[cairo] Survey of polygon rasterization techniques
david at freetype.org
Tue Jul 31 04:12:48 PDT 2007
> The thing that made a noticeable difference for us was adding a y
> coordinate to the spans. This made it possible to generate more spans in one go (we
> increased the FT_MAX_GRAY_SPANS from 32 to 256). It made a big difference
> for smaller polygons where function call overhead was actually dominating the
Ah, nice trick, and good to know :-)
I can understand why this would make such a difference for small polygons.
this function call over-head doesn't appear on my typical benchmarks, because
my inputs are glyph vectors which are generally more complex.
but for general-purpose graphics rendering, that's absolutely neat, bravo.
> I'm not sure whether that patch makes a lot of sense for
> FreeType main, but if you're interested I could extract the patches and send them
> to you sometime this week.
I think I can extract the changes myself easily. However, since the span interface
is part of the public FreeType API, I'm not going to change it :-(
that's still valuable information. Thanks !
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