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/Composition.hpp"
  13 #include "../creature/Creature.hpp"
  14 #include "../graphics/Viewport.hpp"
  15 #include "../math/const.hpp"
  16 #include "../math/OctaveNoise.hpp"
  17 #include "../math/SimplexNoise.hpp"
  18
  19 #include <algorithm>
  20 #include <cmath>
  21 #include <iostream>
  22 #include <glm/gtc/matrix_transform.hpp>
  23 #include <glm/gtx/euler_angles.hpp>
  24 #include <glm/gtx/io.hpp>
  25 #include <glm/gtx/transform.hpp>
  26
  27 using blobs::G;
  28 using blobs::PI_2p0;
  29
  30 using std::sin;
  31 using std::cos;
  32 using std::pow;
  33 using std::sqrt;
  34
  35
  36 namespace blobs {
  37 namespace world {
  38
  39 Body::Body()
  40 : sim(nullptr)
  41 , parent(nullptr)
  42 , children()
  43 , mass(1.0)
  44 , radius(1.0)
  45 , orbit()
  46 , surface_tilt(0.0, 0.0)
  47 , axis_tilt(0.0, 0.0)
  48 , rotation(0.0)
  49 , angular(0.0)
  50 , orbital(1.0)
  51 , inverse_orbital(1.0)
  52 , local(1.0)
  53 , inverse_local(1.0)
  54 , creatures()
  55 , atmosphere(-1) {
  56 }
  57
  58 Body::~Body() {
  59         for (creature::Creature *c : creatures) {
  60                 delete c;
  61         }
  62 }
  63
  64 void Body::SetSimulation(Simulation &s) noexcept {
  65         sim = &s;
  66         for (auto child : children) {
  67                 child->SetSimulation(s);
  68         }
  69 }
  70
  71 void Body::SetParent(Body &p) {
  72         if (HasParent()) {
  73                 UnsetParent();
  74         }
  75         parent = &p;
  76         parent->AddChild(*this);
  77 }
  78
  79 void Body::UnsetParent() {
  80         if (!HasParent()) return;
  81         parent->RemoveChild(*this);
  82         parent = nullptr;
  83 }
  84
  85 void Body::AddChild(Body &c) {
  86         children.push_back(&c);
  87         c.SetSimulation(*sim);
  88 }
  89
  90 void Body::RemoveChild(Body &c) {
  91         auto entry = std::find(children.begin(), children.end(), &c);
  92         if (entry != children.end()) {
  93                 children.erase(entry);
  94         }
  95 }
  96
  97 double Body::Inertia() const noexcept {
  98         // assume solid sphere for now
  99         return (2.0/5.0) * Mass() * pow(Radius(), 2);
 100 }
 101
 102 double Body::GravitationalParameter() const noexcept {
 103         return G * Mass();
 104 }
 105
 106 double Body::OrbitalPeriod() const noexcept {
 107         if (parent) {
 108                 return PI_2p0 * sqrt(pow(orbit.SemiMajorAxis(), 3) / (G * (parent->Mass() + Mass())));
 109         } else {
 110                 return 0.0;
 111         }
 112 }
 113
 114 double Body::RotationalPeriod() const noexcept {
 115         if (std::abs(angular) < std::numeric_limits<double>::epsilon()) {
 116                 return std::numeric_limits<double>::infinity();
 117         } else {
 118                 return PI_2p0 * Inertia() / angular;
 119         }
 120 }
 121
 122 glm::dmat4 Body::ToUniverse() const noexcept {
 123         glm::dmat4 m(1.0);
 124         const Body *b = this;
 125         while (b->HasParent()) {
 126                 m = b->ToParent() * m;
 127                 b = &b->Parent();
 128         }
 129         return m;
 130 }
 131
 132 glm::dmat4 Body::FromUniverse() const noexcept {
 133         glm::dmat4 m(1.0);
 134         const Body *b = this;
 135         while (b->HasParent()) {
 136                 m *= b->FromParent();
 137                 b = &b->Parent();
 138         }
 139         return m;
 140 }
 141
 142 namespace {
 143 std::vector<creature::Creature *> ccache;
 144 }
 145
 146 void Body::Tick(double dt) {
 147         rotation += dt * AngularMomentum() / Inertia();
 148         Cache();
 149         ccache = Creatures();
 150         for (creature::Creature *c : ccache) {
 151                 c->Tick(dt);
 152         }
 153         for (auto c = Creatures().begin(); c != Creatures().end();) {
 154                 if ((*c)->Removable()) {
 155                         delete *c;
 156                         c = Creatures().erase(c);
 157                 } else {
 158                         ++c;
 159                 }
 160         }
 161 }
 162
 163 void Body::Cache() noexcept {
 164         if (parent) {
 165                 orbital =
 166                         orbit.Matrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()))
 167                         * glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 168                 inverse_orbital =
 169                         glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x)
 170                         * orbit.InverseMatrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
 171         } else {
 172                 orbital = glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 173                 inverse_orbital = glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x);
 174         }
 175         local =
 176                 glm::eulerAngleY(rotation)
