Re: [ft-devel] TTFAutohint Without TT Point Numbers

[Adam Twardoch (List)]

In other words, computational checking that something "has gone wrong" between 
two versions of a font is easier if your system relies on point numbers. 

If it relies on some more abstract data (like point names), chances of horrible 
things happening and going undetected are actually higher. :) 

Sent from my mobile phone.

> On 12.04.2016, at 07:32, Adam Twardoch (List) <address@hidden> wrote:
> 
> I agree with Werner.
> 
> There are concepts like point names or UIDs in UFO but by themselves they're 
> not really anymore robust than point numbers. 
> 
> Software that deals with point names/UIDs needs to keep them (make sure they 
> don't get lost), and it's actually the same as making sure you keep point ids 
> in sync and renumber them if needed. 
> 
> It's like glyph ids and names. When you author software, there is no 
> guarantee you keep or break glyph ids, but there is also no guarantee you 
> keep or break the names. 
> 
> I've had situations where I relied on glyph names but I had those where I 
> relied on glyph ids (numbers) and it was a superior choice. If I have 1239 
> glyphs in one font and 1239 glyphs in another, chances that the glyph IDs are 
> consistent are actually high. I only need to check what's going on if one 
> font has 1239 and the other 1242 glyphs. 
> 
> But with names, I have to check everything. 
> 
> I think the same is true for point numbers vs some other identification. 
> Relying on point numbers is actually not as bad as some might think. :)
> 
> Sent from my mobile phone.
> 
>> On 11.04.2016, at 07:44, Werner LEMBERG <address@hidden> wrote:
>> 
>> 
>>> On twitter, Behdad said of ttfautohint control files,
>>> 
>>> "Any reliance on ttf point numbers is futile..."
>> 
>> Well, if you have a TTF, there's nothing else.  Any high-level
>> operation is inevitably bound to its design tool; it's simply not
>> possible to have *any* reliable mapping: Coordinates might change,
>> glyphs might be scaled, the whole font's EM value might change, etc.,
>> etc.
>> 
>> A tool that suddenly changes point coordinates between releases is,
>> well, not reliable IMHO.
>> 
>> Just assume that you are doing manual hints!  Hinting with ttfautohint
>> is essentiall the same: It's the very last step before shipping.
>> 
>> 
>>   Werner
>> 
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