Re: "uniform-stretching" messes up note-spacing around time-signature changes

[Trevor Bača]

On 3/13/06, Marcus Macauley <address@hidden> wrote:
> When following Trevor's suggestion, to use
> \override SpacingSpanner #'uniform-stretching = ##t
> if I wanted my tuplets spaced evenly, I discovered one and then two spacing 
> bugs
> which occur only when uniform-stretching is on, and which appear to affect all
> notes (not just tuplets) near a change of time signature, whether it occurs in
> the middle of a line (which causes one problem) or at the end of a line (which
> causes a different problem).
>
> The following Lilypond file contains a description and several examples of 
> each
> problem.
>
> Marcus
>
>
> % Bug: The command, \override SpacingSpanner #'uniform-stretching = ##t
> % , causes at least two distinct problems with spacing of notes (tuplets or
> % straight notes) around time-signature changes.
> %    First, needless extra space is created after a mid-line time-signature
> % change. (measures 4, 6, 8, 10, 12, 13)
> %    Second, needed space is taken away from the end of the measure 
> immediately
> % before an end-of-line time-signature change. (measures 15, 17, 19)
> %    Both of these problems seeem to occur regardless of whether tuplets are
> % involved in any way.
> %    When the \override line is commented out, the spacing is correct.
>
> \version "2.7.38"
>
> \score {
>
> \new Score \with {
> % Comment out the next line to see the tuplets spaced correctly.
> \override SpacingSpanner #'uniform-stretching = ##t
> }
>
> \relative c'' { \time 2/4
> \times 2/3 {c4 c c} \times 2/3 {c4 c c} \break % 1|2|
> \times 2/3 {c4 c c} \time 2/4 \times 2/3 {c4 c c} \break % 3|4|
> c8 c c c \time 2/4 \times 2/3 {c4 c c} \break % 5|6|
> \times 2/3 {c4 c c} \time 2/4 c8 c c c \break % 7|8|
> c8 c c c \time 2/4 c8 c c c \break  % 9|10|
> c8 c c c \time 1/4 c8 c \time 2/4 c8 c c c \break % 11|12|13|
> \times 2/3 {c4 c c} \times 2/3 {c4 c c} \break \time 2/4 % 14|15|
> c8 c c c \times 4/5 {c8 c c c c}\break \time 3/4 % 16|17|
> \times 3/4 {c4 c c c} c4 c c \break \time 2/4 % 18|19|
> }
>
> \layout  {
> indent = #0
> line-width = #75
> }
>
> }

Hi Marcus,

Yeah, unfortunately I don't have an answer for this one and you're
examples look like a valid report.

I know Erik likes to keep bug examples as small as possible, so maybe
we could extract two particularly good bits from the example above?

Measure 1 through 4 demonstrate the beginning-of-measure gap quite clearly:

%%%%% uniform-stretching SPACING BUG 1 %%%%%
% Marcus Macauley

\version "2.7.38"

\new Score \with {
\override SpacingSpanner #'uniform-stretching = ##t
}

\relative c'' {
   \time 2/4
   \times 2/3 {c4 c c}
   \times 2/3 {c4 c c} \break
   \times 2/3 {c4 c c}
   \time 2/4 \times 2/3 {c4 c c} % BEG-OF-MEASURE BUG: gap after time signature
}

\layout  {
indent = #0
line-width = #75
}

%%%%%%%%% END 1 %%%%%%%%%%%%%%%%%%


And measures 16 & 17 show the end-of-measure problem particularly well
since there's an actual collision:

%%%%% uniform-stretching SPACING BUG 2 %%%%%
% Marcus Macauley

\version "2.7.38"

\new Score \with {
\override SpacingSpanner #'uniform-stretching = ##t
}

\relative c'' {
   \time 2/4
   c8 c c c
   \times 4/5 {c8 c c c c} \break % END-OF-MEASURE BUG: collision
   \time 3/4
}

\layout  {
indent = #0
line-width = #75
}

%%%%%%%%% END 2 %%%%%%%%%%%%%%%%%%


Then again, Erik might be perfectly happy with the original example, too.

Either way the pair of bugs probably aren't release critical since
uniform-stretching became available only recently in 2.7. (But
hopefully will get some attention once the 2.9 development cycle
begins.)

--
Trevor Bača
address@hidden