xc/lib/font/FreeType/ in "XORG-RELEASE-1"-branch differs fromXfree86 trunk...

[Keith Packard]

Around 13 o'clock on Mar 15, "James H. Cloos Jr." wrote:

> FWIW, do note that the popular fonts (esp from legacy partitions)
> w/ embedded bitmaps do not have bitmaps for all scalable glyphs,
> so a single flag per font will not guarantee accuracy.

Yes indeed -- it may be that testing a single glyph is not sufficient to 
determine whether the font has any bitmap glyphs, but I suspect we can 
construct a short list of glyphs which would cover all known cases.  Which 
glyphs to use needn't be language dependent, because we only need to 
detect the existance of *any* bitmap glyphs to know that the fast path 
cannot be used.

> (One example I looked at recently was intended for lang=ko and had bitmaps
> for only about 60% or 70% of the rest of the CJK characters it had outlines
> for.)

This means that such fonts will load very slowly in sizes for which they 
provide some bitmaps.  It seems like we need a better way to detect which 
glyphs would be loaded as outlines to allow the faster code path to be 
used for those glyphs; otherwise, this very common case sees no 
performance benefit from the changes.

-keith


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