Fix 1229 Ensure space around prefatory matter

Fix 1229 Ensure space around prefatory matter

NonMusicalPaperColumn gets skyline padding to prevent notes from overlapping
Clef and KeySignature get extra-spacing-width for separation from accidentals

Adjust two regtests that would otherwise fail.
Add regression test.

[Keith, 2011-02-11 08:36:02]

Notable regtest changes:

accidental-broken-tie-spacing.ly

chord-name-exceptions.ly (2.12.3 had much more padding below the names, and bar
lines slipped under.)

script-stack-horizontal.ly (had been failing, now passes per its description)

The padding after a time signature slightly changes many regtests - every test
that begins with an accidental or grace note.  This padding is recommended in
the textbooks, but we might not want to add it, so I uploaded a patch without it
as well.

http://codereview.appspot.com/4187043/diff/7006/input/regression/lyrics-bar.ly
File input/regression/lyrics-bar.ly (right):

http://codereview.appspot.com/4187043/diff/7006/input/regression/lyrics-bar.l...
input/regression/lyrics-bar.ly:32: \context {
Adjust layout so that the lyrics with the repeat bars is vertically centered in
those bars, and so there is normal separation between the repeat bars and the
next line.

http://codereview.appspot.com/4187043/diff/7006/input/regression/stem-length-...
File input/regression/stem-length-estimation.ly (right):

http://codereview.appspot.com/4187043/diff/7006/input/regression/stem-length-...
input/regression/stem-length-estimation.ly:19: indent = #0
Previous version tucked notes under the time signature, and if we prevent the
tucking it will spread to another line (failing the test).  Remove first-line
indent to compensate.

[Carl, 2011-02-12 03:31:07]

LGTM.

Thanks, Keith!

Carl

[Keith, 2011-02-12 06:29:55]

Phooey.  This needs work.  Notes on ledger lines below the staff can slide past
the final bar line, although the current skyline extension should in theory
reach 1.2 staff-space beyond the barline to stop them.

It seems that skyline-vertical-padding does not act symmetrically top-to-bottom.
 If I use purely extra-spacing-height, everything conforms to my expectation, so
the bar-extent does seem to correspond to the visible bar.  I must be
misunderstanding the skylines; give me a couple days.

[Keith, 2011-02-12 07:16:46]

On 2011/02/12 06:29:55, Keith wrote:
> Phooey.  This needs work.  Notes on ledger lines below the staff 
> can slide past the final bar line,

Iff there is only one item in a NonMusicalPaperColumn, then it receives only the
sloped portion of the skyline on the bottom, not the flat portion plus sloped
portion.
Unfortunately this affects the important case of the bar line at the end of each
line of the score.

[Keith, 2011-02-12 21:55:13]

Very simple fix to the skyline implementation, and now skyline-vertical-padding
behaves as expected in detail.

[Neil Puttock, 2011-02-14 21:43:37]

Hi Keith,

My only concern with these changes is the barline avoidance (which you mention
in the tracker as possibly a good thing).  There's one regtest which shows the
problem: in `song-melisma.ly', some extra space has appeared in the second bar
around `daah'.

Cheers,
Neil

[Keith, 2011-02-14 23:25:21]

On Mon, 14 Feb 2011 13:43:37 -0800, <n.puttock@gmail.com> wrote:

>
> My only concern with these changes is the barline avoidance (which you
> mention in the tracker as possibly a good thing).  There's one regtest
> which shows the problem: in `song-melisma.ly', some extra space has
> appeared in the second bar around `daah'.
>
That's my only concern, as well.   I do not think it wise to 'recede' the
spacing height of LyricText to compensate, because I think will leave an
unpleasant surprise waiting until someone uses a very tiny lyric font or
something.

Lyrics are moved horizontally away from barlines *only* if the bottom of the
staff is perfectly clean of notes.  A single note head poking out means that
vertical spacing cannot press lyrics against the staff, which means that
note-spacing can conservatively assume the lyrics will not encroach the
forbidden 1-staff-space zone of the bar line, which means the note column need
not be moved.  This evening I'll put an image showing the effect on the tracker,
and ask explicitly whether this is a good thing or not.

