tst/world/OrbitTest.cpp

   1 #include "OrbitTest.hpp"
   2
   3 #include "../assert.hpp"
   4
   5 #include "math/const.hpp"
   6 #include "world/Orbit.hpp"
   7
   8 CPPUNIT_TEST_SUITE_REGISTRATION(blobs::world::test::OrbitTest);
   9
  10 using blobs::test::AssertEqual;
  11
  12
  13 namespace blobs {
  14 namespace world {
  15 namespace test {
  16
  17 void OrbitTest::setUp() {
  18 }
  19
  20 void OrbitTest::tearDown() {
  21 }
  22
  23
  24 void OrbitTest::testDefault() {
  25         Orbit orbit;
  26         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
  27                 "wrong semi-major axis on default orbit",
  28                 1.0, orbit.SemiMajorAxis(), std::numeric_limits<double>::epsilon()
  29         );
  30         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
  31                 "wrong eccentricity on default orbit",
  32                 0.0, orbit.Eccentricity(), std::numeric_limits<double>::epsilon()
  33         );
  34         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
  35                 "wrong inclination on default orbit",
  36                 0.0, orbit.Inclination(), std::numeric_limits<double>::epsilon()
  37         );
  38         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
  39                 "wrong longitude of ascending node on default orbit",
  40                 0.0, orbit.LongitudeAscending(), std::numeric_limits<double>::epsilon()
  41         );
  42         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
  43                 "wrong argument of periapsis on default orbit",
  44                 0.0, orbit.ArgumentPeriapsis(), std::numeric_limits<double>::epsilon()
  45         );
  46         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
  47                 "wrong mean anomaly on default orbit",
  48                 0.0, orbit.MeanAnomaly(), std::numeric_limits<double>::epsilon()
  49         );
  50
  51         // reference direction is +X, so at t=0, the body should be
  52         // at (sma,0,0) relative to its parent
  53         glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
  54         AssertEqual(
  55                 "wrong position at t=0",
  56                 glm::vec3(1.0f, 0.0f, 0.0f),
  57                 glm::vec3(pos) / pos.w
  58         );
  59
  60         // at 90° position should be (0,0,sma) since the zero inclination
  61         // reference plane is XZ and rotates counter-clockwise
  62         pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
  63         AssertEqual(
  64                 "wrong position at t=90°",
  65                 glm::vec3(0.0f, 0.0f, -1.0f),
  66                 glm::vec3(pos) / pos.w
  67         );
  68
  69         // at 180° position should be (-sma,0,0)
  70         pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
  71         AssertEqual(
  72                 "wrong position at t=180°",
  73                 glm::vec3(-1.0f, 0.0f, 0.0f),
  74                 glm::vec3(pos) / pos.w
  75         );
  76
  77         // at 270° position should be (0,0,-sma)
  78         pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
  79         AssertEqual(
  80                 "wrong position at t=270°",
  81                 glm::vec3(0.0f, 0.0f, 1.0f),
  82                 glm::vec3(pos) / pos.w
  83         );
  84
  85         // at 360° position should be (sma,0,0), the initial position
  86         pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
  87         AssertEqual(
  88                 "wrong position at t=360°",
  89                 glm::vec3(1.0f, 0.0f, 0.0f),
  90                 glm::vec3(pos) / pos.w
  91         );
  92 }
  93
  94 void OrbitTest::testSMA() {
  95         Orbit orbit;
  96         orbit.SemiMajorAxis(2.0);
  97         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
  98                 "wrong semi-major axis on orbit",
  99                 2.0, orbit.SemiMajorAxis(), std::numeric_limits<double>::epsilon()
 100         );
 101
 102         // reference direction is +X, so at t=0, the body should be
