JTS Topology Suite version 1.13

com.vividsolutions.jts.noding.snapround
Class HotPixel

java.lang.Object
  extended by com.vividsolutions.jts.noding.snapround.HotPixel

public class HotPixel
extends java.lang.Object

Implements a "hot pixel" as used in the Snap Rounding algorithm. A hot pixel contains the interior of the tolerance square and the boundary minus the top and right segments.

The hot pixel operations are all computed in the integer domain to avoid rounding problems.

Version:
1.7

Constructor Summary
HotPixel(Coordinate pt, double scaleFactor, LineIntersector li)
          Creates a new hot pixel, using a given scale factor.
 
Method Summary
 boolean addSnappedNode(NodedSegmentString segStr, int segIndex)
          Adds a new node (equal to the snap pt) to the specified segment if the segment passes through the hot pixel
 Coordinate getCoordinate()
          Gets the coordinate this hot pixel is based at.
 Envelope getSafeEnvelope()
          Returns a "safe" envelope that is guaranteed to contain the hot pixel.
 boolean intersects(Coordinate p0, Coordinate p1)
          Tests whether the line segment (p0-p1) intersects this hot pixel.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

HotPixel

public HotPixel(Coordinate pt,
                double scaleFactor,
                LineIntersector li)
Creates a new hot pixel, using a given scale factor. The scale factor must be strictly positive (non-zero).

Parameters:
pt - the coordinate at the centre of the pixel
scaleFactor - the scaleFactor determining the pixel size. Must be > 0
li - the intersector to use for testing intersection with line segments
Method Detail

getCoordinate

public Coordinate getCoordinate()
Gets the coordinate this hot pixel is based at.

Returns:
the coordinate of the pixel

getSafeEnvelope

public Envelope getSafeEnvelope()
Returns a "safe" envelope that is guaranteed to contain the hot pixel. The envelope returned will be larger than the exact envelope of the pixel.

Returns:
an envelope which contains the hot pixel

intersects

public boolean intersects(Coordinate p0,
                          Coordinate p1)
Tests whether the line segment (p0-p1) intersects this hot pixel.

Parameters:
p0 - the first coordinate of the line segment to test
p1 - the second coordinate of the line segment to test
Returns:
true if the line segment intersects this hot pixel

addSnappedNode

public boolean addSnappedNode(NodedSegmentString segStr,
                              int segIndex)
Adds a new node (equal to the snap pt) to the specified segment if the segment passes through the hot pixel

Parameters:
segStr -
segIndex -
Returns:
true if a node was added to the segment

JTS Topology Suite version 1.13