Re: Setting X-offset and Y-offset graphically.

[Richard Shann]

On Tue, 2013-04-23 at 17:31 +0200, Urs Liska wrote:
> Am 23.04.2013 17:25, schrieb Richard Shann:
> > On Tue, 2013-04-23 at 17:16 +0200, Urs Liska wrote:
> >>
> >>
> >> David Nalesnik <address@hidden> schrieb:
> >>
> >>> Hi,
> >>>
> >>>
> >>> On Tue, Apr 23, 2013 at 9:36 AM, Janek Warchoł
> >>> <address@hidden>wrote:
> >>>
> >>>> 2013/4/23 Richard Shann <address@hidden>:
> >>>>> On Sun, 2013-04-21 at 22:11 +0200, Janek Warchoł wrote:
> >>>>>>> what would be the nicest syntax using that data?
> >>>>>> \shape by David Nalesnik (it's awesome!)  Docs are here:
> >>>>>>
> >>> http://www.lilypond.org/doc/v2.17/Documentation/notation/modifying-shapes
> >>>>>> note that \shape syntax is a bit different in 2.16.
> >>>>> I have had a little read of that documentation and it seems that
> >>> \shape
> >>>>> does not use the same data. It seems that to use \shape you would
> >>> need
> >>>>> to know the default values of the control points, which I guess
> >>> could
> >>>>> only be gotten with running LilyPond ...
> >>>> I'm not sure what you mean.
> >>>>
> >>> I'm a little confused here too.  I watched the demo (very cool, BTW!)
> >>> and
> >>> you are starting with a default curve, if I'm not mistaken.
> > Well, only if the user clicks accurately on the control points marked
> > with the red crosses. The user has set up the coordinate system with the
> > first cross-hair click on the center staff line, and then the rest is
> > relative to that.
> >
> >>   Couldn't
> >>> the
> >>> results of dragging the various control points be expressed as
> >>> displacements to the curve you started with, rather than as absolute
> >>> values?  Then adjustments would be made automatically with a change in
> >>> layout.
> >> That's what I thought initially too.
> >> But maybe this default curve isn't Lilypond's? Then he'd be out of luck.
> > What would be needed is to get the user to click on the control points
> > accurately and then work out the differences from there. That could be
> > done...
> Well, is the preview in your editor LilyPond's output or something you 
> provide (sorry, can't check it out myself right now)?
> That is: is the curve the user sees already a 'real' one?
It is the real one, and in fact Denemo has no idea where anything in
that view is until the user clicks there and tells Denemo what he has
clicked on...
        continued in response to your next email...

> >> But of course, setting the control points directly is really problematic.
> > I guess the trouble comes when you change the music, right?
> Yes. With hardcoding the control points the slur will have the same 
> shape regardless of the musical context. With \shape you define some 
> overrides to Lily's own decision. And there is quite some chance (but no 
> guarantee) that it will still work if the music changes.
> 
> > Richard
> >
> >
>