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 "../app/Assets.hpp"
  12 #include "../creature/Creature.hpp"
  13 #include "../graphics/Viewport.hpp"
  14 #include "../math/const.hpp"
  15 #include "../math/OctaveNoise.hpp"
  16 #include "../math/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 , atmosphere(-1) {
  55 }
  56
  57 Body::~Body() {
  58         for (creature::Creature *c : creatures) {
  59                 delete c;
  60         }
  61 }
  62
  63 void Body::SetSimulation(Simulation &s) noexcept {
  64         sim = &s;
  65         for (auto child : children) {
  66                 child->SetSimulation(s);
  67         }
  68 }
  69
  70 void Body::SetParent(Body &p) {
  71         if (HasParent()) {
  72                 UnsetParent();
  73         }
  74         parent = &p;
  75         parent->AddChild(*this);
  76 }
  77
  78 void Body::UnsetParent() {
  79         if (!HasParent()) return;
  80         parent->RemoveChild(*this);
  81         parent = nullptr;
  82 }
  83
  84 void Body::AddChild(Body &c) {
  85         children.push_back(&c);
  86         c.SetSimulation(*sim);
  87 }
  88
  89 void Body::RemoveChild(Body &c) {
  90         auto entry = std::find(children.begin(), children.end(), &c);
  91         if (entry != children.end()) {
  92                 children.erase(entry);
  93         }
  94 }
  95
  96 double Body::Inertia() const noexcept {
  97         // assume solid sphere for now
  98         return (2.0/5.0) * Mass() * pow(Radius(), 2);
  99 }
 100
 101 double Body::GravitationalParameter() const noexcept {
 102         return G * Mass();
 103 }
 104
 105 double Body::OrbitalPeriod() const noexcept {
 106         if (parent) {
 107                 return PI_2p0 * sqrt(pow(orbit.SemiMajorAxis(), 3) / (G * (parent->Mass() + Mass())));
 108         } else {
 109                 return 0.0;
 110         }
 111 }
 112
 113 double Body::RotationalPeriod() const noexcept {
 114         if (std::abs(angular) < std::numeric_limits<double>::epsilon()) {
 115                 return std::numeric_limits<double>::infinity();
 116         } else {
 117                 return PI_2p0 * Inertia() / angular;
 118         }
 119 }
 120
 121 glm::dmat4 Body::ToUniverse() const noexcept {
 122         glm::dmat4 m(1.0);
 123         const Body *b = this;
 124         while (b->HasParent()) {
 125                 m = b->ToParent() * m;
 126                 b = &b->Parent();
 127         }
 128         return m;
 129 }
 130
 131 glm::dmat4 Body::FromUniverse() const noexcept {
 132         glm::dmat4 m(1.0);
 133         const Body *b = this;
 134         while (b->HasParent()) {
 135                 m *= b->FromParent();
 136                 b = &b->Parent();
 137         }
 138         return m;
 139 }
 140
 141 namespace {
 142 std::vector<creature::Creature *> ccache;
 143 }
 144
 145 void Body::Tick(double dt) {
 146         rotation += dt * AngularMomentum() / Inertia();
 147         Cache();
 148         ccache = Creatures();
 149         for (creature::Creature *c : ccache) {
 150                 c->Tick(dt);
 151         }
 152         for (auto c = Creatures().begin(); c != Creatures().end();) {
 153                 if ((*c)->Removable()) {
 154                         delete *c;
 155                         c = Creatures().erase(c);
 156                 } else {
 157                         ++c;
 158                 }
 159         }
 160 }
 161
 162 void Body::Cache() noexcept {
 163         if (parent) {
 164                 orbital =
 165                         orbit.Matrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()))
 166                         * glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 167                 inverse_orbital =
 168                         glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x)
 169                         * orbit.InverseMatrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
 170         } else {
 171                 orbital = glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 172                 inverse_orbital = glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x);
 173         }
 174         local =
 175                 glm::eulerAngleY(rotation)
 176                 * glm::eulerAngleXY(surface_tilt.x, surface_tilt.y);
 177         inverse_local =
 178                 glm::eulerAngleYX(-surface_tilt.y, -surface_tilt.x)
 179                 * glm::eulerAngleY(-rotation);
 180 }
 181
 182 void Body::AddCreature(creature::Creature *c) {
 183         creatures.push_back(c);
 184 }
 185
 186 void Body::RemoveCreature(creature::Creature *c) {
 187         auto entry = std::find(creatures.begin(), creatures.end(), c);