What is simply fascinating, but not in a good way, is why so *much* space
appeared before the 'daah'.  It has the same case as the symptom as Janek
pointed out today.  The check for near-collisions in staff-spacing.cc decides to
increase the spring length to the note-column containing 'daah', enough that it
would be 0.3-staff-space from the bar line in tight spacing, but then in normal
spacing we see a noticeable gap.
-Keith

[Keith, 2011-02-15 18:36:06]

On 2011/02/14 23:25:21, Keith wrote:
> On Mon, 14 Feb 2011 13:43:37 -0800, <mailto:n.puttock@gmail.com> wrote:
> 
> > My only concern with these changes is the barline avoidance (which you
> > mention in the tracker as possibly a good thing).  There's one regtest
> > which shows the problem: in `song-melisma.ly', some extra space has
> > appeared in the second bar around `daah'.
> >
[...]
>  This evening I'll put an image showing the effect on the tracker,
> and ask explicitly whether this is a good thing or not.
> 

Now I'm thinking it was foolish to worry about this.  If there is /any/
protrusion on the lyrics side of the staff, anywhere in the score, then the
PaperColumn skylines used for note-spacing are built as if lyrics are spaced to
clear that protrusion. The bar-lines then slide past this assumed position of
lyrics.

Whether bar-lines avoiding lyrics is good thing or not, no-one is likely to ever
see it in anything longer than a couple bars.

Does this argument put the patch in LGTM state?

[Neil Puttock, 2011-02-15 21:45:02]

On 15 February 2011 18:36,  <k-ohara5a5a@oco.net> wrote:

> Whether bar-lines avoiding lyrics is good thing or not, no-one is likely
> to ever see it in anything longer than a couple bars.

That's exactly what I thought too (and was borne out in every snippet I tested).

> Does this argument put the patch in LGTM state?

No objections here.

Cheers,
Neil

[Trevor Daniels, 2011-02-16 16:08:10]

On 2011/02/15 18:36:06, Keith wrote:

> If there is /any/ protrusion on the lyrics side of the staff, 
> anywhere in the score, then the PaperColumn skylines used for
> note-spacing are built as if lyrics are spaced to clear that
> protrusion. The bar-lines then slide past this assumed position
> of lyrics.

> Whether bar-lines avoiding lyrics is good thing or not, no-one
> is likely to ever see it in anything longer than a couple bars.

Actually it would be quite common for a vocal piece to have no
soprano note above f'', or no bass note below g, .  Such a piece
would have different behaviour for AT and SB wrt lyrics and
bar lines.  I think you're right to worry about this.

Trevor

[Keith, 2011-02-16 20:55:34]

On Wed, 16 Feb 2011 08:08:10 -0800, <tdanielsmusic@googlemail.com> wrote:

> On 2011/02/15 18:36:06, Keith wrote:
>
>> If there is /any/ protrusion on the lyrics side of the staff,
>> anywhere in the score, then the PaperColumn skylines used for
>> note-spacing are built as if lyrics are spaced to clear that
>> protrusion. The bar-lines then slide past this assumed position
>> of lyrics.
>
> Actually it would be quite common for a vocal piece to have no
> soprano note above f'', or no bass note below g, .

The stems on mid-staff notes still protrude in that case, letting the bar-lines
slide past lyrics.

Only in the case of a completely clear bottom edge of the staff, does this patch
expand the bar to fit LyricText.

[t.daniels_treda.co.uk, 2011-02-16 23:20:36]

Keith OHara wrote Wednesday, February 16, 2011 8:54 PM


> On Wed, 16 Feb 2011 08:08:10 -0800, <tdanielsmusic@googlemail.com> 
> wrote:
>
>> On 2011/02/15 18:36:06, Keith wrote:
>>
>>> If there is /any/ protrusion on the lyrics side of the staff,
>>> anywhere in the score, then the PaperColumn skylines used for
>>> note-spacing are built as if lyrics are spaced to clear that
>>> protrusion. The bar-lines then slide past this assumed position
>>> of lyrics.
>>
>> Actually it would be quite common for a vocal piece to have no
>> soprano note above f'', or no bass note below g, .
>
> The stems on mid-staff notes still protrude in that case, letting 
> the bar-lines slide past lyrics.
>
> Only in the case of a completely clear bottom edge of the staff, 
> does this patch expand the bar to fit LyricText.

Ah, of course.  No problem then.

Trevor

[Graham Percival (old account), 2011-02-17 18:32:54]

Ok, it seems we're all ok with this.

Keith, please email the patch to Trevor for pushing.

[t.daniels_treda.co.uk, 2011-02-18 09:35:59]

From: <percival.music.ca@gmail.com> 
Thursday, February 17, 2011 6:32 PM


> Ok, it seems we're all ok with this.
> 
> Keith, please email the patch to Trevor for pushing.
> 
> http://codereview.appspot.com/4187043/

Pushed:
6d751144f402dc58ff3f65df0fcaab021a86908c

and reg tests bumped to 2.13.51:
6ca2619b3ae13ae94b8f43b124e92d86e0d3748c

Thanks Keith

Trevor