Package org.eclipse.graphiti.ui.internal.util.draw2d

Class LineSeg

java.lang.Object
org.eclipse.graphiti.ui.internal.util.draw2d.LineSeg
All Implemented Interfaces:
Serializable, org.eclipse.draw2d.geometry.Translatable
public class LineSeg extends Object implements Serializable, org.eclipse.draw2d.geometry.Translatable
See Also:

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    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

    Constructors
    Constructor
    Description
    LineSeg(org.eclipse.draw2d.geometry.Point ptStart, org.eclipse.draw2d.geometry.Point ptEnd)
    Constructor
    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.

  • Method Summary

    Modifier and Type
    Method
    Description
    final boolean
    containsPoint(org.eclipse.draw2d.geometry.Point aPoint, int tolerance)
    Checks if this line segment contains the given point within a tolerance value.
    final float
    distanceAlong(org.eclipse.draw2d.geometry.Point coord)
    Finds the percentage distance along this line segement where the given point resides.
    final long
    distanceToPoint(int xCoord, int yCoord)
    Finds the perpendicular distance from a point coordinates to this line segment.
    boolean
    equals(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
    final org.eclipse.draw2d.geometry.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]
    org.eclipse.draw2d.geometry.PointList
    getLineIntersectionsWithEllipse(org.eclipse.draw2d.geometry.Rectangle ellipseBounds)
    Calculates intersection points of the line of the line segment and ellipse
    org.eclipse.draw2d.geometry.PointList
    getLineIntersectionsWithLineSegs(org.eclipse.draw2d.geometry.PointList points)
    Calculates intersection points of the line that contains this line segment with a list of other line segments.
    org.eclipse.draw2d.geometry.PointList
    getLinesIntersections(LineSeg line)
    Returns intersection points of two lines that contain this line segment and the argumet line segment.
    org.eclipse.draw2d.geometry.Point
    getOrigin()
    Accesssor to retrieve the origin point of the line segement.
    final LineSeg
    getParallelLineSegThroughPoint(org.eclipse.draw2d.geometry.Point ptLoc)
    Returns a new LineSeg that is parallel to this by the given distance.
    final org.eclipse.draw2d.geometry.Point
    getSupremum()
    Get points representing the highest point value for this line segment.
    org.eclipse.draw2d.geometry.Point
    getTerminus()
    Accesssor to retrieve the terminal point of the line segement.
    LineSeg.TrigValues
    getTrigValues(org.eclipse.draw2d.geometry.Vector ptToVector)
    Gets the trig values associated with the angle from this line segment to the given vector.
    int
    hashCode()
     
    org.eclipse.draw2d.geometry.Point
    intersect(LineSeg line, int nTolerance)
    Determines the intersect point between this line and the line passed in as a parameter.
    final boolean
    isHorizontal()
    Determines if this a horizontal segment
    final boolean
    isVertical()
    Determines if this a vertical segment
    final double
    length()
    Calculate the length of the line segment.
    final org.eclipse.draw2d.geometry.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)
     
    final org.eclipse.draw2d.geometry.Point
    perpIntersect(int startX, int startY)
    Calculates the perpendicular intersection point on the line segment from the given point.
    final float
    perpSlope()
    Calculates the perpendicular slope of this line segment.
    final boolean
    pointOn(long theDistance, LineSeg.KeyPoint fromKeyPoint, org.eclipse.draw2d.geometry.Point ptResult)
    Gets the point on the line segment at the given distance away from the key point.
    final LineSeg.Sign
    positionRelativeTo(org.eclipse.draw2d.geometry.Point rel)
    Returns out a positive or negative value (Positive / Negative) depending on the orientation of the given point to the line.
    final double
    projection(int xCoord, int yCoord)
    Calculates the projection of the given point onto the line segment.
    void
    setOrigin(org.eclipse.draw2d.geometry.Point origin)
    Sets the origin point of the line segment
    void
    setTerminus(org.eclipse.draw2d.geometry.Point terminus)
    Sets the terminating point of the line segment.
    final float
    slope()
    Calculates the slope of this line segment (y=mx+b)

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface org.eclipse.draw2d.geometry.Translatable

    performTranslate, performTranslate, performTranslate

  • Constructor Details

    • LineSeg

      public 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. xdir indicates which direction the segment should go in the x-axis.
      Parameters:
      start - KeyPoint from which the other parameters are relative to
      fromX - int x value of start KeyPoint
      fromY - int y value of start KeyPoint
      slope - float slope of the line
      len - long length of the line
      xdir - direction

