Class HotPixel

Implements a "hot pixel" as used in the Snap Rounding algorithm. A hot pixel is a square region centred on the rounded valud of the coordinate given, and of width equal to the size of the scale factor. It is a partially open region, which contains the interior of the tolerance square and the boundary minus the top and right segments. This ensures that every point of the space lies in a unique hot pixel. It also matches the rounding semantics for numbers.

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

Hot Pixels support being marked as nodes. This is used to prevent introducing nodes at line vertices which do not have other lines snapped to them.

Inheritance

object

HotPixel

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: NetTopologySuite.Noding.Snapround

Assembly: NetTopologySuite.dll

Syntax

public class HotPixel

Constructors

HotPixel(Coordinate, double)

Creates a new hot pixel centered on a rounded point, using a given scale factor. The scale factor must be strictly positive(non-zero).

Declaration

public HotPixel(Coordinate pt, double scaleFactor)

Parameters

Type	Name	Description
Coordinate	pt	The coordinate at the center of the hot pixel (already rounded)
double	scaleFactor	The scale factor determining the pixel size

HotPixel(Coordinate, double, LineIntersector)

Initializes a new instance of the HotPixel class.

Declaration

[Obsolete("LineIntersector is no longer used.")]
public HotPixel(Coordinate pt, double scaleFactor, LineIntersector li)

Parameters

Type	Name	Description
Coordinate	pt	The coordinate at the center of the hot pixel
double	scaleFactor	The scale factor determining the pixel size
LineIntersector	li	The intersector to use for testing intersection with line segments

Properties

Coordinate

Gets the coordinate this hot pixel is based at.

Declaration

public Coordinate Coordinate { get; }

Property Value

Type	Description
Coordinate

IsNode

Gets or sets a value indicating whether this pixel has been marked as a node.

Declaration

public bool IsNode { get; set; }

Property Value

Type	Description
bool	true if the pixel is marked as a node

ScaleFactor

Gets the scale factor for the precision grid for this pixel.

Declaration

public double ScaleFactor { get; }

Property Value

Type	Description
double

Width

Gets the width of the hot pixel in the original coordinate system.

Declaration

public double Width { get; }

Property Value

Type	Description
double

Methods

AddSnappedNode(INodableSegmentString, int)

Adds a new node (equal to the snap pt) to the specified segment if the segment passes through the hot pixel

Declaration

[Obsolete("Moved to MCIndexPointSnapper")]
public bool AddSnappedNode(INodableSegmentString segStr, int segIndex)

Parameters

Type	Name	Description
INodableSegmentString	segStr
int	segIndex

Returns

Type	Description
bool	true if a node was added to the segment

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.

Declaration

[Obsolete("Moved to MCIndexPointSnapper")]
public Envelope GetSafeEnvelope()

Returns

Type	Description
Envelope	An envelope which contains the pixel

Intersects(Coordinate)

Tests whether a coordinate lies in (intersects) this hot pixel.

Declaration

public bool Intersects(Coordinate p)

Parameters

Type	Name	Description
Coordinate	p	The coordinate to test

Returns

Type	Description
bool	true if the coordinate intersects this hot pixel

Intersects(Coordinate, Coordinate)

Tests whether the line segment (p0-p1) intersects this hot pixel.

Declaration

public bool Intersects(Coordinate p0, Coordinate p1)

Parameters

Type	Name	Description
Coordinate	p0	The first coordinate of the line segment to test
Coordinate	p1	The second coordinate of the line segment to test

Returns

Type	Description
bool	true if the line segment intersects this hot pixel.

IntersectsScaled(Coordinate, Coordinate)

Declaration

[Obsolete("This method was never intended to be public and will be removed in a future release.")]
public bool IntersectsScaled(Coordinate p0, Coordinate p1)

Parameters

Type	Name	Description
Coordinate	p0
Coordinate	p1

Returns

Type	Description
bool

ToString()

Declaration

public override string ToString()

Returns

Type	Description
string

Overrides

object.ToString()