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 "../const.hpp"
  12 #include "../app/Assets.hpp"
  13 #include "../creature/Creature.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 , 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 }
 148
 149 void Body::Cache() noexcept {
 150         if (parent) {
 151                 orbital =
 152                         orbit.Matrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()))
 153                         * glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 154                 inverse_orbital =
 155                         glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x)
 156                         * orbit.InverseMatrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
 157         } else {
 158                 orbital = glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 159                 inverse_orbital = glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x);
 160         }
 161         local =
 162                 glm::eulerAngleY(rotation)
 163                 * glm::eulerAngleXY(surface_tilt.x, surface_tilt.y);
 164         inverse_local =
 165                 glm::eulerAngleYX(-surface_tilt.y, -surface_tilt.x)
 166                 * glm::eulerAngleY(-rotation);
 167 }
 168
 169 void Body::AddCreature(creature::Creature *c) {
 170         c->SetBody(*this);
 171         creatures.push_back(c);
 172 }
 173
 174 void Body::RemoveCreature(creature::Creature *c) {
 175         auto entry = std::find(creatures.begin(), creatures.end(), c);
 176         if (entry != creatures.end()) {
 177                 creatures.erase(entry);
 178         }
 179 }
 180
 181
 182 Orbit::Orbit()
 183 : sma(1.0)
 184 , ecc(0.0)
 185 , inc(0.0)
 186 , asc(0.0)
 187 , arg(0.0)
 188 , mna(0.0) {
 189 }
 190
 191 Orbit::~Orbit() {
 192 }
 193
 194 double Orbit::SemiMajorAxis() const noexcept {
 195         return sma;
 196 }
 197
 198 Orbit &Orbit::SemiMajorAxis(double s) noexcept {
 199         sma = s;
 200         return *this;
 201 }
 202
 203 double Orbit::Eccentricity() const noexcept {
 204         return ecc;
 205 }
 206
 207 Orbit &Orbit::Eccentricity(double e) noexcept {
 208         ecc = e;
 209         return *this;
 210 }
 211
 212 double Orbit::Inclination() const noexcept {
 213         return inc;
 214 }
 215
 216 Orbit &Orbit::Inclination(double i) noexcept {
 217         inc = i;
 218         return *this;
 219 }
 220
 221 double Orbit::LongitudeAscending() const noexcept {
 222         return asc;
 223 }
 224
 225 Orbit &Orbit::LongitudeAscending(double l) noexcept {
 226         asc = l;
 227         return *this;
 228 }
 229
 230 double Orbit::ArgumentPeriapsis() const noexcept {
 231         return arg;
 232 }
 233
 234 Orbit &Orbit::ArgumentPeriapsis(double a) noexcept {
 235         arg = a;
 236         return *this;
 237 }
 238
 239 double Orbit::MeanAnomaly() const noexcept {
 240         return mna;
 241 }
 242
 243 Orbit &Orbit::MeanAnomaly(double m) noexcept {
 244         mna = m;
 245         return *this;
 246 }
 247
 248 namespace {
 249
 250 double mean2eccentric(double M, double e) {
 251         double E = M; // eccentric anomaly, solve M = E - e sin E
 252         // limit to 100 steps to prevent deadlocks in impossible situations
 253         for (int i = 0; i < 100; ++i) {
 254                 double dE = (E - e * sin(E) - M) / (1 - e * cos(E));
 255                 E -= dE;
 256                 if (abs(dE) < 1.0e-6) break;
 257         }
 258         return E;
 259 }
 260
 261 }
 262
 263 glm::dmat4 Orbit::Matrix(double t) const noexcept {
 264         double M = mna + t;
 265         double E = mean2eccentric(M, ecc);
 266
 267         // coordinates in orbital plane, P=x, Q=-z
 268         double P = sma * (cos(E) - ecc);
 269         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 270
 271         return glm::yawPitchRoll(asc, inc, arg) * glm::translate(glm::dvec3(P, 0.0, -Q));
 272 }
 273
 274 glm::dmat4 Orbit::InverseMatrix(double t) const noexcept {
 275         double M = mna + t;
 276         double E = mean2eccentric(M, ecc);
 277         double P = sma * (cos(E) - ecc);
 278         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 279         return glm::translate(glm::dvec3(-P, 0.0, Q)) * glm::transpose(glm::yawPitchRoll(asc, inc, arg));
 280 }
 281
 282
 283 Planet::Planet(int sidelength)
 284 : Body()
 285 , sidelength(sidelength)
 286 , tiles(TilesTotal())
 287 , vao() {
 288         Radius(double(sidelength) / 2.0);
 289 }
 290
 291 Planet::~Planet() {
 292 }
 293
 294 glm::dvec3 Planet::TileCenter(int surface, int x, int y) const noexcept {
 295         glm::dvec3 center(0.0f);
 296         center[(surface + 0) % 3] = x + 0.5 - Radius();
 297         center[(surface + 1) % 3] = y + 0.5 - Radius();
