Add Region.getRegions()

lsst · Oct 15, 2024 · 4af5d3f · 4af5d3f
1 parent d98c780
commit 4af5d3f
Show file tree

Hide file tree

Showing 4 changed files with 28 additions and 24 deletions.
diff --git a/include/lsst/sphgeom/Region.h b/include/lsst/sphgeom/Region.h
@@ -149,8 +149,8 @@ class Region {
     static std::unique_ptr<Region> decode(std::uint8_t const * buffer, size_t n);
     ///@}
 
-    /// `flatten` flattens a nested Region to a list of regions.
-    static void flatten(Region const &region, std::vector<std::unique_ptr<Region>> &result);
+    /// `getRegions` returns a vector of Region.
+    static std::vector<std::unique_ptr<Region>> getRegions(Region const &region);
     ///@}
 };
 

diff --git a/python/lsst/sphgeom/_region.cc b/python/lsst/sphgeom/_region.cc
@@ -70,11 +70,7 @@ void defineClass(py::class_<Region, std::unique_ptr<Region>> &cls) {
             "region"_a);
     cls.def("encode", &python::encode);
     cls.def_static("decode", &python::decode<Region>, "bytes"_a);
-    cls.def_static("flatten", [](Region const &region) {
-        std::vector<std::unique_ptr<Region>> result;
-        Region::flatten(region, result);
-        return result;
-    }, "region"_a);
+    cls.def_static("getRegions", Region::getRegions, "region"_a);
 }
 
 }  // sphgeom

diff --git a/src/Region.cc b/src/Region.cc
@@ -72,20 +72,22 @@ std::unique_ptr<Region> Region::decode(std::uint8_t const * buffer, size_t n) {
     }
     throw std::runtime_error("Byte-string is not an encoded Region");
 }
-    void Region::flatten(Region const &region, std::vector<std::unique_ptr<Region>> &result) {
-        if (auto union_region = dynamic_cast<UnionRegion const *>(&region)) {
-            for(int i = 0; i < 2; ++i) {
-                union_region->getOperand(i);
-                flatten(union_region->getOperand(i), result);
-            }
-        } else if(auto intersection_region = dynamic_cast<IntersectionRegion const *>(&region)) {
-            for(int i = 0; i < 2; ++i) {
-                intersection_region->getOperand(i);
-                flatten(intersection_region->getOperand(i), result);
-            }
-        } else {
-            result.emplace_back(region.clone());
+
+std::vector<std::unique_ptr<Region>> Region::getRegions(Region const &region) {
+    std::vector<std::unique_ptr<Region>> result;
+    if (auto union_region = dynamic_cast<UnionRegion const *>(&region)) {
+        for(int i = 0; i < 2; ++i) {
+            result.emplace_back(union_region->getOperand(i).clone());
+        }
+    } else if(auto intersection_region = dynamic_cast<IntersectionRegion const *>(&region)) {
+        for(int i = 0; i < 2; ++i) {
+            intersection_region->getOperand(i);
+            result.emplace_back(intersection_region->getOperand(i).clone());
         }
+    } else {
+        result.emplace_back(region.clone());
     }
+    return result;
+}
 
 }} // namespace lsst:sphgeom
diff --git a/tests/test_CompoundRegion.py b/tests/test_CompoundRegion.py
@@ -201,16 +201,22 @@ def testRelate(self):
         self.assertEqual(self.box.relate(self.instance), CONTAINS)
         self.assertEqual(self.faraway.relate(self.instance), DISJOINT)
 
-    def testFlatten(self):
+    def testGetRegion(self):
         c1 = Circle(UnitVector3d(0.0, 0.0, 1.0), 1.0)
         c2 = Circle(UnitVector3d(1.0, 0.0, 1.0), 2.0)
         b1 = Box.fromDegrees(90, 0, 180, 45)
         b2 = Box.fromDegrees(135, 15, 135, 30)
         u1 = UnionRegion(c1, b1)
         u2 = UnionRegion(c2, b2)
-        c = UnionRegion(u1, u2)
-        d = Region.flatten(c)
-        self.assertEqual(d, [c1, b1, c2, b2])
+        i1 = IntersectionRegion(c1, b1)
+        i2 = IntersectionRegion(c2, b2)
+        ur = UnionRegion(u1, u2)
+        ir = IntersectionRegion(i1, i2)
+        self.assertEqual(Region.getRegions(c1), [c1])
+        self.assertEqual(Region.getRegions(Region.getRegions(ir)[0]), [c1, b1])
+        self.assertEqual(Region.getRegions(Region.getRegions(ir)[1]), [c2, b2])
+        self.assertEqual(Region.getRegions(Region.getRegions(ur)[0]), [c1, b1])
+        self.assertEqual(Region.getRegions(Region.getRegions(ur)[1]), [c2, b2])
 
 
 if __name__ == "__main__":