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java.lang.Objectorg.eclipse.gmf.runtime.draw2d.ui.geometry.LineSeg
public class LineSeg
This is a geometric utility class that allows for manipulation of line segments. A line segment is defined as a set of two points where one point is designated as the origin and the other is the terminal.
Nested Class Summary | |
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static class |
LineSeg.KeyPoint
Enumeration class for defining the keypoint along a line segment. |
static class |
LineSeg.Sign
Enumeration class for defining the orientations of a point relative to the line segment. |
static class |
LineSeg.TrigValues
Structure to hold onto trig values that represent an angle |
Constructor Summary | |
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LineSeg(LineSeg.KeyPoint start,
int fromX,
int fromY,
float slope,
long len,
int xdir)
Creates a segment using (fromX, fromY) as either the first point of the segment (start == Origin) or the midpoint of the segment (start == Midpoint), and using slope as its new slope and len as the new length. |
|
LineSeg(Point ptStart,
Point ptEnd)
Constructor |
Method Summary | |
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boolean |
containsPoint(Point aPoint,
int tolerance)
Checks if this line segment contains the given point within a tolerance value. |
float |
distanceAlong(Point coord)
Finds the percentage distance along this line segement where the given point resides. |
long |
distanceToPoint(int xCoord,
int yCoord)
Finds the perpendicular distance from a point coordinates to this line segment. |
boolean |
equals(java.lang.Object seg)
|
double[] |
getEquation()
Returns array with 3 numbers in it, which are the coefficients of the generalized line equation of the line corresponding to this line segment a*x+b*y=c is the equation => result[0]=a, result[1]=b, result[2]=c |
Point |
getInfimum()
Get a Point representing the lowest point value
for this line segment. |
static double[] |
getLineEquation(double x1,
double y1,
double x2,
double y2)
Returns the coefficients of the generalized equation of the line passing through points (x1,y1) and (x2,y2) Generalized line equation: ax+by=c => a==result[0], b==result[1], c==result[2] |
PointList |
getLineIntersectionsWithEllipse(Rectangle ellipseBounds)
Calculates intersection points of the line of the line segment and ellipse |
PointList |
getLineIntersectionsWithLineSegs(PointList points)
Calculates intersection points of the line that contains this line segment with a list of other line segments. |
PointList |
getLinesIntersections(LineSeg line)
Returns intersection points of two lines that contain this line segment and the argumet line segment. |
Point |
getOrigin()
Accesssor to retrieve the origin point of the line segement. |
LineSeg |
getParallelLineSegThroughPoint(Point ptLoc)
Returns a new LineSeg that is parallel to this by the given distance. |
Point |
getSupremum()
Get points representing the highest point value for this line segment. |
Point |
getTerminus()
Accesssor to retrieve the terminal point of the line segement. |
LineSeg.TrigValues |
getTrigValues(Ray ptToVector)
Gets the trig values associated with the angle from this line segment to the given vector. |
int |
hashCode()
|
Point |
intersect(LineSeg line,
int nTolerance)
Determines the intersect point between this line and the line passed in as a parameter. |
boolean |
isHorizontal()
Determines if this a horizontal segment |
boolean |
isVertical()
Determines if this a vertical segment |
double |
length()
Calculate the length of the line segment. |
Point |
locatePoint(double pctDist,
long theHeight,
LineSeg.Sign asOriented)
Locates a point at a given height and distance along the line segment. |
void |
performScale(double factor)
|
void |
performTranslate(int dx,
int dy)
|
Point |
perpIntersect(int startX,
int startY)
Calculates the perpendicular intersection point on the line segment from the given point. |
float |
perpSlope()
Calculates the perpendicular slope of this line segment. |
boolean |
pointOn(long theDistance,
LineSeg.KeyPoint fromKeyPoint,
Point ptResult)
Gets the point on the line segment at the given distance away from the key point. |
LineSeg.Sign |
positionRelativeTo(Point rel)
Returns out a positive or negative value (Positive / Negative) depending on the orientation of the given point to the line. |
double |
projection(int xCoord,
int yCoord)
Calculates the projection of the given point onto the line segment. |
void |
setOrigin(Point origin)
Sets the origin point of the line segment |
void |
setTerminus(Point terminus)
Sets the terminating point of the line segment. |
float |
slope()
Calculates the slope of this line segment (y=mx+b) |
Methods inherited from class java.lang.Object |
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clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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public LineSeg(Point ptStart, Point ptEnd)
ptStart
- Point indicating the start of the line segmentptEnd
- Point indicating the end of the line segmentpublic LineSeg(LineSeg.KeyPoint start, int fromX, int fromY, float slope, long len, int xdir)
start
- KeyPoint
from which the other parameters are relative tofromX
- int x value of start KeyPoint
fromY
- int y value of start KeyPoint
slope
- float
slope of the linelen
- long
length of the linexdir
- directionMethod Detail |
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public boolean equals(java.lang.Object seg)
equals
in class java.lang.Object
public int hashCode()
hashCode
in class java.lang.Object
public Point getOrigin()
Point
the origin of the line segment.public Point getTerminus()
Point
the terminating point of the line segmentpublic void setOrigin(Point origin)
origin
- Point to set as originpublic void setTerminus(Point terminus)
terminus
- Point to set as terminuspublic final Point getSupremum()
Point
Representing the highest point value.public final Point getInfimum()
Point
representing the lowest point value
for this line segment.
