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34 lines
1.1 KiB
C++
34 lines
1.1 KiB
C++
/*!
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\defgroup within within: detect if a geometry is inside another geometry, a.o. point-in-polygon
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\par Source descriptions:
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- OGC: Returns 1 (TRUE) if this geometric object is "spatially within"
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another Geometry.
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\par Performance
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- 2776 within determinations using bounding box and polygon are done
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in 0.05 seconds (http://trac.osgeo.org/ggl/wiki/Performance#Within1)
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- note that using another strategy the performance can be increased:
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- winding : 0.093 s
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- franklin : 0.062 s
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- Crossings-multiply : 0.047 s
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- but note also that the last two do not detect point-on-border cases
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\par Geometries:
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- \b point + \b polygon: The well-known point-in-polygon, returning true if
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a point falls within a polygon (and not
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within one of its holes) \image html within_polygon.png
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- \b point + \b ring: returns true if point is completely within
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a ring \image html within_ring.png
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- \b point + \b box
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- \b box + \b box
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\par Example:
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The within algorithm is used as following:
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\dontinclude doxygen_1.cpp
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\skip example_within
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\line {
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\until }
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*/
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