a custom-override.
        \once \override Script #'stencil =
          #(lambda (grob)
             (ly:font-get-glyph (ly:grob-default-font grob) "scripts.coda"))

        c''\fermata |
        as'1^"Yogi" |
        b'\breve _"Larry" |
        \mark "Twinkle" e''8 s4.
        \bar "|."
}


\markup "Red dots are added for TimeSignature, Script, BarLine"
\new Staff \with { \printRefpoint ##f #'(TimeSignature Script BarLine) } \mus

\markup "Red dots are added for TextScript plus additional text"
\new Staff \with { \printRefpoint ##t #'TextScript } \mus

\markup "Red dots are added for all grobs"
\new Staff \with { \printRefpoint ##f #'all-grobs } \mus

\markup "Red dots are added for all grobs plus additional text"
\new Staff \with { \printRefpoint ##t #'all-grobs } \mus

\markup "Red dot is added once to Script using \\onceRedScript"
{
        \override NoteHead #'style = #'altdefault
        g'2->
        \onceRedScript
        % Testing if \printRefpoint works with a custom-override.
        \once \override Script #'stencil =
          #(lambda (grob)
             (ly:font-get-glyph (ly:grob-default-font grob) "scripts.coda"))
        c''\fermata |
        as'1^"Yogi" |
        b'\breve _"Larry" |
        \mark "Twinkle" e''8-| s4.
        \bar "|."
}


Code and png are attached, too.

Regards,
  Harm

ref-points-02.png
Description: PNG image

ref-points-02.ly
Description: Binary data