 103         // at (sma,0,0) relative to its parent
 104         glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
 105         AssertEqual(
 106                 "wrong position at t=0",
 107                 glm::vec3(2.0f, 0.0f, 0.0f),
 108                 glm::vec3(pos) / pos.w
 109         );
 110
 111         // at 90° position should be (0,0,sma) since the zero inclination
 112         // reference plane is XZ and rotates counter-clockwise
 113         pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 114         AssertEqual(
 115                 "wrong position at t=90°",
 116                 glm::vec3(0.0f, 0.0f, -2.0f),
 117                 glm::vec3(pos) / pos.w
 118         );
 119
 120         // at 180° position should be (-sma,0,0)
 121         pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 122         AssertEqual(
 123                 "wrong position at t=180°",
 124                 glm::vec3(-2.0f, 0.0f, 0.0f),
 125                 glm::vec3(pos) / pos.w
 126         );
 127
 128         // at 270° position should be (0,0,-sma)
 129         pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 130         AssertEqual(
 131                 "wrong position at t=270°",
 132                 glm::vec3(0.0f, 0.0f, 2.0f),
 133                 glm::vec3(pos) / pos.w
 134         );
 135
 136         // at 360° position should be (sma,0,0), the initial position
 137         pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 138         AssertEqual(
 139                 "wrong position at t=360°",
 140                 glm::vec3(2.0f, 0.0f, 0.0f),
 141                 glm::vec3(pos) / pos.w
 142         );
 143 }
 144
 145 void OrbitTest::testEcc() {
 146         Orbit orbit;
 147         orbit.Eccentricity(0.5);
 148         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
 149                 "wrong eccentricity on orbit",
 150                 0.5, orbit.Eccentricity(), std::numeric_limits<double>::epsilon()
 151         );
 152
 153         glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
 154         AssertEqual(
 155                 "wrong position at t=0",
 156                 glm::vec3(0.5f, 0.0f, 0.0f),
 157                 glm::vec3(pos) / pos.w
 158         );
 159
 160         pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 161         AssertEqual(
 162                 "wrong position at t=90°",
 163                 glm::vec3(-0.935130834579468f, 0.0f, -0.779740869998932f),
 164                 glm::vec3(pos) / pos.w
 165         );
 166
 167         pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 168         AssertEqual(
 169                 "wrong position at t=180°",
 170                 glm::vec3(-1.5f, 0.0f, 0.0f),
 171                 glm::vec3(pos) / pos.w
 172         );
 173
 174         pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 175         AssertEqual(
 176                 "wrong position at t=270°",
 177                 glm::vec3(-0.935130834579468f, 0.0f, 0.779740869998932f),
 178                 glm::vec3(pos) / pos.w
 179         );
 180
 181         pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 182         AssertEqual(
 183                 "wrong position at t=360°",
 184                 glm::vec3(0.5f, 0.0f, 0.0f),
 185                 glm::vec3(pos) / pos.w
 186         );
 187 }
 188
 189 void OrbitTest::testInc() {
 190         Orbit orbit;
 191         orbit.Inclination(PI * 0.25); // 45°
 192         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
 193                 "wrong inclination on orbit",
 194                 PI * 0.25, orbit.Inclination(), std::numeric_limits<double>::epsilon()
 195         );
 196
 197         // inclination rotates counter clockwise around +X, so at t=0 should be
 198         // at (sma,0,0) relative to its parent
 199         glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
 200         AssertEqual(
 201                 "wrong position at t=0",
 202                 glm::vec3(1.0f, 0.0f, 0.0f),
