Re: [Devel] Dropouts in AA text

[Keith Packard]

> The problem you're experimenting comes from the fact that the two diagonal
> edges of the "z" are simply superposed, resulting in a covered pixel area
> of exactly 0.

This makes sense except that smaller sizes have the diagonal present so at 
least in the raw form, the diagonal edges are not coincident.  It must be 
the TrueType hints which are causing the problem.  The output at smaller 
sizes looks as if no hinting was done.

> There is no generic way of solving the problem of "incorrectly" hinted
> glyphs. We could try to provide drop-out control in the anti-aliasing
> renderer, but this would require significant work. Another solution is
> to use a monochrome renderer to generate 4x times bigger glyph _with_
> drop out control, then filter them down..

Even the monochrome rasterizer won't completely solve the problem; I 
suspect the diagonal would be one pixel wide at the oversampled resolution 
and then nearly disappear when resampled.

I guess I should go buy better fonts.

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