A description of the features and functions provided by JTS, linked to the relevant Javadoc for the current version.

Geometry Model

• Support for all Geometry types defined in the OGC Simple Features for SQL specification, including:
  • Point and MultiPoint
  • LineString and MultiLineString
  • Polygon and MultiPolygon
  • heterogeneous GeometryCollection

Geometry Operations

• Topological validity checking
• Area and Length/Perimeter
• Distance between geometries and isWithinDistance predicate
• Spatial Predicates based on the Egenhofer DE-9IM model, including the named predicates:
  • contains, within
  • covers, coveredBy
  • intersects, disjoint
  • crosses
  • overlaps
  • touches
  • equals
  and the general relate operation returning the DE-9IM intersection matrix.
• Overlay functions including
  • intersection,
  • difference,
  • union,
  • symmetric difference
  • unary union, providing fast union of geometry collections
• Buffer computation (also known as Minkowski sum with a circle)
  • selection of different end-cap and join styles.
• Convex hull
• Geometric simplification including the Douglas-Peucker algorithm and topology-preserving simplification
• Geometric densification
• Linear referencing

Precision Handling

• Explicit coordinate Precision Model
• Geometry precision reduction

Geometric Constructions

• Delaunay triangulation and Conforming Delaunay triangulation
• Voronoi diagram generation
• Minimum Diameter of a geometry
• Minimum Enclosing Rectangle
• Minimum Bounding Circle

Metric Functions

• Distance between geometries, with supporting points
• Discrete Hausdorff distance
• Area and Hausdorff similarity measures

Spatial algorithms

• Robust line segment intersection
• Efficient line arrangement intersection and noding
• Snap-rounding for noding line arrangements
• Efficient Point-in-Polygon testing

Mathematical Functions

• Angle computation
• Vector arithmetic

Spatial structures

• Spatial index structures including:
  • Quadtree
  • STR-tree
  • KD-tree
  • Interval R-tree
  • Monotone Chains
• Planar graphs and graph algorithms

Input/Output

• WKT (Well-Known Text) reading and writing
• WKB (Well-Known Binary) reading and writing
• GML(Geography Markup Language) Version 2 reading and writing
• Java Swing/AWT Shape writing

High-Precision Arithmetic

• Robust evaluation of 2x2 double-precision determinants
• DoubleDouble extended-precision arithmetic