Re: [Devel] Monochrome glyph rendering - problem.

[David Turner]

Hello Niels,

Niels Moseley a écrit :
> 
> Hi guys,
> 
> To help indicate the problem of monochrome glyph rendering I've attached a
> .PNG file with the same font rendered by FreeType and PaintShop Pro
> (windows). It looks like there is a round off problem or something. If I
> knew anything about rendering fonts I'd help you people to figure this out
> but I have no experience in this matter.. so .. All I can do is beg..
> 
Thanks, I've fixed the problem by now. Please update your CVS.

I first thought that this was a problem with "ftstring", but a little
search revealed that the font driver didn't return hinted advance
widths at all, as it should, resulting in incorrect glyph positions/offsets
in the text layout pass..

Actually, _all_ of the scalable font format drivers did share this
bug. That's a bit hard to believe, but I suspect that this wasn't
detected before mainly because most users/applications round the
results anyway..

Actually, I use "ftview" quite heavily to test the library, and this
one automatically rounds advances automatically (since it uses the cache)

Finally, note that there was a small bug in the centering code of
"ftstring" anyway, that caused half-pixel translation of the rendered
text (and bad rendering) anyway sometimes..


> Please please please please please fix this... (looking like a big eyed
> puppy now....) - I'm somewhat desperate..
>
Hope you'll feel better now :-)

Besides, there is still a discrepancy between FT1 and FT2 when it
comes to rendering of TrueType glyphs. This will probably take quite
some time to track down.

I'll start to check releases 2.0, 2.0.1, etc.. until 2.0.5 to see if
this problem can be spotted to some changes we've made..


Regards,

- David