# (C) Copyright 2005- ECMWF.

# TEMPLATE 3.90, Space view perspective or orthographic
include "grib2/template.3.shape_of_the_earth.def"

constant isGridded = true;

unsigned[4] Nx : dump;
alias Ni = Nx;
alias numberOfPointsAlongXAxis = Nx;
alias geography.Nx=Nx;

unsigned[4] Ny : dump;
alias Nj = Ny;
alias numberOfPointsAlongYAxis  = Nj;
alias numberOfPointsAlongAMeridian = Nj;
alias geography.Ny=Ny;

# Lap - latitude of sub-satellite point
signed[4] latitudeOfSubSatellitePoint;

# Lop - longitude of sub-satellite point
signed[4] longitudeOfSubSatellitePoint;

meta geography.latitudeOfSubSatellitePointInDegrees   scale(latitudeOfSubSatellitePoint,one,grib2divider,truncateDegrees) : dump;
meta geography.longitudeOfSubSatellitePointInDegrees   scale(longitudeOfSubSatellitePoint,one,grib2divider,truncateDegrees) : dump;

include "grib2/template.3.resolution_flags.def"

# dx - apparent diameter of Earth in grid lengths, in X-direction
unsigned[4] dx : dump;
alias geography.dx=dx;

# dy - apparent diameter of Earth in grid lengths, in Y-direction
unsigned[4] dy : dump;
alias geography.dy=dy;

# Xp - X-coordinate of sub-satellite point
# (in units of 10^-3 grid length expressed as an integer)
unsigned[4] Xp : no_copy;
meta geography.XpInGridLengths scale(Xp,one,thousand) : dump;
alias xCoordinateOfSubSatellitePoint=XpInGridLengths;

# Yp - Y-coordinate of sub-satellite point
# (in units of 10^-3 grid length expressed as an integer)
unsigned[4] Yp : no_copy;
meta geography.YpInGridLengths scale(Yp,one,thousand) : dump;
alias yCoordinateOfSubSatellitePoint=YpInGridLengths;

include "grib2/template.3.scanning_mode.def"

# Orientation of the grid; i.e. the angle between the increasing Y-axis and the meridian
# of the sub-satellite point in the direction of increasing latitude
signed[4] orientationOfTheGrid : edition_specific;
meta geography.orientationOfTheGridInDegrees
    scale(orientationOfTheGrid,oneConstant,grib2divider,truncateDegrees) : dump;

# Nr - altitude of the camera from the Earth's centre, measured in units of the Earth's
# (equatorial) radius multiplied by a scale factor of 10^6
unsigned[4] Nr : edition_specific,can_be_missing,no_copy;
alias altitudeOfTheCameraFromTheEarthsCentreMeasuredInUnitsOfTheEarthsRadius = Nr;
meta geography.NrInRadiusOfEarth scale(Nr,oneConstant,oneMillionConstant,truncateDegrees) : dump;
alias NrInRadiusOfEarthScaled=NrInRadiusOfEarth;

# Xo - X-coordinate of origin of sector image
unsigned[4] Xo  : dump;
alias xCoordinateOfOriginOfSectorImage=Xo;
alias geography.Xo=Xo;

# Yo - Y-coordinate of origin of sector image
unsigned[4] Yo  : dump;
alias yCoordinateOfOriginOfSectorImage=Yo;
alias geography.Yo=Yo;

iterator space_view(numberOfPoints, missingValue, values, radius,
          earthIsOblate,
          earthMajorAxis, earthMinorAxis,
          Nx, Ny,
          latitudeOfSubSatellitePointInDegrees,
          longitudeOfSubSatellitePointInDegrees,
          dx, dy, XpInGridLengths, YpInGridLengths,
          orientationOfTheGridInDegrees,
          NrInRadiusOfEarthScaled, Xo, Yo,
          iScansNegatively, jScansPositively,
          jPointsAreConsecutive, alternativeRowScanning);

nearest space_view(values,radius,Nx,Ny);

meta latLonValues latlonvalues(values);
alias latitudeLongitudeValues=latLonValues;
meta latitudes latitudes(values,0);
meta longitudes longitudes(values,0);
meta distinctLatitudes latitudes(values,1);
meta distinctLongitudes longitudes(values,1);
