Anuj,
Each curved segment has a large number of neighboring grid points.
each of which has a unique nearest projection on the curve. The curve
is naturally sampled by this projection points a very large number of
times and quite uniformly. Therefore, why not divide the curve into a
large number of segments to begin with and then just find whatever
point is close to each grid? It could be a lot faster to find the
distance this way.
So... You subdivide the curves into lines. Can you sketch what you do then?
I did think about "rasterizing" the outline and mark all pixels that have distance < 1.0 to the outline, and then "propagate" the distance out. But as I've shown in my GLyphy talk, no matter how much I thought about this, I found that there can be points far from the curve such that the closest edge for this point is different from the closest edge for all its neighboring pixels. As such, the only way to use this optimization is if each pixel kept a list of edges that are closest, within a range.... That then suggests that just using a coarse grid is even better, hence what I suggested.
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