Bidi Resolution

[fantasai]

Several members of the layout team got together last month to talk
about optimizing bidi resolution. bz took some notes, I figured I'd
post them here for general consumption / archival.

~fantasai

On 12/8/2009 2:24 PM, Boris Zbarsky wrote:
> Decided:
>
> 1) Store the bidi embedding level at the end of each line box at the
> end of each line box.
> 2) On insert/append walk backwards through neutral characters looking
> for the right place to start reresolving the bidi runs. And
> forward looking for a place to stop. Do this at frame-insertion
> time.
> 3) Need a "line needs bidi resolution" bit. The walk in item #2 would
> set this bit on the lines it walks over, and stop once hitting a
> line with the bit.
> 4) Roc will find a victim.
> 5) Treat <br> and LF as line breaks. Treat empty lines in <pre> as
> paragraph separators. Or something.
>
> -Boris

Simon Montagu wrote:
> I want to think in a bit more detail about the "or something" in point
> 5 above. Assuming that there's no sane way to identify reliably which
> line breaks in preformatted text are really line separators and which
> are really paragraph separators, I tend to believe that we should err
> in the direction of paragraph separators, probably to the extent of
> treating all line breaks as paragraph separators.
>
> This is because I think the potential misrendering caused by treating
> paragraph separators as line separators will usually be much worse
> than the opposite case. Cases like numbered lists or tabular data in
> plain text can become totally unreadable if the line breaks are
> interpreted as line separators, but I think if line breaks in running
> text are interpreted as paragraph separators the text can end up
> looking a little squiffy, but it never reaches the point of unreadability.

[fantasai]

On 01/04/2010 03:10 PM, fantasai wrote:
> Several members of the layout team got together last month to talk
> about optimizing bidi resolution. bz took some notes, I figured I'd
> post them here for general consumption / archival.

On a related note, the i18n Core WG is discussing bidi issues related
to HTML. We probably want to track what happens with the issues they've
brought up, some of which overlap with the bidi resolution discussions
we had.

http://www.w3.org/International/wiki/BidiProposal

~fantasai