[cairo] Struggling with subpixel text (last blocker for 1.8)

[Behdad Esfahbod]

Carl Worth wrote:
> So I stayed up all night trying to get the 1.8 release done.

Thanks Carl!

> The final result I got to was a single test not passing, (I
> intentionally wasn't testing xlib to avoid X server/driver issues):
> 
> 	text-antialias-subixel
> 
> And this one is a regression. It's giving me grayscale antialiasing
> instead of subpixel on image and other backends. The text passes fine
> back in 1.6.4.

I suspect your fontconfig configuration.  I've seen you have this problem
before :).  I just compiled FreeType with subpixel enabled and confirmed that
I get subpixel rendering form that test (were not getting before).  It's
slightly different from the ref image, but looks as correct.

> Behdad, do you have some guidance here?

It basically comes down to this bug against fontconfig:

  https://bugs.freedesktop.org/show_bug.cgi?id=17722

Send me your config and I'll try to make sense of it.

> Can you fix the code so that the test suite works?

Works for me.

> Or shall we just go ahead with the revert and bring
> back the LCD filter functionality in 1.8.2 or so?

I don't see any reason for that.

Cheers,

behdad

> I know you were hoping
> to wake up and see that the release had already happened. Sorry that
> didn't happen, but this is really the last issue left.
> 
> -Carl (overdue for sleep)