Initial implementation of a Cubed Sphere 2 grid builder

JCSDA-internal · Dec 2, 2024 · d905290 · d905290
1 parent 3e78945
commit d905290
Show file tree

Hide file tree

Showing 4 changed files with 106 additions and 0 deletions.
diff --git a/src/atlas/grid/CubedSphereGrid2.h b/src/atlas/grid/CubedSphereGrid2.h
@@ -1,12 +1,18 @@
 #pragma once
 
 #include "atlas/grid/Grid.h"
+#include "atlas/grid/detail/grid/CubedSphere2.h"
 
 namespace atlas {
 
 class CubedSphereGrid2 : public atlas::Grid {
 public:
+    using grid_t = grid::detail::grid::CubedSphere2;
+
     CubedSphereGrid2(idx_t resolution);
+
+private:
+    const grid_t* grid_;
 };
 
 }  // namespace atlas
diff --git a/src/atlas/grid/detail/grid/CubedSphere2.cc b/src/atlas/grid/detail/grid/CubedSphere2.cc
@@ -1,15 +1,23 @@
 #include "atlas/grid/detail/grid/CubedSphere2.h"
 
 #include <cmath>
+#include <iomanip>
 
+#include "atlas/grid/CubedSphereGrid2.h"
+#include "atlas/grid/detail/grid/GridBuilder.h"
+#include "atlas/grid/detail/grid/GridFactory.h"
+#include "atlas/runtime/Exception.h"
 #include "eckit/geometry/Sphere.h"
 #include "eckit/utils/Hash.h"
+#include "eckit/utils/Translator.h"
 
 namespace atlas {
 namespace grid {
 namespace detail {
 namespace grid {
 
+static eckit::Translator<std::string, int> to_int;
+
 // Public methods
 
 CubedSphere2::CubedSphere2(idx_t resolution) : N_(resolution) {}
@@ -135,6 +143,87 @@ PointXYZ CubedSphere2::tangent_to_xyz_coord(PointXY& tan_coord, idx_t tile) cons
     return {xyz(0), xyz(1), xyz(2)};
 }
 
+namespace {
+GridFactoryBuilder<CubedSphere2> __register_CubedSphere2(CubedSphere2::static_type());
+}
+
+static class cubedsphere2_lfric : public GridBuilder {
+public:
+    cubedsphere2_lfric():
+        GridBuilder("cubedsphere2_lfric", {"^[Cc][Ss][_-][Ll][Ff][Rr][-_]([1-9][0-9]*)[_-][2]$"},
+                    {"CS-LFR-<N>-2"}) {}
+
+    void print(std::ostream& os) const override {
+        os << std::left << std::setw(20) << "CS-LFR-<n>-2"
+           << "Cubed sphere for LFRic";
+    }
+
+    // Factory constructor
+    const atlas::Grid::Implementation* create(const std::string& name, const Grid::Config& config) const override {
+        int id;
+        std::vector<std::string> matches;
+        if (match(name, matches, id)) {
+            util::Config gridconf(config);
+            int N = to_int(matches[0]);
+            gridconf.set("type", type());
+            gridconf.set("N", N);
+            return create(gridconf);
+        }
+        return nullptr;
+    }
+
+    // Factory constructor
+    const atlas::Grid::Implementation* create(const Grid::Config& config) const override {
+        int N = 0;
+        if (not config.get("N", N)) {
+            throw_AssertionFailed("Could not find \"N\" in configuration of cubed sphere grid 2", Here());
+        }
+
+        return new CubedSphereGrid2::grid_t(N);
+
+        // TODO: requires CubedSphereGrid2 constructor with projection
+
+        // std::string name = "CS-LFR-" + std::to_string(N) + "-2";
+        // util::Config projconf;
+        // projconf.set("type", "cubedsphere2");
+        // projconf.set("tile.type", "cubedsphere2_lfric");
+
+        // // Shift projection by a longitude
+        // if (config.has("ShiftLon")) {
+        //     double shiftLon = 0.0;
+        //     config.get("ShiftLon", shiftLon);
+        //     projconf.set("ShiftLon", shiftLon);
+        // }
+
+        // // Apply a Schmidt transform
+        // if (config.has("DoSchmidt")) {
+        //     bool doSchmidt = false;
+        //     config.get("DoSchmidt", doSchmidt);
+        //     if (doSchmidt) {
+        //         double stretchFac;
+        //         double targetLon;
+        //         double targetLat;
+        //         config.get("StretchFac", stretchFac);
+        //         config.get("TargetLon", targetLon);
+        //         config.get("TargetLat", targetLat);
+        //         projconf.set("DoSchmidt", doSchmidt);
+        //         projconf.set("StretchFac", stretchFac);
+        //         projconf.set("TargetLon", targetLon);
+        //         projconf.set("TargetLat", targetLat);
+        //     }
+        // }
+
+        // return new CubedSphereGrid2::grid_t(name, N, Projection(projconf));
+    }
+
+    void force_link() {}
+
+} cubedsphere2_lfric_;
+
+void force_link_CubedSphere2() {
+    cubedsphere2_lfric_.force_link();
+}
+
 }  // namespace grid
 }  // namespace detail
 }  // namespace grid

diff --git a/src/atlas/grid/detail/grid/GridBuilder.cc b/src/atlas/grid/detail/grid/GridBuilder.cc
@@ -121,6 +121,7 @@ static void init() {
 namespace detail {
 namespace grid {
 void force_link_CubedSphere();
+void force_link_CubedSphere2();
 void force_link_Gaussian();
 void force_link_LonLat();
 void force_link_Regional();
@@ -130,6 +131,7 @@ void force_link_Regional_var_resolution();
 
 const GridBuilder::Registry& GridBuilder::nameRegistry() {
     detail::grid::force_link_CubedSphere();
+    detail::grid::force_link_CubedSphere2();
     detail::grid::force_link_Gaussian();
     detail::grid::force_link_LonLat();
     detail::grid::force_link_Regional();

diff --git a/src/tests/grid/test_cubedsphere_2.cc b/src/tests/grid/test_cubedsphere_2.cc
@@ -63,6 +63,15 @@ CASE("cubed_sphere_grid_kgo") {
     EXPECT(compare_2D_points<PointXY>(points_xy, kgo_lonlat));
 }
 
+CASE("cubed_sphere_grid_builder") {
+    const int n = 2;
+    const std::string name = "CS-LFR-" + std::to_string(n) + "-2";
+    const Grid grid = Grid(name);
+    EXPECT(grid.name() == name);
+    EXPECT(grid.type() == "cubedsphere2");
+    EXPECT(grid.size() == n * n * 6);
+}
+
 }  // namespace
 }  // namespace test
 }  // namespace atlas