src/world/world.cpp

   1 #include "Body.hpp"
   2 #include "Orbit.hpp"
   3 #include "Planet.hpp"
   4 #include "Resource.hpp"
   5 #include "Set.hpp"
   6 #include "Simulation.hpp"
   7 #include "Sun.hpp"
   8 #include "Tile.hpp"
   9 #include "TileType.hpp"
  10
  11 #include "Creature.hpp"
  12 #include "../const.hpp"
  13 #include "../app/Assets.hpp"
  14 #include "../graphics/Viewport.hpp"
  15 #include "../rand/OctaveNoise.hpp"
  16 #include "../rand/SimplexNoise.hpp"
  17
  18 #include <algorithm>
  19 #include <cmath>
  20 #include <iostream>
  21 #include <glm/gtc/matrix_transform.hpp>
  22 #include <glm/gtx/euler_angles.hpp>
  23 #include <glm/gtx/io.hpp>
  24 #include <glm/gtx/transform.hpp>
  25
  26 using blobs::G;
  27 using blobs::PI_2p0;
  28
  29 using std::sin;
  30 using std::cos;
  31 using std::pow;
  32 using std::sqrt;
  33
  34
  35 namespace blobs {
  36 namespace world {
  37
  38 Body::Body()
  39 : sim(nullptr)
  40 , parent(nullptr)
  41 , children()
  42 , mass(1.0)
  43 , radius(1.0)
  44 , orbit()
  45 , surface_tilt(0.0, 0.0)
  46 , axis_tilt(0.0, 0.0)
  47 , rotation(0.0)
  48 , angular(0.0)
  49 , orbital(1.0)
  50 , inverse_orbital(1.0)
  51 , local(1.0)
  52 , inverse_local(1.0)
  53 , creatures() {
  54 }
  55
  56 Body::~Body() {
  57         for (Creature *c : creatures) {
  58                 delete c;
  59         }
  60 }
  61
  62 void Body::SetSimulation(Simulation &s) noexcept {
  63         sim = &s;
  64         for (auto child : children) {
  65                 child->SetSimulation(s);
  66         }
  67 }
  68
  69 void Body::SetParent(Body &p) {
  70         if (HasParent()) {
  71                 UnsetParent();
  72         }
  73         parent = &p;
  74         parent->AddChild(*this);
  75 }
  76
  77 void Body::UnsetParent() {
  78         if (!HasParent()) return;
  79         parent->RemoveChild(*this);
  80         parent = nullptr;
  81 }
  82
  83 void Body::AddChild(Body &c) {
  84         children.push_back(&c);
  85         c.SetSimulation(*sim);
  86 }
  87
  88 void Body::RemoveChild(Body &c) {
  89         auto entry = std::find(children.begin(), children.end(), &c);
  90         if (entry != children.end()) {
  91                 children.erase(entry);
  92         }
  93 }
  94
  95 double Body::Inertia() const noexcept {
  96         // assume solid sphere for now
  97         return (2.0/5.0) * Mass() * pow(Radius(), 2);
  98 }
  99
 100 double Body::GravitationalParameter() const noexcept {
 101         return G * Mass();
 102 }
 103
 104 double Body::OrbitalPeriod() const noexcept {
 105         if (parent) {
 106                 return PI_2p0 * sqrt(pow(orbit.SemiMajorAxis(), 3) / (G * (parent->Mass() + Mass())));
 107         } else {
 108                 return 0.0;
 109         }
 110 }
 111
 112 double Body::RotationalPeriod() const noexcept {
 113         if (std::abs(angular) < std::numeric_limits<double>::epsilon()) {
 114                 return std::numeric_limits<double>::infinity();
 115         } else {
 116                 return PI_2p0 * Inertia() / angular;
 117         }
 118 }
 119
 120 glm::dmat4 Body::ToUniverse() const noexcept {
 121         glm::dmat4 m(1.0);
 122         const Body *b = this;
 123         while (b->HasParent()) {
 124                 m = b->ToParent() * m;
 125                 b = &b->Parent();
 126         }
 127         return m;
 128 }
 129
 130 glm::dmat4 Body::FromUniverse() const noexcept {
 131         glm::dmat4 m(1.0);
 132         const Body *b = this;
 133         while (b->HasParent()) {
 134                 m *= b->FromParent();
 135                 b = &b->Parent();
 136         }
 137         return m;
 138 }
 139
 140 void Body::Cache() noexcept {
 141         if (parent) {
 142                 orbital =
 143                         orbit.Matrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()))
 144                         * glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 145                 inverse_orbital =
 146                         glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x)
 147                         * orbit.InverseMatrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
 148         } else {
 149                 orbital = glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 150                 inverse_orbital = glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x);
 151         }
 152         local =
 153                 glm::eulerAngleY(rotation)
