Currently when you italicize RTL text, LibreOffice 7.1.0 does this as if it is for LTR text “کلمه” bent clockwise (/), where as for RTL it should be bent counter-clockwise like this: \
This is absolutely wrong according to the conventional Orthography of Arabic/Persian languages, not sure about other RTL languages but I guess this must be the case for Hebrew as well.
Does it also happen in previous versions?
Font creators normally provide variants for their fonts: regular, italic, bold + combinations of these. Please note that in traditional typography “italic” is not a synonym for slanted. “Italic” is supposed to offer a distinctive shape of the glyphs so that the words can be recognised as being emphasised according to author’s choice. This means an “italic” font may offer any graphical style not necessarily related to the “regular” shapes.
One implementation of “italic” is to slant the regular font but this is not mandatory.
Slanted shapes are quite easy to derive from the regular shapes that it has been offered ever since the beginning of computers (e.g. dot-matrix printers could be driven so as to produce slanted glyphs). This may be why “italic” is very often used instead of the more correct “slanted” word.
When you select italic, the font renderer will look for a specific font file implementing this variant. If no file is found, the font renderer will generate a slanted version from the regular file. I don’t think the language information is given to the font renderer to use an adapted angle. This is were the RTL attribute should be taken into account.
IMHO, LO can’t be blamed. It uses whatever font renderer is installed in the OS. I have no idea about the interface between a font renderer and application programs. I don’t know if this interface has provision for RTL/LTR attribute.
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Thanks for your clarifications.
I’ve checked the LO 6.x series and observed the same behavior over there as well.
I have installed all the available variants of some popular fonts (namely: Italic, Bold, Regular etc.) but it doesn’t make any difference.
Also, both (→/) and (←) directions for italic are used across different publications, so this must be a pretty viral issue. But still I think it’s a simple option that should be provided, at least for RTLs.