Maybe the below message will get through later, but maybe it's blocked because of the attachement size, so I resend it with the attachments uploaded to
https://cloud.ursliska.de/index.php/s/km6cHCuuMF7AcWt and https://cloud.ursliska.de/index.php/s/6R90WOE3JPOGNKL (these may not be permanent!) Best Urs Am 21.09.2016 um 18:01 schrieb Urs Liska: > > Hey all, > > I wouldn't claim production readiness yet, but I've gone a long way > with multi-segmented slurs :-) > > As you can see from the attached PDF files (if they don't block the > message from being delivered ...) we can now print slurs with an > arbitrary number of connected segments! The slur in the first system > is along the lines of the orginal print, and I've added a "fancy" > example with the red slur in the lower system. > > Of course it's somewhat tedious to finetune these slurs, but I found > it's surprisingly convenient to do, and with little surprises. The > critical point is that the segments are completely independent -with > the exeption of the forced equal angle at the inflection points. So > what one basically does is add one inflection point after another, and > one can independently tweak the slur to the left of each inflection > point, without serious side-effects. > > I've completely disposed of any "offset" specification except for the > positioning of the two ends. For all the control point editing you > will give it an angle (which is relative to the baseline of the > segment) and a ratio (in relation to the length of that baseline). > This gives very predictable results and makes tweaking as easy as one > can expect with such complex notation. Of course this even more begs > for a graphical tweaking interface ... But of course this function is > substantially more reliable than anything you can do with other tools. > > I don't copy the whole code into the email anymore, the sources are > now at > https://github.com/openlilylib/snippets/tree/compound-slur/notation-snippets/shaping-bezier-curves, > in the files compound-slurs.ily and common-math-and-stencils.ily. I'll > go through another round of tidying up, but I'm happy about any > suggestions to improve the code. > > To give an idea about the interface, this is the definition of the > (first few inflections of the) upper Sorabij slur: > > ^\compoundSlur \with { > annotate = ##t > % show-original-slur = ##t > > start-point = #'(0 . 3) > start-angle = 65 > start-ratio = 0.6 > end-point = #'(2.5 . 4) > end-angle = -70 > > inflection = > #'((point . (.215 . 1.55)) > (angle . -55) > (ratio-left . 0.4) > (ratio-right . 0.22)) > > inflection = > #'((point . (.26 . -0.2)) > (angle . 60) > (ratio-left . .45) > (ratio-right . .4)) > > inflection = > #'((point . (.49 . 0.35)) > (angle . 33) > (ratio-left . .45) > (ratio-right . .15)) > > % ... > } > > So you give a few general properties for the start and end points and > then each inflection as an individual unit. The "point" is the ratio > between the end points of the slur. Angle is given relative to the > *left* base-line (and the spline to the right will exactly mirror that > value). ratio-left and ratio-right specify the length of the two > handles around the inflection point. > > I think it's already pretty clean with regard to type checking and > falling back to defaults for missing or wrong-type properties (while > issuing a warning). > > If you want to try it out you will have to have scholarLY installed > separately, in the version from https://github.com/oll-core/scholarly. > But it may be worth the effort, as it also demonstrates one of the > GSoC news: triggering footnotes from annotations. > > So far I have the impression it works very well, with some minor and > not-so-minor glitches. > > The minor one is that I'd like to specify the starting point relative > to the note head instead of to LilyPond's default decision. I think > whenever such compound slurs are necessary LilyPond's default slur > will be completely irrelevant to us, and we can instead specify the > end points explicitly anyway. \shapeII already has this as an option, > so I'll look for that. > > One larger thing is that I don't support broken slurs yet (and I won't > go after that right now - hopefully someone else chimes in now). > > The other thing I came across is the specification of the inflection > *point*. Basically the idea of specifying independent X and Y ratios > between the slur's endpoints seems practical, as it is pretty > predictable. But I realized that this only works well when the > endpoints are sufficiently different on the Y-scale. If the slur is > horizontal then *any* inflection will necessarily be on that same > horizontal line! So I need a suggestion what could be a suitable, > predictable *and* un-limited approach to specifying this. > > Another minor wish I would like to implement is printing an optional > grid which will ease finding the right inflection points, and maybe a > raster along the handles (going beyond their current length. This > would make it much easier to find the right values for these. > > Have fun > > Urs > > Am 20.09.2016 um 13:53 schrieb Trevor Daniels: >> Impressive work, Urs! Kudos! >> >> Trevor >> >> >> ----- Original Message ----- >> *From:* Urs Liska <mailto:u...@openlilylib.org> >> *To:* lilypond-user@gnu.org <mailto:lilypond-user@gnu.org> >> *Sent:* Monday, September 19, 2016 11:40 PM >> *Subject:* Re: What to do wanting a 4th order Bézier? >> >> >> >> Am 19.09.2016 um 22:49 schrieb Urs Liska: >>> Am 19.09.2016 um 20:50 schrieb David Kastrup: >>>> Urs Liska <u...@openlilylib.org> writes: >>>> >>>> [...] >>>> >>>> You are working with slopes here. Don't. They don't support vertical >>>> lines. >>>> >>> Yes, that's what I realized ... >>> >>>> Please take a look at the recently added functions >>>> >>>> ly:length ly:angle ly:directed >>>> >>>> They will usually make it easy to do the operations you want. In >>>> particular ly:directed can also use a vector as a direction without >>>> ever >>>> calculating its angle. >>> Thanks! From looking at the docs it seems they'll do exactly what I want >>> (and had partially implemented in Scheme). Can't wait to return to my >>> LilyPond computer :-) >>> >> >> I think I now have it in a state where we can work from. The >> angle of the inflection is now given as an angle relative to the >> line connecting the end points of the whole slur. While an angle >> relative to the horizontal line would be somewhat more >> straightforward I think this approach is more robust against >> changes (for example when the slur is cross-staff and the >> staff-staff distance changes). >> >> TODO: >> >> * support more than two segments >> (shouldn't be *that* difficult, just tedious and slightly >> complex) >> * support broken slurs >> (each sibling should be togglable between multi-segment or >> not, and it should be \shape-able) >> * support Slur, PhrasingSlur and Tie (like \shape) >> * specify shapes as polar coordinates (or all options that >> \shapeII has) >> >> The code is now at >> >> https://github.com/openlilylib/snippets/tree/compound-slur/notation-snippets/shaping-bezier-curves >> >> Best >> Urs >> >> ------------------------------------------------------------------------ >> _______________________________________________ >> lilypond-user mailing list >> lilypond-user@gnu.org >> https://lists.gnu.org/mailman/listinfo/lilypond-user >> >
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