float &depth,
glm::vec3 &normal) noexcept;
-
+/// Plane defined by a surface norml and distance to the origin such that
+/// the point (normal * dist) lies on the plane.
struct Plane {
glm::vec3 normal;
float dist;
std::ostream &operator <<(std::ostream &, const Plane &);
+/// Shortest distance from point to plane.
+float Distance(const glm::vec3 &point, const Plane &plane);
+/// Shortest distance from point to plane with sign indicating whether
+/// it's in front of (positive, in direction of normal) or behind
+/// (negative, counter direction of normal) the surface.
+float SignedDistance(const glm::vec3 &point, const Plane &plane);
+
struct Frustum {
Plane plane[6];
Plane &Left() noexcept { return plane[0]; }
bool CullTest(const AABB &box, const glm::mat4 &) noexcept;
bool CullTest(const AABB &box, const Frustum &) noexcept;
+struct Sphere {
+ glm::vec3 origin;
+ float radius;
+};
+
+std::ostream &operator <<(std::ostream &, const Sphere &);
+
+/// Test for intersection of sphere with double sided infinite plane.
+/// If true, dist will hold the smaller interpenetration depth and norm
+/// the respective contact normal.
+bool Intersection(
+ const Sphere &sphere,
+ const Plane &plane,
+ float &dist,
+ glm::vec3 &norm) noexcept;
+
+/// Test for intersection of sphere with half space defined by the
+/// backface of given plane.
+/// In all cases, dist will hold the distance between the near points
+/// of plane and sphere. Contact normal will always be the plane's normal.
+bool Intersection(
+ const Sphere &sphere,
+ const Plane &plane,
+ float &dist) noexcept;
+
}
}
}
-void IntersectionTest::testSimpleRayBoxIntersection() {
+void IntersectionTest::testSimpleRayBox() {
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
);
}
-void IntersectionTest::testRayBoxIntersection() {
+void IntersectionTest::testRayBox() {
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
glm::mat4 M(1); // no transformation
);
}
-void IntersectionTest::testBoxBoxIntersection() {
+void IntersectionTest::testBoxBox() {
const float delta = std::numeric_limits<float>::epsilon();
float depth = 0;
glm::vec3 normal(0);
);
}
+void IntersectionTest::testSpherePlane() {
+ const float delta = std::numeric_limits<float>::epsilon();
+
+ // unit sphere at origin
+ Sphere sphere{{ 0.0f, 0.0f, 0.0f }, 1.0f};
+ // horizontal plane at origin (the XZ plane)
+ Plane plane{{ 0.0f, 1.0f, 0.0f }, 0.0f };
+ float depth;
+ glm::vec3 normal;
+
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere at origin does not intersect plane at origin",
+ Intersection(sphere, plane, depth, normal)
+ );
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ "bad penetration depth of sphere with plane",
+ 1.0f, depth, delta
+ );
+ // normal is actually undefined in this case, but either will work
+ CPPUNIT_ASSERT_MESSAGE(
+ "bad contact normal of sphere intersecting plane",
+ normal == glm::vec3(0.0f, 1.0f, 0.0f) || normal == glm::vec3(0.0f, -1.0f, 0.0f)
+ );
+
+ // center above, but still intersecting
+ sphere.origin.y = 0.5f;
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere does not intersect plane",
+ Intersection(sphere, plane, depth, normal)
+ );
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ "bad penetration depth of sphere with plane",
+ 0.5f, depth, delta
+ );
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "bad contact normal of sphere intersecting plane",
+ glm::vec3(0.0f, 1.0f, 0.0f), normal
+ );
+
+ // center below, but still intersecting
+ sphere.origin.y = -0.5f;
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere does not intersect plane",
+ Intersection(sphere, plane, depth, normal)
+ );
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ "bad penetration depth of sphere with plane",
+ 0.5f, depth, delta
+ );
+ CPPUNIT_ASSERT_EQUAL_MESSAGE(
+ "bad contact normal of sphere intersecting plane",
+ glm::vec3(0.0f, -1.0f, 0.0f), normal
+ );
+
+ // sphere completely above
+ sphere.origin.y = 1.5f;
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere above plane intersects",
+ !Intersection(sphere, plane, depth, normal)
+ );
+
+ // sphere completely below
+ sphere.origin.y = -1.5f;
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere below plane intersects",
+ !Intersection(sphere, plane, depth, normal)
+ );
+}
+
+void IntersectionTest::testSphereHalfSpace() {
+ const float delta = std::numeric_limits<float>::epsilon();
+
+ // unit sphere at origin
+ Sphere sphere{{ 0.0f, 0.0f, 0.0f }, 1.0f};
+ // horizontal plane at origin (the XZ plane)
+ Plane plane{{ 0.0f, 1.0f, 0.0f }, 0.0f };
+ float depth;
+
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere at origin does not intersect half space to origin",
+ Intersection(sphere, plane, depth)
+ );
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ "bad penetration depth of sphere with half space",
+ 1.0f, depth, delta
+ );
+
+ sphere.origin.y = 0.5f;
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere does not intersect half space",
+ Intersection(sphere, plane, depth)
+ );
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ "bad penetration depth of sphere with half space",
+ 0.5f, depth, delta
+ );
+
+ sphere.origin.y = -0.5f;
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere does not intersect half space",
+ Intersection(sphere, plane, depth)
+ );
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ "bad penetration depth of sphere with half space",
+ 1.5f, depth, delta
+ );
+
+ sphere.origin.y = -1.5f;
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere inside half space does not intersect",
+ Intersection(sphere, plane, depth)
+ );
+ CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+ "bad penetration depth of sphere with half space",
+ 2.5f, depth, delta
+ );
+
+ sphere.origin.y = 1.5f;
+ CPPUNIT_ASSERT_MESSAGE(
+ "sphere outside half space intersects",
+ !Intersection(sphere, plane, depth)
+ );
+}
+
}
}
}
projects / gong.git / commitdiff