Class OffsetCurveBuilder

java.lang.Object
org.locationtech.jts.operation.buffer.OffsetCurveBuilder

public class OffsetCurveBuilder extends Object
Computes the raw offset curve for a single Geometry component (ring, line or point). A raw offset curve line is not noded - it may contain self-intersections (and usually will). The final buffer polygon is computed by forming a topological graph of all the noded raw curves and tracing outside contours. The points in the raw curve are rounded to a given PrecisionModel.
Version:
1.7
  • Constructor Details

  • Method Details

    • getBufferParameters

      public BufferParameters getBufferParameters()
      Gets the buffer parameters being used to generate the curve.
      Returns:
      the buffer parameters being used
    • getLineCurve

      public Coordinate[] getLineCurve(Coordinate[] inputPts, double distance)
      This method handles single points as well as LineStrings. LineStrings are assumed not to be closed (the function will not fail for closed lines, but will generate superfluous line caps).
      Parameters:
      inputPts - the vertices of the line to offset
      distance - the offset distance
      Returns:
      a Coordinate array representing the curve or null if the curve is empty
    • isLineOffsetEmpty

      public boolean isLineOffsetEmpty(double distance)
      Tests whether the offset curve for line or point geometries at the given offset distance is empty (does not exist). This is the case if:
      • the distance is zero,
      • the distance is negative, except for the case of singled-sided buffers
      Parameters:
      distance - the offset curve distance
      Returns:
      true if the offset curve is empty
    • getRingCurve

      public Coordinate[] getRingCurve(Coordinate[] inputPts, int side, double distance)
      This method handles the degenerate cases of single points and lines, as well as valid rings.
      Parameters:
      inputPts - the coordinates of the ring (must not contain repeated points)
      side - side the side Position of the ring on which to construct the buffer line
      distance - the positive distance at which to create the offset
      Returns:
      a Coordinate array representing the curve, or null if the curve is empty
    • getOffsetCurve

      public Coordinate[] getOffsetCurve(Coordinate[] inputPts, double distance)