[aat] Difference in WAW spacing between CoreText and HB AAT

[drott]

Using GeezaPro from Mac OS 10.10:

CoreText

$ ../test/shaping/hb-unicode-encode U+0648,U+0644,U+064A | ./hb-shape ~/dev/geeza_pro/GeezaPro_10_10.ttc --shaper=coretext  --direction=rtl
[u064a.final.yeh.001=2+1545|u0644.initial.lam=1+353|u0648.waw=0+868]

HB AAT:

$ ../test/shaping/hb-unicode-encode U+0648,U+0644,U+064A | ./hb-shape ~/dev/geeza_pro/GeezaPro_10_10.ttc --shaper=ot --font-funcs=ot  --direction=rtl
[u064a.final.yeh.001=2+1545|u0644.initial.lam=1+515|u0648.waw=0+868]

So, HarfBuzz AAT computes a much wieder advance for u0644.initial.lam for some reason.

[behdad]

I think I'm appyling kern wrong, adding space instead of removing...

[drott]

Images

CoreText

HB AAT

[behdad]

Thanks.

[behdad]

Okay, it's not kerning at all. Debugging.

[behdad]

Oh, it's kern table format 1. Basically, mort of the kerx.

[ebraminio]

Basically, mort of the kerx.

Hehehe. Looks much better now.