Package nl.tudelft.simulation.language.d2

Class DirectionalLine

java.lang.Object
java.awt.geom.Line2D
java.awt.geom.Line2D.Double
nl.tudelft.simulation.language.d2.DirectionalLine
All Implemented Interfaces:
Shape, Serializable, Cloneable
public class DirectionalLine extends Line2D.Double
A directional line with normal vector. Based on the BSPLine-example from the book Developing games in Java from David Brackeen.

Copyright (c) 2003-2024 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See for project information https://simulation.tudelft.nl. The DSOL project is distributed under a three-clause BSD-style license, which can be found at https://https://simulation.tudelft.nl/dsol/docs/latest/license.html.

Author:
Roy Chin
See Also:

  • Constructor Details

    • DirectionalLine

      public DirectionalLine(double x1, double y1, double x2, double y2)
      Creates a new DirectionalLine based on the specified coordinates.
      Parameters:
      x1 - double; Coordinate x1
      y1 - double; Coordinate y1
      x2 - double; Coordinate x2
      y2 - double; Coordinate y2

    • DirectionalLine

      public DirectionalLine(float x1, float y1, float x2, float y2)
      Creates a new DirectionalLine based on the specified (float) coordinates.
      Parameters:
      x1 - float; Coordinate x1
      y1 - float; Coordinate y1
      x2 - float; Coordinate x2
      y2 - float; Coordinate y2

  • Method Details

    • calcNormal

      public void calcNormal()
      Calculates the normal to this line. The normal of (a, b) is (-b, a).

    • normalize

      public void normalize()
      Normalizes the normal of this line (make the normal's length 1).

    • setLine

      public void setLine(float x1, float y1, float x2, float y2)
      Set the line using floats.
      Parameters:
      x1 - float; x1 coordinate
      y1 - float; y1 coordinate
      x2 - float; x2 coordinate
      y2 - float; y2 coordinate

    • setLine

      public void setLine(double x1, double y1, double x2, double y2)
      Overrides:
      setLine in class Line2D.Double

    • flip

      public void flip()
      Flips this line so that the end points are reversed (in other words, (x1,y1) becomes (x2,y2) and vice versa) and the normal is changed to point the opposite direction.

    • equalsCoordinates

      public boolean equalsCoordinates(DirectionalLine line)
      Returns true if the endpoints of this line match the endpoints of the specified line. Ignores normal and height values.
      Parameters:
      line - DirectionalLine; another line
      Returns:
      true if this line's coordinates are equal to the other line's coordinates

    • equalsCoordinatesIgnoreOrder

      public boolean equalsCoordinatesIgnoreOrder(DirectionalLine line)
      Returns true if the endpoints of this line match the endpoints of the specified line, ignoring endpoint order (if the first point of this line is equal to the second point of the specified line, and vice versa, returns true). Ignores normal and height values.
      Parameters:
      line - DirectionalLine; another line
      Returns:
      true if coordinates match independent of the order

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • getSideThick

      public DirectionalLine.Side getSideThick(double x, double y)
      Gets the side of this line the specified point is on. This method treats the line as 1-unit thick, so points within this 1-unit border are considered collinear. For this to work correctly, the normal of this line must be normalized, either by setting this line to a polygon or by calling normalize(). Returns either FRONTSIDE, BACKSIDE, or COLLINEAR.
      Parameters:
      x - double; coordinate x
      y - double; coordinate y
      Returns:
      the side

    • getSideThin

      public DirectionalLine.Side getSideThin(double x, double y)
      Gets the side of this line the specified point is on. Because of doubling point inaccuracy, a collinear line will be rare. For this to work correctly, the normal of this line must be normalized, either by setting this line to a polygon or by calling normalize(). Returns either FRONTSIDE, BACKSIDE, or COLLINEAR.
      Parameters:
      x - double; coordinate x
      y - double; coordinate y
      Returns:
      the side

    • getSide

      public DirectionalLine.Side getSide(Line2D.Double line)
      Gets the side of this line that the specified line segment is on. Returns either FRONT, BACK, COLINEAR, or SPANNING.
      Parameters:
      line - Line2D.Double; line segment
      Returns:
      the side

    • getIntersection

      public double getIntersection(Line2D.Double line)
      Returns the fraction of intersection along this line. Returns a value from 0 to 1 if the segments intersect. For example, a return value of 0 means the intersection occurs at point (x1, y1), 1 means the intersection occurs at point (x2, y2), and .5 mean the intersection occurs halfway between the two endpoints of this line. Returns -1 if the lines are parallel.
      Parameters:
      line - Line2D.Double; a line
      Returns:
      the intersection

    • getIntersectionPoint

      public Point2D.Double getIntersectionPoint(Line2D.Double line)
      Returns the intersection point of this line with the specified line.
      Parameters:
      line - Line2D.Double; a line
      Returns:
      intersection point

    • getLineThickness

      public double getLineThickness()
      Gets the thickness of the line.
      Returns:
      returns the lineThickness

    • setLineThickness

      public void setLineThickness(double lineThickness)
      Sets the thickness of the line.
      Parameters:
      lineThickness - double; the lineThickness to set

    • getNormalx

      public double getNormalx()
      Returns:
      returns the normalX

    • getNormaly

      public double getNormaly()
      Returns:
      returns the normalY