 298         center[(surface + 2) % 3] = surface < 3 ? Radius() : -Radius();
 299         return center;
 300 }
 301
 302 void Planet::BuildVAO(const Set<TileType> &ts) {
 303         vao.Bind();
 304         vao.BindAttributes();
 305         vao.EnableAttribute(0);
 306         vao.EnableAttribute(1);
 307         vao.AttributePointer<glm::vec3>(0, false, offsetof(Attributes, position));
 308         vao.AttributePointer<glm::vec3>(1, false, offsetof(Attributes, tex_coord));
 309         vao.ReserveAttributes(TilesTotal() * 4, GL_STATIC_DRAW);
 310         {
 311                 auto attrib = vao.MapAttributes(GL_WRITE_ONLY);
 312                 float offset = Radius();
 313
 314                 // srf  0  1  2  3  4  5
 315                 //  up +Z +X +Y -Z -X -Y
 316
 317                 for (int index = 0, surface = 0; surface < 6; ++surface) {
 318                         for (int y = 0; y < sidelength; ++y) {
 319                                 for (int x = 0; x < sidelength; ++x, ++index) {
 320                                         float tex = ts[TileAt(surface, x, y).type].texture;
 321                                         const float tex_u_begin = surface < 3 ? 1.0f : 0.0f;
 322                                         const float tex_u_end = surface < 3 ? 0.0f : 1.0f;
 323                                         attrib[4 * index + 0].position[(surface + 0) % 3] = x + 0 - offset;
 324                                         attrib[4 * index + 0].position[(surface + 1) % 3] = y + 0 - offset;
 325                                         attrib[4 * index + 0].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 326                                         attrib[4 * index + 0].tex_coord[0] = tex_u_begin;
 327                                         attrib[4 * index + 0].tex_coord[1] = 1.0f;
 328                                         attrib[4 * index + 0].tex_coord[2] = tex;
 329
 330                                         attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
 331                                         attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
 332                                         attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 333                                         attrib[4 * index + 1].tex_coord[0] = tex_u_end;
 334                                         attrib[4 * index + 1].tex_coord[1] = 1.0f;
 335                                         attrib[4 * index + 1].tex_coord[2] = tex;
 336
 337                                         attrib[4 * index + 2].position[(surface + 0) % 3] = x + 1 - offset;
 338                                         attrib[4 * index + 2].position[(surface + 1) % 3] = y + 0 - offset;
 339                                         attrib[4 * index + 2].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 340                                         attrib[4 * index + 2].tex_coord[0] = tex_u_begin;
 341                                         attrib[4 * index + 2].tex_coord[1] = 0.0f;
 342                                         attrib[4 * index + 2].tex_coord[2] = tex;
 343
 344                                         attrib[4 * index + 3].position[(surface + 0) % 3] = x + 1 - offset;
 345                                         attrib[4 * index + 3].position[(surface + 1) % 3] = y + 1 - offset;
 346                                         attrib[4 * index + 3].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 347                                         attrib[4 * index + 3].tex_coord[0] = tex_u_end;
 348                                         attrib[4 * index + 3].tex_coord[1] = 0.0f;
 349                                         attrib[4 * index + 3].tex_coord[2] = tex;
 350                                 }
 351                         }
 352                 }
 353         }
 354         vao.BindElements();
 355         vao.ReserveElements(TilesTotal() * 6, GL_STATIC_DRAW);
 356         {
 357                 auto element = vao.MapElements(GL_WRITE_ONLY);
 358                 int index = 0;
 359                 for (int surface = 0; surface < 3; ++surface) {
 360                         for (int y = 0; y < sidelength; ++y) {
 361                                 for (int x = 0; x < sidelength; ++x, ++index) {
 362                                         element[6 * index + 0] = 4 * index + 0;
 363                                         element[6 * index + 1] = 4 * index + 2;
 364                                         element[6 * index + 2] = 4 * index + 1;
 365                                         element[6 * index + 3] = 4 * index + 1;
 366                                         element[6 * index + 4] = 4 * index + 2;
 367                                         element[6 * index + 5] = 4 * index + 3;
 368                                 }
 369                         }