 188         if (entry != creatures.end()) {
 189                 creatures.erase(entry);
 190         }
 191 }
 192
 193
 194 Orbit::Orbit()
 195 : sma(1.0)
 196 , ecc(0.0)
 197 , inc(0.0)
 198 , asc(0.0)
 199 , arg(0.0)
 200 , mna(0.0) {
 201 }
 202
 203 Orbit::~Orbit() {
 204 }
 205
 206 double Orbit::SemiMajorAxis() const noexcept {
 207         return sma;
 208 }
 209
 210 Orbit &Orbit::SemiMajorAxis(double s) noexcept {
 211         sma = s;
 212         return *this;
 213 }
 214
 215 double Orbit::Eccentricity() const noexcept {
 216         return ecc;
 217 }
 218
 219 Orbit &Orbit::Eccentricity(double e) noexcept {
 220         ecc = e;
 221         return *this;
 222 }
 223
 224 double Orbit::Inclination() const noexcept {
 225         return inc;
 226 }
 227
 228 Orbit &Orbit::Inclination(double i) noexcept {
 229         inc = i;
 230         return *this;
 231 }
 232
 233 double Orbit::LongitudeAscending() const noexcept {
 234         return asc;
 235 }
 236
 237 Orbit &Orbit::LongitudeAscending(double l) noexcept {
 238         asc = l;
 239         return *this;
 240 }
 241
 242 double Orbit::ArgumentPeriapsis() const noexcept {
 243         return arg;
 244 }
 245
 246 Orbit &Orbit::ArgumentPeriapsis(double a) noexcept {
 247         arg = a;
 248         return *this;
 249 }
 250
 251 double Orbit::MeanAnomaly() const noexcept {
 252         return mna;
 253 }
 254
 255 Orbit &Orbit::MeanAnomaly(double m) noexcept {
 256         mna = m;
 257         return *this;
 258 }
 259
 260 namespace {
 261
 262 double mean2eccentric(double M, double e) {
 263         double E = M; // eccentric anomaly, solve M = E - e sin E
 264         // limit to 100 steps to prevent deadlocks in impossible situations
 265         for (int i = 0; i < 100; ++i) {
 266                 double dE = (E - e * sin(E) - M) / (1 - e * cos(E));
 267                 E -= dE;
 268                 if (abs(dE) < 1.0e-6) break;
 269         }
 270         return E;
 271 }
 272
 273 }
 274
 275 glm::dmat4 Orbit::Matrix(double t) const noexcept {
 276         double M = mna + t;
 277         double E = mean2eccentric(M, ecc);
 278
 279         // coordinates in orbital plane, P=x, Q=-z
 280         double P = sma * (cos(E) - ecc);
 281         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 282
 283         return glm::yawPitchRoll(asc, inc, arg) * glm::translate(glm::dvec3(P, 0.0, -Q));
 284 }
 285
 286 glm::dmat4 Orbit::InverseMatrix(double t) const noexcept {
 287         double M = mna + t;
 288         double E = mean2eccentric(M, ecc);
 289         double P = sma * (cos(E) - ecc);
 290         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 291         return glm::translate(glm::dvec3(-P, 0.0, Q)) * glm::transpose(glm::yawPitchRoll(asc, inc, arg));
 292 }
 293
 294
 295 Planet::Planet(int sidelength)
 296 : Body()
 297 , sidelength(sidelength)
 298 , tiles(TilesTotal())
 299 , vao() {
 300         Radius(double(sidelength) / 2.0);
 301 }
 302
 303 Planet::~Planet() {
 304 }
 305
 306 const TileType &Planet::TypeAt(int srf, int x, int y) const {
 307         return GetSimulation().TileTypes()[TileAt(srf, x, y).type];
 308 }
 309
 310 glm::ivec2 Planet::SurfacePosition(int srf, const glm::dvec3 &pos) const noexcept {
 311         return glm::ivec2(
 312                 PositionToTile(pos[(srf + 0) % 3]),
 313                 PositionToTile(pos[(srf + 1) % 3]));
 314 }
 315
 316 double Planet::SurfaceElevation(int srf, const glm::dvec3 &pos) const noexcept {
 317         return srf < 3
 318                 ? pos[(srf + 2) % 3] - Radius()
 319                 : -pos[(srf + 2) % 3] - Radius();
 320 }
 321
 322 glm::dvec3 Planet::TileCenter(int srf, int x, int y, double e) const noexcept {
 323         glm::dvec3 center(0.0f);
 324         center[(srf + 0) % 3] = x + 0.5 - Radius();
 325         center[(srf + 1) % 3] = y + 0.5 - Radius();
 326         center[(srf + 2) % 3] = srf < 3 ? (Radius() + e) : -(Radius() + e);
 327         return center;
 328 }
 329
 330 void Planet::BuildVAO(const Set<TileType> &ts) {
 331         vao.reset(new graphics::SimpleVAO<Attributes, unsigned int>);
 332         vao->Bind();
 333         vao->BindAttributes();
 334         vao->EnableAttribute(0);
 335         vao->EnableAttribute(1);
 336         vao->AttributePointer<glm::vec3>(0, false, offsetof(Attributes, position));
 337         vao->AttributePointer<glm::vec3>(1, false, offsetof(Attributes, tex_coord));
 338         vao->ReserveAttributes(TilesTotal() * 4, GL_STATIC_DRAW);
 339         {
 340                 auto attrib = vao->MapAttributes(GL_WRITE_ONLY);
 341                 float offset = Radius();
 342
 343                 // srf  0  1  2  3  4  5
 344                 //  up +Z +X +Y -Z -X -Y