 177                 * glm::eulerAngleXY(surface_tilt.x, surface_tilt.y);
 178         inverse_local =
 179                 glm::eulerAngleYX(-surface_tilt.y, -surface_tilt.x)
 180                 * glm::eulerAngleY(-rotation);
 181 }
 182
 183 void Body::AddCreature(creature::Creature *c) {
 184         creatures.push_back(c);
 185 }
 186
 187 void Body::RemoveCreature(creature::Creature *c) {
 188         auto entry = std::find(creatures.begin(), creatures.end(), c);
 189         if (entry != creatures.end()) {
 190                 creatures.erase(entry);
 191         }
 192 }
 193
 194
 195 Orbit::Orbit()
 196 : sma(1.0)
 197 , ecc(0.0)
 198 , inc(0.0)
 199 , asc(0.0)
 200 , arg(0.0)
 201 , mna(0.0) {
 202 }
 203
 204 Orbit::~Orbit() {
 205 }
 206
 207 double Orbit::SemiMajorAxis() const noexcept {
 208         return sma;
 209 }
 210
 211 Orbit &Orbit::SemiMajorAxis(double s) noexcept {
 212         sma = s;
 213         return *this;
 214 }
 215
 216 double Orbit::Eccentricity() const noexcept {
 217         return ecc;
 218 }
 219
 220 Orbit &Orbit::Eccentricity(double e) noexcept {
 221         ecc = e;
 222         return *this;
 223 }
 224
 225 double Orbit::Inclination() const noexcept {
 226         return inc;
 227 }
 228
 229 Orbit &Orbit::Inclination(double i) noexcept {
 230         inc = i;
 231         return *this;
 232 }
 233
 234 double Orbit::LongitudeAscending() const noexcept {
 235         return asc;
 236 }
 237
 238 Orbit &Orbit::LongitudeAscending(double l) noexcept {
 239         asc = l;
 240         return *this;
 241 }
 242
 243 double Orbit::ArgumentPeriapsis() const noexcept {
 244         return arg;
 245 }
 246
 247 Orbit &Orbit::ArgumentPeriapsis(double a) noexcept {
 248         arg = a;
 249         return *this;
 250 }
 251
 252 double Orbit::MeanAnomaly() const noexcept {
 253         return mna;
 254 }
 255
 256 Orbit &Orbit::MeanAnomaly(double m) noexcept {
 257         mna = m;
 258         return *this;
 259 }
 260
 261 namespace {
 262
 263 double mean2eccentric(double M, double e) {
 264         double E = M; // eccentric anomaly, solve M = E - e sin E
 265         // limit to 100 steps to prevent deadlocks in impossible situations
 266         for (int i = 0; i < 100; ++i) {
 267                 double dE = (E - e * sin(E) - M) / (1 - e * cos(E));
 268                 E -= dE;
 269                 if (abs(dE) < 1.0e-6) break;
 270         }
 271         return E;
 272 }
 273
 274 }
 275
 276 glm::dmat4 Orbit::Matrix(double t) const noexcept {
 277         double M = mna + t;
 278         double E = mean2eccentric(M, ecc);
 279
 280         // coordinates in orbital plane, P=x, Q=-z
 281         double P = sma * (cos(E) - ecc);
 282         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 283
 284         return glm::yawPitchRoll(asc, inc, arg) * glm::translate(glm::dvec3(P, 0.0, -Q));
 285 }
 286
 287 glm::dmat4 Orbit::InverseMatrix(double t) const noexcept {
 288         double M = mna + t;
 289         double E = mean2eccentric(M, ecc);
 290         double P = sma * (cos(E) - ecc);
 291         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 292         return glm::translate(glm::dvec3(-P, 0.0, Q)) * glm::transpose(glm::yawPitchRoll(asc, inc, arg));
 293 }
 294
 295
 296 Planet::Planet(int sidelength)
 297 : Body()
 298 , sidelength(sidelength)
 299 , tiles(TilesTotal())
 300 , vao() {
 301         Radius(double(sidelength) / 2.0);
 302 }
 303
 304 Planet::~Planet() {
 305 }
 306
 307 const TileType &Planet::TypeAt(int srf, int x, int y) const {
 308         return GetSimulation().TileTypes()[TileAt(srf, x, y).type];
 309 }
 310
 311 glm::ivec2 Planet::SurfacePosition(int srf, const glm::dvec3 &pos) const noexcept {
 312         return glm::ivec2(
 313                 PositionToTile(pos[(srf + 0) % 3]),
 314                 PositionToTile(pos[(srf + 1) % 3]));
 315 }
 316
 317 double Planet::SurfaceElevation(int srf, const glm::dvec3 &pos) const noexcept {
 318         return srf < 3
 319                 ? pos[(srf + 2) % 3] - Radius()
 320                 : -pos[(srf + 2) % 3] - Radius();
 321 }
 322
 323 glm::dvec3 Planet::TileCenter(int srf, int x, int y, double e) const noexcept {
 324         glm::dvec3 center(0.0f);
 325         center[(srf + 0) % 3] = x + 0.5 - Radius();
 326         center[(srf + 1) % 3] = y + 0.5 - Radius();
 327         center[(srf + 2) % 3] = srf < 3 ? (Radius() + e) : -(Radius() + e);
 328         return center;
 329 }
 330
 331 void Planet::BuildVAO(const Set<TileType> &ts) {
 332         vao.reset(new graphics::SimpleVAO<Attributes, unsigned int>);
 333         vao->Bind();
 334         vao->BindAttributes();
 335         vao->EnableAttribute(0);
 336         vao->EnableAttribute(1);
 337         vao->AttributePointer<glm::vec3>(0, false, offsetof(Attributes, position));
 338         vao->AttributePointer<glm::vec3>(1, false, offsetof(Attributes, tex_coord));
 339         vao->ReserveAttributes(TilesTotal() * 4, GL_STATIC_DRAW);
