Re: [ft-devel] [patch] TrueType GX/AAT validator

[George Williams]

On Tue, 2005-08-23 at 18:06, address@hidden wrote:
> I agree. I remove it from the error list.
Yes, sorry about that.

> No, I was meaning about the hole of predefined range.
> According to http://developer.apple.com/fonts/Registry/index.html,
> 
> >   kanaSpacingType = 25,
> 
> >   ideographicSpacingType = 26,
> 
> >   cjkRomanSpacingType = 103,
> There is a hole from 27 to 99, I thought it is reserved area,
> although I could not find any documentation about it.
> It should be used as same as the undefined area > 105?
I haven't the faintest idea. You might be right. It didn't occur to me.
But AquaKanaRegular.dfont (Copyright Apple) uses feature 27 for Unicode
decomposition. 

> >Or do you mean more settings are defined than are present in the
> >registry? I think that should be ok.
> 
> The latter. I was meaning the nSetting value is out of range
> defined in Apple registry. For example, feature number 1
> (ligatureType) has 15 settings aslike:

> [ftvalid:gx] validation targets: mort
> -------------------------------------------------------------------
> validation mort table
> validate chain 1/2
>   mort chain header table
>     mort feature list table
> ...
>     featureType 1 is registered    setting 2    
>     featureType 1 is registered    setting 3    
>     featureType 1 is registered    setting 32    out of defined range 15
>     featureType 1 is registered    setting 33    out of defined range 15
> 
> setting 32, 33 are out of defined range.
> 
> Your suggestion is that undefined setting values should be handled
> as the same way for user-defined feature number (so they are not errors)?
> If so, I will remove this from the error list.
My thought is that if the setting is defined in the 'feat' table then
it's ok to use in mort/morx. (or in the case of a non-exclusive feature,
if the even version of the setting is defined, the odd never seems to
be).

I don't know, I just don't see any limits placed on the use of
feature/settings in the docs... so my tendency is to assume there are
none.

Just as a type designer might need extra features, I expect one might
decide that s/he needed extra settings, for example a way to turn off
long-s ligatures in a latin font, or perhaps a way to turn on or off
ligatures depending on different styles of arabic writing. 

Unfortunately the courier on my Mac 9.0.4 does not have the version of
courier you describe so I could not check and see if this is what
happened there.