 345
 346                 for (int index = 0, surface = 0; surface < 6; ++surface) {
 347                         for (int y = 0; y < sidelength; ++y) {
 348                                 for (int x = 0; x < sidelength; ++x, ++index) {
 349                                         float tex = ts[TileAt(surface, x, y).type].texture;
 350                                         const float tex_u_begin = surface < 3 ? 1.0f : 0.0f;
 351                                         const float tex_u_end = surface < 3 ? 0.0f : 1.0f;
 352                                         attrib[4 * index + 0].position[(surface + 0) % 3] = x + 0 - offset;
 353                                         attrib[4 * index + 0].position[(surface + 1) % 3] = y + 0 - offset;
 354                                         attrib[4 * index + 0].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 355                                         attrib[4 * index + 0].tex_coord[0] = tex_u_begin;
 356                                         attrib[4 * index + 0].tex_coord[1] = 1.0f;
 357                                         attrib[4 * index + 0].tex_coord[2] = tex;
 358
 359                                         attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
 360                                         attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
 361                                         attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 362                                         attrib[4 * index + 1].tex_coord[0] = tex_u_end;
 363                                         attrib[4 * index + 1].tex_coord[1] = 1.0f;
 364                                         attrib[4 * index + 1].tex_coord[2] = tex;
 365
 366                                         attrib[4 * index + 2].position[(surface + 0) % 3] = x + 1 - offset;
 367                                         attrib[4 * index + 2].position[(surface + 1) % 3] = y + 0 - offset;
 368                                         attrib[4 * index + 2].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 369                                         attrib[4 * index + 2].tex_coord[0] = tex_u_begin;
 370                                         attrib[4 * index + 2].tex_coord[1] = 0.0f;
 371                                         attrib[4 * index + 2].tex_coord[2] = tex;
 372
 373                                         attrib[4 * index + 3].position[(surface + 0) % 3] = x + 1 - offset;
 374                                         attrib[4 * index + 3].position[(surface + 1) % 3] = y + 1 - offset;
 375                                         attrib[4 * index + 3].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 376                                         attrib[4 * index + 3].tex_coord[0] = tex_u_end;
 377                                         attrib[4 * index + 3].tex_coord[1] = 0.0f;
 378                                         attrib[4 * index + 3].tex_coord[2] = tex;
 379                                 }
 380                         }
 381                 }
 382         }
 383         vao->BindElements();
 384         vao->ReserveElements(TilesTotal() * 6, GL_STATIC_DRAW);
 385         {
 386                 auto element = vao->MapElements(GL_WRITE_ONLY);
 387                 int index = 0;
 388                 for (int surface = 0; surface < 3; ++surface) {
 389                         for (int y = 0; y < sidelength; ++y) {
 390                                 for (int x = 0; x < sidelength; ++x, ++index) {
 391                                         element[6 * index + 0] = 4 * index + 0;
 392                                         element[6 * index + 1] = 4 * index + 2;
 393                                         element[6 * index + 2] = 4 * index + 1;
 394                                         element[6 * index + 3] = 4 * index + 1;
 395                                         element[6 * index + 4] = 4 * index + 2;
 396                                         element[6 * index + 5] = 4 * index + 3;
 397                                 }
 398                         }
 399                 }
 400                 for (int surface = 3; surface < 6; ++surface) {
 401                         for (int y = 0; y < sidelength; ++y) {
 402                                 for (int x = 0; x < sidelength; ++x, ++index) {
 403                                         element[6 * index + 0] = 4 * index + 0;
 404                                         element[6 * index + 1] = 4 * index + 1;
 405                                         element[6 * index + 2] = 4 * index + 2;
 406                                         element[6 * index + 3] = 4 * index + 2;
 407                                         element[6 * index + 4] = 4 * index + 1;
