Projection.cpp

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#include "Projection.h"

#include <QObject>

#include <cfloat>
#include <cmath>
#include <iomanip>
#include <sstream>
#include <vector>

#include <SpiceUsr.h>

#include "Constants.h"
#include "Displacement.h"
#include "FileName.h"
#include "IException.h"
#include "IString.h"
#include "Longitude.h"
#include "NaifStatus.h"
#include "Pvl.h"
#include "PvlGroup.h"
#include "PvlKeyword.h"
#include "RingPlaneProjection.h"
#include "SpecialPixel.h"
#include "TProjection.h"
#include "WorldMapper.h"

using namespace std;
namespace Isis {
  Projection::Projection(Pvl &label) : m_mappingGrp("Mapping") {
    try {
      // Try to read the mapping group
      m_mappingGrp = label.findGroup("Mapping", Pvl::Traverse);

      // TODO** Try to generalize these to keep in parent Projection class and use for both azimuth and longitude
      // Get the RingLongitudeDomain or LongitudeDomain
      // if ((string) m_mappingGrp["LongitudeDomain"] == "360") {
      //   m_longitudeDomain = 360;
      // }
      // else if ((string) m_mappingGrp["LongitudeDomain"] == "180") {
      //   m_longitudeDomain = 180;
      // }
      // else {
      //   IString msg = "Projection failed. Invalid value for keyword "
      //                 "[LongitudeDomain] must be [180 or 360]";
      //   throw IException(IException::Unknown, msg, _FILEINFO_);
      // }

      // Get the map rotation
      m_rotation = 0.0;
      if (m_mappingGrp.hasKeyword("Rotation")) {
        m_rotation = m_mappingGrp["Rotation"];
      }

      // Initialize miscellaneous protected data elements
      m_good = false;

      m_pixelResolution = 1.0;
      if (m_mappingGrp.hasKeyword("PixelResolution")) {
        m_pixelResolution = m_mappingGrp["PixelResolution"];
      }

      m_minimumX = DBL_MAX;
      m_maximumX = -DBL_MAX;
      m_minimumY = DBL_MAX;
      m_maximumY = -DBL_MAX;

      m_mapper = NULL;

      m_sky = false;
      if (m_mappingGrp.hasKeyword("TargetName")) {
        QString str = m_mappingGrp["TargetName"];
        if (str.toUpper() == "SKY") m_sky = true;
      }

      // initialize the rest of the x,y,lat,lon member variables
      m_x = Null;
      m_y = Null;
    }
    catch(IException &e) {
      QString msg = "Projection failed.  Invalid label group [Mapping]";
      throw IException(e, IException::Unknown, msg, _FILEINFO_);
    }
  }

  Projection::~Projection() {
    if(m_mapper) delete m_mapper;
  }


  bool Projection::operator== (const Projection &proj) {
    if (Resolution() != proj.Resolution()) return false;
    if (Name() != proj.Name()) return false;
    return true;
  }


  bool Projection::operator!= (const Projection &proj) {
    return !(*this == proj);
  }


  void Projection::setProjectionType(const ProjectionType ptype) {
    m_projectionType = ptype;
  }


  Projection::ProjectionType Projection::projectionType() const {
    return m_projectionType;
  }


  bool Projection::IsSky() const {
    return m_sky;
  }


  bool Projection::IsEquatorialCylindrical() {
    return false;
  }

  // bool Projection::IsPositiveEast() const {
  //   return m_longitudeDirection == PositiveEast;
  // }

  // bool Projection::IsPositiveWest() const {
  //   return m_longitudeDirection == PositiveWest;
  // }


  // string Projection::LongitudeDirectionString() const {
  //   if (m_longitudeDirection == PositiveEast) return "PositiveEast";
  //   return "PositiveWest";
  // }

  // bool Projection::Has180Domain() const {
  //   return m_longitudeDomain == 180;
//  }

  // bool Projection::Has360Domain() const {
  //   return m_longitudeDomain == 360;
  // }

  // double Projection::To180Domain(const double lon) {
  //   if (lon == Null) {
  //     throw IException(IException::Unknown, 
  //                      "Unable to convert to 180 degree domain. The given longitude value [" 
  //                      + IString(lon) + "] is invalid.", 
  //                      _FILEINFO_);
  //   }
  //   return Isis::Longitude(lon, Angle::Degrees).force180Domain().degrees();
  // }