 340         {
 341                 auto attrib = vao->MapAttributes(GL_WRITE_ONLY);
 342                 float offset = Radius();
 343
 344                 // srf  0  1  2  3  4  5
 345                 //  up +Z +X +Y -Z -X -Y
 346
 347                 for (int index = 0, surface = 0; surface < 6; ++surface) {
 348                         for (int y = 0; y < sidelength; ++y) {
 349                                 for (int x = 0; x < sidelength; ++x, ++index) {
 350                                         float tex = ts[TileAt(surface, x, y).type].texture;
 351                                         const float tex_v_begin = surface < 3 ? 1.0f : 0.0f;
 352                                         const float tex_v_end = surface < 3 ? 0.0f : 1.0f;
 353                                         attrib[4 * index + 0].position[(surface + 0) % 3] = x + 0 - offset;
 354                                         attrib[4 * index + 0].position[(surface + 1) % 3] = y + 0 - offset;
 355                                         attrib[4 * index + 0].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 356                                         attrib[4 * index + 0].tex_coord[0] = 0.0f;
 357                                         attrib[4 * index + 0].tex_coord[1] = tex_v_begin;
 358                                         attrib[4 * index + 0].tex_coord[2] = tex;
 359
 360                                         attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
 361                                         attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
 362                                         attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 363                                         attrib[4 * index + 1].tex_coord[0] = 0.0f;
 364                                         attrib[4 * index + 1].tex_coord[1] = tex_v_end;
 365                                         attrib[4 * index + 1].tex_coord[2] = tex;
 366
 367                                         attrib[4 * index + 2].position[(surface + 0) % 3] = x + 1 - offset;
 368                                         attrib[4 * index + 2].position[(surface + 1) % 3] = y + 0 - offset;
 369                                         attrib[4 * index + 2].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 370                                         attrib[4 * index + 2].tex_coord[0] = 1.0f;
 371                                         attrib[4 * index + 2].tex_coord[1] = tex_v_begin;
 372                                         attrib[4 * index + 2].tex_coord[2] = tex;
 373
 374                                         attrib[4 * index + 3].position[(surface + 0) % 3] = x + 1 - offset;
 375                                         attrib[4 * index + 3].position[(surface + 1) % 3] = y + 1 - offset;
 376                                         attrib[4 * index + 3].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 377                                         attrib[4 * index + 3].tex_coord[0] = 1.0f;
 378                                         attrib[4 * index + 3].tex_coord[1] = tex_v_end;
 379                                         attrib[4 * index + 3].tex_coord[2] = tex;
 380                                 }
 381                         }
 382                 }
 383         }
 384         vao->BindElements();
 385         vao->ReserveElements(TilesTotal() * 6, GL_STATIC_DRAW);
 386         {
 387                 auto element = vao->MapElements(GL_WRITE_ONLY);
 388                 int index = 0;
 389                 for (int surface = 0; surface < 3; ++surface) {
 390                         for (int y = 0; y < sidelength; ++y) {
 391                                 for (int x = 0; x < sidelength; ++x, ++index) {
 392                                         element[6 * index + 0] = 4 * index + 0;
 393                                         element[6 * index + 1] = 4 * index + 2;
 394                                         element[6 * index + 2] = 4 * index + 1;
 395                                         element[6 * index + 3] = 4 * index + 1;
 396                                         element[6 * index + 4] = 4 * index + 2;
 397                                         element[6 * index + 5] = 4 * index + 3;
 398                                 }
 399                         }
 400                 }
 401                 for (int surface = 3; surface < 6; ++surface) {
 402                         for (int y = 0; y < sidelength; ++y) {
 403                                 for (int x = 0; x < sidelength; ++x, ++index) {
 404                                         element[6 * index + 0] = 4 * index + 0;
 405                                         element[6 * index + 1] = 4 * index + 1;
 406                                         element[6 * index + 2] = 4 * index + 2;
 407                                         element[6 * index + 3] = 4 * index + 2;
 408                                         element[6 * index + 4] = 4 * index + 1;
