Add proj_create_conversion_pole_rotation_netcdf_cf_convention() to address netCDF datasets using a pole rotation method

1 files changed, 72 insertions, 1 deletions

diff --git a/test/unit/test_c_api.cpp b/test/unit/test_c_api.cpp
index 2a82af64..44dceb97 100644
--- a/test/unit/test_c_api.cpp
+++ b/test/unit/test_c_api.cpp
@@ -2805,7 +2805,13 @@ TEST_F(CApi, proj_create_projections) {
         ObjectKeeper keeper_projCRS(projCRS);
         ASSERT_NE(projCRS, nullptr);
     }
-
+    {
+        auto projCRS =
+            proj_create_conversion_pole_rotation_netcdf_cf_convention(
+                m_ctxt, 0, 0, 0, "Degree", 0.0174532925199433);
+        ObjectKeeper keeper_projCRS(projCRS);
+        ASSERT_NE(projCRS, nullptr);
+    }
     /* END: Generated by scripts/create_c_api_projections.py*/
 }
 
@@ -5199,6 +5205,71 @@ TEST_F(CApi, proj_create_derived_geographic_crs) {
 
 // ---------------------------------------------------------------------------
 
+TEST_F(CApi, proj_create_derived_geographic_crs_netcdf_cf) {
+
+    PJ *crs_4019 = proj_create(m_ctxt, "EPSG:4019");
+    ObjectKeeper keeper_crs_4019(crs_4019);
+    ASSERT_NE(crs_4019, nullptr);
+
+    PJ *conversion = proj_create_conversion_pole_rotation_netcdf_cf_convention(
+        m_ctxt, 2, 3, 4, "Degree", 0.0174532925199433);
+    ObjectKeeper keeper_conversion(conversion);
+    ASSERT_NE(conversion, nullptr);
+
+    PJ *cs = proj_crs_get_coordinate_system(m_ctxt, crs_4019);
+    ObjectKeeper keeper_cs(cs);
+    ASSERT_NE(cs, nullptr);
+
+    PJ *derived_crs = proj_create_derived_geographic_crs(
+        m_ctxt, "my rotated CRS", crs_4019, conversion, cs);
+    ObjectKeeper keeper_derived_crs(derived_crs);
+    ASSERT_NE(derived_crs, nullptr);
+
+    auto wkt = proj_as_wkt(m_ctxt, derived_crs, PJ_WKT2_2019, nullptr);
+    const char *expected_wkt =
+        "GEOGCRS[\"my rotated CRS\",\n"
+        "    BASEGEOGCRS[\"Unknown datum based upon the GRS 1980 ellipsoid\",\n"
+        "        DATUM[\"Not specified (based on GRS 1980 ellipsoid)\",\n"
+        "            ELLIPSOID[\"GRS 1980\",6378137,298.257222101,\n"
+        "                LENGTHUNIT[\"metre\",1]]],\n"
+        "        PRIMEM[\"Greenwich\",0,\n"
+        "            ANGLEUNIT[\"degree\",0.0174532925199433]]],\n"
+        "    DERIVINGCONVERSION[\"Pole rotation (netCDF CF convention)\",\n"
+        "        METHOD[\"Pole rotation (netCDF CF convention)\"],\n"
+        "        PARAMETER[\"Grid north pole latitude (netCDF CF "
+        "convention)\",2,\n"
+        "            ANGLEUNIT[\"degree\",0.0174532925199433,\n"
+        "                ID[\"EPSG\",9122]]],\n"
+        "        PARAMETER[\"Grid north pole longitude (netCDF CF "
+        "convention)\",3,\n"
+        "            ANGLEUNIT[\"degree\",0.0174532925199433,\n"
+        "                ID[\"EPSG\",9122]]],\n"
+        "        PARAMETER[\"North pole grid longitude (netCDF CF "
+        "convention)\",4,\n"
+        "            ANGLEUNIT[\"degree\",0.0174532925199433,\n"
+        "                ID[\"EPSG\",9122]]]],\n"
+        "    CS[ellipsoidal,2],\n"
+        "        AXIS[\"geodetic latitude (Lat)\",north,\n"
+        "            ORDER[1],\n"
+        "            ANGLEUNIT[\"degree\",0.0174532925199433,\n"
+        "                ID[\"EPSG\",9122]]],\n"
+        "        AXIS[\"geodetic longitude (Lon)\",east,\n"
+        "            ORDER[2],\n"
+        "            ANGLEUNIT[\"degree\",0.0174532925199433,\n"
+        "                ID[\"EPSG\",9122]]]]";
+
+    ASSERT_NE(wkt, nullptr);
+    EXPECT_EQ(wkt, std::string(expected_wkt));
+
+    auto proj_5 = proj_as_proj_string(m_ctxt, derived_crs, PJ_PROJ_5, nullptr);
+    ASSERT_NE(proj_5, nullptr);
+    EXPECT_EQ(proj_5, std::string("+proj=ob_tran +o_proj=longlat +o_lon_p=4 "
+                                  "+o_lat_p=2 +lon_0=183 +ellps=GRS80 +no_defs "
+                                  "+type=crs"));
+}
+
+// ---------------------------------------------------------------------------
+
 TEST_F(CApi, proj_context_set_sqlite3_vfs_name) {
 
     PJ_CONTEXT *ctx = proj_context_create();