com.revolsys.jts.operation.buffer

Class Buffer

java.lang.Object

com.revolsys.jts.operation.buffer.Buffer

public class Buffer
extends Object

Computes the buffer of a geometry, for both positive and negative buffer distances.

In GIS, the positive (or negative) buffer of a geometry is defined as the Minkowski sum (or difference) of the geometry with a circle of radius equal to the absolute value of the buffer distance. In the CAD/CAM world buffers are known as offset curves. In morphological analysis the operation of postive and negative buffering is referred to as erosion and dilation

The buffer operation always returns a polygonal result. The negative or zero-distance buffer of lines and points is always an empty Polygon.

Since true buffer curves may contain circular arcs, computed buffer polygons can only be approximations to the true geometry. The user can control the accuracy of the curve approximation by specifying the number of linear segments used to approximate curves.

The end cap style of a linear buffer may be specified. The following end cap styles are supported:

BufferParameters.CAP_ROUND - the usual round end caps
• BufferParameters.CAP_FLAT - end caps are truncated flat at the line ends
• BufferParameters.CAP_SQUARE - end caps are squared off at the buffer distance beyond the line ends

Version:

1.7

Constructor Summary

Constructors

Constructor and Description
Buffer()

Method Summary

Methods

Modifier and Type	Method and Description
static Geometry	buffer(Geometry geometry, double distance) Computes the buffer of a geometry for a given buffer distance.
static Geometry	buffer(Geometry geometry, double distance, BufferParameters parameters) Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation.
static Geometry	buffer(Geometry geometry, double distance, int quadrantSegments) Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation.
static Geometry	buffer(Geometry geometry, double distance, int quadrantSegments, int endCapStyle) Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation.
static Geometry	buffer(Geometry geometry, double distance, int quadrantSegments, int endCapStyle, int joinStyle, double mitreLimit)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Buffer

public Buffer()

Method Detail

buffer

public static Geometry buffer(Geometry geometry,
              double distance)

Computes the buffer of a geometry for a given buffer distance.

Parameters:

g - the geometry to buffer

distance - the buffer distance

Returns:

the buffer of the input geometry

buffer

public static Geometry buffer(Geometry geometry,
              double distance,
              BufferParameters parameters)

Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation.

Parameters:

g - the geometry to buffer

distance - the buffer distance

parameters - the buffer parameters to use

Returns:

the buffer of the input geometry

buffer

public static Geometry buffer(Geometry geometry,
              double distance,
              int quadrantSegments)

Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation.

Parameters:

g - the geometry to buffer

distance - the buffer distance

quadrantSegments - the number of segments used to approximate a quarter circle

Returns:

the buffer of the input geometry

buffer

public static Geometry buffer(Geometry geometry,
              double distance,
              int quadrantSegments,
              int endCapStyle)

Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation.

Parameters:

g - the geometry to buffer

distance - the buffer distance

quadrantSegments - the number of segments used to approximate a quarter circle

endCapStyle - the end cap style to use

Returns:

the buffer of the input geometry

buffer

public static Geometry buffer(Geometry geometry,
              double distance,
              int quadrantSegments,
              int endCapStyle,
              int joinStyle,
              double mitreLimit)