Changed isNonEarthDem usage, added custom surface support

Signed-off-by: Aditya <aditya050995@gmail.com>

geospatial/include/gz/common/geospatial/Dem.hh

@@ -60,12 +60,12 @@ namespace gz
       /// \brief Indicate that this is a non Earth DEM.
       /// \param[in] _isNonEarthDem Should be true if this is a
       /// non earth DEM, otherwise false.
-      public: void SetNonEarthDEM(bool _isNonEarthDem);
+      public: void SetUnknownDEM(bool _isNonEarthDem);
 
       /// \brief Check if the loaded DEM is not from the Earth.
       /// \return True if the loaded DEM is from the Earth, otherwise
       /// returns False.
-      public: bool GetNonEarthDEM();
+      public: bool UnknownDEM();
 
       /// \brief Get the elevation of a terrain's point in meters.
       /// \param[in] _x X coordinate of the terrain.

geospatial/src/Dem.cc

@@ -58,10 +58,10 @@ class gz::common::Dem::Implementation
   /// \brief Full filename used to load the dem.
   public: std::string filename;
 
-  /// \brief Whether the DEM will be handled as from non-Earth.
+  /// \brief Whether the DEM will be handled as unknown.
   /// If true, worldWidth & worldHeight = -1
   /// and GeoReference[Origin] can not be used (will return false)
-  public: bool isNonEarthDem = false;
+  public: bool isUnknownDem = false;
 
   /// \brief Holds the spherical coordinates object from the world.
   public : math::SphericalCoordinates sphericalCoordinates =
@@ -93,15 +93,15 @@ void Dem::SetSphericalCoordinates(
 }
 
 //////////////////////////////////////////////////
-void Dem::SetNonEarthDEM(bool _isNonEarthDem)
+void Dem::SetUnknownDEM(bool _isUnknownDem)
 {
-  this->dataPtr->isNonEarthDem = _isNonEarthDem;
+  this->dataPtr->isUnknownDem = _isUnknownDem;
 }
 
 //////////////////////////////////////////////////
-bool Dem::GetNonEarthDEM()
+bool Dem::UnknownDEM()
 {
-  return this->dataPtr->isNonEarthDem;
+  return this->dataPtr->isUnknownDem;
 }
 
 //////////////////////////////////////////////////
@@ -181,7 +181,7 @@ int Dem::Load(const std::string &_filename)
             << std::endl;
 
     this->dataPtr->worldWidth = this->dataPtr->worldHeight = -1;
-    this->dataPtr->isNonEarthDem = true;
+    this->dataPtr->isUnknownDem = true;
   }
 
   // Set the terrain's side (the terrain will be squared after the padding)
@@ -285,17 +285,17 @@ float Dem::MaxElevation() const
 bool Dem::GeoReference(double _x, double _y,
     gz::math::Angle &_latitude, gz::math::Angle &_longitude) const
 {
-  if (this->dataPtr->isNonEarthDem)
+  if (this->dataPtr->isUnknownDem)
   {
-    gzerr << "Can not retrieve WGS84 coordinates from non-Earth DEM."
+    gzerr << "Can not retrieve WGS84 coordinates from unknown DEM."
             << std::endl;
     return false;
   }
 
   double geoTransf[6];
   if (this->dataPtr->dataSet->GetGeoTransform(geoTransf) == CE_None)
   {
-    OGRCoordinateTransformation *cT;
+    OGRCoordinateTransformation *cT = nullptr;
     double xGeoDeg, yGeoDeg;
 
