Class TLcdLonLatBuffer

All Implemented Interfaces:
ILcdBounded, ILcdPointList, ILcdShape, ILcd2DEditablePointList, ILcd2DEditableShape, ILcdCache, ILcdCloneable, Serializable, Cloneable

public class TLcdLonLatBuffer extends ALcd2DEditableShape implements ILcd2DEditablePointList, ILcdCache
This class represents a buffer around a polyline on an ellipsoid, with a given width, in the geodetic space.

All longitude/latitude coordinates are expressed in degrees. Lengths are expressed in meters.

The buffer's width is from the axis to the edge of the buffer on both sides, so the buffer is 2 * width wide.

This buffer implementation has the following limitations:

  • for efficiency reasons the current implementation works with a spherical approximation where the radius of the sphere is the major axis of the ellipsoid.
  • contours with holes (i.e., caused by axis intersections) cannot be represented, since the contour is modeled as a single polygon (ILcdPolygon),
  • the corners of the contour at the axis points are sharp instead of rounded, which make it less suitable for buffers that have sharp angles between its consecutive axis segments; it has also has as consequence that the distance between the contour and the axis exceeds the given buffer distance in the corners,
  • the calculated contour is only an estimate, because it uses a reduced number of contour points; when the start and end point of a segment are further removed from each other, the connected contour lines no longer lie at the given distance from the axis at each intermediate point.
For an improved buffer implementation that solves these limitations, please refer to TLcdLonLatGeoBuffer and TLcdEllipsoidUtil.computeBufferContour2D.

This class is thread-safe for concurrent read-only access of its contents. For read-write access, external locking must be used. Such locking is typically done at the model level.

See Also:
  • Constructor Details

    • TLcdLonLatBuffer

      public TLcdLonLatBuffer(TLcdLonLatPolyline aAxisPolyline, double aWidth, ILcdEllipsoid aEllipsoid)
      Creates a new TLcdLonLatBuffer with the specified parameters.
      Parameters:
      aAxisPolyline - the polyline defining the axis of the corridor.
      aWidth - the width in meters of the corridor, from the axis to the buffer edge
    • TLcdLonLatBuffer

      public TLcdLonLatBuffer(ILcd2DEditablePoint[] aAxisPointArray, double aWidth, ILcdEllipsoid aEllipsoid)
      Creates a new TLcdLonLatBuffer with the specified parameters.
      Parameters:
      aAxisPointArray - the array of points defining the axis of the corridor.
      aWidth - the width in meters of the corridor, from the axis to the buffer edge
    • TLcdLonLatBuffer

      public TLcdLonLatBuffer(TLcdLonLatPolyline aAxisPolyline, double aWidth)
      Creates a new TLcdLonLatBuffer with the specified parameters.
      Parameters:
      aAxisPolyline - the polyline defining the axis of the corridor.
      aWidth - the width in meters of the corridor, from the axis to the buffer edge
    • TLcdLonLatBuffer

      public TLcdLonLatBuffer(ILcd2DEditablePoint[] aAxisPointArray, double aWidth)
      Creates a new TLcdLonLatBuffer with the specified parameters.
      Parameters:
      aAxisPointArray - the array of points defining the axis of the corridor.
      aWidth - the width in meters of the corridor, from the axis to the buffer edge
    • TLcdLonLatBuffer

      public TLcdLonLatBuffer()
  • Method Details

    • getWidth

      public final double getWidth()
      Returns the distance from the axis to the buffer edge.

      The buffer is 2 * width wide in total.

      Returns:
      The width of the buffer, from axis to edge
    • setWidth

      public void setWidth(double aWidth)
      Set the distance is from the axis to the buffer edge.

      The buffer is 2 * width wide in total.

      Parameters:
      aWidth - the width in meters of the corridor (>= 0), from axis to the edge
    • getEllipsoid

      public ILcdEllipsoid getEllipsoid()
    • setEllipsoid

      public void setEllipsoid(ILcdEllipsoid aEllipsoid)
    • getPointCount

      public final int getPointCount()
      Description copied from interface: ILcdPointList
      Returns the number of ILcdPoint objects in the list.
      Specified by:
      getPointCount in interface ILcdPointList
      Returns:
      the number of ILcdPoint objects in the list.
    • getPoint

      public final ILcdPoint getPoint(int aIndex)
      Description copied from interface: ILcdPointList
      Returns the ILcdPoint at a given index.
      Specified by:
      getPoint in interface ILcdPointList
      Parameters:
      aIndex - a valid index in the list of ILcdPoint objects.
      Returns:
      the ILcdPoint at the given index.
    • removePointAt

      public void removePointAt(int aIndex)
      Description copied from interface: ILcd2DEditablePointList
      Removes the point at the given index from this ILcd2DEditablePointList.
      Specified by:
      removePointAt in interface ILcd2DEditablePointList
      Parameters:
      aIndex - a valid index in the list of ILcdPoint objects.
    • move2D

      public void move2D(double aX, double aY)
      Description copied from class: ALcd2DEditableShape
      Translates this shape so that its focus point ends up at the specified position.
      Specified by:
      move2D in interface ILcd2DEditableShape
      Overrides:
      move2D in class ALcd2DEditableShape
      Parameters:
      aX - the x coordinate of the point.
      aY - the y coordinate of the point.
    • translate2D

      public void translate2D(double aX, double aY)
      Description copied from interface: ILcd2DEditablePointList
      Translates all the points of this ILcd2DEditablePointList from their current positions over the given translation vector in the 2D space. Only the first two dimensions of the points are considered. The third dimension is left unchanged.
      Specified by:
      translate2D in interface ILcd2DEditablePointList
      Specified by:
      translate2D in interface ILcd2DEditableShape
      Parameters:
      aX - the x coordinate of the translation vector.
      aY - the y coordinate of the translation vector.
    • move2DPoint

