Package com.jme3.math

Class LineSegment

java.lang.Object
com.jme3.math.LineSegment
All Implemented Interfaces:
Savable, Serializable, Cloneable
public class LineSegment extends Object implements Cloneable, Savable, Serializable

LineSegment represents a segment in the space. This is a portion of a Line that has a limited start and end points.

A LineSegment is defined by an origin, a direction and an extent (or length). Direction should be a normalized vector. It is not internally normalized.

This class provides methods to calculate distances between LineSegments, Rays and Vectors. It is also possible to retrieve both end points of the segment getPositiveEnd(Vector3f) and getNegativeEnd(Vector3f). There are also methods to check whether a point is within the segment bounds.

See Also:

  • Constructor Details

    • LineSegment

      public LineSegment()
      Instantiate a zero-length segment at the origin.

    • LineSegment

      public LineSegment(LineSegment ls)
      Instantiate a copy of the specified segment.
      Parameters:
      ls - the LineSegment to copy (not null, unaffected)

    • LineSegment

      public LineSegment(Vector3f origin, Vector3f direction, float extent)

      Creates a new LineSegment with the given origin, direction and extent.

      Note that the origin is not one of the ends of the LineSegment, but its center.

      Parameters:
      origin - the location of the desired midpoint (alias created)
      direction - the desired direction vector (alias created)
      extent - the extent: 1/2 of the desired length, assuming direction is a unit vector

    • LineSegment

      public LineSegment(Vector3f start, Vector3f end)

      Creates a new LineSegment with a given origin and end. This constructor will calculate the center, the direction and the extent.

      Parameters:
      start - location of the negative endpoint (not null, unaffected)
      end - location of the negative endpoint (not null, unaffected)

  • Method Details

    • set

      public void set(LineSegment ls)
      Copy the specified segment to this one.
      Parameters:
      ls - the LineSegment to copy (not null, unaffected)

    • distance

      public float distance(Vector3f point)
      Calculate the distance between this segment and the specified point.
      Parameters:
      point - a location vector (not null, unaffected)
      Returns:
      the minimum distance (≥0)

    • distance

      public float distance(LineSegment ls)
      Calculate the distance between this segment and another.
      Parameters:
      ls - the other LineSegment (not null, unaffected)
      Returns:
      the minimum distance (≥0)

    • distance

      public float distance(Ray r)
      Calculate the distance between this segment and the specified Ray.
      Parameters:
      r - the input Ray (not null, unaffected)
      Returns:
      the minimum distance (≥0)

    • distanceSquared

      public float distanceSquared(Vector3f point)
      Calculate the squared distance between this segment and the specified point.
      Parameters:
      point - location vector of the input point (not null, unaffected)
      Returns:
      the square of the minimum distance (≥0)

    • distanceSquared

      public float distanceSquared(LineSegment test)
      Calculate the squared distance between this segment and another.
      Parameters:
      test - the other LineSegment (not null, unaffected)
      Returns:
      the square of the minimum distance (≥0)

    • distanceSquared

      public float distanceSquared(Ray r)
      Calculate the squared distance between this segment and the specified Ray.
      Parameters:
      r - the input Ray (not null, unaffected)
      Returns:
      the square of the minimum distance (≥0)

    • getDirection

      public Vector3f getDirection()
      Access the direction of this segment.
      Returns:
      the pre-existing direction vector

    • setDirection

      public void setDirection(Vector3f direction)
      Alter the direction of this segment.
      Parameters:
      direction - the desired direction vector (alias created!)

    • getExtent

      public float getExtent()
      Read the extent of this segment.
      Returns:
      the extent

    • setExtent

      public void setExtent(float extent)
      Alter the extent of this segment.
      Parameters:
      extent - the desired extent

    • getOrigin

      public Vector3f getOrigin()
      Access the origin of this segment.
      Returns:
      the pre-existing location vector

    • setOrigin

      public void setOrigin(Vector3f origin)
      Alter the origin of this segment.
      Parameters:
      origin - the desired location vector (alias created!)

    • getPositiveEnd

      public Vector3f getPositiveEnd(Vector3f store)
      Determine the location of this segment's positive end.
      Parameters:
      store - storage for the result (modified if not null)
      Returns:
      a location vector (either store or a new vector)

    • getNegativeEnd

      public Vector3f getNegativeEnd(Vector3f store)
      Determine the location of this segment's negative end.
      Parameters:
      store - storage for the result (modified if not null)
      Returns:
      a location vector (either store or a new vector)

    • write

      public void write(JmeExporter e) throws IOException
      Serialize this segment to the specified exporter, for example when saving to a J3O file.
      Specified by:
      write in interface Savable
      Parameters:
      e - (not null)
      Throws:
      IOException - from the exporter

    • read

      public void read(JmeImporter importer) throws IOException
      De-serialize this segment from the specified importer, for example when loading from a J3O file.
      Specified by:
      read in interface Savable
      Parameters:
      importer - (not null)
      Throws:
      IOException - from the importer

    • clone

      public LineSegment clone()
      Create a copy of this segment.
      Overrides:
      clone in class Object
      Returns:
      a new instance, equivalent to this one

    • toString

      public String toString()
      Returns a string representation of the LineSegment, which is unaffected. For example, a segment extending from (1,0,0) to (1,1,0) is represented by: 
       LineSegment [Origin: (1.0, 0.0, 0.0)  Direction: (0.0, 1.0, 0.0)  Extent: 1.0]
      Overrides:
      toString in class Object
      Returns:
      the string representation (not null, not empty)

    • isPointInsideBounds

      public boolean isPointInsideBounds(Vector3f point)
      /**

      Evaluates whether a given point is contained within the axis aligned bounding box that contains this LineSegment.

      This function is float error aware.

      Parameters:
      point - the location of the input point (not null, unaffected)
      Returns:
      true if contained in the box, otherwise false

    • isPointInsideBounds

      public boolean isPointInsideBounds(Vector3f point, float error)

      Evaluates whether a given point is contained within the axis aligned bounding box that contains this LineSegment.

      This function accepts an error parameter, which is added to the extent of the bounding box.

      Parameters:
      point - the location of the input point (not null, unaffected)
      error - the desired margin for error
      Returns:
      true if contained in the box, otherwise false