[cairo] Survey of polygon rasterization techniques
david at freetype.org
Tue Jul 31 02:19:40 PDT 2007
> Rendering to QImage (or just rendering on Qt/Windows) invokes software
> rasterizer that is a mixture of freetype2/agg rasterization techniques
> and should be faster than both.
Could you elaborate on this "should be faster than both" ? I'm interested
to know what kind of improvement you made.
I just had a quick look at src/gui/painting/qgrayraster.c in Qt 4.3 and
I don't see much differences from a relatively old version of the
FreeType anti-aliasing rasterizer. Maybe some details escape me ?
Also, you may find interesting that the current FreeType rasterizer sources
use a scanline-bucket scheme now, instead of QSort, to sort the cells. I've
done this because in some relatively common cases, it provided a x1.25 speedup
in rendering time.
Hope this helps,
- David Turner
- The FreeType Project (www.freetype.org)
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