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java.lang.Object com.vividsolutions.jts.operation.buffer.BufferOp
public class BufferOp
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:
CAP_ROUND
- the usual round end caps
CAP_BUTT
- end caps are truncated flat at the line ends
CAP_SQUARE
- end caps are squared off at the buffer distance beyond the line ends
Field Summary | |
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static int |
CAP_BUTT
Deprecated. use BufferParameters |
static int |
CAP_FLAT
Deprecated. use BufferParameters |
static int |
CAP_ROUND
Deprecated. use BufferParameters |
static int |
CAP_SQUARE
Deprecated. use BufferParameters |
Constructor Summary | |
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BufferOp(Geometry g)
Initializes a buffer computation for the given geometry |
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BufferOp(Geometry g,
BufferParameters bufParams)
Initializes a buffer computation for the given geometry with the given set of parameters |
Method Summary | |
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static Geometry |
bufferOp(Geometry g,
double distance)
Computes the buffer of a geometry for a given buffer distance. |
static Geometry |
bufferOp(Geometry g,
double distance,
BufferParameters params)
Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation. |
static Geometry |
bufferOp(Geometry g,
double distance,
int quadrantSegments)
Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation. |
static Geometry |
bufferOp(Geometry g,
double distance,
int quadrantSegments,
int endCapStyle)
Comutes the buffer for a geometry for a given buffer distance and accuracy of approximation. |
Geometry |
getResultGeometry(double distance)
Returns the buffer computed for a geometry for a given buffer distance. |
void |
setEndCapStyle(int endCapStyle)
Specifies the end cap style of the generated buffer. |
void |
setQuadrantSegments(int quadrantSegments)
Sets the number of segments used to approximate a angle fillet |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
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public static final int CAP_ROUND
public static final int CAP_BUTT
public static final int CAP_FLAT
public static final int CAP_SQUARE
Constructor Detail |
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public BufferOp(Geometry g)
g
- the geometry to bufferpublic BufferOp(Geometry g, BufferParameters bufParams)
g
- the geometry to bufferbufParams
- the buffer parameters to useMethod Detail |
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public static Geometry bufferOp(Geometry g, double distance)
g
- the geometry to bufferdistance
- the buffer distance
public static Geometry bufferOp(Geometry g, double distance, BufferParameters params)
g
- the geometry to bufferdistance
- the buffer distanceparams
- the buffer parameters to use
public static Geometry bufferOp(Geometry g, double distance, int quadrantSegments)
g
- the geometry to bufferdistance
- the buffer distancequadrantSegments
- the number of segments used to approximate a quarter circle
public static Geometry bufferOp(Geometry g, double distance, int quadrantSegments, int endCapStyle)
g
- the geometry to bufferdistance
- the buffer distancequadrantSegments
- the number of segments used to approximate a quarter circleendCapStyle
- the end cap style to use
public void setEndCapStyle(int endCapStyle)
CAP_ROUND
, CAP_BUTT
, and CAP_SQUARE
.
The default is CAP_ROUND.
endCapStyle
- the end cap style to specifypublic void setQuadrantSegments(int quadrantSegments)
quadrantSegments
- the number of segments in a fillet for a quadrantpublic Geometry getResultGeometry(double distance)
distance
- the buffer distance
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