[XeTeX] New feature REQUEST for xetex

ShreeDevi Kumar shreeshrii at gmail.com
Mon Feb 22 14:38:56 CET 2016

Hi Jonathan,

I am using xetex/xelatex for typesetting of devanagari texts.
eg. http://sanskritdocuments.org/doc_devii/gangAShTakamkAlidAsa.pdf
(HTML TEXT version of the same)

However, when the devanagri text is copied from the pdf, it does not
display correctly - which is the case with complex scripts with most pdf
creators (as far as I know).

॥ गङ्गाष्टकं कालिदासकृतम् ॥
is displayed as
॥ गाकं कािलदासकृतम ॥

Is it possible to add a feature to xetex to support search and copy of
complex script text in scripts such as devanagari?

It would really be great to have this ​​​​"coming soon to a XeTeX near
you"....... :-)


भजन - कीर्तन - आरती @ http://bhajans.ramparivar.com

On Thu, Feb 18, 2016 at 4:28 PM,
Jonathan Kew <jfkthame at gmail.com> wrote:

> This is a pretty specialized feature, likely to be interest only to a
> small minority of users. But for those it concerns, here's something that
> is
> ​​
> "coming soon to a XeTeX near you".......
> I've recently implemented a new feature, controlled by the integer
> parameter \XeTeXinterwordspaceshaping. This will be available in the TL'16
> release, if all goes well.
> This feature is relevant only when using OpenType/Graphite/AAT fonts, not
> legacy .tfm-based fonts.
> When \XeTeXinterwordspaceshaping is greater than 0, XeTeX will attempt to
> support fonts where the width of inter-word spaces may vary contextually,
> depending on the preceding and following text. This is needed by fonts such
> as SIL's Awami Nastaliq (in development) where words are expected to kern
> together across spaces.
> The default behavior of xetex is to measure each word in isolation, and
> simply string together a sequence of such word and space (glue) nodes to
> form the horizontal list that is then line-broken to form a paragraph.
> Normally, when inter-word spaces do not depend on the adjacent words, this
> works fine; but in Awami the width of inter-word spaces may vary
> drastically, even becoming negative in some cases.
> Setting \XeTeXinterwordspaceshaping=1 tells xetex to measure such spaces
> "in context" and take account of the contextually-modified widths during
> line breaking. This greatly improves the typeset result with such a font.
> Each word is still shaped and rendered individually, but line-breaking and
> word spacing respects the inter-word kerning.
> A further complication occurs when not only the width of the space but
> also the glyphs of the adjacent words themselves may be subject to
> contextual changes. An example of this would be a font that has OpenType
> ligature rules that apply to multiple-word sequences; e.g. a symbol font
> that ligates the text "credit card" to render a credit-card icon. Another
> example is the word-final swash forms in Hoefler Italic, which are intended
> to be used at end-of-line but NOT before word spaces within the line.
> These cases are addressed with \XeTeXinterwordspaceshaping=2. With this
> value, not only are inter-word spaces measured in context, but also each
> run of text (words and intervening spaces) in a single font will be
> re-shaped as a unit at \shipout time. This allows full shaping (contextual
> swashes, ligatures, etc) to take effect across inter-word spaces.
> Currently, this feature is implemented only in the "contextual-space"
> branch of the code at sourceforge; anyone interested in testing it will
> need to check out and build the code from there. After some time, if no
> major problems show up, I expect to merge it to the master branch, and then
> to the TeXLive source tree.
> Feedback welcome..........
> JK
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