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