  // double Projection::To360Domain(const double lon) {
  //   if (lon == Null) {
  //     throw IException(IException::Unknown, 
  //                      "Unable to convert to 360 degree domain. The given longitude value [" 
  //                      + IString(lon) + "] is invalid.", 
  //                      _FILEINFO_);
  //   }
  //   double result = lon;

  //   if ( (lon < 0.0 || lon > 360.0) &&
  //       !qFuzzyCompare(lon, 0.0) && !qFuzzyCompare(lon, 360.0)) {
  //    result = Isis::Longitude(lon, Angle::Degrees).force360Domain().degrees();
  //   }

  //   return result;
  // }

  // string Projection::LongitudeDomainString() const {
  //   if (m_longitudeDomain == 360) return "360";
  //   return "180";
  // }

  bool Projection::HasGroundRange() const {
    return m_groundRangeGood;
  }


  double Projection::Rotation() const {
    return m_rotation;
  }


  bool Projection::IsGood() const {
    return m_good;
  }


  double Projection::XCoord() const {
    return m_x;
  }


  double Projection::YCoord() const {
    return m_y;
  }


  bool Projection::SetUniversalGround(const double coord1, const double coord2) {
    if (coord1 == Null || coord2 == Null) {
      m_good = false;
      return m_good;
    }
    if (projectionType() == Triaxial) {
      TProjection *tproj = (TProjection *) this;
      return tproj->SetUniversalGround(coord1, coord2); 
    }
    else {
      RingPlaneProjection *rproj = (RingPlaneProjection *) this;
      return rproj->SetUniversalGround(coord1, coord2);
    }
  }


  void Projection::SetWorldMapper(WorldMapper *mapper) {
    m_mapper = mapper;
  }

  bool Projection::SetWorld(const double worldX, const double worldY) {
    double projectionX;
    double projectionY;

    if (m_mapper != NULL) {
      projectionX = m_mapper->ProjectionX(worldX);
      projectionY = m_mapper->ProjectionY(worldY);
    }
    else {
      projectionX = worldX;
      projectionY = worldY;
    }

    return SetCoordinate(projectionX, projectionY);
  }

  double Projection::WorldX() const {
    if (m_mapper != NULL) {
      return m_mapper->WorldX(m_x);
    }
    else {
      return m_x;
    }
  }

  double Projection::WorldY() const {
    if (m_mapper != NULL) {
      return m_mapper->WorldY(m_y);
    }
    else {
      return m_y;
    }
  }

  double Projection::ToWorldX(const double projectionX) const {
    if (projectionX == Null) {
      throw IException(IException::Unknown, 
                       "Unable to convert to world x.  The given x-value [" 
                       + IString(projectionX) + "] is invalid.", 
                       _FILEINFO_);
    }
    if (m_mapper != NULL) {
      return m_mapper->WorldX(projectionX);
    }
    else {
      return projectionX;
    }
  }

  double Projection::ToWorldY(const double projectionY) const {
    if (projectionY == Null) {
      throw IException(IException::Unknown, 
                       "Unable to convert to world y.  The given y-value [" 
                       + IString(projectionY) + "] is invalid.", 
                       _FILEINFO_);
    }
    if (m_mapper != NULL) {
      return m_mapper->WorldY(projectionY);
    }
    else {
      return projectionY;
    }
  }

  double Projection::ToProjectionX(const double worldX) const {
    if (worldX == Null) {
      throw IException(IException::Unknown, 
                       "Unable to convert to projection x.  The given x-value [" 
                       + IString(worldX) + "] is invalid.", 
                       _FILEINFO_);
    }
    if (m_mapper != NULL) {
      return m_mapper->ProjectionX(worldX);
    }
    else {
      return worldX;
    }
  }

  double Projection::ToProjectionY(const double worldY) const {
    if (worldY == Null) {
      throw IException(IException::Unknown, 
                       "Unable to convert to projection y.  The given y-value [" 
                       + IString(worldY) + "] is invalid.", 
                       _FILEINFO_);
    }
    if (m_mapper != NULL) {
      return m_mapper->ProjectionY(worldY);
    }
    else {
      return worldY;
    }
  }

