Re: FootnoteItem positioning

[David Kastrup]

"Trevor Daniels" <address@hidden> writes:

> While considering how to add a footnotes to TextScript I came across
> this, which could be intended or a bug.  If the positioning number pair
> is set to #'(0 . 0) the footnote mark is located in both x and y directions
> on the centre of the TextScript object, but if the values are set to any
> non-zero value the offsets are calculated from the top-right corner of the
> TextScript object.  So to position the mark where it would normally be
> after text you have to set the values to any tiny non-zero value.
>
> Here's an example to play with:
>
> \book {
>   \header { tagline = ##f }
>   \relative c' {
>     a'4 b8
>     \once \override Staff.FootnoteItem #'annotation-line = ##f
>     \footnote  #'(0.0001 . 0.0001) #'TextScript \markup { "Prout has rall." } 
> \default
>     e^\markup { "rit." } c4 d4
>   }
> }
>
> It would be better if #'(0 . 0) resulted in the correct positioning for 
> TextScript.

I don't see what the "correct positioning" would even be in that case:
if a coordinate is positive, you go from the upper respectively right
border, if it is negative, from the lower respectively left border, if
it is zero, from the center.  That makes _perfect_ sense as long as at
least one coordinate is non-zero.  If _both_ are zero, how to choose
among the 8 possible border points?

Picking the center at least is consistent.

-- 
David Kastrup