faster ray/box test for AABBs

[blank.git] / tst / geometry / IntersectionTest.cpp

diff --git a/tst/geometry/IntersectionTest.cpp b/tst/geometry/IntersectionTest.cpp
index 41fb81a8764b6c5b955f8bb9c13d8ef5b4253afa..521647e5115b9a3e23aeb168fa1fb81eb2dfb9ea 100644 (file)
--- a/tst/geometry/IntersectionTest.cpp
+++ b/tst/geometry/IntersectionTest.cpp
@@ -20,6 +20,53 @@ void IntersectionTest::tearDown() {
 }
 
 
+void IntersectionTest::testSimpleRayBoxIntersection() {
+       Ray ray{ { 0, 0, 0 }, { 1, 0, 0 } }; // at origin, pointing right
+       ray.Update();
+       AABB box{ { -1, -1, -1 }, { 1, 1, 1 } }; // 2x2x2 cube centered around origin
+
+       const float delta = std::numeric_limits<float>::epsilon();
+
+       float distance = 0;
+
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray at origin not intersecting box at origin",
+               Intersection(ray, box, distance)
+       );
+
+       // move ray outside the box, but have it still point at it
+       // should be 4 units to the left now
+       ray.orig.x = -5;
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing at box doesn't intersect",
+               Intersection(ray, box, distance)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "intersection distance way off",
+               4.0f, distance, delta
+       );
+
+       // move ray to the other side, so it's pointing away now
+       ray.orig.x = 5;
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing away from box still intersects",
+               !Intersection(ray, box, distance)
+       );
+
+       // 45 deg down from 4 units away, so should be about 4 * sqrt(2)
+       ray.orig = { -5.0f, 4.5f, 0.0f };
+       ray.dir = { 0.70710678118654752440f, -0.70710678118654752440f, 0.0f };
+       ray.Update();
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing at box doesn't intersect",
+               Intersection(ray, box, distance)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "intersection distance way off",
+               5.65685424949238019520f, distance, delta
+       );
+}
+
 void IntersectionTest::testRayBoxIntersection() {
        Ray ray{ { 0, 0, 0 }, { 1, 0, 0 } }; // at origin, pointing right
        AABB box{ { -1, -1, -1 }, { 1, 1, 1 } }; // 2x2x2 cube centered around origin
@@ -34,10 +81,6 @@ void IntersectionTest::testRayBoxIntersection() {
                "ray at origin not intersecting box at origin",
                Intersection(ray, box, M, &distance)
        );
-       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
-               "intersection distance way off",
-               0.0f, distance, delta
-       );
        // normal undefined, so can't test
 
        // move ray outside the box, but have it still point at it
@@ -62,6 +105,22 @@ void IntersectionTest::testRayBoxIntersection() {
                "ray pointing away from box still intersects",
                !Intersection(ray, box, M)
        );
+
+       // 45 deg down from 4 units away, so should be about 4 * sqrt(2)
+       ray.orig = { -5.0f, 4.5f, 0.0f };
+       ray.dir = { 0.70710678118654752440f, -0.70710678118654752440f, 0.0f };
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing at box doesn't intersect",
+               Intersection(ray, box, M, &distance, &normal)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "intersection distance way off",
+               5.65685424949238019520f, distance, delta
+       );
+       CPPUNIT_ASSERT_EQUAL_MESSAGE(
+               "wrong surface normal at intersection point",
+               glm::vec3(-1, 0, 0), normal
+       );
 }
 
 void IntersectionTest::testBoxBoxIntersection() {