Subject: Re: [boost] Formal Review: Boost.Polygon starts today August 24, 2009
From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2009-08-25 15:02:14
Dear Luke & others,
Congratulations on getting this library as far as a review. I feared
that the scope of the subject might make it impossible for anyone to
ever get this far. Perhaps we have Luke's employer to thank for this.
I hope to have time to try out the library with at least a couple of
real-world examples. I'll describe the problems that I have in mind
now and update later with my experiences.
Marker Merging: I have lots of small square markers indicating search
results on a map. If the map is zoomed out so that the whole planet is
visible and you search for something common like "lake", it will
attempt to draw many thousands of overlapping markers which is slow.
Since the markers are just squares of solid colour, I would like to
merge them into a single polygon-set and plot that. Speed is the main
concern. It it also interesting to consider what would happen if the
markers were circles. Here's an example of the sort of output I need: http://chezphil.org/tmp/six_thousand_lakes.jpeg
Border Simplification: I have data describing state outlines as
polygon-sets. I want to pre-process that into a format that permits
rapid rendering; specifically, I want to generate multi-resolution
versions with smoothing and interpolation as necessary. I also want to
reduce it from polygons with common edges to polylines, so that each
border is plotted once rather than twice. This is something that
happens off-line as part of a build process, so speed is much less
important than ease of coding. Example output:
http://chezphil.org/tmp/state_borders.jpeg (yes, it's an iPhone app...
hey, we all have to pay the rent somehow...)
p.s. has anyone worked out where this thread has gone on gmane.org?
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