All Implemented Interfaces:
Serializable, Parameterized, LenientComparable, org.opengis.referencing.operation.MathTransform, org.opengis.referencing.operation.MathTransform2D

public class Orthographic extends NormalizedProjection
Orthographic projection (EPSG:9840). See the following references for an overview:

Description

This is a perspective azimuthal (planar) projection that is neither conformal nor equal-area. It resembles a globe viewed from a point of perspective at infinite distance. Only one hemisphere can be seen at a time. While not useful for accurate measurements, this projection is useful for pictorial views of the world.
Since:
1.1
Version:
1.1
See Also:
  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      For compatibility with different versions during deserialization.
      See Also:
    • sinφ0

      private final double sinφ0
      Sine and cosine of latitude of origin.
    • cosφ0

      private final double cosφ0
      Sine and cosine of latitude of origin.
    • mℯ2_cosφ0

      private final double mℯ2_cosφ0
      Value of (1 – ℯ²)⋅cosφ₀.
  • Constructor Details

    • Orthographic

      public Orthographic(org.opengis.referencing.operation.OperationMethod method, Parameters parameters)
      Creates an orthographic projection from the given parameters. The method argument can be the description of one of the following:
      • "Orthographic".
      Parameters:
      method - description of the projection parameters.
      parameters - the parameter values of the projection to create.
    • Orthographic

      @Workaround(library="JDK", version="1.8") private Orthographic(Initializer initializer)
      Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").
  • Method Details

    • initializer

      @Workaround(library="JDK", version="1.8") private static Initializer initializer(org.opengis.referencing.operation.OperationMethod method, Parameters parameters)
      Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").
    • getInternalParameterNames

      final String[] getInternalParameterNames()
      Returns the names of additional internal parameters which need to be taken in account when comparing two Orthographic projections or formatting them in debug mode.

      We could report any of the internal parameters. But since they are all derived from φ₀ and the eccentricity and since the eccentricity is already reported by the super-class, we report only φ₀ as a representative of the internal parameters.

      Overrides:
      getInternalParameterNames in class NormalizedProjection
    • getInternalParameterValues

      final double[] getInternalParameterValues()
      Returns the values of additional internal parameters which need to be taken in account when comparing two Orthographic projections or formatting them in debug mode.
      Overrides:
      getInternalParameterValues in class NormalizedProjection
    • transform

      public org.opengis.referencing.operation.Matrix transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) throws ProjectionException
      Projects the specified (λ,φ) coordinates and stores the result in dstPts. The units of measurement are implementation-specific (see super-class javadoc). The results must be multiplied by the denormalization matrix before to get linear distances.
      Specified by:
      transform in class NormalizedProjection
      Parameters:
      srcPts - the array containing the source point coordinates, as (longitude, latitude) angles in radians.
      srcOff - the offset of the single coordinate tuple to be converted in the source array.
      dstPts - the array into which the converted coordinates is returned (may be the same than srcPts). Coordinates will be expressed in a dimensionless unit, as a linear distance on a unit sphere or ellipse.
      dstOff - the offset of the location of the converted coordinates that is stored in the destination array.
      derivate - true for computing the derivative, or false if not needed.
      Returns:
      the matrix of the projection derivative at the given source position, or null if the derivate argument is false.
      Throws:
      ProjectionException - if the coordinates cannot be converted.
      See Also:
    • transform

      final double transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, Matrix2 derivative)
      Implementation of transform(double[], int, double[], int, boolean) with possibility to recycle an existing matrix instance.
      Implementation note: in other map projections, we use a different class for ellipsoidal formulas. But the orthographic projection is a bit different; for this one it is more convenient to use if statements.
      Parameters:
      derivative - where to store the Jacobian matrix, or null if none. If this matrix is an Inverter instance, we take that as a flag meaning to not set out-of-range results to NaN.
      Returns:
      cos(φ), useful for error tolerance check.
    • inverseTransform

      protected void inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) throws ProjectionException
      Converts the specified (x,y) coordinates and stores the result in dstPts (angles in radians).
      Specified by:
      inverseTransform in class NormalizedProjection
      Parameters:
      srcPts - the array containing the source point coordinates, as linear distance on a unit sphere or ellipse.
      srcOff - the offset of the point to be converted in the source array.
      dstPts - the array into which the converted point coordinates is returned (may be the same than srcPts). Coordinates will be (longitude, latitude) angles in radians.
      dstOff - the offset of the location of the converted point that is stored in the destination array.
      Throws:
      ProjectionException - if the point cannot be converted.