Class TLcdMercator

All Implemented Interfaces:
ILcdCylindrical, ILcdProjection, ILcdPropertyChangeSource, Serializable, Cloneable
Direct Known Subclasses:
TLcdPseudoMercator

public class TLcdMercator extends ALcdCylindrical
Mercator projection.

Introduction Link icon

Cylindrical conformal projection.

Properties Link icon

  • The projection is conformal.
  • Meridians are equally spaced straight lines. Parallels are also straight lines but they are unequally spaced.
  • The scale of the projection is true along the equator.
  • Loxodromes (rhumb lines) are shown as straight lines.
  • The poles are at infinity, there is a great distortion of area in the polar regions.

Example Link icon

Sample code Link icon

ILcdProjection projection =
new TLcdMercator(0.0, 0.0);

Implementation aspects Link icon

The equations of the mercator projection are taken from [Snyder1987].

See Also:
  • Constructor Details Link icon

    • TLcdMercator Link icon

      public TLcdMercator()
      Constructs a mercator projection with the central meridian at 0.0.
    • TLcdMercator Link icon

      public TLcdMercator(double aCentralMeridian)
      Constructs a mercator projection with the specified central meridian.
      Parameters:
      aCentralMeridian - the central meridian of the mercator projection.
  • Method Details Link icon

    • lonlatheight2worldOnEllipsoidSFCT Link icon

      public void lonlatheight2worldOnEllipsoidSFCT(ILcdPoint aLLHP, ILcdEllipsoid aEllipsoid, ILcd2DEditablePoint aXYPointSFCT) throws TLcdOutOfBoundsException
      Description copied from class: ALcdProjection
      Default implementation calls lonlatheight2worldOnEllipsoidSFCT with aEllipsoid.getAuxRadius() as sphere radius.
      Specified by:
      lonlatheight2worldOnEllipsoidSFCT in interface ILcdProjection
      Overrides:
      lonlatheight2worldOnEllipsoidSFCT in class ALcdProjection
      Parameters:
      aLLHP - point to be projected.
      aEllipsoid - ellipsoid on which the point is defined.
      aXYPointSFCT - projected point as side effect.
      Throws:
      TLcdOutOfBoundsException - If the ILcdPoint aLLHP is not within the valid area of the projection (visible area), then this exception is thrown.
    • lonlatheight2worldOnSphereSFCT Link icon

      public void lonlatheight2worldOnSphereSFCT(ILcdPoint aLLHP, double aRadius, ILcd2DEditablePoint aXYPointSFCT) throws TLcdOutOfBoundsException
      Description copied from interface: ILcdProjection
      Transforms an ILcd2DEditablePoint on a sphere into the cartesian coordinate system of the projection.
      Parameters:
      aLLHP - point to be projected.
      aRadius - radius of the sphere (meters).
      aXYPointSFCT - projected point as side effect.
      Throws:
      TLcdOutOfBoundsException - If the ILcdPoint aLLHP is not within the valid area of the projection (visible area), then this exception is thrown.
    • getTrueScaleLatitude Link icon

      public double getTrueScaleLatitude()
      Returns the latitude which is made standard, with true scale.
      Returns:
      the latitude which is true to scale.
    • setTrueScaleLatitude Link icon

      public void setTrueScaleLatitude(double aLatitude)
      Sets the latitude which is made standard, with true scale. Note that the parallel with the opposite latitude automatically becomes standard as well.
      Parameters:
      aLatitude - the latitude which is true to scale
    • world2lonlatOnSphereSFCT Link icon

      public void world2lonlatOnSphereSFCT(ILcdPoint aXYPoint, double aRadius, ILcd2DEditablePoint aLLPSFCT) throws TLcdOutOfBoundsException
      Description copied from interface: ILcdProjection
      Transforms an ILcdPoint from the cartesian coordinate system of the projection into an ILcd2DEditablePoint onto a sphere.
      Parameters:
      aXYPoint - projected point for which the corresponding geodetic point is sought.
      aRadius - radius of the sphere (meters).
      aLLPSFCT - resulting geodetic coordinate as side effect.
      Throws:
      TLcdOutOfBoundsException - If the ILcdPoint aXYPoint is not within the valid area of the projection (visible area), then this exception is thrown.
    • world2lonlatOnEllipsoidSFCT Link icon

