[mpeg-OTspec] Suggestion for minor correction on figure styles

[Thomas Phinney]

Yes, I should be clear that I do not believe these suggested changes
are in any sense a change from the "reality on the ground"—they simply
reflect the correct(ed) logic of the features, both in theory, and as
they are currently implemented by many type designers.

Regards,

T

On Fri, Mar 26, 2010 at 2:13 PM, Levantovsky, Vladimir
<Vladimir.Levantovsky at monotypeimaging.com> wrote:
> Just to clarify things – the suggested changes in any way affect feature
> functionality or layout engine behavior – they are either bug fixes or
> simply additional language intended to clarify things.
>
>
>
> This is why I do not consider them an amendment in a true ISO sense of the
> word, and they can be implemented by corrigendum (which is good for us
> because we have one under ballot right now, and it’s not too late to make a
> comment if we believe the bug fix is necessary).
>
>
>
> Regards,
>
> Vlad
>
>
>
>
>
> From: thomas.phinney at gmail.com [mailto:thomas.phinney at gmail.com] On Behalf
> Of Thomas Phinney
> Sent: Friday, March 26, 2010 5:08 PM
> To: Levantovsky, Vladimir
> Cc: mpeg-OTspec at yahoogroups.com
> Subject: Re: [mpeg-OTspec] Suggestion for minor correction on figure styles
>
>
>
> Yes, that is a good additional amendment, IMO.
>
>
>
> T
>
> On Fri, Mar 26, 2010 at 2:01 PM, Levantovsky, Vladimir
> <Vladimir.Levantovsky at monotypeimaging.com> wrote:
>
> Thank you, Thomas.
>
>
>
> All, I would like to ask you to review this proposal and see if this is
> something we can reach a consensus on. We do have few more days for ballot
> comments to be submitted (until March 30), and we can make this proposal a
> part of the ballot comments to be included in the current draft corrigendum.
>
>
>
> On the subject of the proposed amended text – I also noticed that the UI
> suggestion section for ‘lnum’ feature recommends that “This feature should
> be inactive by default.” while the UI suggestion for ‘onum’ is silent about
> feature default state. Should we also include the recommendation that the
> ‘onum’ feature should be inactive by default? This question about
> unidentified default state was also asked on the W3C CSS mailing list.
>
>
>
> Thank you,
>
> Vladimir
>
>
>
>
>
> From: mpeg-OTspec at yahoogroups.com [mailto:mpeg-OTspec at yahoogroups.com] On
> Behalf Of Thomas Phinney
> Sent: Friday, March 26, 2010 4:50 PM
> To: mpeg-OTspec at yahoogroups.com
> Subject: [mpeg-OTspec] Suggestion for minor correction on figure styles
>
>
>
>
>
> From a conversation between me and John Daggett of Mozilla, on a CSS
> mailing list. He wrote:
>
>> OpenType spec just says "Users can switch between the lining and
>> oldstyle sets by turning this feature on or off."
>>
>> I think that may be a bug in the spec, if a designer uses old-style
>> figures as the default glyphs for numerals then the statement above
>> will be incorrect.
>
> He is of course correct. Further, the default figures in a typeface
> may be neither lining nor oldstyle, but in between or something else!
> To allow for default figures that are non-lining, or even neither
> lining nor oldstyle, I have made a more formal proposal out of my
> response.
>
> Currently the 'lnum' and 'onum' feature tags in 6.4.3.2 "Feature
> descriptions and implementations," include the following language
> (assuming they are the same as the current OT spec).
>
> LNUM
>
> Function: This feature changes selected figures from oldstyle to the
> default lining form.
> Example: The user invokes this feature in order to get lining figures,
> which fit better with all-capital text. Various characters designed to
> be used with figures may also be covered by this feature. In cases
> where lining figures are the default form, this feature would undo
> previous substitutions.
> Recommended implementation: The lnum table maps each oldstyle figure,
> and any associated characters to the corresponding lining form (GSUB
> lookup type 1).
> Application interface: For GIDs found in the lnum coverage table, the
> application passes a GID to the onum table and gets back a new GID.
> Even if the current figures resulted from an earlier substitution, it
> may not be correct to simply revert to the original GIDs, because of
> interaction with the figure width features, so it's best to use this
> table.
> UI suggestion: This feature should be inactive by default. Users can