 409                                         element[6 * index + 5] = 4 * index + 3;
 410                                 }
 411                         }
 412                 }
 413         }
 414         vao->Unbind();
 415 }
 416
 417 void Planet::Draw(app::Assets &assets, graphics::Viewport &viewport) {
 418         if (!vao) return;
 419
 420         vao->Bind();
 421         const glm::mat4 &MV = assets.shaders.planet_surface.MV();
 422         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, 1.0f, 0.0f)));
 423         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 0);
 424         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(1.0f, 0.0f, 0.0f, 0.0f)));
 425         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 1);
 426         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 1.0f, 0.0f, 0.0f)));
 427         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 2);
 428         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, -1.0f, 0.0f)));
 429         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 3);
 430         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(-1.0f, 0.0f, 0.0f, 0.0f)));
 431         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 4);
 432         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, -1.0f, 0.0f, 0.0f)));
 433         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 5);
 434 }
 435
 436
 437 void GenerateEarthlike(const Set<TileType> &tiles, Planet &p) noexcept {
 438         math::SimplexNoise elevation_gen(0);
 439         math::SimplexNoise variation_gen(45623752346);
 440
 441         const int ice = tiles["ice"].id;
 442         const int ocean = tiles["ocean"].id;
 443         const int water = tiles["water"].id;
 444         const int sand = tiles["sand"].id;
 445         const int grass = tiles["grass"].id;
 446         const int tundra = tiles["tundra"].id;
 447         const int taiga = tiles["taiga"].id;
 448         const int desert = tiles["desert"].id;
 449         const int mntn = tiles["mountain"].id;
 450         const int algae = tiles["algae"].id;
 451         const int forest = tiles["forest"].id;
 452         const int jungle = tiles["jungle"].id;
 453         const int rock = tiles["rock"].id;
 454         const int wheat = tiles["wheat"].id;
 455
 456         constexpr double ocean_thresh = -0.2;
 457         constexpr double water_thresh = 0.0;
 458         constexpr double beach_thresh = 0.05;
 459         constexpr double highland_thresh = 0.4;
 460         constexpr double mountain_thresh = 0.5;
 461
 462         const glm::dvec3 axis(glm::dvec4(0.0, 1.0, 0.0, 0.0) * glm::eulerAngleXY(p.SurfaceTilt().x, p.SurfaceTilt().y));
 463         const double cap_thresh = std::abs(std::cos(p.AxialTilt().x));
 464         const double equ_thresh = std::abs(std::sin(p.AxialTilt().x)) / 2.0;
 465         const double fzone_start = equ_thresh - (equ_thresh - cap_thresh) / 3.0;
 466         const double fzone_end = cap_thresh + (equ_thresh - cap_thresh) / 3.0;
 467
 468         for (int surface = 0; surface <= 5; ++surface) {
 469                 for (int y = 0; y < p.SideLength(); ++y) {
 470                         for (int x = 0; x < p.SideLength(); ++x) {
 471                                 glm::dvec3 to_tile = p.TileCenter(surface, x, y);
 472                                 double near_axis = std::abs(glm::dot(glm::normalize(to_tile), axis));
 473                                 if (near_axis > cap_thresh) {
 474                                         p.TileAt(surface, x, y).type = ice;
 475                                         continue;
 476                                 }
 477                                 float elevation = math::OctaveNoise(
 478                                         elevation_gen,
 479                                         to_tile / p.Radius(),
 480                                         3,   // octaves
 481                                         0.5, // persistence
 482                                         5 / p.Radius(), // frequency
 483                                         2,   // amplitude
 484                                         2    // growth
 485                                 );
 486                                 float variation = math::OctaveNoise(
 487                                         variation_gen,
 488                                         to_tile / p.Radius(),
 489                                         3,   // octaves
 490                                         0.5, // persistence
 491                                         16 / p.Radius(), // frequency
 492                                         2,   // amplitude
 493                                         2    // growth
 494                                 );
 495                                 if (elevation < ocean_thresh) {
 496                                         p.TileAt(surface, x, y).type = ocean;
 497                                 } else if (elevation < water_thresh) {
