Re: [ft-devel] [Patch] CJK autofit/autohint blue zones

[Just Fill Bugs]

On 04/21/2011 09:24 PM, Just Fill Bugs wrote:
> I meant some steps were missing in the code. The bluezone is not
> properly grid fit before the numbers being used to align segments.

There are indeed some problems with the patch. They happened when
the bluezones were scaled at af_cjk_metrics_scale_dim()

1. The shoot in cjk means undershoot, so the shoot should be the
   smaller one.

2. The fit can be set at 1/2 a pixel in the patch. Maybe that is
   useful for latin round edge. But for CJK, undershoot are straight
   edge too. So 1/2 pixel is meaningless except creating blur.

3. The undershoot is compared to the un-fitted reference when
   calculating a grid fit distance. But its fitted position was
   calculated from fitted reference + fitted distance. This could
   over-compensate the offset.

I update the patch to the current git and address the problems.
Please review the logic behind the idea.

There could be other improvements when scaling the bluezone. Like under
small size, round the bluezones to the ceiling unconditionally. That
could make glyph bigger and clearer. But could make it 1 pixel extra
bigger than the intended size.

cjk-autofit-blue-zone-v2.diff
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