Re: Springs and rods
On Thu 23 Jul 2020 at 19:15:25 (+1000), Andrew Bernard wrote: > There are some things in lilypond that I just think are not explained > anywhere. What is this springs-and-rods business? For Hairpins, I read > this? > > minimum-length (dimension, in staff space): > 2.0 > > Try to make a spanner at least this long, normally in the horizontal > direction. This requires an appropriate callback for the > springs-and-rods property. If added to a Tie, this sets the minimum > distance between noteheads. > > And: > springs-and-rods (boolean): > ly:spanner::set-spacing-rods > > Dummy variable for triggering spacing routines. > > > With all due respect to our fantastic developers, I find this > unintelligible and less than helpful. What is springs-and-rods > supposed to be set to: ly:spanner::set-spacing-rods, or ##t, or ##f > and when, and why? What exactly is meant by 'dummy' in this context? > I use that word to mean a temporary placeholder, but there are many > usages. WHat is 'an appropriate callback'? No example is provided. > > If I had any idea at all about this I would write a small section in > the NR on it and submit it, but I am stumped. if this _is_ in the NR, > please let me know. No references as this is just coming out of my head. I've always assumed that the concept of springs and rods is analogous to TeX's glue and little boxes, respectively. Knuth IIRC makes the analogy of the compositor's stick, with boxes instead of metal type. When the next word would overfill the line, tne interword spacing is increased to justify the line. (I don't remember whether the extra space is filled with stretched glue, or with glued leading.) With test, you have the complications of kerning, and of changes in font (like italics/upright). With music, the complications are greater: if you increase the spacing between notes, you've got to tell the hairpins to lengthen and decrease their apical angle. Presumably, that's the callback for springs, resisting and reacting to stretching. The rods are presumably what prevents notes getting so close that LP can't draw a tie between them. Unlike, say, lyrics, which are allowed to squeeze lyric-hyphens out of existence. In TeX, boxes can kern, but are otherwise incompressible. Cheers, David.
Re: Springs and rods
- Original Message - From: "Andrew Bernard" To: "lilypond-user Mailinglist" Sent: Thursday, July 23, 2020 10:15 AM Subject: Springs and rods There are some things in lilypond that I just think are not explained anywhere. What is this springs-and-rods business? For Hairpins, I read this? minimum-length (dimension, in staff space): 2.0 Try to make a spanner at least this long, normally in the horizontal direction. This requires an appropriate callback for the springs-and-rods property. If added to a Tie, this sets the minimum distance between noteheads. And: springs-and-rods (boolean): ly:spanner::set-spacing-rods Dummy variable for triggering spacing routines. With all due respect to our fantastic developers, I find this unintelligible and less than helpful. What is springs-and-rods supposed to be set to: ly:spanner::set-spacing-rods, or ##t, or ##f and when, and why? What exactly is meant by 'dummy' in this context? I use that word to mean a temporary placeholder, but there are many usages. WHat is 'an appropriate callback'? No example is provided. If I had any idea at all about this I would write a small section in the NR on it and submit it, but I am stumped. if this _is_ in the NR, please let me know. There is some documentation here: http://lilypond.org/doc/v2.20/Documentation/notation/spanners Is this what you need? -- Phil Holmes
Re: Springs and rods
Hi Andrew, thanks for raising this question I have always been too afraid to ask ;-) Urs Am Donnerstag, den 23.07.2020, 19:15 +1000 schrieb Andrew Bernard: > There are some things in lilypond that I just think are not explained > anywhere. What is this springs-and-rods business? For Hairpins, I > read > this? > > minimum-length (dimension, in staff space): > 2.0 > > Try to make a spanner at least this long, normally in the horizontal > direction. This requires an appropriate callback for the > springs-and-rods property. If added to a Tie, this sets the minimum > distance between noteheads. > > And: > springs-and-rods (boolean): > ly:spanner::set-spacing-rods > > Dummy variable for triggering spacing routines. > > > With all due respect to our fantastic developers, I find this > unintelligible and less than helpful. What is springs-and-rods > supposed to be set to: ly:spanner::set-spacing-rods, or ##t, or ##f > and when, and why? What exactly is meant by 'dummy' in this context? > I use that word to mean a temporary placeholder, but there are many > usages. WHat is 'an appropriate callback'? No example is provided. > > If I had any idea at all about this I would write a small section in > the NR on it and submit it, but I am stumped. if this _is_ in the NR, > please let me know. > > > Andrew >