    • LineSeg

      public LineSeg(org.eclipse.draw2d.geometry.Point ptStart, org.eclipse.draw2d.geometry.Point ptEnd)
      Constructor
      Parameters:
      ptStart - Point indicating the start of the line segment
      ptEnd - Point indicating the end of the line segment

  • Method Details

    • getLineEquation

      public 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]
      Parameters:
      x1 - - x coordinate of the 1st point
      y1 - - y coordinate of the 1st point
      x2 - - x coordinate of the 2nd point
      y2 - - y coordinate of the 2nd point
      Returns:
      the coefficients of the generalized equation of the line passing through points (x1,y1) and (x2,y2)

    • containsPoint

      public final boolean containsPoint(org.eclipse.draw2d.geometry.Point aPoint, int tolerance)
      Checks if this line segment contains the given point within a tolerance value.
      Parameters:
      aPoint - Point to test if contained in this line.
      tolerance - int tolerance value for detecting the intersection.
      Returns:
      boolean true if the given point lies on this segment, false otherwise.

    • distanceAlong

      public final float distanceAlong(org.eclipse.draw2d.geometry.Point coord)
      Finds the percentage distance along this line segement where the given point resides.
      Parameters:
      coord - Point to determine how far along the line segment it resides.
      Returns:
      float the distance along the line segment where the ptCoord is in a percentage from.

    • distanceToPoint

      public final long distanceToPoint(int xCoord, int yCoord)
      Finds the perpendicular distance from a point coordinates to this line segment. If point is "inside" line segment, then use distance from point to the line, otherwise use distance to nearest endpoint of segment
      Parameters:
      xCoord - the x coordinate of the point.
      yCoord - the y coordinate of the point.
      Returns:
      long the distance from the line segment to the given point.

    • equals

      public boolean equals(Object seg)
      Overrides:
      equals in class Object

    • getEquation

      public 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
      Returns:
      an array with 3 numbers in it, which are the coefficients of the generalized line equation

    • getInfimum

      public final org.eclipse.draw2d.geometry.Point getInfimum()
      Get a Point representing the lowest point value for this line segment.
      Returns:
      Point Representing the lowest point value.

    • getLineIntersectionsWithEllipse

      public org.eclipse.draw2d.geometry.PointList getLineIntersectionsWithEllipse(org.eclipse.draw2d.geometry.Rectangle ellipseBounds)
      Calculates intersection points of the line of the line segment and ellipse
      Parameters:
      ellipseBounds - - width and height of the ellipse
      Returns:
      - PointList containing all intersection points

    • getLineIntersectionsWithLineSegs

      public org.eclipse.draw2d.geometry.PointList getLineIntersectionsWithLineSegs(org.eclipse.draw2d.geometry.PointList points)
      Calculates intersection points of the line that contains this line segment with a list of other line segments. If the list of points (line segments) form a closed PolyLine, i.e form a closed polygon figure, then the method will claculate intersections of a line and a figure
      Parameters:
      points - - list of points that form linesegments, i.e the PolyLine
      Returns:
      the intersection points of the line that contains this line segment with a list of other line segments.

    • getLinesIntersections

      public org.eclipse.draw2d.geometry.PointList getLinesIntersections(LineSeg line)
      Returns intersection points of two lines that contain this line segment and the argumet line segment. The list of intersection points may contain at most two points and will contain 2 points if and only if the lines are equal. The 2 points will be the end points of the parameter line segment
      Parameters:
      line - - the line segment
      Returns:
      intersection points of two lines that contain this line segment and the argumet line segment.

    • getOrigin

      public org.eclipse.draw2d.geometry.Point getOrigin()
      Accesssor to retrieve the origin point of the line segement.
      Returns:
      Point the origin of the line segment.

    • getParallelLineSegThroughPoint

      public final LineSeg getParallelLineSegThroughPoint(org.eclipse.draw2d.geometry.Point ptLoc)
      Returns a new 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.
      Parameters:
      ptLoc - Point value to constrain the line to.
      Returns:
      LineSeg line that was calculated going through the given point

    • getSupremum

      public final org.eclipse.draw2d.geometry.Point getSupremum()
      Get points representing the highest point value for this line segment.
      Returns:
      Point Representing the highest point value.