 370                 }
 371                 for (int surface = 3; surface < 6; ++surface) {
 372                         for (int y = 0; y < sidelength; ++y) {
 373                                 for (int x = 0; x < sidelength; ++x, ++index) {
 374                                         element[6 * index + 0] = 4 * index + 0;
 375                                         element[6 * index + 1] = 4 * index + 1;
 376                                         element[6 * index + 2] = 4 * index + 2;
 377                                         element[6 * index + 3] = 4 * index + 2;
 378                                         element[6 * index + 4] = 4 * index + 1;
 379                                         element[6 * index + 5] = 4 * index + 3;
 380                                 }
 381                         }
 382                 }
 383         }
 384         vao.Unbind();
 385 }
 386
 387 void Planet::Draw(app::Assets &assets, graphics::Viewport &viewport) {
 388         vao.Bind();
 389         const glm::mat4 &MV = assets.shaders.planet_surface.MV();
 390         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, 1.0f, 0.0f)));
 391         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 0);
 392         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(1.0f, 0.0f, 0.0f, 0.0f)));
 393         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 1);
 394         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 1.0f, 0.0f, 0.0f)));
 395         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 2);
 396         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, -1.0f, 0.0f)));
 397         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 3);
 398         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(-1.0f, 0.0f, 0.0f, 0.0f)));
 399         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 4);
 400         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, -1.0f, 0.0f, 0.0f)));
 401         vao.DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 5);
 402 }
 403
 404
 405 void GenerateEarthlike(const Set<TileType> &tiles, Planet &p) noexcept {
 406         rand::SimplexNoise elevation_gen(0);
 407         rand::SimplexNoise variation_gen(45623752346);
 408
 409         const int ice = tiles["ice"].id;
 410         const int ocean = tiles["ocean"].id;
 411         const int water = tiles["water"].id;
 412         const int sand = tiles["sand"].id;
 413         const int grass = tiles["grass"].id;
 414         const int tundra = tiles["tundra"].id;
 415         const int taiga = tiles["taiga"].id;
 416         const int desert = tiles["desert"].id;
 417         const int mntn = tiles["mountain"].id;
 418         const int algae = tiles["algae"].id;
 419         const int forest = tiles["forest"].id;
 420         const int jungle = tiles["jungle"].id;
 421         const int rock = tiles["rock"].id;
 422         const int wheat = tiles["wheat"].id;
 423
 424         constexpr double ocean_thresh = -0.2;
 425         constexpr double water_thresh = 0.0;
 426         constexpr double beach_thresh = 0.05;
 427         constexpr double highland_thresh = 0.4;
 428         constexpr double mountain_thresh = 0.5;
 429
 430         const glm::dvec3 axis(glm::dvec4(0.0, 1.0, 0.0, 0.0) * glm::eulerAngleXY(p.SurfaceTilt().x, p.SurfaceTilt().y));
 431         const double cap_thresh = std::abs(std::cos(p.AxialTilt().x));
 432         const double equ_thresh = std::abs(std::sin(p.AxialTilt().x)) / 2.0;
 433         const double fzone_start = equ_thresh - (equ_thresh - cap_thresh) / 3.0;
 434         const double fzone_end = cap_thresh + (equ_thresh - cap_thresh) / 3.0;
 435
 436         for (int surface = 0; surface <= 5; ++surface) {
 437                 for (int y = 0; y < p.SideLength(); ++y) {
 438                         for (int x = 0; x < p.SideLength(); ++x) {
 439                                 glm::dvec3 to_tile = p.TileCenter(surface, x, y);
 440                                 double near_axis = std::abs(glm::dot(glm::normalize(to_tile), axis));
 441                                 if (near_axis > cap_thresh) {
 442                                         p.TileAt(surface, x, y).type = ice;
 443                                         continue;
 444                                 }
 445                                 float elevation = rand::OctaveNoise(
 446                                         elevation_gen,
 447                                         to_tile / p.Radius(),
 448                                         3,   // octaves
 449                                         0.5, // persistence
 450                                         5 / p.Radius(), // frequency
 451                                         2,   // amplitude
 452                                         2    // growth
 453                                 );