      public void world2lonlatOnEllipsoidSFCT(ILcdPoint aXYPoint, ILcdEllipsoid aEllipsoid, ILcd2DEditablePoint aLLPSFCT) throws TLcdOutOfBoundsException
      Description copied from class: ALcdProjection
      Default implementation calls world2lonlatOnSphereSFCT with aEllipsoid.getAuxRadius() as sphere radius.
      Specified by:
      world2lonlatOnEllipsoidSFCT in interface ILcdProjection
      Overrides:
      world2lonlatOnEllipsoidSFCT in class ALcdProjection
      Parameters:
      aXYPoint - projected point for which the corresponding geodetic point is sought.
      aEllipsoid - ellipsoid on which the geodetic coordinate is defined.
      aLLPSFCT - resulting geodetic coordinate as side effect.
      Throws:
      TLcdOutOfBoundsException - If the ILcdPoint aXYPoint is not within the valid area of the projection (visible area), then this exception is thrown.
    • isAllInBounds Link icon

      public boolean isAllInBounds()
      Description copied from interface: ILcdProjection
      If all geodetic coordinates (l ,j ) are projected (visible) by an ILcdProjection and all (x,y ) coordinates are bounded this is true. All ILcdProjection objects have bounded (x,y ) coordinates because the projection is cut off if necessary.
      Returns:
      true if all LonLatPoints are within the bounds of the projection, false otherwise.
    • isContinuous Link icon

      public boolean isContinuous()
      Description copied from interface: ILcdProjection
      An ILcdProjection is continuous if there are no interruptions in the world coordinates. Most projections are continuous.
      Specified by:
      isContinuous in interface ILcdProjection
      Overrides:
      isContinuous in class ALcdCylindrical
      Returns:
      true if the projection is continuous, false otherwise.
    • inLonLatBounds Link icon

      public boolean inLonLatBounds(ILcdPoint aLLP)
      Description copied from interface: ILcdProjection
      Checks if an ILcdPoint is inside the valid area of geodetic coordinates of the projection. The valid area is determined by the LonLatPoints that are visible and for which the corresponding cartesian coordinate is within the boundaries.
      Parameters:
      aLLP - ILcdPoint to be checked upon.
      Returns:
      true if valid, false if invalid.
    • boundaryLons Link icon

      public double[][] boundaryLons(double lat)
      Description copied from class: ALcdProjection
      Default implementation. To be redefined for specific projections.
      Specified by:
      boundaryLons in interface ILcdProjection
      Overrides:
      boundaryLons in class ALcdProjection
      Parameters:
      lat - latitude in decimal degrees and -90.0 <= aLat<= 90.0.
      Returns:
      the array of pairs of longitudes[0] and longitudes[1], where the closed interval longitudes[0] -> longitudes[1] is in visible area and -180.0 <= lon[i] <= 180.0.
    • boundaryLats Link icon

      public double[][] boundaryLats(double lon)
      Description copied from class: ALcdProjection
      Default implementation. To be redefined for specific projections.
      Specified by:
      boundaryLats in interface ILcdProjection
      Overrides:
      boundaryLats in class ALcdProjection
      Parameters:
      lon - longitude in decimal degrees -180.0 <= lon <= 180.0 .
      Returns:
      the array of pairs of latitudes lats[0] and lats[1], where the closed interval lats[0] -> lats[1] is in visible area and -90.0 <= lats[i] <= 90.0 .
    • setLatitudeLimits Link icon

      public void setLatitudeLimits(ILcdInterval aLatitudeInterval)
      Changes the upper and lower latitude boundaries of the projection. Anything higher than the upper boundary or lower than the lower boundary will not be included in the projection.
      Parameters:
      aLatitudeInterval - the latitude boundaries of the projection. The interval should not extend [ -89.5, 89.5 ]
      Throws:
      IllegalArgumentException - if the interval extends [ -89.5, 89.5 ]
    • getLatitudeLimits Link icon

      public ILcdInterval getLatitudeLimits()
      Returns the upper and lower latitude boundaries of the projection. The default is the interval [ -89.5, 89.5 ]
      Returns:
      the latitude boundaries of the projection
    • inWorldBoundsOnSphere Link icon

      public boolean inWorldBoundsOnSphere(ILcdPoint aXYPoint, double aRadius)
      Description copied from interface: ILcdProjection
      Checks if a ILcdPoint is inside the valid cartesian area of the projection. The valid cartesian area is determined naturally by the projection bounds or by an artificial introduced boundary limit because some cartesian points are at infinity. The shape of the valid cartesian area is in many cases rectangular or circular although it might be more complex.
      Parameters:
      aXYPoint - point to be checked upon.
      aRadius - radius of the sphere.
      Returns:
      true if valid, false if invalid.
    • inWorldBoundsOnEllipsoid Link icon