  double Projection::Resolution() const {
    if (m_mapper != NULL) {
      return m_mapper->Resolution();
    }
    else {
      return 1.0;
    }
  }


  double Projection::ToHours(double angle) {
    return angle / 15.0;
  }

  QString Projection::ToDMS(double angle) {
    int iangle = (int)angle;
    double mins = abs(angle - iangle) * 60.0;
    int imins = (int)mins;
    double secs = (mins - imins) * 60.0;
    int isecs = (int)secs;
    double frac = (secs - isecs) * 1000.0;
    if (frac >= 1000.0) {
      frac -= 1000.0;
      isecs++;
    }
    if (isecs >= 60) {
      isecs -= 60;
      imins++;
    }
    if (imins >= 60) {
      imins -= 60;
      iangle++;
    }
    stringstream s;
    s << iangle << " " << setw(2) << setfill('0')
      << imins << "m " << setw(2) << setfill('0') << isecs << "."  <<
      setprecision(3) << frac << "s";
    return s.str().c_str();
  }

  QString Projection::ToHMS(double angle) {
    double tangle = angle;
    while (tangle < 0.0) tangle += 360.0;
    while (tangle > 360.0) tangle -= 360.0;
    double hrs = ToHours(tangle);
    int ihrs = (int)(hrs);
    double mins = (hrs - ihrs) * 60.0;
    int imins = (int)(mins);
    double secs = (mins - imins) * 60.0;
    int isecs = (int)(secs);
    double msecs = (secs - isecs) * 1000.0;
    int imsecs = (int)(msecs + 0.5);
    if (imsecs >= 1000) {
      imsecs -= 1000;
      isecs++;
    }
    if (isecs >= 60) {
      isecs -= 60;
      imins++;
    }
    if (imins >= 60) {
      imins -= 60;
      ihrs++;
    }
    stringstream s;
    s << setw(2) << setfill('0') << ihrs << "h " << setw(2) << setfill('0') <<
      imins << "m " << setw(2) << setfill('0') << isecs << "." << imsecs << "s";
    return s.str().c_str();
  }

  void Projection::SetComputedXY(double x, double y) {
    if (x == Null || y == Null) {
      m_good = false;
      return;
    }
    if (m_rotation == 0.0) {
      m_x = x;
      m_y = y;
    }
    else {
      double rot = m_rotation * PI / 180.0;
      m_x = x * cos(rot) + y * sin(rot);
      m_y = y * cos(rot) - x * sin(rot);
    }
  }

  void Projection::SetXY(double x, double y) {
    if (x == Null || y == Null) {
      m_good = false;
    }
    m_x = x;
    m_y = y;
    return;
  }

  double Projection::GetX() const {
    if (m_rotation == 0.0) return m_x;
    double rot = m_rotation * PI / 180.0;
    return m_x * cos(rot) - m_y * sin(rot);
  }

  double Projection::GetY() const {
    if (m_rotation == 0.0) return m_y;
    double rot = m_rotation * PI / 180.0;
    return m_y * cos(rot) + m_x * sin(rot);
  }

  double Projection::PixelResolution() const {
    return m_pixelResolution;
  }


  // /** 
  //  * This method is used to find the XY range for oblique aspect projections 
  //  * (non-polar projections) by "walking" around each of the min/max lat/lon. 
  //  *  
  //  * @param minX Minimum x projection coordinate which covers the latitude
  //  *             longitude range specified in the labels.
  //  * @param maxX Maximum x projection coordinate which covers the latitude
  //  *             longitude range specified in the labels.
  //  * @param minY Minimum y projection coordinate which covers the latitude
  //  *             longitude range specified in the labels.
  //  * @param maxY Maximum y projection coordinate which covers the latitude
  //  *             longitude range specified in the labels.
  //  * 
  //  * @return @b bool Indicates whether the method was successful.
  //  * @see XYRange()
  //  * @author Stephen Lambright 
  //  * @internal
  //  *   @history 2011-07-02 Jeannie Backer - Moved this code from
  //  *                           ObliqueCylindrical class to its own method here.
  //  */
  // bool Projection::xyRangeOblique(double &minX, double &maxX, 
  //                                 double &minY, double &maxY) {
  //   if (minX == Null || maxX == Null || minY == Null || maxY == Null) {
  //     return false;
  //   }
  //   //For oblique, we'll have to walk all 4 sides to find out min/max x/y values
  //   if (!HasGroundRange()) return false; // Don't have min/max lat/lon, 
  //                                       //can't continue

