Re: [ft-devel] Tweak CJK Blue zone parameters

[Just Fill Bugs]

On 05/09/2011 08:21 AM, address@hidden wrote:

> If further tweak is needed for CJK bluezone, the code
> would be unmatured, I will disable it by default.
> In fact, the original demonstration was given by 11pt
> glyph of WenQuanYi-ZenHei, but your new tweak seems to
> change the dist value for the glyphs smaller than 17pt
> I think 17pt is unstable/temporal tuning value and not
> determined deducively. It makes me afraid that the code
> includes some ad-hoc parameters and they are not tested
> well.


You don't have to include it. It's just some my brain storms I want to 
share with the list.

The numbers are just some guess of mine. It is less aggressive than the 
numbers I tried at the beginning. When I test it, I meanly focused on 
11pt, and tried to not over optimize it.

One effect is that for 意 11pt, it raised the top horizontal edge to the 
top blue zone. Effectively pushed the dot over the blue zone.

Limiting to 17pt is because I felt that, larger than 16pt, my eyes were 
more tolerant to the small even bottom line.

Also around 15pt, the best_dist0 raised to 38 and was turned down to 36 
by the safe guard in place. wqy-zenhei has an EM of 1024.

> How long do you need to find stable values for the tunable
> parameters? If it is difficult to estimate, I will propose
> new API to manipulate the parameters by FT2 clients.

That's even better. Just don't know how many clients will use the API. 
Maybe through fontconfig?