 154                 * glm::eulerAngleXY(surface_tilt.x, surface_tilt.y);
 155         inverse_local =
 156                 glm::eulerAngleYX(-surface_tilt.y, -surface_tilt.x)
 157                 * glm::eulerAngleY(-rotation);
 158 }
 159
 160 void Body::AddCreature(Creature *c) {
 161         c->SetBody(*this);
 162         creatures.push_back(c);
 163 }
 164
 165
 166 Orbit::Orbit()
 167 : sma(1.0)
 168 , ecc(0.0)
 169 , inc(0.0)
 170 , asc(0.0)
 171 , arg(0.0)
 172 , mna(0.0) {
 173 }
 174
 175 Orbit::~Orbit() {
 176 }
 177
 178 double Orbit::SemiMajorAxis() const noexcept {
 179         return sma;
 180 }
 181
 182 Orbit &Orbit::SemiMajorAxis(double s) noexcept {
 183         sma = s;
 184         return *this;
 185 }
 186
 187 double Orbit::Eccentricity() const noexcept {
 188         return ecc;
 189 }
 190
 191 Orbit &Orbit::Eccentricity(double e) noexcept {
 192         ecc = e;
 193         return *this;
 194 }
 195
 196 double Orbit::Inclination() const noexcept {
 197         return inc;
 198 }
 199
 200 Orbit &Orbit::Inclination(double i) noexcept {
 201         inc = i;
 202         return *this;
 203 }
 204
 205 double Orbit::LongitudeAscending() const noexcept {
 206         return asc;
 207 }
 208
 209 Orbit &Orbit::LongitudeAscending(double l) noexcept {
 210         asc = l;
 211         return *this;
 212 }
 213
 214 double Orbit::ArgumentPeriapsis() const noexcept {
 215         return arg;
 216 }
 217
 218 Orbit &Orbit::ArgumentPeriapsis(double a) noexcept {
 219         arg = a;
 220         return *this;
 221 }
 222
 223 double Orbit::MeanAnomaly() const noexcept {
 224         return mna;
 225 }
 226
 227 Orbit &Orbit::MeanAnomaly(double m) noexcept {
 228         mna = m;
 229         return *this;
 230 }
 231
 232 namespace {
 233
 234 double mean2eccentric(double M, double e) {
 235         double E = M; // eccentric anomaly, solve M = E - e sin E
 236         // limit to 100 steps to prevent deadlocks in impossible situations
 237         for (int i = 0; i < 100; ++i) {
 238                 double dE = (E - e * sin(E) - M) / (1 - e * cos(E));
 239                 E -= dE;
 240                 if (abs(dE) < 1.0e-6) break;
 241         }
 242         return E;
 243 }
 244
 245 }
 246
 247 glm::dmat4 Orbit::Matrix(double t) const noexcept {
 248         double M = mna + t;
 249         double E = mean2eccentric(M, ecc);
 250
 251         // coordinates in orbital plane, P=x, Q=-z
 252         double P = sma * (cos(E) - ecc);
 253         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 254
 255         return glm::yawPitchRoll(asc, inc, arg) * glm::translate(glm::dvec3(P, 0.0, -Q));
 256 }
 257
 258 glm::dmat4 Orbit::InverseMatrix(double t) const noexcept {
 259         double M = mna + t;
 260         double E = mean2eccentric(M, ecc);
 261         double P = sma * (cos(E) - ecc);
 262         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 263         return glm::translate(glm::dvec3(-P, 0.0, Q)) * glm::transpose(glm::yawPitchRoll(asc, inc, arg));
 264 }
 265
 266
 267 Planet::Planet(int sidelength)
 268 : Body()
 269 , sidelength(sidelength)
 270 , tiles(TilesTotal())
 271 , atmosphere(-1)
 272 , vao() {
 273         Radius(double(sidelength) / 2.0);
 274 }
 275
 276 Planet::~Planet() {
 277 }
 278
 279 glm::dvec3 Planet::TileCenter(int surface, int x, int y) const noexcept {
 280         glm::dvec3 center(0.0f);
 281         center[(surface + 0) % 3] = x + 0.5 - Radius();
 282         center[(surface + 1) % 3] = y + 0.5 - Radius();
 283         center[(surface + 2) % 3] = surface < 3 ? Radius() : -Radius();
 284         return center;
 285 }
 286
 287 void Planet::BuildVAO(const Set<TileType> &ts) {
 288         vao.Bind();
 289         vao.BindAttributes();
 290         vao.EnableAttribute(0);
 291         vao.EnableAttribute(1);
 292         vao.AttributePointer<glm::vec3>(0, false, offsetof(Attributes, position));
 293         vao.AttributePointer<glm::vec3>(1, false, offsetof(Attributes, tex_coord));
 294         vao.ReserveAttributes(TilesTotal() * 4, GL_STATIC_DRAW);
 295         {
 296                 auto attrib = vao.MapAttributes(GL_WRITE_ONLY);
 297                 float offset = Radius();
 298
 299                 // srf  0  1  2  3  4  5
 300                 //  up +Z +X +Y -Z -X -Y
 301
 302                 for (int index = 0, surface = 0; surface < 6; ++surface) {
 303                         for (int y = 0; y < sidelength; ++y) {
 304                                 for (int x = 0; x < sidelength; ++x, ++index) {
