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  1. JDK
  2. JDK-6438263

Need to handle new TrueType 'gasp' table version in vista fonts



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        JDK is not picking up the standard font smoothing setting for some
        of the new Vista fonts.

        The reason is that Microsoft have updated the 'gasp' (grid fitting and
        scan conversion table) to Version 1 in some of these fonts, notably Segoe UI
        and likely other 'cleartype' fon's and JDK consequently decides to substitute
        default values on the grounds that it may not understand the table.
        The reason for the new table version is unclear: the spec on the MS website
        still says Version 0 is current.

        But the values that are seen in Segoe UI set bits 2 and 3 of the flags
        which are previously unused bits. Only bits 0 and 1 were previously specified.
        So the interpretation of those bits is unclear. But it seems that the
        interpretation of bits 0 and 1 is unchanged and so JDK could ignore the
        version in its interpretation, so we'll have to ask what the new bits mean.

        The importance of the fact that we are skipping the table is that these
        fonts specify *all* point size ranges at which to 'do grey' which is a huge
        departure from the norm. The reason for this is that Segoe UI looks quite
        poor if you render it in B&W as its just not hinted for that.
        Microsoft's UI guidelines call it 'marginal' for B&W.

        So it appears that to compensate Microsoft specified that these fonts
        should always do greyscale in 'Standard' font smoothing mode. I did think
        I checked into this in earlier builds as it was something I would have expected
        because of the poor rendering in B&W but perhaps I missed it, or perhaps
        Microsoft just made this change in Beta 2 or a build close to it.

        It does remain true that if you turn off Font Smoothing completely on your
        desktop (its more of a challenge to find where to do this on Vista
        than XP although Beta 2 made it marginally less challenging than earlier builds)
        that Segoe UI will go back to B&W and look poor but I think this is an attempt
        to answer the people who dislike ClearType rendering. Unfortunately the greyscale
        text looks much fuzzier than the cleartype that people dislike but I doubt there
        was another easy answer that MS could come up with at this stage


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                prr Philip Race
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