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Re: [TTML2] tts:{width,height} rename

From: Glenn Adams <glenn@skynav.com>
Date: Tue, 27 Jan 2015 09:46:58 -0700
Message-ID: <CACQ=j+faiv2gOP6b0W3O_QLBg4v6Xs85E2EVwHPgCDG8JDSd2g@mail.gmail.com>
To: Pierre-Anthony Lemieux <pal@sandflow.com>
Cc: David Singer <singer@apple.com>, TTWG <public-tt@w3.org>
On Tue, Jan 27, 2015 at 9:38 AM, Pierre-Anthony Lemieux <pal@sandflow.com>
wrote:

> > tts:{ipd,bpd} are used to specify constraints on the dimensions of areas
> generated by content elements
>
> This is in addition to region height/width, or instead, or something else?
>
> Is there a ticket related to this feature?
>

not a new feature: just a name change from what was introduced as the
solution for ISSUE-237 [1]

[1] http://www.w3.org/AudioVideo/TT/tracker/issues/237


>
> Best,
>
> -- Pierre
>
> On Tue, Jan 27, 2015 at 8:12 AM, Glenn Adams <glenn@skynav.com> wrote:
> > ipd = inline progression dimension
> > bpd = block progression dimension
> >
> > they are the writing mode relative counterparts to width and height; the
> > problem with the latter is that they are strongly associated with
> absolute
> > axes (horizontal and vertical), while the former {ipd,bpd} don't suffer
> from
> > that association
> >
> > it also requires less spec text and results in less confusion in the
> spec,
> > since in all places at present (except for line height), width and height
> > are interpreted in an absolute sense independent of writing mode
> >
> > tts:{ipd,bpd} are used to specify constraints on the dimensions of areas
> > generated by content elements
> >
> > On Tue, Jan 27, 2015 at 7:37 AM, David Singer <singer@apple.com> wrote:
> >>
> >> yikes
> >>
> >> it’s nice if the terms are readable.  Linewidth and Lineheight have
> some …
> >> recognition, albeit mostly in writing systems that use horizontal lines
> >> assembled into vertical blocks.
> >>
> >> ipd and bpd are directions, not measurements, aren’t they? and they
> don’t
> >> exactly roll off the tongue or leap to mind in terms of recognizability
> >>
> >> > On Jan 26, 2015, at 1:01 , Glenn Adams <glenn@skynav.com> wrote:
> >> >
> >> > The use of width and height as writing mode relative properties is
> >> > confusing. Change their names to ipd and bpd, abbreviations for inline
> >> > progression dimension and block progression dimension, respectively,
> and
> >> > document convention that width and height (as well as horizontal and
> >> > vertical) are always absolute and not writing mode relative. The only
> >> > exception being that 'height' in lineHeight remains writing mode
> relative,
> >> > i.e., specifies the nominal bpd of a line area.
> >> >
> >> > Change image to use tts:extent instead of the former
> tts:{width,height}
> >> > in order to use absolute axes in expressing explicit image dimensions.
> >> >
> >> > Addressed above comments in [1].
> >> >
> >> > [1] https://dvcs.w3.org/hg/ttml/rev/69877acd9380
> >>
> >> David Singer
> >> Manager, Software Standards, Apple Inc.
> >>
> >>
> >
>
Received on Tuesday, 27 January 2015 16:47:45 UTC

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