 305                                         float tex = ts[TileAt(surface, x, y).type].texture;
 306                                         const float tex_u_begin = surface < 3 ? 1.0f : 0.0f;
 307                                         const float tex_u_end = surface < 3 ? 0.0f : 1.0f;
 308                                         attrib[4 * index + 0].position[(surface + 0) % 3] = x + 0 - offset;
 309                                         attrib[4 * index + 0].position[(surface + 1) % 3] = y + 0 - offset;
 310                                         attrib[4 * index + 0].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 311                                         attrib[4 * index + 0].tex_coord[0] = tex_u_begin;
 312                                         attrib[4 * index + 0].tex_coord[1] = 1.0f;
 313                                         attrib[4 * index + 0].tex_coord[2] = tex;
 314
 315                                         attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
 316                                         attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
 317                                         attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 318                                         attrib[4 * index + 1].tex_coord[0] = tex_u_end;
 319                                         attrib[4 * index + 1].tex_coord[1] = 1.0f;
 320                                         attrib[4 * index + 1].tex_coord[2] = tex;
 321
 322                                         attrib[4 * index + 2].position[(surface + 0) % 3] = x + 1 - offset;
 323                                         attrib[4 * index + 2].position[(surface + 1) % 3] = y + 0 - offset;
 324                                         attrib[4 * index + 2].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 325                                         attrib[4 * index + 2].tex_coord[0] = tex_u_begin;
 326                                         attrib[4 * index + 2].tex_coord[1] = 0.0f;
 327                                         attrib[4 * index + 2].tex_coord[2] = tex;
 328
 329                                         attrib[4 * index + 3].position[(surface + 0) % 3] = x + 1 - offset;
 330                                         attrib[4 * index + 3].position[(surface + 1) % 3] = y + 1 - offset;
 331                                         attrib[4 * index + 3].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 332                                         attrib[4 * index + 3].tex_coord[0] = tex_u_end;
 333                                         attrib[4 * index + 3].tex_coord[1] = 0.0f;
 334                                         attrib[4 * index + 3].tex_coord[2] = tex;
 335                                 }
 336                         }
 337                 }
 338         }
 339         vao.BindElements();
 340         vao.ReserveElements(TilesTotal() * 6, GL_STATIC_DRAW);
 341         {
 342                 auto element = vao.MapElements(GL_WRITE_ONLY);
 343                 int index = 0;
 344                 for (int surface = 0; surface < 3; ++surface) {
 345                         for (int y = 0; y < sidelength; ++y) {
 346                                 for (int x = 0; x < sidelength; ++x, ++index) {
 347                                         element[6 * index + 0] = 4 * index + 0;
 348                                         element[6 * index + 1] = 4 * index + 2;
 349                                         element[6 * index + 2] = 4 * index + 1;
 350                                         element[6 * index + 3] = 4 * index + 1;
 351                                         element[6 * index + 4] = 4 * index + 2;
 352                                         element[6 * index + 5] = 4 * index + 3;
 353                                 }
 354                         }
 355                 }
 356                 for (int surface = 3; surface < 6; ++surface) {
 357                         for (int y = 0; y < sidelength; ++y) {
 358                                 for (int x = 0; x < sidelength; ++x, ++index) {
 359                                         element[6 * index + 0] = 4 * index + 0;
 360                                         element[6 * index + 1] = 4 * index + 1;
 361                                         element[6 * index + 2] = 4 * index + 2;
 362                                         element[6 * index + 3] = 4 * index + 2;
 363                                         element[6 * index + 4] = 4 * index + 1;
