relative coordinates of different note heads

[Marc Hohl]

Hello,

I'm forwarding this to -devel according to Carl's proposals.

David Stocker has written an overview of desired features for lilypond 
and I am
trying to write some music functions as a preliminary step for the 
implemetation.
For this, I need to know the x and y coordinates of two consecutive 
noteheads
to draw pointed slurs and bend arrows, respectively.
I have some postscript code already available, but I didn't manage to 
get the
coordinates I need to draw the stuff.

Any hints/help is gladly apprechiated.

Marc

-------- Original-Nachricht --------
Betreff:        Re: start [was: Re: Take 1]
Datum:  Wed, 1 Jul 2009 07:57:28 -0600
Von:    Carl D. Sorensen <address@hidden>
An:     Marc Hohl <address@hidden>



Marc,

This question should be asked on the -devel list; somebody there will be
able to help you.

Carl


On 7/1/09 1:47 AM, "Marc Hohl" <address@hidden> wrote:

> [...]
> > I agree that the syntax will eventually be important.  And if it's decided
> > to do the engraver and create the new syntax, it'll need to be thought
> > through carefully.
> >
> > But it's seldom the best way to get *started*.
> >  
> Ok. As I use MusiXTeX for guitar music, I defined the pointed slurs and the
> bend arrows by use of postscript, so I think the code could be reused here.
>
> For the pointed slurs, I need the coordinates of the noteheads
> (i.e. the height and the distance) to calculate the three points needed.
> The only coordinates I can get so far are the x- and y-extensions of the
> note heads themselves. This is important for placing the edges of the slurs
> properly, but I have no idea how to get coordinates relative to each other.
>
> This is what I got so far:
>
> \version "2.13.1"
>
> #(define (check grob)
>    (let* ((stencil (ly:note-head::print grob))
>           (x-ext (ly:stencil-extent stencil X))
>           (y-ext (ly:stencil-extent stencil Y)))
>     (display x-ext)(display y-ext)(newline)
>     stencil))
>
>
> example = \relative c {
>    \clef "G_8"
>    c4 d e f
> }
>
>
>
> \layout {
>   \context {
>   \Staff
>   \override NoteHead #'stencil = #check
> }}
>
> \score { \example }
>
> It shows the coordinates of the note heads on the display and draws them
> as usual.
>
> Any hints/help appreciated!
>
> Marc
> > Thanks again for all your work.
> >
> > Carl
> >
> >
> >