 203                 glm::vec3(pos) / pos.w
 204         );
 205
 206         pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 207         AssertEqual(
 208                 "wrong position at t=90°",
 209                 glm::vec3(0.0f, 0.70710676908493f, -0.70710676908493f),
 210                 glm::vec3(pos) / pos.w
 211         );
 212
 213         pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 214         AssertEqual(
 215                 "wrong position at t=180°",
 216                 glm::vec3(-1.0f, 0.0f, 0.0f),
 217                 glm::vec3(pos) / pos.w
 218         );
 219
 220         pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 221         AssertEqual(
 222                 "wrong position at t=270°",
 223                 glm::vec3(0.0f, -0.70710676908493f, 0.70710676908493f),
 224                 glm::vec3(pos) / pos.w
 225         );
 226
 227         pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 228         AssertEqual(
 229                 "wrong position at t=360°",
 230                 glm::vec3(1.0f, 0.0f, 0.0f),
 231                 glm::vec3(pos) / pos.w
 232         );
 233 }
 234
 235 void OrbitTest::testLngAsc() {
 236         Orbit orbit;
 237         orbit.LongitudeAscending(PI * 0.25); // 45°
 238         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
 239                 "wrong longitude of ascending node on orbit",
 240                 PI * 0.25, orbit.LongitudeAscending(), std::numeric_limits<double>::epsilon()
 241         );
 242         // using an inclination of 90° as well to make the rotation more apparent
 243         orbit.Inclination(PI * 0.5);
 244
 245         // inclination rotates counter clockwise around +X, while LAN rotates it
 246         // around +Y, so at t=0 should be at (sma*sin(45°),0,-sma*cos(45°))
 247         glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
 248         AssertEqual(
 249                 "wrong position at t=0",
 250                 glm::vec3(0.70710676908493f, 0.0f, -0.70710676908493f),
 251                 glm::vec3(pos) / pos.w
 252         );
 253
 254         pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 255         AssertEqual(
 256                 "wrong position at t=90°",
 257                 glm::vec3(0.0f, 1.0f, 0.0f),
 258                 glm::vec3(pos) / pos.w
 259         );
 260
 261         pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 262         AssertEqual(
 263                 "wrong position at t=180°",
 264                 glm::vec3(-0.70710676908493f, 0.0f, 0.70710676908493f),
 265                 glm::vec3(pos) / pos.w
 266         );
 267
 268         pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 269         AssertEqual(
 270                 "wrong position at t=270°",
 271                 glm::vec3(0.0f, -1.0f, 0.0f),
 272                 glm::vec3(pos) / pos.w
 273         );
 274
 275         pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 276         AssertEqual(
 277                 "wrong position at t=360°",
 278                 glm::vec3(0.70710676908493f, 0.0f, -0.70710676908493f),
 279                 glm::vec3(pos) / pos.w
 280         );
 281 }
 282
 283 void OrbitTest::testArgPe() {
 284         Orbit orbit;
 285         orbit.ArgumentPeriapsis(PI * 0.25); // 45°
 286         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
 287                 "wrong argument of periapsis node on orbit",
 288                 PI * 0.25, orbit.ArgumentPeriapsis(), std::numeric_limits<double>::epsilon()
 289         );
 290         // using an inclination of 90° as well to make the rotation more apparent
 291         orbit.Inclination(PI * 0.5);
 292
 293         // inclination rotates counter clockwise around +X, while APe rotates it
 294         // around +Y in the rotated coordinate system, so at t=0 should be at
 295         // (sma*sin(45°),0,sma*cos(45°))
 296         glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
 297         AssertEqual(
 298                 "wrong position at t=0",