Springs and rods
There are some things in lilypond that I just think are not explained anywhere. What is this springs-and-rods business? For Hairpins, I read this? minimum-length (dimension, in staff space): 2.0 Try to make a spanner at least this long, normally in the horizontal direction. This requires an appropriate callback for the springs-and-rods property. If added to a Tie, this sets the minimum distance between noteheads. And: springs-and-rods (boolean): ly:spanner::set-spacing-rods Dummy variable for triggering spacing routines. With all due respect to our fantastic developers, I find this unintelligible and less than helpful. What is springs-and-rods supposed to be set to: ly:spanner::set-spacing-rods, or ##t, or ##f and when, and why? What exactly is meant by 'dummy' in this context? I use that word to mean a temporary placeholder, but there are many usages. WHat is 'an appropriate callback'? No example is provided. If I had any idea at all about this I would write a small section in the NR on it and submit it, but I am stumped. if this _is_ in the NR, please let me know. Andrew
Re: Springs and rods
Andrew Bernard wrote 18/01/2019 04:33:12 Subject: Springs and rods Yet another annoying question about documentation from me. After figuring out how to make a glissando longer, and discovering this in the NR under the spanner interface: minimum-length (dimension, in staff space) Try to make a spanner at least this long, normally in the horizontal direction. This requires an appropriate callback for the springs-and-rods property. If added to a Tie, this sets the minimum distance between noteheads. I can only ask and I think reasonably where is this mystical springs-and-rods mechanism explained? Why does one need to do this: \override Glissando #'minimum-length = #4 \override Glissando #'springs-and-rods = #ly:spanner::set-spacing-rods This is acknowledged to be sub-optimal. AIUI, it stems from the multiple uses of the 'minimum-length property. It is used in several interfaces, including lyric-hyphen, multi-measure-rest, etc, as well as spanner. Some of these require the additional override to work correctly; others don't. The solution would be to separate out the two types of use of the 'minimum-length property into two separate properties, one incorporating set-spacing-rods, but the difficulties involved in doing that seem severe as it's at least 6 years since this was discussed as an issue. I don't understand what the complexities are - maybe one of the devs could explain further. But in the expectation this would eventually be fixed (and so the need for documentation obviated) it has never been documented properly. Trevor ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
Springs and rods
Yet another annoying question about documentation from me. After figuring out how to make a glissando longer, and discovering this in the NR under the spanner interface: minimum-length (dimension, in staff space) Try to make a spanner at least this long, normally in the horizontal direction. This requires an appropriate callback for the springs-and-rods property. If added to a Tie, this sets the minimum distance between noteheads. I can only ask and I think reasonably where is this mystical springs-and-rods mechanism explained? Why does one need to do this: \override Glissando #'minimum-length = #4 \override Glissando #'springs-and-rods = #ly:spanner::set-spacing-rods How is one meant to know what an 'appropriate callback is'? What other callback would one use? And what for? I have to honestly say that if I could ever understand the lilypond internals I would readily volunteer to rewrite these sections in the NR, which occur far too often I am afraid. I've been using lilypond heavily for years, and sections like this simply make me feel dumb. Perhaps I missed something fundamental along the learning curve. None of this criticism is aimed at any person. I am well aware this sort of manual is reference and not tutorial. There used to be a series of computer publications called [X]: The Missing Manual. I feel we need the missing manual for lilypond. I don't know enough to write it. All help most appreciated. Andrew ___ lilypond-user mailing list lilypond-user@gnu.org https://lists.gnu.org/mailman/listinfo/lilypond-user