 408                                         element[6 * index + 5] = 4 * index + 3;
 409                                 }
 410                         }
 411                 }
 412         }
 413         vao->Unbind();
 414 }
 415
 416 void Planet::Draw(app::Assets &assets, graphics::Viewport &viewport) {
 417         if (!vao) return;
 418
 419         vao->Bind();
 420         const glm::mat4 &MV = assets.shaders.planet_surface.MV();
 421         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, 1.0f, 0.0f)));
 422         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 0);
 423         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(1.0f, 0.0f, 0.0f, 0.0f)));
 424         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 1);
 425         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 1.0f, 0.0f, 0.0f)));
 426         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 2);
 427         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, -1.0f, 0.0f)));
 428         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 3);
 429         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(-1.0f, 0.0f, 0.0f, 0.0f)));
 430         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 4);
 431         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, -1.0f, 0.0f, 0.0f)));
 432         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 5);
 433 }
 434
 435
 436 void GenerateEarthlike(const Set<TileType> &tiles, Planet &p) noexcept {
 437         math::SimplexNoise elevation_gen(0);
 438         math::SimplexNoise variation_gen(45623752346);
 439
 440         const int ice = tiles["ice"].id;
 441         const int ocean = tiles["ocean"].id;
 442         const int water = tiles["water"].id;
 443         const int sand = tiles["sand"].id;
 444         const int grass = tiles["grass"].id;
 445         const int tundra = tiles["tundra"].id;
 446         const int taiga = tiles["taiga"].id;
 447         const int desert = tiles["desert"].id;
 448         const int mntn = tiles["mountain"].id;
 449         const int algae = tiles["algae"].id;
 450         const int forest = tiles["forest"].id;
 451         const int jungle = tiles["jungle"].id;
 452         const int rock = tiles["rock"].id;
 453         const int wheat = tiles["wheat"].id;
 454
 455         constexpr double ocean_thresh = -0.2;
 456         constexpr double water_thresh = 0.0;
 457         constexpr double beach_thresh = 0.05;
 458         constexpr double highland_thresh = 0.4;
 459         constexpr double mountain_thresh = 0.5;
 460
 461         const glm::dvec3 axis(glm::dvec4(0.0, 1.0, 0.0, 0.0) * glm::eulerAngleXY(p.SurfaceTilt().x, p.SurfaceTilt().y));
 462         const double cap_thresh = std::abs(std::cos(p.AxialTilt().x));
 463         const double equ_thresh = std::abs(std::sin(p.AxialTilt().x)) / 2.0;
 464         const double fzone_start = equ_thresh - (equ_thresh - cap_thresh) / 3.0;
 465         const double fzone_end = cap_thresh + (equ_thresh - cap_thresh) / 3.0;
 466
 467         for (int surface = 0; surface <= 5; ++surface) {
 468                 for (int y = 0; y < p.SideLength(); ++y) {
 469                         for (int x = 0; x < p.SideLength(); ++x) {
 470                                 glm::dvec3 to_tile = p.TileCenter(surface, x, y);
 471                                 double near_axis = std::abs(glm::dot(glm::normalize(to_tile), axis));
 472                                 if (near_axis > cap_thresh) {
 473                                         p.TileAt(surface, x, y).type = ice;
 474                                         continue;
 475                                 }
 476                                 float elevation = math::OctaveNoise(
 477                                         elevation_gen,
 478                                         to_tile / p.Radius(),
 479                                         3,   // octaves
 480                                         0.5, // persistence
 481                                         5 / p.Radius(), // frequency
 482                                         2,   // amplitude
 483                                         2    // growth
 484                                 );
 485                                 float variation = math::OctaveNoise(
 486                                         variation_gen,
 487                                         to_tile / p.Radius(),
 488                                         3,   // octaves
 489                                         0.5, // persistence
 490                                         16 / p.Radius(), // frequency
 491                                         2,   // amplitude