 299                 glm::vec3(0.70710676908493f, 0.0f, 0.70710676908493f),
 300                 glm::vec3(pos) / pos.w
 301         );
 302
 303         pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 304         AssertEqual(
 305                 "wrong position at t=90°",
 306                 glm::vec3(0.0f, 1.0f, 0.0f),
 307                 glm::vec3(pos) / pos.w
 308         );
 309
 310         pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 311         AssertEqual(
 312                 "wrong position at t=180°",
 313                 glm::vec3(-0.70710676908493f, 0.0f, -0.70710676908493f),
 314                 glm::vec3(pos) / pos.w
 315         );
 316
 317         pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 318         AssertEqual(
 319                 "wrong position at t=270°",
 320                 glm::vec3(0.0f, -1.0f, 0.0f),
 321                 glm::vec3(pos) / pos.w
 322         );
 323
 324         pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 325         AssertEqual(
 326                 "wrong position at t=360°",
 327                 glm::vec3(0.70710676908493f, 0.0f, 0.70710676908493f),
 328                 glm::vec3(pos) / pos.w
 329         );
 330 }
 331
 332 void OrbitTest::testMnAn() {
 333         Orbit orbit;
 334         orbit.MeanAnomaly(PI * 0.25); // 45°
 335         CPPUNIT_ASSERT_DOUBLES_EQUAL_MESSAGE(
 336                 "wrong mean anomaly on default orbit",
 337                 PI * 0.25, orbit.MeanAnomaly(), std::numeric_limits<double>::epsilon()
 338         );
 339
 340         // mean anomaly just phase shifts the orbit
 341         glm::vec4 pos(orbit.Matrix(0.0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
 342         AssertEqual(
 343                 "wrong position at t=0",
 344                 glm::vec3(0.70710676908493f, 0.0f, -0.70710676908493f),
 345                 glm::vec3(pos) / pos.w
 346         );
 347
 348         // at 90° position should be (0,0,sma) since the zero inclination
 349         // reference plane is XZ and rotates counter-clockwise
 350         pos = orbit.Matrix(PI_0p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 351         AssertEqual(
 352                 "wrong position at t=90°",
 353                 glm::vec3(-0.70710676908493f, 0.0f, -0.70710676908493f),
 354                 glm::vec3(pos) / pos.w
 355         );
 356
 357         // at 180° position should be (-sma,0,0)
 358         pos = orbit.Matrix(PI) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 359         AssertEqual(
 360                 "wrong position at t=180°",
 361                 glm::vec3(-0.70710676908493f, 0.0f, 0.70710676908493f),
 362                 glm::vec3(pos) / pos.w
 363         );
 364
 365         // at 270° position should be (0,0,-sma)
 366         pos = orbit.Matrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 367         AssertEqual(
 368                 "wrong position at t=270°",
 369                 glm::vec3(0.70710676908493f, 0.0f, 0.70710676908493f),
 370                 glm::vec3(pos) / pos.w
 371         );
 372
 373         // at 360° position should be (sma,0,0), the initial position
 374         pos = orbit.Matrix(PI_2p0) * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
 375         AssertEqual(
 376                 "wrong position at t=360°",
 377                 glm::vec3(0.70710676908493f, 0.0f, -0.70710676908493f),
 378                 glm::vec3(pos) / pos.w
 379         );
 380 }
 381
 382 void OrbitTest::testInverseDefault() {
 383         Orbit orbit;
 384
 385         // inverse matrix should project expected orbit position back to the origin
 386         glm::vec4 pos(orbit.InverseMatrix(0.0) * glm::vec4(1.0f, 0.0f, 0.0f, 1.0f));
 387         AssertEqual(
 388                 "wrong position at t=0",
 389                 glm::vec3(0.0f, 0.0f, 0.0f),
 390                 glm::vec3(pos) / pos.w
 391         );
 392
 393         // at 90° position should be (0,0,sma) since the zero inclination
 394         // reference plane is XZ and rotates counter-clockwise
