Thought to share my findings. May be, they’ll be of use to somebody with a similar project. The present scope is a Lepcha font produced with Glyphs 1.4.5. OT features are limited to mark (GPOS) and liga (GSUB).
Despite being co-developing partner and trademark owner of OpenType, Microsoft provides poor support for the font format in applications and Windows itself. Third-party software is required for proper input and display of Unicode Lepcha script.
First of all, one has to embrace Windows-logic discarding the conception that a text ought to be produced with a text editor. And, frankly speaking, surveying plenty of applications for OpenType feature support evokes a feeling of attempting something terribly avant-garde …
Tested working solutions are
- Tavultesoft Keyman Desktop versions 8 or 9 (for input) combined with either
- Adobe InDesign versions CS3 to CS6 in Windows XP, versions CS3 to CC 2015 in Windows 7, 8 and 10, or
- CorelDraw X6 to X8 in Windows 7 and 8 (broken in Windows 10)
I’ve been amazed at the broad compatibility of ID CS3 (the lowest version tried). On the other hand, the lacking support of OT features in OpenOffice and LibreOffice is a major disappointment. They’d require conversion to TTF and supplementary Graphite tables to handle the font. And finally, hard to believe, but true: QuarkXPress 2015 supports ligatures but no mark to base positioning at all!
Though Indian users usually ‘avoid payment’ of licence fees for software (recent investigations estimate a piracy rate of 60%), it did not feel good to only offer high-priced apps to the few indigenous users of the script. That’s why I’m happy my tedious search finally bore a
WINDOWS LOW-COST SOLUTION:
The text tool of GIMP 2.8 works perfectly with the OpenType features of the font and input with Keyman 9 (free). The GIMP file in .xcf format provides cross-platform interchangeability to a large extent. Almost every PC can run GIMP and virtually everybody can afford the app (it‘s free). The Lepcha text can be copied and pasted into any other document created with a suitable application.
Written on a canvas sized 595 x 842 pixels, for example, the file can be exported to a pdf-document in A4 format. The suitability for copy & paste is, however, broken with the pdf-version.
Works in Win7, Win8 and Win10.