The font fallback mechanisms built into _Windows_ generally aren't designed to 
be user-configurable. But not everything necessarily relies on these Windows 
mechanisms. E.g., Office apps have their own mechanisms, and it's not clear to 
me if or when a Windows fallback mechanism might have effect when using an 
Office app.

Within Windows, there are multiple mechanisms, created in different eras for 
different purposes and used in different contexts. A few in the GDI stack can 
interact; in particular, there's a "font fallback" mechanism in Uniscribe (used 
in the GDI text stack) that interacts with a "font linking" mechanism in a 
(mostly) complementary way. Font linking is driven by registry entries, which a 
brave admin could try tweaking. (Note: these are tailored by the system locale 
setting, and if you change the system locale setting, any tweaks will get 
overwritten.)

Some things in Windows use the RichEdit control, which has some of its own font 
handling logic. It has default font behaviours, but it also exposes APIs that 
allow a desktop app to control font binding behaviours. (I don't think these 
are exposed via WinRT APIs in Windows 8, though.)

DirectWrite has fallback data that is not read from the registry or in any way 
configurable. In Windows 8.1, though, APIs have been introduced that allow an 
app to specify its own fallback. (It's similar to the WPF APIs for creating a 
composite font definition.)

I'm not well versed in IE's font handling, though I know that it  has a 
registry entries that get used to specify fonts for fallbacks for different 
scripts. There's UI that allows the user to configure this to some extent (the 
Fonts dialog in Internet Options). The mechanisms were not improved for several 
versions, but I know there are some updates that have been made for IE 11.


Peter

-----Original Message-----
From: Christopher Fynn [mailto:[email protected]] 
Sent: 12 July 2013 09:41 PM
To: Peter Constable
Cc: Unicode List
Subject: Re: Ways to show Unicode contents on Windows?

Peter

I'm wondering how do you change the fonts selected by the built-in font fall 
back in various versions of Windows? I've found that the rendering for certain 
scripts is less than ideal with some of these fonts. Also the fallback font 
sometimes overides the font selected by the user in Office and other 
applications even when the selected font is available.

The only way round this that I've found is to remove the offending fallback 
font from the system (not always easy)

- Chris

On 11/07/2013, Peter Constable <[email protected]> wrote:
...
> For simple scripts that do not require shaping that are not yet 
> supported, if you have the font and can select the font in your app, 
> then text in those scripts can be displayed. Of course, we don't have 
> built-in font fallback for such scripts.
>
>
> Peter




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