Re: [css-writing-modes] on using the advance height of U+6C34

On 07/17/2014 11:48 AM, Masataka Yakura wrote:
> 1. In the last paragraph in Section 9.1.3 it says:
>
>> In some fonts, the ideographic glyphs are given a compressed design such that they are 1em wide but shorter than 1em tall. To accommodate such fonts, the UA may vertically scale the the composition to match the advance height of 水 U+6C34.
>
> However, in the first paragraph in Section 9.1.2 it says:
>
>> The effective size of the composition is assumed to be 1em square
>
> What if the font is an extended font? Will the composition still be 1em square even if the UA doesn't scale the composition?

No, you are right. It should have the advance height of 水 U+6C34.

> 2. What happens if the font doesn't have a character for U+6C34.
> Furthermore, which font should the UA choose, the first available font?

It should use the font settings that 水 U+6C34 would be rendered in.
(The first available font is the first specified font that is on the
system, not necessarily one that has the requested glyph.)

I've clarified the spec as follows:

   # To accommodate such fonts, the UA may vertically scale
   # the composition to match the advance height of 水 U+6C34
   # as rendered according to the specified font settings.
   # In such a case the resulting composition assumes the
   # advance height of 水 U+6C34 rather than 1em.

Please let me know if this addresses your questions~

~fantasai

Received on Tuesday, 25 August 2015 00:34:58 UTC