Re: [ft-devel] [ttfautohint] stem width handling is now selectable

[Alexei Podtelezhnikov]

On Tue, Jul 3, 2012 at 2:58 PM, Werner LEMBERG <address@hidden> wrote:
>
>>> widths which are different less than or equal to 1% of the em size
>>> are unified; this is certainly not noticeable visually.
>>
>> 1/64 is better heuristic than 1%. Why not avoid costly division with
>> divide by 64 instead.
>
> I doubt that it is `costly' since the routine is called exactly twice
> *per font* (and not per glyph).

Just for the record: since i8086 or maybe earlier, a division takes 10
times more CPU time than an addition or a multiplication.

>
> Personally, I think that the value 1% is easier to comprehend than the
> value 1.5625% (to which a division by 64 is equivalent), so in this
> case I prefer the human to the computer.

Tell this to any American who would prefer 1/32th of an inch to a
millimetre before you finish your sentence. You defending this more
than just a heuristic value, there is a European pride behind it :)