Am Sa., 1. Juni 2019 um 14:33 Uhr schrieb David Kastrup <[email protected]>: > > Thomas Morley <[email protected]> writes: > > > Hi, > > > > currently I continue my work to create a Slash-grob for automatic slashed > > Beams. > > The Slash-stencil needs to know Beam-properties (X-positions, > > positions) to be adjusted. If I call those beam-properties directly > > the Beam collopses, because this call is done before the Beam is > > ready. > > But if I wrap the Slash-stencil in another procedure like > > (define slash-stil (lambda (grob) (lambda (grob) ...))) > > all works. > > > > Questions: > > - Why does it work? (it seems the outer procedure is called > > before-line-breaking, the inner after-line-breaking) > > - Is this something I can rely on (I'm thinking of patch) or am I > > doing bug-using? > > Depends on whether someone asks for your stencil prematurely. We have a > lot of those implicit dependencies though. > > > - Is there a better/different method? > > An unpure/pure container has somewhat more defined semantics when its > respective callbacks are exercised. But if it works without, go for it.
So far I didn't encounter other problems, apart from my insufficient math... I just asked on -user for some problem. > If it doesn't and the Beam uses unpure-pure-containers, you can also use > an unpure-pure-container and work with ly:pure-call and ly:unpure-call > in your respective callbacks: those work even when the definition of > Beam changes significantly. Beam uses `grob::unpure-vertical-skylines-from-stencil´ for vertical-skylines. I plan to use `grob::always-vertical-skylines-from-stencil´ there for Slash. Though, as far as I know this has no direct impact on the used stencil procedure. Thanks, Harm _______________________________________________ lilypond-devel mailing list [email protected] https://lists.gnu.org/mailman/listinfo/lilypond-devel
