JTS Topology Suite is an open-sourceJavasoftware library that provides an object model for Euclidean planar linear geometry together with a set of fundamental geometric functions. JTS is primarily intended to be used as a core component of vector-basedgeomatics software such as geographical information systems. It can also be used as a general-purpose library providing algorithms in computational geometry. JTS implements the geometry model and API defined in the OpenGIS Consortium Simple Features Specification for SQL. JTS defines a standards-compliant geometry system for building spatial applications; examples include viewers, spatial query processors, and tools for performing data validation, cleaning and integration. In addition to the Java library, the foundations of JTS and selected functions are maintained in a C++ port, for use in C-style linking on all major operating systems, in the form of the GEOS software library. Up to JTS 1.14, and the GEOS port, are published under the GNU Lesser General Public License. With the LocationTech adoption future releases will be under the EPL/BSD licenses.
Scope
JTS provides the following functionality:
Geometry model
Geometry classes support modelling points, linestrings, polygons, and collections. Geometries are linear, in the sense that boundaries are implicitly defined by linear interpolation between vertices. Geometries are embedded in the 2-dimensional Euclidean plane. Geometry vertices may also carry a Z value. User-defined precision models are supported for geometry coordinates. Computation is performed using algorithms which provide robust geometric computation under all precision models.
Geometric functions
Topological validity checking
Area and Distance functions
Spatial Predicates based on the Egenhofer DE-9IM model
GEOS is the C/C++ port of a subset of JTS and selected functions. GEOS is noteworthy as a foundation component in a software ecosystem of native, compiled executable binaries on Linux, Mac and Windows platforms. Due to the runtime construction of Java and the Java Virtual Machine, code libraries that are written in Java are basically not usable as libraries from a standardized cross-linking environment. Linux, Microsoft Windows and the BSD family, including Mac OSX, use a linking structure that enables libraries from various languages to be integrated into a native runtime executable. Java, by design, does not participate in this interoperability without unusual measures.
Applications Using GEOS
links and ships internally in popular applications listed below; and, by delineating and implementing standards-based geometry classes available to GDAL, which in turn is a widely supported inner-engine in GIS, GEOS becomes a core geometry implementation in even more applications:
Funding for the initial work on JTS was obtained in the Fall 2000 from GeoConnections and the Government of British Columbia, based on a proposal put forward by Mark Sondheim and David Skea. The work was carried out by Martin Davis and Jonathan Aquino, both of Vivid Solutions at the time. Since then JTS has been maintained as an independent software project by Martin Davis. Since late 2016/early 2017 JTS has been adopted by LocationTech.
Platforms
JTS is developed under the Java JDK 1.4 platform. It is 100% pure Java. It will run on all more recent JDKs as well. A JTS subset has been ported to C++, with entry points declared as C interfaces, as the GEOS library. JTS has been ported to the.NET Framework as the Net Topology Suite.