> switch between the lining and oldstyle sets by turning this feature on
> or off. Note that this feature is distinct from the figure width
> features (pnum and tnum). When the user invokes this feature, the
> application may wish to inquire whether a change in width is also
> desired.
>
> ONUM
>
> Function: This feature changes selected figures from the default
> lining style to oldstyle form.
> Example: The user invokes this feature to get oldstyle figures, which
> fit better into the flow of normal upper- and lowercase text. Various
> characters designed to be used with figures may also have oldstyle
> versions.
> Recommended implementation: The onum table maps each lining figure,
> and any associated characters, to the corresponding oldstyle form
> (GSUB lookup type 1).
> Application interface: For GIDs found in the onum coverage table, the
> application passes a GID to the onum table and gets back a new GID.
> UI suggestion: Users can switch between the lining and oldstyle sets
> by turning this feature on or off. Note: This feature is separate from
> the figure-width features pnum and tnum. When the user changes figure
> style, the application may want to query whether a change in width is
> also desired.
> Script/language sensitivity: None.
> Feature interaction: This feature overrides the results of the Lining
> Figures feature (lnum).
>
> I hereby propose those sections of these two feature descriptions be
> replaced as follows. (Note that this also corrects a typo in the
> "lnum" application interface description, where onum was incorrectly
> referenced. Note also that there are parts both before and after the
> blocks I am amending, which can remain untouched.)
>
> LNUM
>
> Function: This feature changes selected non-lining figures to lining
> figures.
> Example: The user invokes this feature in order to get lining figures,
> which fit better with all-capital text. Various characters designed to
> be used with figures may also be covered by this feature. In cases
> where lining figures are the default form, this feature would undo
> previous substitutions.
> Recommended implementation: The lnum table maps each oldstyle figure,
> and any associated characters to the corresponding lining form (GSUB
> lookup type 1). If the default figures are non-lining, they too are
> mapped to the corresponding lining form.
> Application interface: For GIDs found in the lnum coverage table, the
> application passes a GID to the lnum table and gets back a new GID.
> Even if the current figures resulted from an earlier substitution, it
> may not be correct to simply revert to the original GIDs, because of
> interaction with the figure width features, so it's best to use this
> table.
> UI suggestion: This feature should be inactive by default. Users can
> switch between the default and lining figure sets by turning this
> feature on or off. Note that this feature is distinct from the figure
> width features (pnum and tnum). When the user invokes this feature,
> the application may wish to inquire whether a change in width is also
> desired.
>
> ONUM
>
> Function: This feature changes selected figures from the default or
> lining style to oldstyle form.
> Example: The user invokes this feature to get oldstyle figures, which
> fit better into the flow of normal upper- and lowercase text. Various
> characters designed to be used with figures may also have oldstyle
> versions.
> Recommended implementation: The onum table maps each lining figure,
> and any associated characters, to the corresponding oldstyle form
> (GSUB lookup type 1). If the default figures are non-lining, they too
> are mapped to the corresponding oldstyle form.
> Application interface: For GIDs found in the onum coverage table, the
> application passes a GID to the onum table and gets back a new GID.
> UI suggestion: Users can switch between the default and oldstyle
> figure sets by turning this feature on or off. Note: This feature is
> separate from the figure-width features pnum and tnum. When the user
> changes figure style, the application may want to query whether a
> change in width is also desired.
>
> 
>
>
> --
> "The rat's perturbed; it must sense nanobots! Code grey! We have a Helvetica
> scenario!" — http://xkcd.com/683/



-- 
"The rat's perturbed; it must sense nanobots! Code grey! We have a
Helvetica scenario!" — http://xkcd.com/683/