stem length becomes short for stem up note when pitch increase

• Aug 8, 2012 - 03:19
Type
Functional
Severity
S4 - Minor
Status
active
Project

git ce351a2ed7

add eight note with no beam, press "x" to stem up.
- expect: the stem length remains same
- actual: the stem length become shorter and shorter when pitch increase

stem length

Attachment Size
stem-up-len.png 8.32 KB
stem-up-len.mscz 1.81 KB

Comments

I believe it's a feature (?). See Style -> Edit general style -> Note -> Reduce stem length.
I'm not sure why this feature exists, and if it should be on by default. Maybe it should only apply to notes without hook?

It's ST_shortenStem in Style, and can be set through score->style()->set(ST_shortenStem, false)

"I'm not sure why this feature exists, and if it should be on by default."
mm, me too.

" Maybe it should only apply to notes without hook?"
in beam notes should shorten length?

I don't know the official rules - presumably Elaine Gould has something to say about it - but it does seem to be a pretty common thing in the published music I have. The posted excerpt looks pretty much spot-on to me.

Lilypond has a "stem-shorten" array: "How much a stem in a forced direction should be shortened. The list gives an amount depending on the number of flags and beams."
See http://lilypond.org/doc/v2.14/Documentation/internals/stem_002dinterface
According to the regression test suite stem-shorten.ly: "If note head is ‘over’ the center line, the stem is shortened. This happens with forced stem directions, and with some chord configurations."

In the code you can read
;; Stems in unnatural (forced) direction should be shortened by
;; one staff space, according to [Roush & Gourlay].
;; Flagged stems we shorten only half a staff space.
(stem-shorten . (1.0 0.5))

I believe this is for unbeamed notes. For beams, there is another property named beamed-stem-shorten

;; If we shorten beamed stems less than normal stems (1 staff-space),
;; or high order less than 8th beams, patterns like
;; c''4 [c''8 c''] c''4 [c''16 c]
;; are ugly (different stem lengths).
;;
;; But if we shorten 16th beams as much as 8th beams, a single
;; forced 16th beam looks *very* short.

;; We choose to shorten 8th beams the same as single stems,
;; and high order beams less than 8th beams, so that all
;; isolated shortened beams look nice and a bit shortened,
;; sadly possibly breaking patterns with high order beams.
(beamed-stem-shorten . (1.0 0.5 0.25))