    • getTerminus

      public org.eclipse.draw2d.geometry.Point getTerminus()
      Accesssor to retrieve the terminal point of the line segement.
      Returns:
      Point the terminating point of the line segment

    • getTrigValues

      public LineSeg.TrigValues getTrigValues(org.eclipse.draw2d.geometry.Vector ptToVector)
      Gets the trig values associated with the angle from this line segment to the given vector.
      Parameters:
      ptToVector - Ray value to calculate trig values of.
      Returns:
      TrigValues object representing the trigonometry values for the angle of the passed in Ray relative to this or null if calculation is not possible,

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • intersect

      public org.eclipse.draw2d.geometry.Point intersect(LineSeg line, int nTolerance)
      Determines the intersect point between this line and the line passed in as a parameter. If they intersect, then true is returned and the point reference passed in will be set to the intersect point. If they don't intersect, then the method returns false.
      Parameters:
      line - LineSeg to test the intersection against.
      nTolerance - int tolerance value for detecting the intersection.
      Returns:
      Point that represents the intersection with this line, or null if the calculation is not possible.

    • isHorizontal

      public final boolean isHorizontal()
      Determines if this a horizontal segment
      Returns:
      boolean true if horizontal, false otherwise.

    • isVertical

      public final boolean isVertical()
      Determines if this a vertical segment
      Returns:
      boolean true if vertical, false otherwise.

    • length

      public final double length()
      Calculate the length of the line segment.
      Returns:
      the double length of the line segment.

    • locatePoint

      public final org.eclipse.draw2d.geometry.Point locatePoint(double pctDist, long theHeight, LineSeg.Sign asOriented)
      Locates a point at a given height and distance along the line segment. B (the point we are looking for) + | dist |h this segment P1-----------+-------------------> A get point A (on picture above)
      Parameters:
      pctDist - double distance along the line
      theHeight - long height above the line
      asOriented - Sign indicating relative position of the point to be located
      Returns:
      Point value that was located on the line.

    • performScale

      public void performScale(double factor)
      Specified by:
      performScale in interface org.eclipse.draw2d.geometry.Translatable

    • performTranslate

      public void performTranslate(int dx, int dy)
      Specified by:
      performTranslate in interface org.eclipse.draw2d.geometry.Translatable

    • perpIntersect

      public final org.eclipse.draw2d.geometry.Point perpIntersect(int startX, int startY)
      Calculates the perpendicular intersection point on the line segment from the given point.
      Parameters:
      startX - the x coordinate of the point
      startY - the y coordinate of the point
      Returns:
      Point value containment the perpendicular intersection point.

    • perpSlope

      public final float perpSlope()
      Calculates the perpendicular slope of this line segment. This calculates the slope and then inverts it. Again, to avoid divide by zero errors, the constant BIGSLOPE is returned if the calculated slope before inverting it was zero.
      Returns:
      float the perpendicular slope value of the line segment.

    • pointOn

      public final boolean pointOn(long theDistance, LineSeg.KeyPoint fromKeyPoint, org.eclipse.draw2d.geometry.Point ptResult)
      Gets the point on the line segment at the given distance away from the key point.
      Parameters:
      theDistance - long distance along the line
      fromKeyPoint - KeyPoint to calculate the distance from
      ptResult - Point where the resulting calculating value is stored.
      Returns:
      boolean true if point can be calculated, false otherwise.

    • positionRelativeTo

      public final LineSeg.Sign positionRelativeTo(org.eclipse.draw2d.geometry.Point rel)
      Returns out a positive or negative value (Positive / Negative) depending on the orientation of the given point to the line. Point on this side: Positive. P1------------------------------> this segment Point on this side: Negative.
      Parameters:
      rel - Point to test the relative position against this line.
      Returns:
      Sign value indicating the relative position of the given point.

    • projection

      public final double projection(int xCoord, int yCoord)
      Calculates the projection of the given point onto the line segment.
      Parameters:
      xCoord - the x coordinate of the point.
      yCoord - the y coordinate of the point.
      Returns:
      double value of the calculated projection.

    • setOrigin

      public void setOrigin(org.eclipse.draw2d.geometry.Point origin)
      Sets the origin point of the line segment
      Parameters:
      origin - Point to set as origin

    • setTerminus

      public void setTerminus(org.eclipse.draw2d.geometry.Point terminus)
      Sets the terminating point of the line segment.
      Parameters:
      terminus - Point to set as terminus

    • slope

      public final float slope()
      Calculates the slope of this line segment (y=mx+b)
      Returns:
      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.