Hello Adam
Le 31/07/12 01:20, Adam Estrada a écrit :
Where in your code is the geometry support? I need a heads up on where to find
it.
In the "pending" source code repository of Geotk, directory
modules/geometry. However this particular topic is still work in
progress, both on our side and on OGC side, and deserve a bit of context:
Geometries are defined by the ISO 19107 international standard, which is
reputed complex. Indeed, I'm not aware of any open source library
implementing fully this standard. Most projects use the simpler Java
Topology Suite (JTS) library. However JTS is designed for
two-dimensional geometries in a Cartesian space (JTS can store a 'z'
ordinate value, but doesn't use it). By contrast, ISO 19107 is designed
for 1D, 2D and 3D geometries in arbitrary coordinate systems.
In 2007, a Ph.D. student published his thesis on an implementation of
ISO 19107 geometries
(http://w1.cirrelt.ca/~jena/files/DiplThesisJena07.pdf). In our company,
we also supported a Ph.D. student who finished his thesis last year. We
are considering to support yet an other Ph.D. student on this topic -
this is to say that this particular topic is difficult. The ISO 19107
editor is aware of those kind of difficulties and is in the process of
revising the ISO 19107 standard at OGC.
In the main time, we are using a mixed approach: we use the ISO 19107
Java interfaces in some code, but the JTS library as the underlying
implementation. So the "geometry" group of modules contains a module
that provide a partial ISO 19107 implementation as wrappers around JTS
implementation. This has the JTS limits (2D, Cartesian), but may be the
most functional implementation for now...
Martin