 364                                         element[6 * index + 5] = 4 * index + 3;
 365                                 }
 366                         }
 367                 }
 368         }
 369         vao.Unbind();
 370 }
 371
 372 void Planet::Draw(app::Assets &assets, graphics::Viewport &viewport) {
 373         vao.Bind();
 374         const glm::mat4 &MV = assets.shaders.planet_surface.MV();
 375         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, 1.0f, 0.0f)));
 376         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 0);
 377         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(1.0f, 0.0f, 0.0f, 0.0f)));
 378         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 1);
 379         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 1.0f, 0.0f, 0.0f)));
 380         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 2);
 381         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, -1.0f, 0.0f)));
 382         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 3);
 383         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(-1.0f, 0.0f, 0.0f, 0.0f)));
 384         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 4);
 385         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, -1.0f, 0.0f, 0.0f)));
 386         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 5);
 387 }
 388
 389
 390 void GenerateEarthlike(const Set<TileType> &tiles, Planet &p) noexcept {
 391         rand::SimplexNoise elevation_gen(0);
 392         rand::SimplexNoise variation_gen(45623752346);
 393
 394         const int ice = tiles["ice"].id;
 395         const int ocean = tiles["ocean"].id;
 396         const int water = tiles["water"].id;
 397         const int sand = tiles["sand"].id;
 398         const int grass = tiles["grass"].id;
 399         const int tundra = tiles["tundra"].id;
 400         const int taiga = tiles["taiga"].id;
 401         const int desert = tiles["desert"].id;
 402         const int mntn = tiles["mountain"].id;
 403         const int algae = tiles["algae"].id;
 404         const int forest = tiles["forest"].id;
 405         const int jungle = tiles["jungle"].id;
 406         const int rock = tiles["rock"].id;
 407         const int wheat = tiles["wheat"].id;
 408
 409         constexpr double ocean_thresh = -0.2;
 410         constexpr double water_thresh = 0.0;
 411         constexpr double beach_thresh = 0.05;
 412         constexpr double highland_thresh = 0.4;
 413         constexpr double mountain_thresh = 0.5;
 414
 415         const glm::dvec3 axis(glm::dvec4(0.0, 1.0, 0.0, 0.0) * glm::eulerAngleXY(p.SurfaceTilt().x, p.SurfaceTilt().y));
 416         const double cap_thresh = std::abs(std::cos(p.AxialTilt().x));
 417         const double equ_thresh = std::abs(std::sin(p.AxialTilt().x)) / 2.0;
 418         const double fzone_start = equ_thresh - (equ_thresh - cap_thresh) / 3.0;
 419         const double fzone_end = cap_thresh + (equ_thresh - cap_thresh) / 3.0;
 420
 421         for (int surface = 0; surface <= 5; ++surface) {
 422                 for (int y = 0; y < p.SideLength(); ++y) {
 423                         for (int x = 0; x < p.SideLength(); ++x) {
 424                                 glm::dvec3 to_tile = p.TileCenter(surface, x, y);
 425                                 double near_axis = std::abs(glm::dot(glm::normalize(to_tile), axis));
 426                                 if (near_axis > cap_thresh) {
 427                                         p.TileAt(surface, x, y).type = ice;
 428                                         continue;
 429                                 }
 430                                 float elevation = rand::OctaveNoise(
 431                                         elevation_gen,
 432                                         to_tile / p.Radius(),
 433                                         3,   // octaves
 434                                         0.5, // persistence
 435                                         5 / p.Radius(), // frequency
 436                                         2,   // amplitude
 437                                         2    // growth
 438                                 );
 439                                 float variation = rand::OctaveNoise(
 440                                         variation_gen,
 441                                         to_tile / p.Radius(),
 442                                         3,   // octaves
 443                                         0.5, // persistence
