Re: self-alignment-X has negligible effects on dynamics

[David Kastrup]

Janek Warchoł <address@hidden> writes:

> Hi,
>
> 2014-07-28 16:13 GMT+02:00 David Nalesnik <address@hidden>:
>> In the following example, the ordinary overrides of self-alignment-X appear
>> to have no effect on the position pf the dynamics (or an effect I can't
>> see).  Large numbers are needed for an obvious shift.
>>
>> Is this a bug, or something I'm doing wrong?
>
> You're misusing self-alignment-X.  This feature is *not* for shifting
> stuff - it is meant for aligning particular point of an object on a
> particular point of its parent.  For example, self-alignment-X = #LEFT
> means "place this object so that its left edge (i.e. left end of
> X-extent) is horizontally aligned with its parent's left edge".

The documentation states:

    3.2.98 self-alignment-interface
    -------------------------------

    Position this object on itself and/or on its parent.  To this end, the
    following functions are provided:

    ‘Self_alignment_interface::[xy]_aligned_on_self’
         Align self on reference point, using ‘self-alignment-X’ and
         ‘self-alignment-Y’.
    ‘Self_alignment_interface::aligned_on_[xy]_parent’
    ‘Self_alignment_interface::centered_on_[xy]_parent’
         Shift the object so its own reference point is centered on the
         extent of the parent

    User settable properties:
    .........................

         ‘self-alignment-X’ (number)
              Specify alignment of an object.  The value ‘-1’ means left
              aligned, ‘0’ centered, and ‘1’ right-aligned in X direction.
              Other numerical values may also be specified.
         ‘self-alignment-Y’ (number)
              Like ‘self-alignment-X’ but for the Y axis.

Now a number of grobs have their definition of X-offset changed in a
manner where they will behave quite differently to previously, and
particularly differently with regard to self-alignment-X which
previously was used in several cases to only affect the self-alignment
with regard to a parent reference point.

Compare
<URL:http://lilypond.org/doc/v2.18/Documentation/notation/aligning-objects#-Self_002daligning-objects-in-both-directions>
with
<URL:http://lilypond.org/doc/v2.19/Documentation/notation/aligning-objects#-Self_002daligning-objects-in-both-directions>

It's not just that the example looks different, the code comments no
longer fit either.

This is a mechanism that has been _advertised_ for tweaking the
positioning.  It _still_ is advertised in that manner.

-- 
David Kastrup