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

From: David Singer <singer@apple.com>
Date: Tue, 27 Jan 2015 17:34:57 +0100
Cc: TTWG <public-tt@w3.org>
Message-id: <7AF03BB8-E560-484E-B2C8-1C150E8AAAA4@apple.com>
To: Glenn Adams <glenn@skynav.com>

> On Jan 27, 2015, at 17:12 , Glenn Adams <glenn@skynav.com> wrote:
> 
> ipd = inline progression dimension
> bpd = block progression dimension

ah, sorry, I thought d = direction.

> 
> 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

OK, but what is wrong with something a little less terse, such as inlineLength and stackingLength?

> 
> 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.
> 
> 
> 

David Singer
Manager, Software Standards, Apple Inc.
Received on Tuesday, 27 January 2015 16:35:28 UTC

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