Equirectangular.cpp

 
/* SPDX-License-Identifier: CC0-1.0 */
#include "Equirectangular.h"
 
#include <cmath>
#include <cfloat>
 
#include "Constants.h"
#include "IException.h"
#include "TProjection.h"
#include "Pvl.h"
#include "PvlGroup.h"
#include "PvlKeyword.h"
 
using namespace std;
namespace Isis {
  Equirectangular::Equirectangular(Pvl &label, bool allowDefaults) :
    TProjection::TProjection(label) {
    try {
      // Try to read the mapping group
      PvlGroup &mapGroup = label.findGroup("Mapping", Pvl::Traverse);
 
      // Compute the default value if allowed and needed
      if (!mapGroup.hasKeyword("CenterLongitude")) {
        if (allowDefaults) {
          double lon = (m_minimumLongitude + m_maximumLongitude) / 2.0;
          mapGroup += PvlKeyword("CenterLongitude", toString(lon));
        }
        else {
          QString message = "Cannot project using Equirectangular Cylindrical";
          message += " without [CenterLongitude] value.  Keyword does not exist";
          message += " in labels and defaults are not allowed.";
          throw IException(IException::Unknown, message, _FILEINFO_);
        }
      }
 
      if (!mapGroup.hasKeyword("CenterLatitude")) {
        if (allowDefaults) {
          double lat = (m_minimumLatitude + m_maximumLatitude) / 2.0;
          mapGroup += PvlKeyword("CenterLatitude", toString(lat));
        }
        else {
          QString message = "Cannot project using Equirectangular Cylindrical";
          message += " without [CenterLatitude] value.  Keyword does not exist";
          message += " in labels and defaults are not allowed.";
          throw IException(IException::Unknown, message, _FILEINFO_);
        }
      }
 
      // Get the center longitude, convert to radians, adjust for longitude
      // direction
      m_centerLongitude = mapGroup["CenterLongitude"];
      m_centerLongitude *= PI / 180.0;
      if (m_longitudeDirection == PositiveWest) m_centerLongitude *= -1.0;
 
      // Get the center latitude, the radius at the clat, and convert to radians
      m_centerLatitude = mapGroup["CenterLatitude"];
      m_clatRadius = LocalRadius(m_centerLatitude);
      m_centerLatitude *= PI / 180.0;
 
      // This keyword is just for user's information, and was put in for Hirise
      if (!mapGroup.hasKeyword("CenterLatitudeRadius")) {
        mapGroup += PvlKeyword("CenterLatitudeRadius");
      }
 
      mapGroup["CenterLatitudeRadius"] = toString(m_clatRadius);
 
      // Compute cos of the center latitude and make sure it is valid as
      // we will be dividing with it later on
      m_cosCenterLatitude = cos(m_centerLatitude);
      if (fabs(m_cosCenterLatitude) < DBL_EPSILON) {
        QString message = "Keyword value for CenterLatitude is "
                         "too close to the pole";
        throw IException(IException::Io, message, _FILEINFO_);
      }
    }
    catch(IException &e) {
      QString message = "Invalid label group [Mapping]";
      throw IException(e, IException::Io, message, _FILEINFO_);
    }
  }
 
  Equirectangular::~Equirectangular() {
  }
 
  bool Equirectangular::operator== (const Projection &proj) {
    if (!Projection::operator==(proj)) return false;
    // dont do the below it is a recusive plunge
    //  if (Projection::operator!=(proj)) return false;
    Equirectangular *equi = (Equirectangular *) &proj;
    if (equi->m_centerLongitude != m_centerLongitude) return false;
    if (equi->m_centerLatitude != m_centerLatitude) return false;
    return true;
  }
 
  QString Equirectangular::Name() const {
    return "Equirectangular";
  }
 
  QString Equirectangular::Version() const {
    return "1.0";
  }
 
  double Equirectangular::TrueScaleLatitude() const {
    return m_centerLatitude * 180.0 / PI;
  }
 
  bool Equirectangular::IsEquatorialCylindrical() {
    return true;
  }
 
  bool Equirectangular::SetGround(const double lat, const double lon) {
    // Convert to radians
    m_latitude = lat;
    m_longitude = lon;
    double latRadians = lat * PI / 180.0;
    double lonRadians = lon * PI / 180.0;
    if (m_longitudeDirection == PositiveWest) lonRadians *= -1.0;
 
    // Compute the coordinate
    double deltaLon = (lonRadians - m_centerLongitude);
    double x = m_clatRadius * m_cosCenterLatitude * deltaLon;
    double y = m_clatRadius * latRadians;
    SetComputedXY(x, y);
    m_good = true;
    return m_good;
  }
 
  bool Equirectangular::SetCoordinate(const double x, const double y) {
    // Save the coordinate
    SetXY(x, y);
 
    // Compute latitude and make sure it is not above 90
    m_latitude = GetY() / m_clatRadius;
    if ((fabs(m_latitude) - HALFPI) > DBL_EPSILON) {
      m_good = false;
      return m_good;
    }
 
    // Compute longitude
    m_longitude = m_centerLongitude +
                  GetX() / (m_clatRadius * m_cosCenterLatitude);
 
    // Convert to degrees
    m_latitude *= 180.0 / PI;
    m_longitude *= 180.0 / PI;
 
    // Cleanup the longitude
    if (m_longitudeDirection == PositiveWest) m_longitude *= -1.0;
    // Do these if the projection is circular
    //  m_longitude = To360Domain (m_longitude);
    //  if (m_longitudeDomain == 180) m_longitude = To180Domain(m_longitude);
 
    m_good = true;
    return m_good;
  }
 
  bool Equirectangular::XYRange(double &minX, double &maxX,
                                double &minY, double &maxY) {
    // Check the corners of the lat/lon range
    XYRangeCheck(m_minimumLatitude, m_minimumLongitude);
    XYRangeCheck(m_maximumLatitude, m_minimumLongitude);
    XYRangeCheck(m_minimumLatitude, m_maximumLongitude);
    XYRangeCheck(m_maximumLatitude, m_maximumLongitude);
 
    // Make sure everything is ordered
    if (m_minimumX >= m_maximumX) return false;
    if (m_minimumY >= m_maximumY) return false;
 
    // Return X/Y min/maxs
    minX = m_minimumX;
    maxX = m_maximumX;
    minY = m_minimumY;
    maxY = m_maximumY;
    return true;
  }
 
  PvlGroup Equirectangular::Mapping() {
    PvlGroup mapping = TProjection::Mapping();
 
    mapping += m_mappingGrp["CenterLatitude"];
    mapping += m_mappingGrp["CenterLongitude"];
 
    return mapping;
  }
 
  PvlGroup Equirectangular::MappingLatitudes() {
    PvlGroup mapping = TProjection::MappingLatitudes();
 
    mapping += m_mappingGrp["CenterLatitude"];
 
    return mapping;
  }
 
  PvlGroup Equirectangular::MappingLongitudes() {
    PvlGroup mapping = TProjection::MappingLongitudes();
 
    mapping += m_mappingGrp["CenterLongitude"];
 
    return mapping;
  }
 
}
 
extern "C" Isis::Projection *EquirectangularPlugin(Isis::Pvl &lab,
    bool allowDefaults) {
  return new Isis::Equirectangular(lab, allowDefaults);
}