 492                                         2    // growth
 493                                 );
 494                                 if (elevation < ocean_thresh) {
 495                                         p.TileAt(surface, x, y).type = ocean;
 496                                 } else if (elevation < water_thresh) {
 497                                         if (variation > 0.3) {
 498                                                 p.TileAt(surface, x, y).type = algae;
 499                                         } else {
 500                                                 p.TileAt(surface, x, y).type = water;
 501                                         }
 502                                 } else if (elevation < beach_thresh) {
 503                                         p.TileAt(surface, x, y).type = sand;
 504                                 } else if (elevation < highland_thresh) {
 505                                         if (near_axis < equ_thresh) {
 506                                                 if (variation > 0.6) {
 507                                                         p.TileAt(surface, x, y).type = grass;
 508                                                 } else if (variation > 0.2) {
 509                                                         p.TileAt(surface, x, y).type = sand;
 510                                                 } else {
 511                                                         p.TileAt(surface, x, y).type = desert;
 512                                                 }
 513                                         } else if (near_axis < fzone_start) {
 514                                                 if (variation > 0.4) {
 515                                                         p.TileAt(surface, x, y).type = forest;
 516                                                 } else if (variation < -0.5) {
 517                                                         p.TileAt(surface, x, y).type = jungle;
 518                                                 } else if (variation > -0.02 && variation < 0.02) {
 519                                                         p.TileAt(surface, x, y).type = wheat;
 520                                                 } else {
 521                                                         p.TileAt(surface, x, y).type = grass;
 522                                                 }
 523                                         } else if (near_axis < fzone_end) {
 524                                                 p.TileAt(surface, x, y).type = tundra;
 525                                         } else {
 526                                                 p.TileAt(surface, x, y).type = taiga;
 527                                         }
 528                                 } else if (elevation < mountain_thresh) {
 529                                         if (variation > 0.3) {
 530                                                 p.TileAt(surface, x, y).type = mntn;
 531                                         } else {
 532                                                 p.TileAt(surface, x, y).type = rock;
 533                                         }
 534                                 } else {
 535                                         p.TileAt(surface, x, y).type = mntn;
 536                                 }
 537                         }
 538                 }
 539         }
 540         p.BuildVAO(tiles);
 541 }
 542
 543 void GenerateTest(const Set<TileType> &tiles, Planet &p) noexcept {
 544         for (int surface = 0; surface <= 5; ++surface) {
 545                 for (int y = 0; y < p.SideLength(); ++y) {
 546                         for (int x = 0; x < p.SideLength(); ++x) {
 547                                 if (x == p.SideLength() / 2 && y == p.SideLength() / 2) {
 548                                         p.TileAt(surface, x, y).type = surface;
 549                                 } else {
 550                                         p.TileAt(surface, x, y).type = (x == p.SideLength()/2) + (y == p.SideLength()/2) + 6;
 551                                 }
 552                         }
 553                 }
 554         }
 555         p.BuildVAO(tiles);
 556 }
 557
 558
 559 Sun::Sun()
 560 : Body() {
 561 }
 562
 563 Sun::~Sun() {
 564 }
 565
 566
 567 std::vector<TileType::Yield>::const_iterator TileType::FindResource(int r) const {
 568         auto yield = resources.cbegin();
 569         for (; yield != resources.cend(); ++yield) {
 570                 if (yield->resource == r) {
 571                         break;
 572                 }
 573         }
 574         return yield;
 575 }
 576
 577 }
 578 }