Hello, I am in the process of writing a rasterizer of quadratic and cubic splines, and am trying to learn what the current state of the art is in drawing shapes with anti-aliased spline boundaries. Do you know of any good reference papers (preferably academic), or a document that gives an overview of the rasterizer used in FreeType?
I also have a couple of specific questions about the FreeType rasterizer. I noticed that the function Split_Conic subdivides Bezier splines into smaller arcs. Does FreeType calculate coverage exactly (i.e. directly from the spline), or are splines approximated by piecewise linear segments that are calculated through Split_Conic? If line segments are used, is a metric used to guarantee accuracy to within some tolerance (presumably to the number of grey levels, but maybe curvature)? >From the description in http://people.gnome.org/~mathieu/libart/internals.html (from http://old.nabble.com/The-FreeType-rasterizer-to14715693.html#a14715693) it appears that a running sum of coverages are calculated from line segments along a scan line. Does this ever result in numerical inaccuracies where small residuals bleed out of the glyph at the end of a scan line? Thanks a lot. -- View this message in context: http://old.nabble.com/Rasterizer-specifics-tp29168321p29168321.html Sent from the Freetype - User mailing list archive at Nabble.com. _______________________________________________ Freetype mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/freetype