  //   m_specialLatCases.clear();
  //   m_specialLonCases.clear();

  //   // First, search longitude for min X/Y
  //   double minFoundX1, minFoundX2;
  //   double minFoundY1, minFoundY2;

  //   // Search for minX between minlat and maxlat along minlon
  //   doSearch(MinimumLatitude(), MaximumLatitude(), 
  //            minFoundX1, MinimumLongitude(), true, true, true);
  //   // Search for minX between minlat and maxlat along maxlon
  //   doSearch(MinimumLatitude(), MaximumLatitude(), 
  //            minFoundX2, MaximumLongitude(), true, true, true);
  //   // Search for minY between minlat and maxlat along minlon
  //   doSearch(MinimumLatitude(), MaximumLatitude(), 
  //            minFoundY1, MinimumLongitude(), false, true, true);
  //   // Search for minY between minlat and maxlat along maxlon
  //   doSearch(MinimumLatitude(), MaximumLatitude(), 
  //            minFoundY2, MaximumLongitude(), false, true, true);

  //   // Second, search latitude for min X/Y
  //   double minFoundX3, minFoundX4;
  //   double minFoundY3, minFoundY4;

  //   // Search for minX between minlon and maxlon along minlat
  //   doSearch(MinimumLongitude(), MaximumLongitude(), 
  //            minFoundX3, MinimumLatitude(), true, false, true);
  //   // Search for minX between minlon and maxlon along maxlat
  //   doSearch(MinimumLongitude(), MaximumLongitude(), 
  //            minFoundX4, MaximumLatitude(), true, false, true);
  //   // Search for minY between minlon and maxlon along minlat
  //   doSearch(MinimumLongitude(), MaximumLongitude(), 
  //            minFoundY3, MinimumLatitude(), false, false, true);
  //   // Search for minY between minlon and maxlon along maxlat
  //   doSearch(MinimumLongitude(), MaximumLongitude(), 
  //            minFoundY4, MaximumLatitude(), false, false, true);

  //   // We've searched all possible minimums, go ahead and store the lowest
  //   double minFoundX5 = min(minFoundX1, minFoundX2);
  //   double minFoundX6 = min(minFoundX3, minFoundX4);
  //   m_minimumX = min(minFoundX5, minFoundX6);

  //   double minFoundY5 = min(minFoundY1, minFoundY2);
  //   double minFoundY6 = min(minFoundY3, minFoundY4);
  //   m_minimumY = min(minFoundY5, minFoundY6);

  //   // Search longitude for max X/Y
  //   double maxFoundX1, maxFoundX2;
  //   double maxFoundY1, maxFoundY2;

  //   // Search for maxX between minlat and maxlat along minlon
  //   doSearch(MinimumLatitude(), MaximumLatitude(), 
  //            maxFoundX1, MinimumLongitude(), true, true, false);
  //   // Search for maxX between minlat and maxlat along maxlon
  //   doSearch(MinimumLatitude(), MaximumLatitude(), 
  //            maxFoundX2, MaximumLongitude(), true, true, false);
  //   // Search for maxY between minlat and maxlat along minlon
  //   doSearch(MinimumLatitude(), MaximumLatitude(), 
  //            maxFoundY1, MinimumLongitude(), false, true, false);
  //   // Search for maxY between minlat and maxlat along maxlon
  //   doSearch(MinimumLatitude(), MaximumLatitude(), 
  //            maxFoundY2, MaximumLongitude(), false, true, false);

  //   // Search latitude for max X/Y
  //   double maxFoundX3, maxFoundX4;
  //   double maxFoundY3, maxFoundY4;

  //   // Search for maxX between minlon and maxlon along minlat
  //   doSearch(MinimumLongitude(), MaximumLongitude(), 
  //            maxFoundX3, MinimumLatitude(), true, false, false);
  //   // Search for maxX between minlon and maxlon along maxlat
  //   doSearch(MinimumLongitude(), MaximumLongitude(), 
  //            maxFoundX4, MaximumLatitude(), true, false, false);
  //   // Search for maxY between minlon and maxlon along minlat
  //   doSearch(MinimumLongitude(), MaximumLongitude(), 
  //            maxFoundY3, MinimumLatitude(), false, false, false);
  //   // Search for maxY between minlon and maxlon along maxlat
  //   doSearch(MinimumLongitude(), MaximumLongitude(), 
  //            maxFoundY4, MaximumLatitude(), false, false, false);

