Re: [css-writing-modes] feedback: bottom-to-top scripts?

On 10/14/2013 10:42 AM, Martin Holmes wrote:
>
> I wasn't aware that all bottom-to-top scripts also happen to be LTR; that's intriguing. Could you give me an example, then, of
> how to handle an Ogham inscription? The Unicode Ogham glyphs have the horizontal orientation; am I right in saying that a
> vertical btt Ogham inscription can be handled completely by simply setting "text-orientation: sideways-left"? It seems to me
> that it could.

Yep, you'd just want to set
   writing-mode: vertical-lr;
   text-orientation: sideways-left;
and that will handle a line or paragraph of Ogham text
running bottom to top.

> The same effect could be achieved by using CSS "transform: rotate(270deg)", couldn't it? Is there any implication in the
> choice of one of these over the other? Would the choice of "transform" imply that the rotation was "for effect" rather than a
> directionality option intrinsic to the script itself?

'transform' is an after-layout graphical effect, whereas
'writing-mode' affects layout.

Let's consider that you have a line of text that is 40em
long and 1em tall. If you choose to lay it out vertically,
either way it will be 40em in height and 1em in width.

If you use 'writing-mode', layout will take its actual
size (40em high, 1em wide) into account. However, if you
use 'transform' the space it takes up is a that of its
equivalent horizontal layout: 40em wide and 1em high.
The gap in layout given to the line of text therefore
does not at all match the actual size of the transformed
text.

Another difference is that vertical writing modes trigger
appropriate vertical typesetting settings in the font. But
for Ogham, that won't really make a difference -- it's
mainly East Asian scripts that would be affected.

~fantasai

Received on Tuesday, 15 October 2013 01:02:08 UTC