Add ST_DistanceIndexed function

[dbaston]

Add an ST_DistanceIndexed function that delegates to the IndexedFacetDistance implementation in GEOS. In the future, this may be replaced with a native LWGEOM implementation.

[dbaston]

The indexed distance calculations in GEOS use a particular definition of "distance." From the JTS docs:

Distances will be computed to all facets of the input geometry. The facets of the geometry are the discrete segments and points contained in its components. In the case of Lineal and Puntal inputs, this is equivalent to computing the conventional distance. In the case of Polygonal inputs, this is equivalent to computing the distance to the polygons boundaries.

When one polygon is entirely contained within another polygon, the distance between them is greater than zero.

I think this functionality is valuable in PostGIS, but the name ST_DistanceIndexed risks creating confusion.

Is one of these options better?

• ST_LinearDistanceIndexed
• ST_BoundaryDistanceIndexed
• ST_IndexedFacetDistance (the JTS name)

?

[robe]

how about we go with the JTS name.

[robe]

Are you going to get to this in next week or so. If not can we push this to 2.5

[robe]

pushing this to 2.5 since no word on it.

[dbaston]

Now that Paul merged the distance tree code into liblwgeom, I see no reason to do this.