y.geom
Class LineSegment

java.lang.Object
  y.geom.LineSegment

All Implemented Interfaces:

PlaneObject

public class LineSegment
extends java.lang.Object
implements PlaneObject

This class represents a line segment in the plane. A line segment is defined by its two end points.

Constructor Summary

LineSegment(YPoint p1, YPoint p2)
Returns a new LineSegment.

Method Summary

static boolean	boxIntersectsSegment(double boxX1, double boxY1, double boxX2, double boxY2, double sX1, double sY1, double sX2, double sY2) Checks whether a line segment intersects a paraxial box.
static boolean	boxIntersectsSegment(YRectangle box, double x1, double y1, double x2, double y2) Checks whether a line segment intersects a box.
static boolean	boxIntersectsSegment(YRectangle box, YPoint s, YPoint t) Checks whether a line segment intersects a box.
boolean	contains(YPoint point) Checks whether a given point lies on this line segment.
YRectangle	getBoundingBox() Returns the smallest Rectangle which contains the object.
double	getDeltaX() Returns the distance from start to end point in x-coordinates.
double	getDeltaY() Returns the distance from start to end point in y-coordinates.
YPoint	getFirstEndPoint() Returns the first end point of the line segment.
static YPoint	getIntersection(LineSegment s1, LineSegment s2) Returns intersection point between the two line segments, if there is one or null if the two line segments do not intersect.
double	getScope() Returns the slope of the line segment.
YPoint	getSecondEndPoint() Returns the second end point of the line segment.
double	getXOffset() Returns the y value of the line on x coordinate 0.
boolean	intersects(YPoint p) Checks whether the line segment intersects a point.
boolean	intersects(YRectangle box) Checks whether the line segment intersects a box.
boolean	isHorizontal() Returns if this segment is considered horizontal, that is, the y values of the end points differ by at most 1e-8.
static boolean	isHorizontal(YPoint p1, YPoint p2) Determines if the given points define a horizontal line segment.
boolean	isInXIntervall(double x) Returns if the projection on the X axis of the line segment covers a certain point on the X Axis.
boolean	isInYIntervall(double y) Returns if the projection on the Y axis of the line segment covers a certain point on the Y Axis.
boolean	isVertical() Returns if this segment is considered vertical, that is, the x values of the end points differ by at most 1e-8.
static boolean	isVertical(YPoint p1, YPoint p2) Determines if the given points define a vertical line segment.
double	length() Returns the length of the line segment, this is the value of the Euclidean norm.
AffineLine	toAffineLine() Returns the affine line defined by the end points of the line segment.
java.lang.String	toString() String representation of the line.
YVector	toYVector() Returns the vector pointing from the first end point to the second end point of the line segment.

Methods inherited from class java.lang.Object

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

Constructor Detail

LineSegment

public LineSegment(YPoint p1,
                   YPoint p2)

Returns a new LineSegment.

Parameters:

p1 - the first end point of the line segment.

p2 - the second end point of the line segment.

Method Detail

isVertical

public boolean isVertical()

Returns if this segment is considered vertical, that is, the x values of the end points differ by at most 1e-8.

Returns:

true if this segment is considered vertical, false otherwise.

isVertical

public static boolean isVertical(YPoint p1,
                                 YPoint p2)

Determines if the given points define a vertical line segment.

This methods allows for x-coordinate differences of up to 1e-8.

Returns:

true if the given points define a vertical line segment; false otherwise.

isHorizontal

public boolean isHorizontal()

Returns if this segment is considered horizontal, that is, the y values of the end points differ by at most 1e-8.

Returns:

true if the segment is considered horizontal, false otherwise.

isHorizontal

public static boolean isHorizontal(YPoint p1,
                                   YPoint p2)

Determines if the given points define a horizontal line segment.

This methods allows for y-coordinate differences of up to 1e-8.