  //   // We've searched all possible maximums, go ahead and store the highest
  //   double maxFoundX5 = max(maxFoundX1, maxFoundX2);
  //   double maxFoundX6 = max(maxFoundX3, maxFoundX4);
  //   m_maximumX = max(maxFoundX5, maxFoundX6);

  //   double maxFoundY5 = max(maxFoundY1, maxFoundY2);
  //   double maxFoundY6 = max(maxFoundY3, maxFoundY4);
  //   m_maximumY = max(maxFoundY5, maxFoundY6);

  //   // Look along discontinuities for more extremes
  //   vector<double> specialLatCases = m_specialLatCases;
  //   for (unsigned int specialLatCase = 0; 
  //       specialLatCase < specialLatCases.size(); 
  //       specialLatCase ++) {
  //     double minX, maxX, minY, maxY;

  //     // Search for minX between minlon and maxlon along latitude discontinuities
  //     doSearch(MinimumLongitude(), MaximumLongitude(), 
  //              minX, specialLatCases[specialLatCase], true,  false, true);
  //     // Search for minY between minlon and maxlon along latitude discontinuities
  //     doSearch(MinimumLongitude(), MaximumLongitude(), 
  //              minY, specialLatCases[specialLatCase], false, false, true);
  //     // Search for maxX between minlon and maxlon along latitude discontinuities
  //     doSearch(MinimumLongitude(), MaximumLongitude(), 
  //              maxX, specialLatCases[specialLatCase], true,  false, false);
  //     // Search for maxX between minlon and maxlon along latitude discontinuities
  //     doSearch(MinimumLongitude(), MaximumLongitude(), 
  //              maxY, specialLatCases[specialLatCase], false, false, false);

  //     m_minimumX = min(minX, m_minimumX);
  //     m_maximumX = max(maxX, m_maximumX);
  //     m_minimumY = min(minY, m_minimumY);
  //     m_maximumY = max(maxY, m_maximumY);
  //   }

  //   vector<double> specialLonCases = m_specialLonCases;
  //   for (unsigned int specialLonCase = 0; 
  //       specialLonCase < specialLonCases.size(); 
  //       specialLonCase ++) {
  //     double minX, maxX, minY, maxY;

  //     // Search for minX between minlat and maxlat along longitude discontinuities
  //     doSearch(MinimumLatitude(), MaximumLatitude(), 
  //              minX, specialLonCases[specialLonCase], true,  true, true);
  //     // Search for minY between minlat and maxlat along longitude discontinuities
  //     doSearch(MinimumLatitude(), MaximumLatitude(), 
  //              minY, specialLonCases[specialLonCase], false, true, true);
  //     // Search for maxX between minlat and maxlat along longitude discontinuities
  //     doSearch(MinimumLatitude(), MaximumLatitude(), 
  //              maxX, specialLonCases[specialLonCase], true,  true, false);
  //     // Search for maxY between minlat and maxlat along longitude discontinuities
  //     doSearch(MinimumLatitude(), MaximumLatitude(), 
  //              maxY, specialLonCases[specialLonCase], false, true, false);

  //     m_minimumX = min(minX, m_minimumX);
  //     m_maximumX = max(maxX, m_maximumX);
  //     m_minimumY = min(minY, m_minimumY);
  //     m_maximumY = max(maxY, m_maximumY);
  //   }

  //   m_specialLatCases.clear();
  //   m_specialLonCases.clear();

  //   // 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;
  // }

  // void Projection::doSearch(double minBorder, double maxBorder, 
  //                           double &extremeVal, const double constBorder, 
  //                           bool searchX, bool searchLongitude, bool findMin) {
  //   if (minBorder == Null || maxBorder == Null || constBorder == Null) {
  //     return;
  //   }
  //   const double TOLERANCE = m_pixelResolution/2;
  //   const int NUM_ATTEMPTS = (unsigned int)DBL_DIG; // It's unsafe to go past 
  //                                                   // this precision

