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Re: [css3-text] Appendix G: Text Processing Order of Operations

From: Peter Moulder <peter.moulder@monash.edu>
Date: Tue, 04 Dec 2012 20:36:23 +1100
To: www-style@w3.org
Message-id: <20121204093623.GA15124@bowman.infotech.monash.edu.au>
On Mon, Dec 03, 2012 at 10:57:15PM -0800, John Daggett wrote:

> Why does justification affect glyph selection?  Because of letter
> spacing affecting ligature formation?

(Another example would be OpenType 'jalt' stuff, i.e. selecting alternate
glyphs with different widths to help the line's text to fill the available
"width".)

> This is a bad idea, it creates
> a feedback loop within layout operations.

I don't know how web browsers would end up choosing to implement this,
but FWIW it doesn't absolutely have to involve a loop as such: the approach
I'm more familiar with (in the context of optimal line breaking) is that
the various possibilities for altering the apparent width of a line (glyph
selection possibilities, word spacing, letter spacing, kashida, etc.)
influence the choice of line break, and then glyphs etc. are chosen
according to how much that line break requires the line's text to stretch
or shrink.

pjrm.
Received on Tuesday, 4 December 2012 09:36:50 GMT

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