 498                                         if (variation > 0.3) {
 499                                                 p.TileAt(surface, x, y).type = algae;
 500                                         } else {
 501                                                 p.TileAt(surface, x, y).type = water;
 502                                         }
 503                                 } else if (elevation < beach_thresh) {
 504                                         p.TileAt(surface, x, y).type = sand;
 505                                 } else if (elevation < highland_thresh) {
 506                                         if (near_axis < equ_thresh) {
 507                                                 if (variation > 0.6) {
 508                                                         p.TileAt(surface, x, y).type = grass;
 509                                                 } else if (variation > 0.2) {
 510                                                         p.TileAt(surface, x, y).type = sand;
 511                                                 } else {
 512                                                         p.TileAt(surface, x, y).type = desert;
 513                                                 }
 514                                         } else if (near_axis < fzone_start) {
 515                                                 if (variation > 0.4) {
 516                                                         p.TileAt(surface, x, y).type = forest;
 517                                                 } else if (variation < -0.5) {
 518                                                         p.TileAt(surface, x, y).type = jungle;
 519                                                 } else if (variation > -0.02 && variation < 0.02) {
 520                                                         p.TileAt(surface, x, y).type = wheat;
 521                                                 } else {
 522                                                         p.TileAt(surface, x, y).type = grass;
 523                                                 }
 524                                         } else if (near_axis < fzone_end) {
 525                                                 p.TileAt(surface, x, y).type = tundra;
 526                                         } else {
 527                                                 p.TileAt(surface, x, y).type = taiga;
 528                                         }
 529                                 } else if (elevation < mountain_thresh) {
 530                                         if (variation > 0.3) {
 531                                                 p.TileAt(surface, x, y).type = mntn;
 532                                         } else {
 533                                                 p.TileAt(surface, x, y).type = rock;
 534                                         }
 535                                 } else {
 536                                         p.TileAt(surface, x, y).type = mntn;
 537                                 }
 538                         }
 539                 }
 540         }
 541         p.BuildVAO(tiles);
 542 }
 543
 544 void GenerateTest(const Set<TileType> &tiles, Planet &p) noexcept {
 545         for (int surface = 0; surface <= 5; ++surface) {
 546                 for (int y = 0; y < p.SideLength(); ++y) {
 547                         for (int x = 0; x < p.SideLength(); ++x) {
 548                                 if (x == p.SideLength() / 2 && y == p.SideLength() / 2) {
 549                                         p.TileAt(surface, x, y).type = surface;
 550                                 } else {
 551                                         p.TileAt(surface, x, y).type = (x == p.SideLength()/2) + (y == p.SideLength()/2) + 6;
 552                                 }
 553                         }
 554                 }
 555         }
 556         p.BuildVAO(tiles);
 557 }
 558
 559
 560 Sun::Sun()
 561 : Body() {
 562 }
 563
 564 Sun::~Sun() {
 565 }
 566
 567
 568 std::vector<TileType::Yield>::const_iterator TileType::FindResource(int r) const {
 569         auto yield = resources.cbegin();
 570         for (; yield != resources.cend(); ++yield) {
 571                 if (yield->resource == r) {
 572                         break;
 573                 }
 574         }
 575         return yield;
 576 }
 577
 578 std::vector<TileType::Yield>::const_iterator TileType::FindBestResource(const creature::Composition &comp) const {
 579         auto best = resources.cend();
 580         double best_value = 0.0;
 581         for (auto yield = resources.cbegin(); yield != resources.cend(); ++yield) {
 582                 double value = comp.Get(yield->resource);
 583                 if (value > best_value) {
 584                         best = yield;
 585                         best_value = value;
 586                 }
 587         }
 588         return best;
 589 }
 590
 591 }
 592 }