Unicode on Win 98/ME

Mark Waddingham 36degrees at runrev.com
Mon Oct 17 03:54:25 CDT 2005


Hi Trevor,

At present Revolution uses the available OS features for its Unicode
support - which effectively means that for Win98/ME you don't get a
great deal.

The OS support for Unicode on these platforms is somewhat sketchy as
(internally) all text is still treated as being in the appropriate
language-specific character encoding. Basically, at the OS level all one
can do is convert strings, measure strings and draw strings consisting
of Unicode characters. However, there is no complex script support, and
there are some limitations.

Basically, the support provided on these platforms is certainly suitable
for localisation of an application to the system language present on the
target OS but not necessarily for multi-lingual applications. (e.g. You
can write an application that is localised in Chinese to run on Chinese
Windows 98, but attempting to run the Chinese version on the pan-
European edition of Windows 98 will most-likely fail).

Also there are some oddities. For example, Chinese Windows 98 is
(apparantly) unable to draw text containing characters with unicode
codepoints 128-255 - as (even when passed Unicode 2-byte characters) it
sees any of these as a shift to a 2-byte character. The upshot being
that Roman accents get eaten along with the subsequent character and
displayed as a random Chinese glyph. (What is even more strange is that
Japanese Windows 98 does not display this phenomenon even though it uses
a similar multi-byte encoding at its core).

Overall, if you are just localising an application to a target language
then you should be fine. However, if you are wishing to mix alphabets on
a single application then do some testing on the target versions of
Windows 98/ME first - install any required fonts and check that you can
display text using glyphs from them just in case there are any other
Chinese-like gremlins lurking.

Warmest Regards,

Mark.
 
------------------------------------------------------------------
 Mark Waddingham ~ 36degrees at runrev.com ~ http://www.runrev.com
       Runtime Revolution ~ User-Centric Development Tools




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