From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Sun, 12 Nov 2017 22:04:00 +0000 (+0100)
Subject: basic orbit tests
X-Git-Url: https://git.localhorst.tv/?a=commitdiff_plain;h=6b6827e81cd13b35249ca44fca31fe2773db6209;p=blobs.git

basic orbit tests
---

diff --git a/tst/world/OrbitTest.cpp b/tst/world/OrbitTest.cpp
index e4c96a0..ea13860 100644
--- a/tst/world/OrbitTest.cpp
+++ b/tst/world/OrbitTest.cpp
@@ -21,13 +21,32 @@ void OrbitTest::tearDown() {
 }
 
 
-void OrbitTest::testSMA() {
+void OrbitTest::testDefaultOrbit() {
 	Orbit orbit;
-	orbit.SemiMajorAxis(1.0);
 	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
-		"wrong semi-major axis on orbit",
+		"wrong semi-major axis on default orbit",
 		1.0, orbit.SemiMajorAxis(), std::numeric_limits<double>::epsilon()
 	);
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong eccentricity on default orbit",
+		0.0, orbit.Eccentricity(), std::numeric_limits<double>::epsilon()
+	);
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong inclination on default orbit",
+		0.0, orbit.Inclination(), std::numeric_limits<double>::epsilon()
+	);
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong longitude of ascending node on default orbit",
+		0.0, orbit.LongitudeAscending(), std::numeric_limits<double>::epsilon()
+	);
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong argument of periapsis on default orbit",
+		0.0, orbit.ArgumentPeriapsis(), std::numeric_limits<double>::epsilon()
+	);
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong mean anomaly on default orbit",
+		0.0, orbit.MeanAnomaly(), std::numeric_limits<double>::epsilon()
+	);
 
 	// reference direction is +X, so at t=0, the body should be
 	// at (sma,0,0) relative to its parent
@@ -72,6 +91,294 @@ void OrbitTest::testSMA() {
 	);
 }
 