      public void move2DPoint(int aIndex, double aX, double aY)
      Description copied from interface: ILcd2DEditablePointList
      Moves the specified point of this ILcd2DEditablePointList to the given point in the 2D space. Only the first two dimensions of the ILcdShape are considered. The third dimension is left unchanged.
      Specified by:
      move2DPoint in interface ILcd2DEditablePointList
      Parameters:
      aIndex - a valid index in the list of points.
      aX - the x coordinate of the point.
      aY - the y coordinate of the point.
    • translate2DPoint

      public void translate2DPoint(int aIndex, double aX, double aY)
      Description copied from interface: ILcd2DEditablePointList
      Translates the specified point of this ILcd2DEditablePointList from its current position over the given translation vector in the 2D space. Only the first two dimensions of the points are considered. The third dimension is left unchanged.
      Specified by:
      translate2DPoint in interface ILcd2DEditablePointList
      Parameters:
      aX - the x coordinate of the translation vector.
      aY - the y coordinate of the translation vector.
    • insert2DPoint

      public void insert2DPoint(int aIndex, double aX, double aY)
      Description copied from interface: ILcd2DEditablePointList
      Inserts a point at the given index into this ILcd2DEditablePointList.
      Specified by:
      insert2DPoint in interface ILcd2DEditablePointList
      Parameters:
      aIndex - a valid new index in the list of points.
      aX - the x coordinate of the new point.
      aY - the y coordinate of the new point.
    • getContour

      public ILcd2DEditablePolygon getContour()
    • getAxisPolyline

      public final ILcd2DEditablePolyline getAxisPolyline()
    • contains2D

      public boolean contains2D(ILcdPoint aPoint)
      Description copied from class: ALcdShape
      Checks whether this ALcdShape contains the given point in the 2D cartesian plane.
      Specified by:
      contains2D in interface ILcdShape
      Overrides:
      contains2D in class ALcdShape
      Parameters:
      aPoint - the point to test.
      Returns:
      the boolean result of the containment test.
      See Also:
    • contains2D

      public boolean contains2D(double x, double y)
      Description copied from interface: ILcdShape
      Checks whether this ILcdShape contains the given point in the 2D space. Only the first two dimensions of the ILcdShape are considered.
      Specified by:
      contains2D in interface ILcdShape
      Parameters:
      x - the x coordinate of the point.
      y - the y coordinate of the point.
      Returns:
      the boolean result of the containment test.
    • getFocusPoint

      public ILcdPoint getFocusPoint()
      Description copied from interface: ILcdShape
      Returns the focus point of this ILcdShape.
      Specified by:
      getFocusPoint in interface ILcdShape
      Returns:
      the focus point of this ILcdShape.
    • getBounds

      public ILcdBounds getBounds()
      Description copied from interface: ILcdBounded
      Returns the ILcdBounds by which the geometry of this ILcdBounded object is bounded.

      If the geometry does not allow retrieving valid bounds (for example a polyline with 0 points) the return value is unspecified. It is highly recommended to return an undefined bounds. You can create undefined bounds using the default constructors of TLcdLonLatBounds or TLcdXYBounds.

      Specified by:
      getBounds in interface ILcdBounded
      Returns:
      the ILcdBounds by which the geometry of this ILcdBounded object is bounded.
    • insertIntoCache

      public void insertIntoCache(Object aKey, Object aObject)
      Description copied from interface: ILcdCache
      Inserts a cache Object corresponding to the given key Object.
      Specified by:
      insertIntoCache in interface ILcdCache
      Parameters:
      aKey - the key Object that will be used to identify the Object. The key must therefore be a unique identifier, typically the caller itself: insertIntoCache(this, ...).
      aObject - the Object to be cached.
    • getCachedObject

      public Object getCachedObject(Object aKey)
      Description copied from interface: ILcdCache
      Looks up and returns the cached Object corresponding to the given key.
      Specified by:
      getCachedObject in interface ILcdCache
      Parameters:
      aKey - the key Object that was used for storing the cache Object.
      Returns:
      the cached Object, or null if there is no Object corresponding to the given key.
    • removeCachedObject

      public Object removeCachedObject(Object aKey)
      Description copied from interface: ILcdCache
      Looks up and removes the cached Object corresponding to the given key.
      Specified by:
      removeCachedObject in interface ILcdCache
      Parameters:
      aKey - the key Object that was used for storing the cache Object.
      Returns:
      the cached Object, or null if there was no Object corresponding to the given key.
    • clearCache

      public void clearCache()
      Description copied from interface: ILcdCache
      Clears the cache.
      Specified by:
      clearCache in interface ILcdCache
    • clone

      public Object clone()
      Creates and returns a copy of this object.

      The contained ellipsoid and axis polyline are copied without being cloned.

      The cache is not copied or cloned at all.

      Specified by:
      clone in interface ILcdCloneable
      Overrides:
      clone in class ALcdShape
      See Also:
    • equals

      public boolean equals(Object aObject)
      Returns whether the given object has the same class, coordinates, and radius.
      Overrides:
      equals in class ALcdShape
    • hashCode

      public int hashCode()
      Description copied from class: ALcdShape
      The hash code of this shape is the hash code of its class, in order to be consistent with the ALcdShape.equals(Object) method. Extensions should refine this implementation, based on their properties.
      Overrides:
      hashCode in class ALcdShape
    • toString

      public String toString()
      Overrides:
      toString in class Object