Package org.geotools.geometry.jts

Class LineStringCursor

  • Direct Known Subclasses:
    LineStringCursor
    public class LineStringCursor
extends Object
    Allows to move a point cursor along the path of a LineString using a curvilinear coordinate system and either absolute distances (from the start of the line) or offsets relative to the current position, to return the absolute position of the cursor as a Point, and to get the orientation of the current segment.
    Author:
    Andrea Aime

    • Constructor Detail

      • LineStringCursor

        public LineStringCursor​(LineString ls)
        Builds a new cursor

      • LineStringCursor

        public LineStringCursor​(LineStringCursor cursor)
        Copy constructor

    • Method Detail

      • getLineStringLength

        public double getLineStringLength()
        Returns the line string length

      • moveTo

        public void moveTo​(double ordinate)
        Moves the current position to the

      • moveRelative

        public boolean moveRelative​(double offset)
        Moves of the specified distance from the current position.
        Returns:
        true if it was possible to move to the desired offset, false if the movement stopped because the start or end of the LineString was reached

      • getCurrentPosition

        public Coordinate getCurrentPosition()
        Returns the Point representing the current position along the LineString

      • getCurrentPosition

        public Coordinate getCurrentPosition​(Coordinate c)
        Returns the Point representing the current position along the LineString

      • getCurrentOrdinate

        public double getCurrentOrdinate()

      • getCurrentAngle

        public double getCurrentAngle()
        Returns the current segment direction as an angle expressed in radians

      • getSegmentAngle

        protected double getSegmentAngle​(int segmentIdx)

      • getLabelOrientation

        public double getLabelOrientation()
        Returns the current segment direction as an angle expressed in radians

      • getMaxAngleChange

        public double getMaxAngleChange​(double startOrdinate,
                                double endOrdinate)
        Returns the maximum angle change (in radians) between two subsequent segments between the specified curvilinear coordinates.

      • getMaxAngleChange

        @Deprecated
public double getMaxAngleChange​(double startOrdinate,
                                double endOrdinate,
                                double step)
        Deprecated.
        Does not work correctly, will be removed (tried too many times to fix it)
        A variant of getMaxAngleChange(double, double) taking a step and evaluating angle differences at such step. This helps when a line has many little segments and chars would end up showing several segments apart (so the full angle change needs to be considered)

      • getMaxDistanceFromStraightLine

        public double getMaxDistanceFromStraightLine​(double startOrdinate,
                                             double endOrdinate)
        Returns the maximum distance between the curve and a straight line connecting the start and end ordinates.

      • reverse

        public LineStringCursor reverse()
        Returns a line string cursor based on the opposite walking direction.

      • getLineString

        public LineString getLineString()
        The linestrings wrapped by this cursor

      • getSubLineString

        public LineString getSubLineString​(double startOrdinate,
                                   double endOrdinate)
        Returns the linestring that starts and ends at the specified curvilinear coordinates.