Re: [Nautilus-list] Xft Anti-aliasing, Libart antialiasing?

[Alex Larsson <alexl redhat com>]

On Thu, 13 Dec 2001, Moses Lei wrote:

> > What do you mean libart? Both Xft and Nautilus uses freetype to rasterize
> > the font glyphs. Given the same fonts the output should be identical.
> >
> > / Alex
> 
> I don't know much about the internals of Xft or Nautilus, but I was under
> the impression that libart was the source of antialiasing for Nautilus.
> However wrong I may be, however, there is still a visible difference
> between the output of Nautilus and Xft.
> 
> > The Type1 rasterizer in FreeType doesn't do a very good job with hints
> > yet; try getting some good TrueType fonts, and then make sure you've got a
> > version of FreeType with the TT bytecode interpreter enabled.
> >
> 
> I did already have a version of FreeType with the TT bytecode interpreter
> enabled.
> 
> My attempt at matching font face and font sizes can be seen here:
> http://mlei.mtmis.com/nautilus.jpg
> 
> The font was Arial, at size 11 according to gfontsel and at 14 according
> to nautilus. My X dpi is 100x100. (There seems to be some disagreement
> there as to relative font sizes...)
> 
> In the nautilus tree view, the GTK system font is used, with Xft
> antialiasing. (this is with the gdkxft hack.) On the right is the Nautilus
> main window with smooth graphics enabled. Look at the word "AGSatellite"
> since it appears on both the left on the right.
> 
> This is, of course, subjective, but it is obvious to me that 1) the output
> is not identical and 2) the output on the right is smoother and more
> readable. Look especially at the curve of the capital G.

It looks like the gdkxft font is hinted, but the Nautilus one is rendered 
completely unhinted. You can tell that especially by looking at the i's 
and the l's. In the Xft rendering these are completely non-aa, since the 
hinting made them the grid-aligned. The nautilus one is instead blurry on 
the sides, because the letters are really slightly wider than 1 pixel.

I dunno which is best. I'd say the nautilus output looks smother, but the 
Xft output is more readable. I mean, look at the second 't' in nautilus. 
It's mostly a blob.

/ Alex