     if (this->dataPtr->sphericalCoordinates.Surface() ==
@@ -329,6 +329,26 @@ bool Dem::GeoReference(double _x, double _y,
       cT = OGRCreateCoordinateTransformation(
           sourceCs, &targetCs);
     }
+    else if (this->dataPtr->sphericalCoordinates.Surface() ==
+        math::SphericalCoordinates::CUSTOM_SURFACE)
+    {
+      auto sourceCs = this->dataPtr->dataSet->GetSpatialRef();
+      OGRSpatialReference targetCs = OGRSpatialReference();
+
+      int axisEquatorial =
+        this->dataPtr->sphericalCoordinates.SurfaceAxisEquatorial();
+      int axisPolar =
+        this->dataPtr->sphericalCoordinates.SurfaceAxisPolar();
+
+      std::string CUSTOM_SURFACE_LAT_LON_PROJ_STR =
+        "+proj=latlong +a=" + std::to_string(axisEquatorial) +
+        " +b=" + std::to_string(axisPolar);
+
+      targetCs.importFromProj4(CUSTOM_SURFACE_LAT_LON_PROJ_STR.c_str());
+
+      cT = OGRCreateCoordinateTransformation(
+          sourceCs, &targetCs);
+    }
     else
     {
       gzerr << "Unsupported spherical coordinates found" << std::endl;
@@ -383,9 +403,9 @@ unsigned int Dem::Width() const
 //////////////////////////////////////////////////
 double Dem::WorldWidth() const
 {
-  if (this->dataPtr->isNonEarthDem)
+  if (this->dataPtr->isUnknownDem)
   {
-    gzwarn << "Unable to determine world width of non-Earth DEM."
+    gzwarn << "Unable to determine world width of unknown DEM."
             << std::endl;
   }
   return this->dataPtr->worldWidth;
@@ -394,9 +414,9 @@ double Dem::WorldWidth() const
 //////////////////////////////////////////////////
 double Dem::WorldHeight() const
 {
-  if (this->dataPtr->isNonEarthDem)
+  if (this->dataPtr->isUnknownDem)
   {
-    gzwarn << "Unable to determine world height of non-Earth DEM."
+    gzwarn << "Unable to determine world height of unknown DEM."
             << std::endl;
   }
   return this->dataPtr->worldHeight;

geospatial/src/Dem_TEST.cc

@@ -127,6 +127,18 @@ TEST_F(DemTest, BasicAPI)
   EXPECT_TRUE(dem.GeoReferenceOrigin(latitude, longitude));
   EXPECT_FLOAT_EQ(38.001667f, latitude.Degree());
   EXPECT_FLOAT_EQ(-122.22278f, longitude.Degree());
+
+  // Emulate Earth as a custom surface.
+  common::Dem demCustomSurface;
+  auto earthSc = math::SphericalCoordinates();
+  auto customSc = math::SphericalCoordinates(
+      math::SphericalCoordinates::CUSTOM_SURFACE,
+      earthSc.SurfaceRadius(),
+      earthSc.SurfaceRadius());
+  demCustomSurface.SetSphericalCoordinates(customSc);
+  EXPECT_EQ(demCustomSurface.Load(path), 0);
+  EXPECT_FLOAT_EQ(3984.4849f, demCustomSurface.WorldHeight());
+  EXPECT_FLOAT_EQ(3139.7456f, demCustomSurface.WorldWidth());
 }
 
 /////////////////////////////////////////////////
@@ -226,7 +238,7 @@ TEST_F(DemTest, NaNNoData)
 }
 
 /////////////////////////////////////////////////
-TEST_F(DemTest, NonEarthDem)
+TEST_F(DemTest, UnknownDem)
 {
   // moon
   common::Dem dem;
@@ -247,25 +259,34 @@ TEST_F(DemTest, NonEarthDem)
   EXPECT_FALSE(dem.GeoReferenceOrigin(latitude, longitude));
 
   // The Load() method in Dem.cc should set the
-  // isNonEarthDEM flag.
-  EXPECT_TRUE(dem.GetNonEarthDEM());
+  // isUnknownDEM flag.
+  EXPECT_TRUE(dem.UnknownDEM());
 
   // This flag can be overridden externally.
-  dem.SetNonEarthDEM(false);
-  EXPECT_FALSE(dem.GetNonEarthDEM());
+  dem.SetUnknownDEM(false);
+  EXPECT_FALSE(dem.UnknownDEM());
 }
 
 TEST_F(DemTest, LunarDemLoad)
 {
-  // moon
+  // Load Moon DEM
   common::Dem dem;
   auto path = common::testing::TestFile("data", "dem_moon.tif");
   // Providing spherical coordinates object.
   auto moonSc = math::SphericalCoordinates(
       math::SphericalCoordinates::MOON_SCS);
   dem.SetSphericalCoordinates(moonSc);
   EXPECT_EQ(dem.Load(path), 0);
+  EXPECT_NEAR(dem.WorldWidth(), 80.0417, 1e-2);
+  EXPECT_NEAR(dem.WorldHeight(), 80.0417, 1e-2);
 
+  // Use custom spherical coordinates object with same axes as the moon.
+  auto customSc = math::SphericalCoordinates(
+      math::SphericalCoordinates::CUSTOM_SURFACE,
+      moonSc.SurfaceRadius(),
+      moonSc.SurfaceRadius());
+  dem.SetSphericalCoordinates(customSc);
+  EXPECT_EQ(dem.Load(path), 0);
   EXPECT_NEAR(dem.WorldWidth(), 80.0417, 1e-2);
   EXPECT_NEAR(dem.WorldHeight(), 80.0417, 1e-2);
 }