Re: [css-writing-modes][css-inline] synthesizing baseline tables for replaced elements

On 08/27/2015 12:32 PM, Stephen Zilles wrote:
>
> The above problem can be mitigated a bit by careful use of the replaced elements. If all the elements are 1EM high and they
> are positioned with other elements that are 1EM high, it is far less likely that the calculation of the line box height will
> be too short even when the replaced elements are positioned by adjusting the bottom margin.
>
> It has also been suggested that using the bottom margin change would adjust all the baselines, correctly. Even for the two
> baselines currently specified, it is unlikely that this will work for lower case letters with descenders.
>
> The  best solution to the problem of defining baselines for objects which do not naturally have them would be to define a
> property that allows a baseline table to be defined.

Totally agree that the ultimate way forward is a baseline-table
property such as you describe. However, I think that for the
common case of wanting a set of images to be used as glyphs,
it is adequate to design these images on the em square, just as
if they were real glyphs in a font, and use the margin properties.

I.e. to solve the case of gaiji with an alphabetic baseline at
12%, implement each letter in a 1em-tall image, so that aligning
them all in a row creates a 1em tall line of perfectly aligned
text. Then size each image to 1em (height: 1em), and set its
bottom margin to -0.12em. This technique will solve the vast
majority of all cases for image letters.

As you note, it won't solve drop-caps, but neither will alignment-point.

So I think at some point we'll want a baseline-table property,
but not in this level. :)

~fantasai

Received on Thursday, 27 August 2015 21:42:49 UTC