 444                                         16 / p.Radius(), // frequency
 445                                         2,   // amplitude
 446                                         2    // growth
 447                                 );
 448                                 if (elevation < ocean_thresh) {
 449                                         p.TileAt(surface, x, y).type = ocean;
 450                                 } else if (elevation < water_thresh) {
 451                                         if (variation > 0.3) {
 452                                                 p.TileAt(surface, x, y).type = algae;
 453                                         } else {
 454                                                 p.TileAt(surface, x, y).type = water;
 455                                         }
 456                                 } else if (elevation < beach_thresh) {
 457                                         p.TileAt(surface, x, y).type = sand;
 458                                 } else if (elevation < highland_thresh) {
 459                                         if (near_axis < equ_thresh) {
 460                                                 if (variation > 0.6) {
 461                                                         p.TileAt(surface, x, y).type = grass;
 462                                                 } else if (variation > 0.2) {
 463                                                         p.TileAt(surface, x, y).type = sand;
 464                                                 } else {
 465                                                         p.TileAt(surface, x, y).type = desert;
 466                                                 }
 467                                         } else if (near_axis < fzone_start) {
 468                                                 if (variation > 0.4) {
 469                                                         p.TileAt(surface, x, y).type = forest;
 470                                                 } else if (variation < -0.5) {
 471                                                         p.TileAt(surface, x, y).type = jungle;
 472                                                 } else if (variation > -0.02 && variation < 0.02) {
 473                                                         p.TileAt(surface, x, y).type = wheat;
 474                                                 } else {
 475                                                         p.TileAt(surface, x, y).type = grass;
 476                                                 }
 477                                         } else if (near_axis < fzone_end) {
 478                                                 p.TileAt(surface, x, y).type = tundra;
 479                                         } else {
 480                                                 p.TileAt(surface, x, y).type = taiga;
 481                                         }
 482                                 } else if (elevation < mountain_thresh) {
 483                                         if (variation > 0.3) {
 484                                                 p.TileAt(surface, x, y).type = mntn;
 485                                         } else {
 486                                                 p.TileAt(surface, x, y).type = rock;
 487                                         }
 488                                 } else {
 489                                         p.TileAt(surface, x, y).type = mntn;
 490                                 }
 491                         }
 492                 }
 493         }
 494         p.BuildVAO(tiles);
 495 }
 496
 497 void GenerateTest(const Set<TileType> &tiles, Planet &p) noexcept {
 498         for (int surface = 0; surface <= 5; ++surface) {
 499                 for (int y = 0; y < p.SideLength(); ++y) {
 500                         for (int x = 0; x < p.SideLength(); ++x) {
 501                                 if (x == p.SideLength() / 2 && y == p.SideLength() / 2) {
 502                                         p.TileAt(surface, x, y).type = surface;
 503                                 } else {
 504                                         p.TileAt(surface, x, y).type = (x == p.SideLength()/2) + (y == p.SideLength()/2) + 6;
 505                                 }
 506                         }
 507                 }
 508         }
 509         p.BuildVAO(tiles);
 510 }
 511
 512
 513 Sun::Sun()
 514 : Body() {
 515 }
 516
 517 Sun::~Sun() {
 518 }
 519
 520 }
 521 }