Re: using \offset with Slur.positions

[David Nalesnik]

Hi Werner,

On Tue, Apr 8, 2014 at 12:27 AM, Werner LEMBERG <address@hidden> wrote:

[2.19.4]


Folks,


it seems that \offset can't be applied to `Slur.positions'.  Doing

  \relative c' {
  \once \offset positions #'(5 . 5) Slur
    c'2( c)
  }

I get

  Warnung: the property 'positions of #<Grob Slur > cannot be offset

Doing

  \relative c' {
  \once \offset Slur.positions #'(5 . 5)
    c'2( c)
  }

instead I get no warning, but there is no effect at all.  [This looks
like a buglet, since I would expect a warning, too.]

You're right--there should be a warning.

 

Why is that?  In most cases a slur's representation can be most easily
improved by modifying the start and end points.  Using the
`control-points' property is far more complicated IMHO.

A minor issue: Would it be possible to support

  \offset Slur.positions = #'(5 . 5)

as a syntax for to be in sync with \override?

The reason this won't work is that there is no value or procedure to be found in define-grobs.scm for Slur.positions to use for a default to offset against.  Could such a procedure be offered?

BTW, there's a snippet which "offsets positions" (unfortunately, I'm not able to open the LSR to look it up). It offsets the Y-coordinate of the outer control-points then applies these values to 'positions.

--David