  //   double minBorderX, minBorderY, maxBorderX, maxBorderY;
  //   int attempts = 0;

  //   do {
  //     findExtreme(minBorder, maxBorder, minBorderX, minBorderY, maxBorderX, 
  //                 maxBorderY, constBorder, searchX, searchLongitude, findMin);
  //     if (minBorderX == Null && maxBorderX == Null 
  //         && minBorderY == Null && maxBorderY == Null ) {
  //       attempts = NUM_ATTEMPTS;
  //       continue;
  //     }
  //     attempts ++;
  //   }
  //   while ((fabs(minBorderX - maxBorderX) > TOLERANCE 
  //          || fabs(minBorderY - maxBorderY) > TOLERANCE)
  //          && (attempts < NUM_ATTEMPTS)); 
  //   // check both x and y distance in case symmetry of map
  //   // For example, if minBorderX = maxBorderX but minBorderY = -maxBorderY,
  //   // these points may not be close enough.

  //   if (attempts >= NUM_ATTEMPTS) {
  //     // We zoomed in on a discontinuity because our range never shrank, this
  //     // will need to be rechecked later. 
  //     // *min and max border should be nearly identical, so it doesn't matter
  //     //  which is used here
  //     if (searchLongitude) {
  //       m_specialLatCases.push_back(minBorder);
  //     }
  //     else {
  //       m_specialLonCases.push_back(minBorder);
  //     }
  //   }

  //   // These values will always be accurate, even over a discontinuity
  //   if (findMin) {
  //     if (searchX) extremeVal = min(minBorderX, maxBorderX);
  //     else         extremeVal = min(minBorderY, maxBorderY);
  //   }
  //   else {
  //     if (searchX) extremeVal = max(minBorderX, maxBorderX);
  //     else         extremeVal = max(minBorderY, maxBorderY);
  //   }
  //   return;
  // }

  // void Projection::findExtreme(double &minBorder,  double &maxBorder,
  //                              double &minBorderX, double &minBorderY,
  //                              double &maxBorderX, double &maxBorderY, 
  //                              const double constBorder, bool searchX, 
  //                              bool searchLongitude, bool findMin) {
  //   if (minBorder == Null || maxBorder == Null || constBorder == Null) {
  //     minBorderX = Null;
  //     minBorderY = minBorderX;
  //     minBorderX = minBorderX;
  //     minBorderY = minBorderX;
  //     return;
  //   }
  //   if (!searchLongitude && (fabs(fabs(constBorder) - 90.0) < DBL_EPSILON)) {
  //     // it is impossible to search "along" a pole
  //     setSearchGround(minBorder, constBorder, searchLongitude);
  //     minBorderX = XCoord();
  //     minBorderY = YCoord();
  //     maxBorderX = minBorderX;
  //     maxBorderY = minBorderY;
  //     return;
  //   }
  //   // Always do 10 steps
  //   const double STEP_SIZE = (maxBorder - minBorder) / 10.0;
  //   const double LOOP_END = maxBorder + (STEP_SIZE / 2.0); // This ensures we do 
  //                                                          // all of the steps
  //                                                          // properly
  //   double currBorderVal = minBorder;
  //   setSearchGround(minBorder, constBorder, searchLongitude);

  //   // this makes sure that the initial currBorderVal is valid before entering
  //   // the loop below
  //   if (!m_good){
  //     // minBorder = currBorderVal+STEP_SIZE < LOOP_END until setGround is good?
  //     // then, if still not good return?
  //     while (!m_good && currBorderVal <= LOOP_END) {
  //       currBorderVal+=STEP_SIZE;
  //       if (searchLongitude && (currBorderVal - 90.0 > DBL_EPSILON)) {
  //         currBorderVal = 90.0;
  //       }
  //       setSearchGround(currBorderVal, constBorder, searchLongitude);
  //     }
  //     if (!m_good) {
  //       minBorderX = Null;
  //       minBorderY = minBorderX;
  //       minBorderX = minBorderX;
  //       minBorderY = minBorderX;
  //       return;
  //     }
  //   }

  //   // save the values of three consecutive steps from the minBorder towards
  //   // the maxBorder along the constBorder. initialize these three border
  //   // values (the non-constant lat or lon)
  //   double border1 = currBorderVal;
  //   double border2 = currBorderVal;
  //   double border3 = currBorderVal;

