Re: Distance of a grob from its reference point

[Paolo Prete]

Thanks to you Carl.

Now, given that it's nonsense to offset an unknown value, I would remove this property from the offset command of Lilypond. 

Or at least, if that remove is not easily doable in the internal API, raise a *heavy* warning that you are using a random/deprecable command.

Please do not see that as bad criticism. I'm telling that because it could save time to other people.

On Thu, Jan 16, 2020 at 12:22 AM Carl Sorensen <address@hidden> wrote:

 

 

From: Paolo Prete <address@hidden>
Date: Wednesday, January 15, 2020 at 4:16 PM
To: Carl Sorensen <address@hidden>
Cc: Lilypond-User Mailing List <address@hidden>
Subject: Re: Distance of a grob from its reference point

 

I don't mean that with *broken*. I mean that it's unusable, given that the values you put inside this function don't correspond to anything that you can measure. Then, pretty random values.

 

Please note that this doesn't happen with \override SomeGrob.X/Y-offset. In that case, you can measure the offset with a ruler (in a very uncomfortable way, though, given that you have to offset the ruler as well with the ref point of the grob).

 

Yes, this is true.  Because when you \override you replace the unpure-pure-container estimate function with a fixed constant value.

 

\offset adds a fixed constant value to the existing result, which is an *estimate* rather than an actual value in the case of a Y-offset whose default value is a unpure-pure-container function.   The fact that you are offsetting an estimate leads to random values, since the difference between the estimate and the actual value is not predictable before completing the spacing algorithm.

 

Thanks,

 

Carl