corner case, currently check is disabled

typed-geometry @ c9770990

-Subproject commit b86bc12eafc2c06b37b015b3e92871dfceb9f7b4
+Subproject commit c9770990d6869740cc2f79a88727d838e382a36f

tests/feature/intersections/plane-intersect.cc

@@ -54,7 +54,7 @@ TG_FUZZ_TEST(Plane, Intersect)
         auto const box = tg::aabb3(tg::pos3(-10.0f), tg::pos3(10.0f));
 
         {
-            // plane and cylinder have *parallel* normals
+            // cornercase: plane and cylinder have *parallel* normals
             // confirm center position and circle shape of intersection
 
             auto const r = tg::uniform(rng, 0.1f, 10.0f);
@@ -84,6 +84,20 @@ TG_FUZZ_TEST(Plane, Intersect)
                 CHECK(dot(ellipse.axisA, p.normal) == approx(0)); // orthogonal
                 CHECK(length(ellipse.axisA) - length(ellipse.axisB) == approx(0));
             }
+
+            // TODO fix this case in intersection.hh!!
+            // cornercase: plane normal orthogonal to cylinder normal
+            {
+                auto const p = tg::plane3(any_normal(d), center);
+                // the cut should be a circle with radius r with center zero
+                auto const ellipse = tg::intersection(p, c);
+                // check center, directions of normal and length
+                // CHECK(distance(ellipse.center, center) == approx(0));
+
+                (void)ellipse;
+                // TODO -nanf!!
+                // CHECK(length(ellipse.axisA) - length(ellipse.axisB) == approx(0));
+            }
         }
 
         {