Re: box widths

[Han-Wen Nienhuys]

address@hidden writes:
> On Wed, 2004-10-27 at 08:36, Werner LEMBERG wrote:
> > I have a fundamental problem with the width of lilypond output, and
> > which should be fixed before releasing 2.4.  Currently, I use
> > 
> >   (interval-start (ly:stencil-extent page X))
> > 
> > but this isn't the right value.  Reason:  Contrary to TeX boxes,
> > lilypond's horizontal reference point is not always the left edge of
> > the output box:
> > 
> >                      ^
> >                      |
> >                 +----+----------+
> >                 |    |          |
> >                 |    |          |
> >             ----+----+----------+--->
                    A    O          B
> >                 |    |          |
> >                 +----+----------+
> >                      |
> >                      |
> > 
> > We have `height' and `depth' as with TeX boxes, and we have `width'
> > and `extension' (to coin this term), where `width' is the amount right
> > of the y-axis, and `extension' the left amount (and let's assume that
> > `extension' is positive).
> > 
> > The above scheme code gives `width + extension', but I need `width'
> > only.  How can I get that?

ly:stencil-extent will return a pair (A . B) with A < B, and A
typically negative.

I've added a ly:stencil-origin, which returns the coordinates of O.

HTH,

Han-Wen

-- 

 Han-Wen Nienhuys   |   address@hidden   |   http://www.xs4all.nl/~hanwen