Module org.jhotdraw8.geom
Package org.jhotdraw8.geom

Class PolylineToCubicCurve

java.lang.Object
org.jhotdraw8.geom.PolylineToCubicCurve
public class PolylineToCubicCurve extends Object
References: 
     GraphicsGems.c
     2d and 3d Vector C Library
     by Andrew Glassner
     from "Graphics Gems", Academic Press, 1990

  • Method Details

    • main

      public static void main(String[] args)

    • fitBezierPath

      public static void fitBezierPath(@NonNull PathBuilder<?> builder, javafx.geometry.Point2D[] digitizedPoints, double error)
      Fits a bezier path to the specified list of digitized points.

      This is a convenience method for calling fitBezierPath(org.jhotdraw8.geom.PathBuilder<?>, javafx.geometry.Point2D[], double)

      Parameters:
      builder - the builder for the bezier path
      digitizedPoints - digited points.
      error - the maximal allowed error between the bezier path and the digitized points.

    • fitBezierPath

      public static void fitBezierPath(@NonNull PathBuilder<?> builder, @NonNull List<javafx.geometry.Point2D> digitizedPoints, double error)
      Fits a bezier path to the specified list of digitized points.
      Parameters:
      builder - the builder for the bezier path
      digitizedPoints - digited points.
      error - the maximal allowed error between the bezier path and the digitized points.

    • fitBezierPath

      public static void fitBezierPath(@NonNull PathBuilder<?> builder, @NonNull BezierPath digitizedPoints, double error)
      Fits a bezier path to the specified list of digitized points.

      This is a convenience method for calling fitBezierPath(org.jhotdraw8.geom.PathBuilder<?>, javafx.geometry.Point2D[], double).

      Parameters:
      builder - the builder for the bezier path
      digitizedPoints - digited points.
      error - the maximal allowed error between the bezier path and the digitized points.

    • removeClosePoints

      public static @NonNull ArrayList<javafx.geometry.Point2D> removeClosePoints(@NonNull List<javafx.geometry.Point2D> digitizedPoints, double minDistance)
      Removes points which are closer together than the specified minimal distance.

      The minimal distance should be chosen dependent on the size and resolution of the display device, and on the sampling rate. A good value for mouse input on a display with 100% Zoom factor is 2.

      The purpose of this method, is to remove points, which add no additional information about the shape of the curve from the list of digitized points.

      The cleaned up set of digitized points gives better results, when used as input for method splitAtCorners(java.util.List<javafx.geometry.Point2D>, double, double).

      Parameters:
      digitizedPoints - Digitized points
      minDistance - minimal distance between two points. If minDistance is 0, this method only removes sequences of coincident points.
      Returns:
      Digitized points with a minimal distance.

    • splitAtCorners

      public static @NonNull ArrayList<ArrayList<javafx.geometry.Point2D>> splitAtCorners(@NonNull List<javafx.geometry.Point2D> digitizedPoints, double maxAngle, double minDistance)
      Splits the digitized points into multiple segments at each corner point.

      Corner points are both contained as the last point of a segment and the first point of a subsequent segment.

      Parameters:
      digitizedPoints - Digitized points
      maxAngle - maximal angle in radians between the current point and its predecessor and successor up to which the point does not break the digitized list into segments. Recommended value 44° = 44 * 180d / Math.PI
      minDistance - the minimal distance
      Returns:
      Segments of digitized points, each segment having less than maximal angle between points.

    • findCorners

      public static @NonNull IntArrayList findCorners(@NonNull List<javafx.geometry.Point2D> digitizedPoints, double minAngle, double minDistance)
      Finds corners in the provided point list, and returns their indices.
      Parameters:
      digitizedPoints - List of digitized points.
      minAngle - Minimal angle for corner points
      minDistance - Minimal distance between a point and adjacent points for corner detection
      Returns:
      list of corner indices.

    • reduceNoise

      public static @NonNull ArrayList<javafx.geometry.Point2D> reduceNoise(@NonNull List<javafx.geometry.Point2D> digitizedPoints, double weight)
      Reduces noise from the digitized points, by applying an approximation of a gaussian filter to the data.

      The filter does the following for each point P, with weight 0.5:

      x[i] = 0.5*x[i] + 0.25*x[i-1] + 0.25*x[i+1]; y[i] = 0.5*y[i] + 0.25*y[i-1] + 0.25*y[i+1];

      Parameters:
      digitizedPoints - Digitized points
      weight - Weight of the current point
      Returns:
      Digitized points with reduced noise.