 395         pos = orbit.InverseMatrix(PI_0p5) * glm::vec4(0.0f, 0.0f, -1.0f, 1.0f);
 396         AssertEqual(
 397                 "wrong position at t=90°",
 398                 glm::vec3(0.0f, 0.0f, 0.0f),
 399                 glm::vec3(pos) / pos.w
 400         );
 401
 402         // at 180° position should be (-sma,0,0)
 403         pos = orbit.InverseMatrix(PI) * glm::vec4(-1.0f, 0.0f, 0.0f, 1.0f);
 404         AssertEqual(
 405                 "wrong position at t=180°",
 406                 glm::vec3(0.0f, 0.0f, 0.0f),
 407                 glm::vec3(pos) / pos.w
 408         );
 409
 410         // at 270° position should be (0,0,-sma)
 411         pos = orbit.InverseMatrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 1.0f, 1.0f);
 412         AssertEqual(
 413                 "wrong position at t=270°",
 414                 glm::vec3(0.0f, 0.0f, 0.0f),
 415                 glm::vec3(pos) / pos.w
 416         );
 417
 418         // at 360° position should be (sma,0,0), the initial position
 419         pos = orbit.InverseMatrix(PI_2p0) * glm::vec4(1.0f, 0.0f, 0.0f, 1.0f);
 420         AssertEqual(
 421                 "wrong position at t=360°",
 422                 glm::vec3(0.0f, 0.0f, 0.0f),
 423                 glm::vec3(pos) / pos.w
 424         );
 425 }
 426
 427 void OrbitTest::testInverseSMA() {
 428         Orbit orbit;
 429         orbit.SemiMajorAxis(2.0);
 430
 431         // reference direction is +X, so at t=0, the body should be
 432         // at (sma,0,0) relative to its parent
 433         glm::vec4 pos(orbit.InverseMatrix(0.0) * glm::vec4(2.0f, 0.0f, 0.0f, 1.0f));
 434         AssertEqual(
 435                 "wrong position at t=0",
 436                 glm::vec3(0.0f, 0.0f, 0.0f),
 437                 glm::vec3(pos) / pos.w
 438         );
 439
 440         // at 90° position should be (0,0,sma) since the zero inclination
 441         // reference plane is XZ and rotates counter-clockwise
 442         pos = orbit.InverseMatrix(PI_0p5) * glm::vec4(0.0f, 0.0f, -2.0f, 1.0f);
 443         AssertEqual(
 444                 "wrong position at t=90°",
 445                 glm::vec3(0.0f, 0.0f, 0.0f),
 446                 glm::vec3(pos) / pos.w
 447         );
 448
 449         // at 180° position should be (-sma,0,0)
 450         pos = orbit.InverseMatrix(PI) * glm::vec4(-2.0f, 0.0f, 0.0f, 1.0f);
 451         AssertEqual(
 452                 "wrong position at t=180°",
 453                 glm::vec3(0.0f, 0.0f, 0.0f),
 454                 glm::vec3(pos) / pos.w
 455         );
 456
 457         // at 270° position should be (0,0,-sma)
 458         pos = orbit.InverseMatrix(PI_1p5) * glm::vec4(0.0f, 0.0f, 2.0f, 1.0f);
 459         AssertEqual(
 460                 "wrong position at t=270°",
 461                 glm::vec3(0.0f, 0.0f, 0.0f),
 462                 glm::vec3(pos) / pos.w
 463         );
 464
 465         // at 360° position should be (sma,0,0), the initial position
 466         pos = orbit.InverseMatrix(PI_2p0) * glm::vec4(2.0f, 0.0f, 0.0f, 1.0f);
 467         AssertEqual(
 468                 "wrong position at t=360°",
 469                 glm::vec3(0.0f, 0.0f, 0.0f),
 470                 glm::vec3(pos) / pos.w
 471         );
 472 }
 473
 474 void OrbitTest::testInverseEcc() {
 475         Orbit orbit;
 476         orbit.Eccentricity(0.5);
 477
 478         glm::vec4 pos(orbit.InverseMatrix(0.0) * glm::vec4(0.5f, 0.0f, 0.0f, 1.0f));
 479         AssertEqual(
 480                 "wrong position at t=0",
 481                 glm::vec3(0.0f, 0.0f, 0.0f),
 482                 glm::vec3(pos) / pos.w
 483         );
 484
 485         pos = orbit.InverseMatrix(PI_0p5) * glm::vec4(-0.935130834579468f, 0.0f, -0.779740869998932f, 1.0f);
 486         AssertEqual(
 487                 "wrong position at t=90°",
 488                 glm::vec3(0.0f, 0.0f, 0.0f),
 489                 glm::vec3(pos) / pos.w
 490         );
 491
 492         pos = orbit.InverseMatrix(PI) * glm::vec4(-1.5f, 0.0f, 0.0f, 1.0f);
 493         AssertEqual(
