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Subject: [ggl] Clipping/Intersecting efficiency
From: Koying Bing (koying)
Date: 2009-05-29 02:43:10


Profiling my application (Merkaartor, which uses, notably, ggl to do
linestring clipping), I came to realize that clipping takes about 70% of the
time it takes to draw a frame!

2 reasons for that:

 1) My "linestrings" are vectors of POINTERS to points.
I didn't find a way to use pointers as valid point_2D, so I have to recreate
a linestring_2D before intersecting -> malloc -> poor performance.
Is there a way to use a std::vector<point*> as a linestring?

2) intersecting uses outputstream to store its results. This again means
malloc -> poor performances.
Would it be possible to have an option to use a callback function returning
the ordered result?

Other programming practice suggestions are obviously welcome.

- Chris -
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