Returns:

true if the given points define a horizontal line segment; false otherwise.

getFirstEndPoint

public YPoint getFirstEndPoint()

Returns the first end point of the line segment.

getSecondEndPoint

public YPoint getSecondEndPoint()

Returns the second end point of the line segment.

isInYIntervall

public boolean isInYIntervall(double y)

Returns if the projection on the Y axis of the line segment covers a certain point on the Y Axis.

isInXIntervall

public boolean isInXIntervall(double x)

Returns if the projection on the X axis of the line segment covers a certain point on the X Axis.

getXOffset

public double getXOffset()

Returns the y value of the line on x coordinate 0.

getScope

public double getScope()

Returns the slope of the line segment.

Returns:

the slope of the line segment.

length

public double length()

Returns the length of the line segment, this is the value of the Euclidean norm.

Returns:

an value > 0.

getBoundingBox

public YRectangle getBoundingBox()

Returns the smallest Rectangle which contains the object.

Specified by:

getBoundingBox in interface PlaneObject

intersects

public boolean intersects(YRectangle box)

Checks whether the line segment intersects a box.

Parameters:

box - A rectangle.

Returns:

true if the line segments intersects the box, false otherwise.

contains

public boolean contains(YPoint point)

Checks whether a given point lies on this line segment.

Parameters:

point - an arbitrary point.

Returns:

true if the line segments intersects the box, false otherwise.

intersects

public boolean intersects(YPoint p)

Checks whether the line segment intersects a point.

Parameters:

p - a point

Returns:

true if the line segments intersects the given point, false otherwise.

boxIntersectsSegment

public static final boolean boxIntersectsSegment(YRectangle box,
                                                 YPoint s,
                                                 YPoint t)

Checks whether a line segment intersects a box.

Parameters:

box - A rectangle.

s - first end point of the line segment.

t - second end point of the line segment.

Returns:

true if the line segments intersects the box, false otherwise.

boxIntersectsSegment

public static final boolean boxIntersectsSegment(YRectangle box,
                                                 double x1,
                                                 double y1,
                                                 double x2,
                                                 double y2)

Checks whether a line segment intersects a box. Implemented using the Cohen-Sutherland algorithm.

Parameters:

box - A rectangle

x1 - x-coordinate of the first end point of the line segment

y1 - y-coordinate of the first end point of the line segment

x2 - x-coordinate of the second end point of the line segment

y2 - y-coordinate of the second end point of the line segment

Returns:

true if the line segment intersects the box, false otherwise.

boxIntersectsSegment

public static final boolean boxIntersectsSegment(double boxX1,
                                                 double boxY1,
                                                 double boxX2,
                                                 double boxY2,
                                                 double sX1,
                                                 double sY1,
                                                 double sX2,
                                                 double sY2)

Checks whether a line segment intersects a paraxial box. Implemented using the Cohen-Sutherland algorithm.

Parameters:

boxX1 - x-coordinate of the upper left corner of the box

boxY1 - y-coordinate of the upper left corner of the box

boxX2 - x-coordinate of the lower right corner of the box

boxY2 - y-coordinate of the lower right corner of the box

sX1 - x-coordinate of the first end point of the line segment

sY1 - y-coordinate of the first end point of the line segment

sX2 - x-coordinate of the second end point of the line segment

sY2 - y-coordinate of the second end point of the line segment

Returns:

true if the line segment intersects the box, false otherwise.

getIntersection

public static YPoint getIntersection(LineSegment s1,
                                     LineSegment s2)

Returns intersection point between the two line segments, if there is one or null if the two line segments do not intersect.

Parameters:

s1 - first line segment

s2 - second line segment

toYVector

public YVector toYVector()

Returns the vector pointing from the first end point to the second end point of the line segment.

toAffineLine

public AffineLine toAffineLine()

Returns the affine line defined by the end points of the line segment.

getDeltaX

public double getDeltaX()

Returns the distance from start to end point in x-coordinates.

Returns:

the distance from start to end point in x-coordinates.

getDeltaY

public double getDeltaY()

Returns the distance from start to end point in y-coordinates.

Returns:

the distance from start to end point in y-coordinates.

toString

public java.lang.String toString()

String representation of the line.

Overrides:

toString in class java.lang.Object