test ray/sphere intersect

[blobs.git] / tst / math / IntersectTest.cpp

diff --git a/tst/math/IntersectTest.cpp b/tst/math/IntersectTest.cpp
index 2ed07fb2fe7e5e1792817da61d1aa8318f597392..cd5084574d8d3928fae03a50dd04f45314c47a04 100644 (file)
--- a/tst/math/IntersectTest.cpp
+++ b/tst/math/IntersectTest.cpp
@@ -223,6 +223,72 @@ void IntersectTest::testBoxBoxIntersection() {
        );
 }
 
+void IntersectTest::testRaySphereIntersection() {
+       const double epsilon = std::numeric_limits<double>::epsilon();
+       Ray ray{ { 0.0, 0.0, 0.0 }, { 1.0, 0.0, 0.0 } }; // at origin, pointing right
+       Sphere sphere{ { 0.0, 0.0, 0.0 }, 1.0 }; // unit sphere at origin
+
+       glm::dvec3 normal(0.0);
+       double dist = 0.0;
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray at origin does not intersect sphere at origin",
+               Intersect(ray, sphere, normal, dist)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "distance along ray to unit sphere, both at origin, is not 1",
+               1.0, dist, epsilon
+       );
+       AssertEqual(
+               "bad intersection normal",
+               glm::dvec3(1.0, 0.0, 0.0), normal
+       );
+
+       ray.Origin({ 2.0, 0.0, 0.0 }); // move outside
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing away from sphere intersects it for some reason",
+               !Intersect(ray, sphere, normal, dist)
+       );
+
+       ray.Direction({ -1.0, 0.0, 0.0 }); // flip it around
+       CPPUNIT_ASSERT_MESSAGE(
+               "negative X ray does not intersect sphere",
+               Intersect(ray, sphere, normal, dist)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "distance along ray to unit sphere at origin is not 1",
+               1.0, dist, epsilon
+       );
+       AssertEqual(
+               "bad intersection normal",
+               glm::dvec3(1.0, 0.0, 0.0), normal
+       );
+
+       // sphere at 3,0,0; ray at 0,4,0 pointing directly at it
+       // should be 5 units apart, minus one for the radius
+       ray.Origin({ 0.0, 4.0, 0.0 });
+       ray.Direction(glm::normalize(glm::dvec3(3.0, -4.0, 0.0)));
+       sphere.origin = { 3.0, 0.0, 0.0 };
+       CPPUNIT_ASSERT_MESSAGE(
+               "diagonal ray does not intersect sphere",
+               Intersect(ray, sphere, normal, dist)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "distance along ray to unit sphere is not 4",
+               4.0, dist, epsilon
+       );
+       AssertEqual(
+               "bad intersection normal",
+               glm::normalize(glm::dvec3(-3.0, 4.0, 0.0)), normal
+       );
+
+       // point the ray straight down, so it misses
+       ray.Direction({ 0.0, -1.0, 0.0});
+       CPPUNIT_ASSERT_MESSAGE(
+               "vertical ray should not intersect sphere",
+               !Intersect(ray, sphere, normal, dist)
+       );
+}
+
 }
 }
 }