Point
Representing the lowest point value.public final boolean isHorizontal()
boolean
true
if horizontal,
false
otherwise.public final boolean isVertical()
boolean
true
if vertical,
false
otherwise.public final float slope()
float
the slope of this segment. If the slope
is not defined such as when the line segment is vertical, then the
constant BIGSLOPE
is returned to avoid divide by zero
errors.public final float perpSlope()
BIGSLOPE
is returned if the calculated slope
before inverting it was zero.
float
the perpendicular slope value of the
line segment.public final double length()
double
length of the line segment.public Point intersect(LineSeg line, int nTolerance)
false
.
line
- LineSeg
to test the intersection against.nTolerance
- int tolerance value for detecting the intersection.
Point
that represents the intersection with this line,
or null
if the calculation is not possible.public final boolean containsPoint(Point aPoint, int tolerance)
aPoint
- Point
to test if contained in this line.tolerance
- int tolerance value for detecting the intersection.
boolean
true
if the given point lies on this
segment, false
otherwise.public final float distanceAlong(Point coord)
coord
- Point
to determine how far along the line segment it resides.
float
the distance along the line segment where the ptCoord is
in a percentage from.public final long distanceToPoint(int xCoord, int yCoord)
xCoord
- the x coordinate of the point.yCoord
- the y coordinate of the point.
long
the distance from the line segment to the given point.public final Point perpIntersect(int startX, int startY)
startX
- the x coordinate of the pointstartY
- the y coordinate of the point
Point
value containment the perpendicular intersection point.public final double projection(int xCoord, int yCoord)
xCoord
- the x coordinate of the point.yCoord
- the y coordinate of the point.
double
value of the calculated projection.public final LineSeg.Sign positionRelativeTo(Point rel)
rel
- Point
to test the relative position against this line.
Sign
value indicating the relative position of the given point.public final Point locatePoint(double pctDist, long theHeight, LineSeg.Sign asOriented)
pctDist
- double
distance along the linetheHeight
- long
height above the lineasOriented
- Sign
indicating relative position of the point to be located
Point
value that was located on the line.public final boolean pointOn(long theDistance, LineSeg.KeyPoint fromKeyPoint, Point ptResult)
theDistance
- long
distance along the linefromKeyPoint
- KeyPoint
to calculate the distance fromptResult
- Point
where the resulting calculating value is stored.
boolean
true
if point can be calculated,
false
otherwise.public LineSeg.TrigValues getTrigValues(Ray ptToVector)
ptToVector
- Ray
value to calculate trig values of.
TrigValues
object representing the trigonometry values
for the angle of the passed in Ray
relative to this
or null if calculation is not possible,public final LineSeg getParallelLineSegThroughPoint(Point ptLoc)
LineSeg
that is parallel to this by the given distance.
Orientation is relative to the start and end. Negative implies to the
left and Position implies to the right.
ptLoc
- Point
value to constrain the line to.
LineSeg
line that was calculated going through the given pointpublic static double[] getLineEquation(double x1, double y1, double x2, double y2)
x1
- - x coordinate of the 1st pointy1
- - y coordinate of the 1st pointx2
- - x coordinate of the 2nd pointy2
- - y coordinate of the 2nd point
public double[] getEquation()
public PointList getLinesIntersections(LineSeg line)
line
- - the line segment
public PointList getLineIntersectionsWithEllipse(Rectangle ellipseBounds)
ellipseBounds
- - width and height of the ellipse
PointList
containing all intersection pointspublic PointList getLineIntersectionsWithLineSegs(PointList points)
PolyLine
, i.e form a closed polygon figure, then the method will
claculate intersections of a line and a figure
points
- - list of points that form linesegments, i.e the PolyLine
public void performScale(double factor)
performScale
in interface Translatable
public void performTranslate(int dx, int dy)
performTranslate
in interface Translatable
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