 494                 "wrong position at t=180°",
 495                 glm::vec3(0.0f, 0.0f, 0.0f),
 496                 glm::vec3(pos) / pos.w
 497         );
 498
 499         pos = orbit.InverseMatrix(PI_1p5) * glm::vec4(-0.935130834579468f, 0.0f, 0.779740869998932f, 1.0f);
 500         AssertEqual(
 501                 "wrong position at t=270°",
 502                 glm::vec3(0.0f, 0.0f, 0.0f),
 503                 glm::vec3(pos) / pos.w
 504         );
 505
 506         pos = orbit.InverseMatrix(PI_2p0) * glm::vec4(0.5f, 0.0f, 0.0f, 1.0f);
 507         AssertEqual(
 508                 "wrong position at t=360°",
 509                 glm::vec3(0.0f, 0.0f, 0.0f),
 510                 glm::vec3(pos) / pos.w
 511         );
 512 }
 513
 514 void OrbitTest::testInverseInc() {
 515         Orbit orbit;
 516         orbit.Inclination(PI * 0.25); // 45°
 517
 518         // inclination rotates counter clockwise around +X, so at t=0 should be
 519         // at (sma,0,0) relative to its parent
 520         glm::vec4 pos(orbit.InverseMatrix(0.0) * glm::vec4(1.0f, 0.0f, 0.0f, 1.0f));
 521         AssertEqual(
 522                 "wrong position at t=0",
 523                 glm::vec3(0.0f, 0.0f, 0.0f),
 524                 glm::vec3(pos) / pos.w
 525         );
 526
 527         pos = orbit.InverseMatrix(PI_0p5) * glm::vec4(0.0f, 0.70710676908493f, -0.70710676908493f, 1.0f);
 528         AssertEqual(
 529                 "wrong position at t=90°",
 530                 glm::vec3(0.0f, 0.0f, 0.0f),
 531                 glm::vec3(pos) / pos.w
 532         );
 533
 534         pos = orbit.InverseMatrix(PI) * glm::vec4(-1.0f, 0.0f, 0.0f, 1.0f);
 535         AssertEqual(
 536                 "wrong position at t=180°",
 537                 glm::vec3(0.0f, 0.0f, 0.0f),
 538                 glm::vec3(pos) / pos.w
 539         );
 540
 541         pos = orbit.InverseMatrix(PI_1p5) * glm::vec4(0.0f, -0.70710676908493f, 0.70710676908493f, 1.0f);
 542         AssertEqual(
 543                 "wrong position at t=270°",
 544                 glm::vec3(0.0f, 0.0f, 0.0f),
 545                 glm::vec3(pos) / pos.w
 546         );
 547
 548         pos = orbit.InverseMatrix(PI_2p0) * glm::vec4(1.0f, 0.0f, 0.0f, 1.0f);
 549         AssertEqual(
 550                 "wrong position at t=360°",
 551                 glm::vec3(0.0f, 0.0f, 0.0f),
 552                 glm::vec3(pos) / pos.w
 553         );
 554 }
 555
 556 void OrbitTest::testInverseLngAsc() {
 557         Orbit orbit;
 558         orbit.LongitudeAscending(PI * 0.25); // 45°
 559         orbit.Inclination(PI * 0.5);
 560
 561         // inclination rotates counter clockwise around +X, while LAN rotates it
 562         // around +Y, so at t=0 should be at (sma*sin(45°),0,-sma*cos(45°))
 563         glm::vec4 pos(orbit.InverseMatrix(0.0) * glm::vec4(0.70710676908493f, 0.0f, -0.70710676908493f, 1.0f));
 564         AssertEqual(
 565                 "wrong position at t=0",
 566                 glm::vec3(0.0f, 0.0f, 0.0f),
 567                 glm::vec3(pos) / pos.w
 568         );
 569
 570         pos = orbit.InverseMatrix(PI_0p5) * glm::vec4(0.0f, 1.0f, 0.0f, 1.0f);
 571         AssertEqual(
 572                 "wrong position at t=90°",
 573                 glm::vec3(0.0f, 0.0f, 0.0f),
 574                 glm::vec3(pos) / pos.w
 575         );
 576
 577         pos = orbit.InverseMatrix(PI) * glm::vec4(-0.70710676908493f, 0.0f, 0.70710676908493f, 1.0f);
 578         AssertEqual(
 579                 "wrong position at t=180°",
 580                 glm::vec3(0.0f, 0.0f, 0.0f),
 581                 glm::vec3(pos) / pos.w
 582         );
 583
 584         pos = orbit.InverseMatrix(PI_1p5) * glm::vec4(0.0f, -1.0f, 0.0f, 1.0f);
 585         AssertEqual(
 586                 "wrong position at t=270°",
 587                 glm::vec3(0.0f, 0.0f, 0.0f),
 588                 glm::vec3(pos) / pos.w
 589         );
 590
 591         pos = orbit.InverseMatrix(PI_2p0) * glm::vec4(0.70710676908493f, 0.0f, -0.70710676908493f, 1.0f);
 592         AssertEqual(
