com.revolsys.gis.model.coordinates

Class LineSegmentUtil

java.lang.Object

com.revolsys.gis.model.coordinates.LineSegmentUtil

public class LineSegmentUtil
extends Object

Constructor Summary

Constructors

Constructor and Description
LineSegmentUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static Point	closestPoint(Point lineStart, Point lineEnd, Point point)
static double	det(double a, double b, double c, double d)
static double	distanceLineLine(double line1X1, double line1Y1, double line1X2, double line1Y2, double line2X1, double line2Y1, double line2X2, double line2Y2) Computes the distance from a line segment AB to a line segment CD Note: NON-ROBUST!
static double	distanceLineLine(Point line1From, Point line1To, Point line2From, Point line2To)
static double	distanceLinePoint(double x1, double y1, double x2, double y2, double x, double y) Calculate the distance between the line from x1,y1 to x2,y2 and the point x,y.
static double	distanceLinePoint(Point lineStart, Point lineEnd, Point point) Calculate the distance between the line from lineStart to lineEnd and the point.
static boolean	envelopeIntersects(double x1, double y1, double x2, double y2, double x, double y) Check to see if the point (x,y) intersects the envelope of the line from (x1,y1) to (x2,y2).
static boolean	envelopeIntersects(Point lineStart, Point lineEnd, Point point) Check to see if the point intersects the envelope of the line from lineStart to lineEnd.
static boolean	envelopeIntersects(Point line1Start, Point line1End, Point line2Start, Point line2End) Check to see if the envelope one the line from line1Start to line1End intersects the envelope of the line from line2Start to line2End.
static Point	getElevation(GeometryFactory geometryFactory, Point lineStart, Point lineEnd, Point point)
static double	getElevation(Point lineStart, Point lineEnd, Point point)
static LineString	getIntersection(GeometryFactory geometryFactory, Point line1Start, Point line1End, Point line2Start, Point line2End) Get the intersection between line (segment) 1 and line (segment) 2.
static boolean	intersects(Point line1p1, Point line1p2, Point line2p1, Point line2p2)
static boolean	isPointOnLine(double x1, double y1, double x2, double y2, double x, double y, double maxDistance)
static boolean	isPointOnLine(GeometryFactory precisionModel, Point lineStart, Point lineEnd, Point point) Check to see if the point is on the line between lineStart and lineEnd using the precision model to see if a line split at the projection of the point on the line would be the same point.
static boolean	isPointOnLine(Point lineStart, Point lineEnd, Point point, double maxDistance)
static boolean	isPointOnLineMiddle(GeometryFactory precisionModel, Point lineStart, Point lineEnd, Point point)
static Point	midPoint(GeometryFactory precisionModel, Point lineStart, Point lineEnd)
static Point	midPoint(Point lineStart, Point lineEnd)
static int	orientationIndex(Point lineStart, Point lineEnd, Point point)
static double	orientedAngleBetween2d(Point start, Point line1End, Point line2End) Calculate the counter clockwise angle in radians of the difference between the two vectors from the start point and line1End and line2End.
static Point	pointAlong(GeometryFactory precisionModel, Point lineStart, Point lineEnd, Point point)
static Point	pointAlong(Point p0, Point p1, double segmentLengthFraction)
static Point	project(GeometryFactory precisionModel, Point lineStart, Point lineEnd, double r)
static Point	project(GeometryFactory precisionModel, Point lineStart, Point lineEnd, Point point)
static Point	project(int axisCount, Point lineStart, Point lineEnd, double r)
static double	projectionFactor(double x1, double y1, double x2, double y2, double x, double y) Calculate the projection factor of the distance of the point (x,y) coordinates along the line (x1,y1 -> x2,y2).
static double	projectionFactor(Point lineStart, Point lineEnd, Point point) Calculate the projection factor of the distance of the point coordinates along the line.
static double	segmentFraction(Point lineStart, Point lineEnd, Point point)

Methods inherited from class java.lang.Object

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

Constructor Detail

LineSegmentUtil

public LineSegmentUtil()

Method Detail

closestPoint

public static Point closestPoint(Point lineStart,
                 Point lineEnd,
                 Point point)

det

public static double det(double a,
         double b,
         double c,
         double d)

distanceLineLine

public static double distanceLineLine(double line1X1,
                      double line1Y1,
                      double line1X2,
                      double line1Y2,
                      double line2X1,
                      double line2Y1,
                      double line2X2,
                      double line2Y2)

Computes the distance from a line segment AB to a line segment CD Note: NON-ROBUST!

Parameters:

A - a point of one line

B - the second point of (must be different to A)

C - one point of the line

D - another point of the line (must be different to A)

distanceLineLine

public static double distanceLineLine(Point line1From,
                      Point line1To,
                      Point line2From,
                      Point line2To)

distanceLinePoint

public static double distanceLinePoint(double x1,
                       double y1,
                       double x2,
                       double y2,
                       double x,
                       double y)

Calculate the distance between the line from x1,y1 to x2,y2 and the point x,y.

Parameters:

x1 - The x coordinate at the start of the line.

y1 - The y coordinate at the start of the line.

x2 - The x coordinate at the end of the line.

y2 - The y coordinate at the end of the line.

x - The x coordinate of the point.

y - The y coordinate of the point.

Returns:

The distance.

distanceLinePoint

public static double distanceLinePoint(Point lineStart,
                       Point lineEnd,
                       Point point)

Calculate the distance between the line from lineStart to lineEnd and the point.

Parameters:

lineStart - The point at the start of the line.

lineEnd - The point at the end of the line.

point - The point.

point - The coordinates of the point location.

