Dear Simon, > In InDesign, both (1) and (2) get 12 x 1.2 = 14.4pt interline space. > This means that the descender of the "p" in "ipsum" will bump into > letters on the next line. That's clearly wrong. > > In the CSS model, both (1) and (2) get half leading added to the top and > the bottom of the first line. So there is a gap between the first and > second lines of (1) even though there is no large descender using that > gap. That's not *wrong* but I don't like it. Imagine a large drop-cap > "T" at the start of a paragraph - the line spacing after it becomes > inconsistent.
Another approach is to say the ascent and descent of a line is the max(ascent, for all font ascents) and max(descent, for all font descents) on the line. > I am not a typographer, I just play one on the Internet, so I am not > sure what someone who was actually typesetting a book would do in that > situation. My guess would be that they would, basically, do what SILE > does right now (and what TeX does; perhaps Knuth knew what he was doing > after all) - use consistent 14.4pt (or whatever) line spacing in > situation (1) and use larger line spacing which fits in the descender in > situation (2). But I would have to ask a real typesetter to know. I like this, but as stated by Werner, if you think the OS/2 values don't make sense, then you could use the font bounding box and add 1pt interline gap or some such, as a fall back. GB, Martin _______________________________________________ HarfBuzz mailing list HarfBuzz@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/harfbuzz
