[cairo] FreeType internals in new versions of cairo

Behdad Esfahbod behdad at behdad.org
Sun Feb 4 13:09:43 PST 2007

On Sun, 2007-02-04 at 12:53 -0800, Keith Packard wrote:
> The Freetype filters work better on unhinted glyphs than the cairo
> filter, but the cairo filter works better (to my eye) on hinted
> glyphs.
> The cause is intrinsic in the design of the two filters -- the
> cairo/Xft
> filter is entirely intra-pixel, so a solid pixel doesn't leak out into
> the neighboring sub-pixels while the FreeType filter (which is more
> 'correct' from a simplistic DSP perspective) ignores pixel boundaries
> and filters subpixels across both adjacent subpixels.
> I haven't considered using the freetype filter for Xft, and I'm not
> sure we should for cairo either.

Thanks for the explanation.  In that case why not adding cairo/Xft's
filter to FreeType?


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