make Intersection() repeatable for normal

diff --git a/src/geometry/geometry.cpp b/src/geometry/geometry.cpp
index 5db29c8c3ad8488ccb655f3d71b15bcae7c2942c..6ff26cad40b928b761a62630f9538d467c3c6348 100644 (file)
--- a/src/geometry/geometry.cpp
+++ b/src/geometry/geometry.cpp
@@ -109,14 +109,14 @@ bool Intersection(
                glm::vec3 min_all(glm::min(t1, t2));
                if (min_all.x > min_all.y) {
                        if (min_all.x > min_all.z) {
-                               normal->x = t2.x < t1.x ? 1 : -1;
+                               *normal = glm::vec3(t2.x < t1.x ? 1 : -1, 0, 0);
                        } else {
-                               normal->z = t2.z < t1.z ? 1 : -1;
+                               *normal = glm::vec3(0, 0, t2.z < t1.z ? 1 : -1);
                        }
                } else if (min_all.y > min_all.z) {
-                       normal->y = t2.y < t1.y ? 1 : -1;
+                       *normal = glm::vec3(0, t2.y < t1.y ? 1 : -1, 0);
                } else {
-                       normal->z = t2.z < t1.z ? 1 : -1;
+                       *normal = glm::vec3(0, 0, t2.z < t1.z ? 1 : -1);
                }
        }
        return true;

diff --git a/tst/geometry/IntersectionTest.cpp b/tst/geometry/IntersectionTest.cpp
index 1b618383fef1bf948d76da6b9d551056f7e3f144..04980c607c2bdba1e2b9c0df83b07f94ec5a5454 100644 (file)
--- a/tst/geometry/IntersectionTest.cpp
+++ b/tst/geometry/IntersectionTest.cpp
@@ -87,7 +87,7 @@ void IntersectionTest::testRayBoxIntersection() {
        // should be 4 units to the left now
        ray.orig.x = -5;
        CPPUNIT_ASSERT_MESSAGE(
-               "ray pointing at box doesn't intersect",
+               "ray pointing at box to the right doesn't intersect",
                Intersection(ray, box, M, &distance, &normal)
        );
        CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
@@ -102,10 +102,101 @@ void IntersectionTest::testRayBoxIntersection() {
        // 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",
+               "ray pointing away from box to the left still intersects",
                !Intersection(ray, box, M)
        );
 
+       // turn ray around
+       ray.dir.x = -1;
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing at box to the left does not intersect",
+               Intersection(ray, box, M, &distance, &normal)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "intersection distance way off",
+               4.0f, distance, delta
+       );
+       CPPUNIT_ASSERT_EQUAL_MESSAGE(
+               "wrong surface normal at intersection point",
+               glm::vec3(1, 0, 0), normal
+       );
+
+       // ray below
+       ray.orig = { 0, -5, 0 };
+       ray.dir = { 0, 1, 0 };
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing at box above does not intersect",
+               Intersection(ray, box, M, &distance, &normal)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "intersection distance way off",
+               4.0f, distance, delta
+       );
+       CPPUNIT_ASSERT_EQUAL_MESSAGE(
+               "wrong surface normal at intersection point",
+               glm::vec3(0, -1, 0), normal
+       );
+
+       // turn ray around
+       ray.dir.y = -1;
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing away from box above still intersects",
+               !Intersection(ray, box, M)
+       );
+
+       // move ray above
+       ray.orig.y = 5;
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing at box below does not intersect",
+               Intersection(ray, box, M, &distance, &normal)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "intersection distance way off",
+               4.0f, distance, delta
+       );
+       CPPUNIT_ASSERT_EQUAL_MESSAGE(
+               "wrong surface normal at intersection point",
+               glm::vec3(0, 1, 0), normal
+       );
+
+       // ray behind
+       ray.orig = { 0, 0, -5 };
+       ray.dir = { 0, 0, 1 };
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing at box in front does not intersect",
+               Intersection(ray, box, M, &distance, &normal)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "intersection distance way off",
+               4.0f, distance, delta
+       );
+       CPPUNIT_ASSERT_EQUAL_MESSAGE(
+               "wrong surface normal at intersection point",
+               glm::vec3(0, 0, -1), normal
+       );
+
+       // turn ray around
+       ray.dir.z = -1;
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing away from box in front still intersects",
+               !Intersection(ray, box, M)
+       );
+
+       // move ray in front
+       ray.orig.z = 5;
+       CPPUNIT_ASSERT_MESSAGE(
+               "ray pointing at box behind does not intersect",
+               Intersection(ray, box, M, &distance, &normal)
+       );
+       CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+               "intersection distance way off",
+               4.0f, distance, delta
+       );
+       CPPUNIT_ASSERT_EQUAL_MESSAGE(
+               "wrong surface normal at intersection point",
+               glm::vec3(0, 0, 1), normal
+       );
+
        // 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 };