 593                 "wrong position at t=360°",
 594                 glm::vec3(0.0f, 0.0f, 0.0f),
 595                 glm::vec3(pos) / pos.w
 596         );
 597 }
 598
 599 void OrbitTest::testInverseArgPe() {
 600         Orbit orbit;
 601         orbit.ArgumentPeriapsis(PI * 0.25); // 45°
 602         orbit.Inclination(PI * 0.5);
 603
 604         // inclination rotates counter clockwise around +X, while APe rotates it
 605         // around +Y in the rotated coordinate system, so at t=0 should be at
 606         // (sma*sin(45°),0,sma*cos(45°))
 607         glm::vec4 pos(orbit.InverseMatrix(0.0) * glm::vec4(0.70710676908493f, 0.0f, 0.70710676908493f, 1.0f));
 608         AssertEqual(
 609                 "wrong position at t=0",
 610                 glm::vec3(0.0f, 0.0f, 0.0f),
 611                 glm::vec3(pos) / pos.w
 612         );
 613
 614         pos = orbit.InverseMatrix(PI_0p5) * glm::vec4(0.0f, 1.0f, 0.0f, 1.0f);
 615         AssertEqual(
 616                 "wrong position at t=90°",
 617                 glm::vec3(0.0f, 0.0f, 0.0f),
 618                 glm::vec3(pos) / pos.w
 619         );
 620
 621         pos = orbit.InverseMatrix(PI) * glm::vec4(-0.70710676908493f, 0.0f, -0.70710676908493f, 1.0f);
 622         AssertEqual(
 623                 "wrong position at t=180°",
 624                 glm::vec3(0.0f, 0.0f, 0.0f),
 625                 glm::vec3(pos) / pos.w
 626         );
 627
 628         pos = orbit.InverseMatrix(PI_1p5) * glm::vec4(0.0f, -1.0f, 0.0f, 1.0f);
 629         AssertEqual(
 630                 "wrong position at t=270°",
 631                 glm::vec3(0.0f, 0.0f, 0.0f),
 632                 glm::vec3(pos) / pos.w
 633         );
 634
 635         pos = orbit.InverseMatrix(PI_2p0) * glm::vec4(0.70710676908493f, 0.0f, 0.70710676908493f, 1.0f);
 636         AssertEqual(
 637                 "wrong position at t=360°",
 638                 glm::vec3(0.0f, 0.0f, 0.0f),
 639                 glm::vec3(pos) / pos.w
 640         );
 641 }
 642
 643 void OrbitTest::testInverseMnAn() {
 644         Orbit orbit;
 645         orbit.MeanAnomaly(PI * 0.25); // 45°
 646
 647         // mean anomaly just phase shifts the orbit
 648         glm::vec4 pos(orbit.InverseMatrix(0.0) * glm::vec4(0.70710676908493f, 0.0f, -0.70710676908493f, 1.0f));
 649         AssertEqual(
 650                 "wrong position at t=0",
 651                 glm::vec3(0.0f, 0.0f, 0.0f),
 652                 glm::vec3(pos) / pos.w
 653         );
 654
 655         // at 90° position should be (0,0,sma) since the zero inclination
 656         // reference plane is XZ and rotates counter-clockwise
 657         pos = orbit.InverseMatrix(PI_0p5) * glm::vec4(-0.70710676908493f, 0.0f, -0.70710676908493f, 1.0f);
 658         AssertEqual(
 659                 "wrong position at t=90°",
 660                 glm::vec3(0.0f, 0.0f, 0.0f),
 661                 glm::vec3(pos) / pos.w
 662         );
 663
 664         // at 180° position should be (-sma,0,0)
 665         pos = orbit.InverseMatrix(PI) * glm::vec4(-0.70710676908493f, 0.0f, 0.70710676908493f, 1.0f);
 666         AssertEqual(
 667                 "wrong position at t=180°",
 668                 glm::vec3(0.0f, 0.0f, 0.0f),
 669                 glm::vec3(pos) / pos.w
 670         );
 671
 672         // at 270° position should be (0,0,-sma)
 673         pos = orbit.InverseMatrix(PI_1p5) * glm::vec4(0.70710676908493f, 0.0f, 0.70710676908493f, 1.0f);
 674         AssertEqual(
 675                 "wrong position at t=270°",
 676                 glm::vec3(0.0f, 0.0f, 0.0f),
 677                 glm::vec3(pos) / pos.w
 678         );
 679
 680         // at 360° position should be (sma,0,0), the initial position
 681         pos = orbit.InverseMatrix(PI_2p0) * glm::vec4(0.70710676908493f, 0.0f, -0.70710676908493f, 1.0f);
 682         AssertEqual(
 683                 "wrong position at t=360°",
 684                 glm::vec3(0.0f, 0.0f, 0.0f),
 685                 glm::vec3(pos) / pos.w
 686         );
 687 }
 688 }
 689 }
 690 }