 454                                 float variation = rand::OctaveNoise(
 455                                         variation_gen,
 456                                         to_tile / p.Radius(),
 457                                         3,   // octaves
 458                                         0.5, // persistence
 459                                         16 / p.Radius(), // frequency
 460                                         2,   // amplitude
 461                                         2    // growth
 462                                 );
 463                                 if (elevation < ocean_thresh) {
 464                                         p.TileAt(surface, x, y).type = ocean;
 465                                 } else if (elevation < water_thresh) {
 466                                         if (variation > 0.3) {
 467                                                 p.TileAt(surface, x, y).type = algae;
 468                                         } else {
 469                                                 p.TileAt(surface, x, y).type = water;
 470                                         }
 471                                 } else if (elevation < beach_thresh) {
 472                                         p.TileAt(surface, x, y).type = sand;
 473                                 } else if (elevation < highland_thresh) {
 474                                         if (near_axis < equ_thresh) {
 475                                                 if (variation > 0.6) {
 476                                                         p.TileAt(surface, x, y).type = grass;
 477                                                 } else if (variation > 0.2) {
 478                                                         p.TileAt(surface, x, y).type = sand;
 479                                                 } else {
 480                                                         p.TileAt(surface, x, y).type = desert;
 481                                                 }
 482                                         } else if (near_axis < fzone_start) {
 483                                                 if (variation > 0.4) {
 484                                                         p.TileAt(surface, x, y).type = forest;
 485                                                 } else if (variation < -0.5) {
 486                                                         p.TileAt(surface, x, y).type = jungle;
 487                                                 } else if (variation > -0.02 && variation < 0.02) {
 488                                                         p.TileAt(surface, x, y).type = wheat;
 489                                                 } else {
 490                                                         p.TileAt(surface, x, y).type = grass;
 491                                                 }
 492                                         } else if (near_axis < fzone_end) {
 493                                                 p.TileAt(surface, x, y).type = tundra;
 494                                         } else {
 495                                                 p.TileAt(surface, x, y).type = taiga;
 496                                         }
 497                                 } else if (elevation < mountain_thresh) {
 498                                         if (variation > 0.3) {
 499                                                 p.TileAt(surface, x, y).type = mntn;
 500                                         } else {
 501                                                 p.TileAt(surface, x, y).type = rock;
 502                                         }
 503                                 } else {
 504                                         p.TileAt(surface, x, y).type = mntn;
 505                                 }
 506                         }
 507                 }
 508         }
 509         p.BuildVAO(tiles);
 510 }
 511
 512 void GenerateTest(const Set<TileType> &tiles, Planet &p) noexcept {
 513         for (int surface = 0; surface <= 5; ++surface) {
 514                 for (int y = 0; y < p.SideLength(); ++y) {
 515                         for (int x = 0; x < p.SideLength(); ++x) {
 516                                 if (x == p.SideLength() / 2 && y == p.SideLength() / 2) {
 517                                         p.TileAt(surface, x, y).type = surface;
 518                                 } else {
 519                                         p.TileAt(surface, x, y).type = (x == p.SideLength()/2) + (y == p.SideLength()/2) + 6;
 520                                 }
 521                         }
 522                 }
 523         }
 524         p.BuildVAO(tiles);
 525 }
 526
 527
 528 Sun::Sun()
 529 : Body() {
 530 }
 531
 532 Sun::~Sun() {
 533 }
 534
 535 }
 536 }