+void OrbitTest::testSMA() {
+	Orbit orbit;
+	orbit.SemiMajorAxis(2.0);
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong semi-major axis on orbit",
+		2.0, orbit.SemiMajorAxis(), std::numeric_limits<double>::epsilon()
+	);
+
+	// reference direction is +X, so at t=0, the body should be
+	// at (sma,0,0) relative to its parent
+	glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
+	AssertEqual(
+		"wrong position at t=0",
+		glm::vec3(2.0f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	// at 90° position should be (0,0,sma) since the zero inclination
+	// reference plane is XZ and rotates counter-clockwise
+	pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=90°",
+		glm::vec3(0.0f, 0.0f, -2.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	// at 180° position should be (-sma,0,0)
+	pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=180°",
+		glm::vec3(-2.0f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	// at 270° position should be (0,0,-sma)
+	pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=270°",
+		glm::vec3(0.0f, 0.0f, 2.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	// at 360° position should be (sma,0,0), the initial position
+	pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=360°",
+		glm::vec3(2.0f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+}
+
+void OrbitTest::testEcc() {
+	Orbit orbit;
+	orbit.Eccentricity(0.5);
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong eccentricity on orbit",
+		0.5, orbit.Eccentricity(), std::numeric_limits<double>::epsilon()
+	);
+
+	glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
+	AssertEqual(
+		"wrong position at t=0",
+		glm::vec3(0.5f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=90°",
+		glm::vec3(-0.935130834579468f, 0.0f, -0.779740869998932f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=180°",
+		glm::vec3(-1.5f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=270°",
+		glm::vec3(-0.935130834579468f, 0.0f, 0.779740869998932f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=360°",
+		glm::vec3(0.5f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+}
+
+void OrbitTest::testInc() {
+	Orbit orbit;
+	orbit.Inclination(PI * 0.25); // 45°
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong inclination on orbit",
+		PI * 0.25, orbit.Inclination(), std::numeric_limits<double>::epsilon()
+	);
+
+	// inclination rotates counter clockwise around +X, so at t=0 should be
+	// at (sma,0,0) relative to its parent
+	glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
+	AssertEqual(
+		"wrong position at t=0",
+		glm::vec3(1.0f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=90°",
+		glm::vec3(0.0f, 0.70710676908493f, -0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=180°",
+		glm::vec3(-1.0f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=270°",
+		glm::vec3(0.0f, -0.70710676908493f, 0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=360°",
+		glm::vec3(1.0f, 0.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+}
+
+void OrbitTest::testLngAsc() {
+	Orbit orbit;
+	orbit.LongitudeAscending(PI * 0.25); // 45°
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong longitude of ascending node on orbit",
+		PI * 0.25, orbit.LongitudeAscending(), std::numeric_limits<double>::epsilon()
+	);
+	// using an inclination of 90° as well to make the rotation more apparent
+	orbit.Inclination(PI * 0.5);
+
+	// inclination rotates counter clockwise around +X, while LAN rotates it
+	// around +Y, so at t=0 should be at (sma*sin(45°),0,-sma*cos(45°))
+	glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
+	AssertEqual(
+		"wrong position at t=0",
+		glm::vec3(0.70710676908493f, 0.0f, -0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=90°",
+		glm::vec3(0.0f, 1.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=180°",
+		glm::vec3(-0.70710676908493f, 0.0f, 0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=270°",
+		glm::vec3(0.0f, -1.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=360°",
+		glm::vec3(0.70710676908493f, 0.0f, -0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+}
+
+void OrbitTest::testArgPe() {
+	Orbit orbit;
+	orbit.ArgumentPeriapsis(PI * 0.25); // 45°
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong argument of periapsis node on orbit",
+		PI * 0.25, orbit.ArgumentPeriapsis(), std::numeric_limits<double>::epsilon()
+	);
+	// using an inclination of 90° as well to make the rotation more apparent
+	orbit.Inclination(PI * 0.5);
+
+	// inclination rotates counter clockwise around +X, while APe rotates it
+	// around +Y in the rotated coordinate system, so at t=0 should be at
+	// (sma*sin(45°),0,sma*cos(45°))
+	glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
+	AssertEqual(
+		"wrong position at t=0",
+		glm::vec3(0.70710676908493f, 0.0f, 0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=90°",
+		glm::vec3(0.0f, 1.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=180°",
+		glm::vec3(-0.70710676908493f, 0.0f, -0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=270°",
+		glm::vec3(0.0f, -1.0f, 0.0f),
+		glm::vec3(pos) / pos.w
+	);
+
+	pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=360°",
+		glm::vec3(0.70710676908493f, 0.0f, 0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+}
+
+void OrbitTest::testMnAn() {
+	Orbit orbit;
+	orbit.MeanAnomaly(PI * 0.25); // 45°
+	CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
+		"wrong mean anomaly on default orbit",
+		PI * 0.25, orbit.MeanAnomaly(), std::numeric_limits<double>::epsilon()
+	);
+
+	// mean anomaly just phase shifts the orbit
+	glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
+	AssertEqual(
+		"wrong position at t=0",
+		glm::vec3(0.70710676908493f, 0.0f, -0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	// at 90° position should be (0,0,sma) since the zero inclination
+	// reference plane is XZ and rotates counter-clockwise
+	pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=90°",
+		glm::vec3(-0.70710676908493f, 0.0f, -0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	// at 180° position should be (-sma,0,0)
+	pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=180°",
+		glm::vec3(-0.70710676908493f, 0.0f, 0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	// at 270° position should be (0,0,-sma)
+	pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=270°",
+		glm::vec3(0.70710676908493f, 0.0f, 0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+
+	// at 360° position should be (sma,0,0), the initial position
+	pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+	AssertEqual(
+		"wrong position at t=360°",
+		glm::vec3(0.70710676908493f, 0.0f, -0.70710676908493f),
+		glm::vec3(pos) / pos.w
+	);
+}
+
 }
 }
 }
diff --git a/tst/world/OrbitTest.hpp b/tst/world/OrbitTest.hpp
index 2710a44..3f38cce 100644
--- a/tst/world/OrbitTest.hpp
+++ b/tst/world/OrbitTest.hpp
@@ -13,7 +13,14 @@ class OrbitTest
 
 CPPUNIT_TEST_SUITE(OrbitTest);
 
+CPPUNIT_TEST(testDefaultOrbit);
+
 CPPUNIT_TEST(testSMA);
+CPPUNIT_TEST(testEcc);
+CPPUNIT_TEST(testInc);
+CPPUNIT_TEST(testLngAsc);
+CPPUNIT_TEST(testArgPe);
+CPPUNIT_TEST(testMnAn);
 
 CPPUNIT_TEST_SUITE_END();
 
@@ -21,7 +28,14 @@ public:
 	void setUp();
 	void tearDown();
 
+	void testDefaultOrbit();
+
 	void testSMA();
+	void testEcc();
+	void testInc();
+	void testLngAsc();
+	void testArgPe();
+	void testMnAn();
 
 };