Class HotPixel

Namespace

NetTopologySuite.Noding.Snapround

Assembly

NetTopologySuite.dll

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.

public class HotPixel

Inheritance

object

HotPixel

Inherited Members

object.GetType()

object.MemberwiseClone()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

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).

public HotPixel(Coordinate pt, double scaleFactor)

Parameters

pt Coordinate

The coordinate at the center of the hot pixel (already rounded)

scaleFactor double

The scale factor determining the pixel size

HotPixel(Coordinate, double, LineIntersector)

Initializes a new instance of the HotPixel class.

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

Parameters

pt Coordinate

The coordinate at the center of the hot pixel

scaleFactor double

The scale factor determining the pixel size

li LineIntersector

The intersector to use for testing intersection with line segments

Properties

Coordinate

Gets the coordinate this hot pixel is based at.

public Coordinate Coordinate { get; }

Property Value

Coordinate

IsNode

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

public bool IsNode { get; set; }

Property Value

bool

true if the pixel is marked as a node

ScaleFactor

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

public double ScaleFactor { get; }

Property Value

double

Width

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

public double Width { get; }

Property Value

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

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

Parameters

segStr INodableSegmentString

segIndex int

Returns

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.

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

Returns

Envelope

An envelope which contains the pixel

Intersects(Coordinate)

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

public bool Intersects(Coordinate p)

Parameters

p Coordinate

The coordinate to test

Returns

bool

true if the coordinate intersects this hot pixel

Intersects(Coordinate, Coordinate)

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

public bool Intersects(Coordinate p0, Coordinate p1)

Parameters

p0 Coordinate

The first coordinate of the line segment to test

p1 Coordinate

The second coordinate of the line segment to test

Returns

bool

true if the line segment intersects this hot pixel.

IntersectsScaled(Coordinate, Coordinate)

[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

p0 Coordinate

p1 Coordinate

Returns

bool

ToString()

public override string ToString()

Returns

string