      public boolean inWorldBoundsOnEllipsoid(ILcdPoint aXYPoint, ILcdEllipsoid aEllipsoid)
      Description copied from class: ALcdProjection
      Default implementation calls inWorldBoundsOnSphere with aEllipsoid.getAuxRadius() as sphere radius.
      Specified by:
      inWorldBoundsOnEllipsoid in interface ILcdProjection
      Overrides:
      inWorldBoundsOnEllipsoid in class ALcdProjection
      Parameters:
      aXYPoint - point to be checked upon.
      aEllipsoid - ellipsoid on which the geodetic coordinate is defined.
      Returns:
      true if valid, false if invalid.
      See Also:
    • world2DEditableBoundsOnSphereSFCT Link icon

      public void world2DEditableBoundsOnSphereSFCT(double aRadius, ILcd2DEditableBounds aWorldBound)
      Projection is cut off near the poles.
      Parameters:
      aRadius - radius of the sphere.
      aWorldBound - the bounds of the projection in world coordinates as side effect.
    • world2DEditableBoundsOnEllipsoidSFCT Link icon

      public void world2DEditableBoundsOnEllipsoidSFCT(ILcdEllipsoid aEllipsoid, ILcd2DEditableBounds aWorldBound)
      Description copied from class: ALcdProjection
      Default implementation calls world2lonlatOnSphereSFCT with aEllipsoid.getAuxRadius() as sphere radius.
      Specified by:
      world2DEditableBoundsOnEllipsoidSFCT in interface ILcdProjection
      Overrides:
      world2DEditableBoundsOnEllipsoidSFCT in class ALcdProjection
      Parameters:
      aEllipsoid - ellipsoid considered.
      aWorldBound - the bounds of the projection in world coordinates as side effect.
    • writePropertiesSFCT Link icon

      public void writePropertiesSFCT(String aPrefix, Properties aPropertySFCT)
      Writes the property of an ALcdCylindrical: the central meridian of the projection. This method will, given aPrefix, store he property of this ALcdCylindrical into the aPropertiesSFCT object. The value of following key is stored:
      • <aPrefix><the name of the class that extends this abstract class>.centralMeridian
      TLcdMercator also writes the lattitude limits and true scale latitude using the following properties:
      • <aPrefix><the name of the class that extends this abstract class>.trueScaleLatitude
      • <aPrefix><the name of the class that extends this abstract class>.upperLatitude
      • <aPrefix><the name of the class that extends this abstract class>.lowerLatitude
      Specified by:
      writePropertiesSFCT in interface ILcdProjection
      Overrides:
      writePropertiesSFCT in class ALcdCylindrical
      Parameters:
      aPrefix - prefix for the property names.
      aPropertySFCT - Properties object to store the serialized properties by side effect.
    • loadProperties Link icon

      public void loadProperties(String aPrefix, Properties aProperty) throws IllegalArgumentException
      Load the property of an ALcdCylindrical: the central meridian of the projection. This method will, given aPrefix, analyze the aProperties object to set the property of this ALcdCylindrical. The value of following key is retrieved:
      • <aPrefix><the name of the class that extends this abstract class>.centralMeridian
      TLcdMercator also reads the lattitude limits and true scale latitude using the following properties:
      • <aPrefix><the name of the class that extends this abstract class>.trueScaleLatitude
      • <aPrefix><the name of the class that extends this abstract class>.upperLatitude
      • <aPrefix><the name of the class that extends this abstract class>.lowerLatitude
      Specified by:
      loadProperties in interface ILcdProjection
      Overrides:
      loadProperties in class ALcdCylindrical
      Parameters:
      aPrefix - prefix of the property names.
      aProperty - Properties object containing the serialized properties.
      Throws:
      IllegalArgumentException - if the projection cannot be created.
    • toString Link icon

      public String toString()
      Returns the String representation of the mercator projection.
      Specified by:
      toString in interface ILcdProjection
      Overrides:
      toString in class Object
      Returns:
      the String representation of the mercator projection.
    • clone Link icon

      public Object clone()
      Description copied from interface: ILcdProjection
      Makes a deep clone of this ILcdProjection.
      Specified by:
      clone in interface ILcdProjection
      Overrides:
      clone in class ALcdCylindrical
      Returns:
      deep clone of this ILcdProjection.
    • equals Link icon

      public boolean equals(Object o)
      Description copied from interface: ILcdProjection
      Checks if this ILcdProjection equals some other Object.
      Specified by:
      equals in interface ILcdProjection
      Overrides:
      equals in class ALcdCylindrical
      Parameters:
      o - Object to compare with.
      Returns:
      true if the Object is an instance of the same ILcdProjection class and having the same projection properties, false otherwise.
    • hashCode Link icon

      public int hashCode()
      Overrides:
      hashCode in class ALcdCylindrical