[luatex] [lltx] fontspec prevents hyphenation

[Philipp Stephani]

Am 28.11.2010 um 16:36 schrieb Khaled Hosny:

> We can test if the font has
> italic angle and set \fondimen1 accordingly, I just don't know how to
> map the former to the later and don't want to set some seriously broken
> value that would break something else.

The italic angle in the "post" table is a number that measures the angle in degrees between the geometrical vertical and the font glyph vertical. The first font dimension is the slant per point, i.e., the arctangent of the additive inverse of the italic angle. For Latin Modern Roman Italic 10, this gives 0.24, which is very close to the table value of 0.242. Original TeX uses the slant per point for accent placement, while LuaTeX uses the OpenType tables.