Re: Whiteout box function by Thomas Morley / need help

[Thomas Morley]

2014-04-06 11:39 GMT+02:00 Karol Majewski <address@hidden>:
> Thanks Harm.
>
> In SpanBar-Dynamics conflict I still prefer whiteout over 
> DynamicText.extra-spacing-width = ##f. The only problem is that sometimes 
> whiteout box does not cover the whole barline width. Function I'm asking for 
> would allow to control the width of whiteout box.

Hi Karol,

below the revised function.
'moreWhiteout' takes one optional and two normal arguments:
Specifying whether the stencil should be boxed (boolean), which grob
(string) and the values to extent the stencil. These values can be
given as simple pair, affecting only X-axis-extension or as list of
pairs, affecting X- and Y-axis-extent.
The boolean may be of some use for debugging, though it will affect
spacing! Perhaps I should delete it ...

Otherwise I did some clean up and made the function more robust.
Please test.

\version "2.19.3"

moreWhiteout =
#(define-music-function (parser location better-viewing? grob-name adds)
  ((boolean? #f) string? pair?)

  (define (interval-add iv-1 iv-2)
    (cons (+ (car iv-1)(car iv-2))
          (+ (cdr iv-1)(cdr iv-2))))

  (define more-stencil-whiteout
    (lambda (grob)
      (let* ((function (assoc-get 'stencil
                            (reverse (ly:grob-basic-properties grob))))
             (stil ;; Ugh, is there no better way to test that a grob has no
                   ;; 'stencil and that no other previous procedure assigned
                   ;; a stencil-value to said grob?
                   (if (and (procedure? function)
                            (not (eq? (procedure-name function)
                                      'more-stencil-whiteout)))
                   (function grob)
                   (begin
                     (ly:warning "~a has no stencil. Ignoring" grob)
                     #f))))
        (if stil
            (let*((x-ext (ly:stencil-extent stil X))
                  (y-ext (ly:stencil-extent stil Y))
                  (add-to-x-ext (if (pair? (car adds)) (car adds) adds))
                  (add-to-y-ext (if (pair? (cdr adds)) (cadr adds) '(0 . 0)))
                  (new-stil (ly:make-stencil
                               (ly:stencil-expr stil)
                               (interval-add x-ext add-to-x-ext)
                               (interval-add y-ext add-to-y-ext))))


               ;; please note: setting better-viewing #t, will add a little
               ;; padding around the new stil and it will affect spacing in most
               ;; other cases, too.
               ;; We let it in, perhaps it may be of some help in certain cases.
               (if better-viewing?
                   (box-stencil new-stil 0.1 0.01)
                   new-stil))
            #f))))

  #{
    %% Seems no longer needed:
    %\once \override $grob-name . vertical-skylines = #'()
    %% Better to add next two lines:
    \once \override $grob-name . layer = #10
    \once \override $grob-name . whiteout = ##t
    \once \override $grob-name . stencil = #more-stencil-whiteout
  #})

%%%%%%%%%%%%%%%%%%%%%%%
%% EXAMPLE
%%%%%%%%%%%%%%%%%%%%%%%

musicI = { \time 2/4 \repeat unfold 16 b8 }

musicII = {
  r2
  %% apply to X- and Y-axis
  \moreWhiteout TextScript #'((-2 . 0.5)(0 . 2))
  b4^"XXXXXX" b
  r2
  %% apply to X-axis only
  \moreWhiteout ##t TextScript #'(-2 . 0.5)
  b4^"XXXXXX" b
}


\new StaffGroup <<
  \new Staff \relative c'' \musicI
  \new Staff \relative c'' \musicII
>>

Ofcourse the extension happens as a rectangle.
No idea to do it different.

> BTW, In documentation for 2.19 it's written that default value for 
> DynamicText.extra-spacing-width is '(+inf.0 . -inf.0), which is not true 
> anymore.

I think you're wrong.
The following returns '(+inf.0 . -inf.0) !

{
  \override DynamicText.after-line-breaking =
    #(lambda (grob) (write (ly:grob-property grob 'extra-spacing-width)))
  c1\f
}

HTH,
  Harm