CircularArcIntersector: Add tests with nearly-degenerate arcs

libgeos · Oct 3, 2024 · 9910456 · 9910456
1 parent 828fc46
commit 9910456
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diff --git a/include/geos/geom/CircularArc.h b/include/geos/geom/CircularArc.h
@@ -83,7 +83,7 @@ class GEOS_DLL CircularArc {
 
     /// Returns whether this arc forms a straight line (p0, p1, and p2 are collinear)
     bool isLinear() const {
-        return std::isnan(getRadius());
+        return !std::isfinite(getRadius());
     }
 
     /// Return the inner angle of the sector associated with this arc

diff --git a/tests/unit/algorithm/CircularArcIntersectorTest.cpp b/tests/unit/algorithm/CircularArcIntersectorTest.cpp
@@ -464,4 +464,43 @@ void object::test<35>()
                       {0, 0});
 }
 
+template<>
+template<>
+void object::test<36>()
+{
+    set_test_name("intersection between a segment and a degenerate arc (radius = Infinity)");
+
+    checkIntersection({-5, -5}, {0, 0}, {5, 5 + 1e-14},
+                      {-5, 5}, {5, -5},
+                      CircularArcIntersector::ONE_POINT_INTERSECTION,
+                      CoordinateXY{0, 0});
+}
+
+template<>
+template<>
+void object::test<37>()
+{
+    set_test_name("intersection between a segment and a nearly-degenerate arc (radius ~= 1e5)");
+
+    checkIntersection({-5, -5}, {0, 0}, {5, 5 + 1e-4},
+                      {-5, 5}, {5, -5},
+                      CircularArcIntersector::ONE_POINT_INTERSECTION,
+                      CoordinateXY{0, 0});
+}
+
+#if 0
+// failed assertion: Values are not equal: expected `POINT (0 0)` actual `POINT (-5.4568517953157425e-06 5.4568517953157425e-06)`
+template<>
+template<>
+void object::test<38>()
+{
+    set_test_name("intersection between a segment and a nearly-degenerate arc (radius ~= 2e6)");
+
+    checkIntersection({-5, -5}, {0, 0}, {5, 5 + 1e-9},
+                      {-5, 5}, {5, -5},
+                      CircularArcIntersector::ONE_POINT_INTERSECTION,
+                      CoordinateXY{0, 0});
+}
+#endif
+
 }