Returns:

The distance.

envelopeIntersects

public static boolean envelopeIntersects(double x1,
                         double y1,
                         double x2,
                         double y2,
                         double x,
                         double y)

Check to see if the point (x,y) intersects the envelope of the line from (x1,y1) to (x2,y2).

Parameters:

x1 - The x coordinate at the start of the line.

y1 - The y coordinate at the start of the line.

x2 - The x coordinate at the end of the line.

y2 - The y coordinate at the end of the line.

x - The x coordinate of the point.

y - The y coordinate of the point.

Returns:

True if the point intersects the line's envelope.

envelopeIntersects

public static boolean envelopeIntersects(Point lineStart,
                         Point lineEnd,
                         Point point)

Check to see if the point intersects the envelope of the line from lineStart to lineEnd.

Parameters:

lineStart - The point at the start of the line.

lineEnd - The point at the end of the line.

point - The point.

Returns:

True if the point intersects the line's envelope.

envelopeIntersects

public static boolean envelopeIntersects(Point line1Start,
                         Point line1End,
                         Point line2Start,
                         Point line2End)

Check to see if the envelope one the line from line1Start to line1End intersects the envelope of the line from line2Start to line2End.

Parameters:

line1Start - The point at the start of the first line.

line1End - The point at the end of the first line.

line2Start - The point at the start of the second line.

line2End - The point at the end of the second line.

Returns:

True if the envelope of line intersects the envelope of line 2.

getElevation

public static Point getElevation(GeometryFactory geometryFactory,
                 Point lineStart,
                 Point lineEnd,
                 Point point)

getElevation

public static double getElevation(Point lineStart,
                  Point lineEnd,
                  Point point)

getIntersection

public static LineString getIntersection(GeometryFactory geometryFactory,
                         Point line1Start,
                         Point line1End,
                         Point line2Start,
                         Point line2End)

Get the intersection between line (segment) 1 and line (segment) 2. The result will be either and empty collection, a single coordinates value for a crosses intersection or a pair of coordinates for a linear intersection. The results will be rounded according to the precision model. Any z-value interpolation will be calculated using the z-values from line (segment) 1. For linear intersections the order of the points will be the same as the orientation of line1.

Parameters:

geometryFactory -

line1Start -

line1End -

line2Start -

line2End -

Returns:

intersects

public static boolean intersects(Point line1p1,
                 Point line1p2,
                 Point line2p1,
                 Point line2p2)

isPointOnLine

public static boolean isPointOnLine(double x1,
                    double y1,
                    double x2,
                    double y2,
                    double x,
                    double y,
                    double maxDistance)

isPointOnLine

public static boolean isPointOnLine(GeometryFactory precisionModel,
                    Point lineStart,
                    Point lineEnd,
                    Point point)

Check to see if the point is on the line between lineStart and lineEnd using the precision model to see if a line split at the projection of the point on the line would be the same point.

Parameters:

precisionModel - The precision model.

lineStart - The point at the start of the line.

lineEnd - The point at the end of the line.

point - The point.

Returns:

True if the point is on the line.

isPointOnLine

public static boolean isPointOnLine(Point lineStart,
                    Point lineEnd,
                    Point point,
                    double maxDistance)

isPointOnLineMiddle

public static boolean isPointOnLineMiddle(GeometryFactory precisionModel,
                          Point lineStart,
                          Point lineEnd,
                          Point point)

midPoint

public static Point midPoint(GeometryFactory precisionModel,
             Point lineStart,
             Point lineEnd)

midPoint

public static Point midPoint(Point lineStart,
             Point lineEnd)

orientationIndex

public static int orientationIndex(Point lineStart,
                   Point lineEnd,
                   Point point)

orientedAngleBetween2d

public static double orientedAngleBetween2d(Point start,
                            Point line1End,
                            Point line2End)

Calculate the counter clockwise angle in radians of the difference between the two vectors from the start point and line1End and line2End. The angle is relative to the vector from start to line1End. The angle will be in the range 0 -> 2 * PI.

Returns:

The angle in radians.

pointAlong

public static Point pointAlong(GeometryFactory precisionModel,
               Point lineStart,
               Point lineEnd,
               Point point)

pointAlong

public static Point pointAlong(Point p0,
               Point p1,
               double segmentLengthFraction)

project

public static Point project(GeometryFactory precisionModel,
            Point lineStart,
            Point lineEnd,
            double r)

project

public static Point project(GeometryFactory precisionModel,
            Point lineStart,
            Point lineEnd,
            Point point)

project

public static Point project(int axisCount,
            Point lineStart,
            Point lineEnd,
            double r)

projectionFactor

public static double projectionFactor(double x1,
                      double y1,
                      double x2,
                      double y2,
                      double x,
                      double y)

Calculate the projection factor of the distance of the point (x,y) coordinates along the line (x1,y1 -> x2,y2). If the point is within the line the range will be between 0.0 -> 1.0.

Parameters:

x1 - The x coordinate for the start of the line.

y1 - The y coordinate for the start of the line.

x2 - The x coordinate for the end of the line.

y2 - The y coordinate for the end of the line.

x - The x coordinate for the point.

y - The y coordinate for the point.

Returns:

The projection factor from (-inf -> +inf).

projectionFactor

public static double projectionFactor(Point lineStart,
                      Point lineEnd,
                      Point point)

Calculate the projection factor of the distance of the point coordinates along the line. If the point is within the line the range will be between 0.0 -> 1.0.

Parameters:

lineStart - The start coordinates of the line.

lineEnd - The end coordinates of the line.

point - The point coordinates.

Returns:

The projection factor from (-inf -> +inf).

segmentFraction

public static double segmentFraction(Point lineStart,
                     Point lineEnd,
                     Point point)