  //   // save the coordinate (x or y) values that correspond to the first
  //   // two borders that are being saved.
  //   // initialize these two coordinate values (x or y)
  //   double value1 = (searchX) ? XCoord() : YCoord();
  //   double value2 = value1;

  //   // initialize the extreme coordinate value 
  //   // -- this is the largest coordinate value found so far
  //   double extremeVal2 = value2;

  //   // initialize the extreme border values
  //   // -- these are the borders on either side of the extreme coordinate value
  //   double extremeBorder1 = minBorder;
  //   double extremeBorder3 = minBorder;

  //   while (currBorderVal <= LOOP_END) {

  //     // this conditional was added to prevent trying to SetGround with an
  //     // invalid latitude greater than 90 degrees. There is no need check for
  //     // latitude less than -90 since we start at the minBorder (already
  //     // assumed to be valid) and step forward toward (and possibly past)
  //     // maxBorder
  //     if (searchLongitude && (currBorderVal - 90.0 > DBL_EPSILON)) {
  //       currBorderVal = 90.0;
  //     }

  //     // update the current border value along constBorder
  //     currBorderVal += STEP_SIZE;
  //     setSearchGround(currBorderVal, constBorder, searchLongitude);
  //     if (!m_good){ 
  //       continue;
  //     } 
                     
  //     // update the border and coordinate values 
  //     border3 = border2;
  //     border2 = border1;
  //     border1 = currBorderVal;                                             
  //     value2 = value1;
  //     value1 = (searchX) ? XCoord() : YCoord();

  //     if ((findMin && value2 < extremeVal2) 
  //         || (!findMin && value2 > extremeVal2)) {
  //       // Compare the coordinate value associated with the center border with 
  //       // the current extreme. If the updated coordinate value is more extreme
  //       // (smaller or larger, depending on findMin), then we update the
  //       // extremeVal and it's borders.
  //       extremeVal2 = value2;

  //       extremeBorder3 = border3;
  //       extremeBorder1 = border1;
  //     }
  //   }

  //   // update min/max border values to the values on either side of the most 
  //   // extreme coordinate found in this call to this method
    
  //   minBorder = extremeBorder3; // Border 3 is lagging and thus smaller

  //   // since the loop steps past the original maxBorder, we want to retain 
  //   // the original maxBorder value so we don't go outside of the original
  //   // min/max range given
  //   if (extremeBorder1 <= maxBorder ) {
  //     maxBorder = extremeBorder1; // Border 1 is leading and thus larger
  //   }

  //   // update minBorder coordinate values
  //   setSearchGround(minBorder, constBorder, searchLongitude);
  //   // if (!m_good){
  //   //   this should not happen since minBorder has already been verified in 
  //   //   the while loop above
  //   // }

  //   minBorderX = XCoord();
  //   minBorderY = YCoord();

  //   // update maxBorder coordinate values
  //   setSearchGround(maxBorder, constBorder, searchLongitude);
  //   // if (!m_good){
  //   //   this should not happen since maxBorder has already been verified in
  //   //   the while loop above
  //   // }

  //   maxBorderX = XCoord();
  //   maxBorderY = YCoord();
  //   return;
  // }

  // void Projection::setSearchGround(const double variableBorder, 
  //                                  const double constBorder, 
  //                                  bool variableIsLat) {
  //   if (variableBorder == Null || constBorder == Null) {
  //     return;
  //   }
  //   double lat, lon;
  //   if (variableIsLat) {
  //     lat = variableBorder;
  //     lon = constBorder;
  //   }
  //   else {
  //     lat = constBorder;
  //     lon = variableBorder;
  //   }
  //   SetGround(lat, lon);
  //   return;
  // }

  void Projection::SetUpperLeftCorner(const Displacement &x, 
                                      const Displacement &y) {
    PvlKeyword xKeyword("UpperLeftCornerX", toString(x.meters()), "meters");
    PvlKeyword yKeyword("UpperLeftCornerY", toString(y.meters()), "meters");
    m_mappingGrp.addKeyword(xKeyword,Pvl::Replace);
    m_mappingGrp.addKeyword(yKeyword,Pvl::Replace);
  }
} //end namespace isis