src/world/world.cpp

   1 #include "Body.hpp"
   2 #include "CreatureCreatureCollision.hpp"
   3 #include "Orbit.hpp"
   4 #include "Planet.hpp"
   5 #include "Resource.hpp"
   6 #include "Set.hpp"
   7 #include "Simulation.hpp"
   8 #include "Sun.hpp"
   9 #include "Tile.hpp"
  10 #include "TileType.hpp"
  11
  12 #include "../app/Assets.hpp"
  13 #include "../creature/Composition.hpp"
  14 #include "../creature/Creature.hpp"
  15 #include "../graphics/Viewport.hpp"
  16 #include "../math/const.hpp"
  17 #include "../math/geometry.hpp"
  18 #include "../math/OctaveNoise.hpp"
  19 #include "../math/SimplexNoise.hpp"
  20
  21 #include <algorithm>
  22 #include <cmath>
  23 #include <iostream>
  24 #include <glm/gtc/matrix_transform.hpp>
  25 #include <glm/gtx/euler_angles.hpp>
  26 #include <glm/gtx/io.hpp>
  27 #include <glm/gtx/transform.hpp>
  28
  29 using blobs::G;
  30 using blobs::PI_2p0;
  31
  32 using std::sin;
  33 using std::cos;
  34 using std::pow;
  35 using std::sqrt;
  36
  37
  38 namespace blobs {
  39 namespace world {
  40
  41 Body::Body()
  42 : sim(nullptr)
  43 , parent(nullptr)
  44 , children()
  45 , mass(1.0)
  46 , radius(1.0)
  47 , orbit()
  48 , surface_tilt(0.0, 0.0)
  49 , axis_tilt(0.0, 0.0)
  50 , rotation(0.0)
  51 , angular(0.0)
  52 , orbital(1.0)
  53 , inverse_orbital(1.0)
  54 , local(1.0)
  55 , inverse_local(1.0)
  56 , creatures()
  57 , atmosphere(-1) {
  58 }
  59
  60 Body::~Body() {
  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 std::vector<CreatureCreatureCollision> collisions;
 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         // first remove creatures so they don't collide
 154         for (auto c = Creatures().begin(); c != Creatures().end();) {
 155                 if ((*c)->Removable()) {
 156                         (*c)->Removed();
 157                         c = Creatures().erase(c);
 158                 } else {
 159                         ++c;
 160                 }
 161         }
 162         CheckCollision();
 163 }
 164
 165 void Body::Cache() noexcept {
 166         if (parent) {
 167                 orbital =
 168                         orbit.Matrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()))
 169                         * glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 170                 inverse_orbital =
 171                         glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x)
 172                         * orbit.InverseMatrix(PI_2p0 * (GetSimulation().Time() / OrbitalPeriod()));
 173         } else {
 174                 orbital = glm::eulerAngleXY(axis_tilt.x, axis_tilt.y);
 175                 inverse_orbital = glm::eulerAngleYX(-axis_tilt.y, -axis_tilt.x);
 176         }
 177         local =
 178                 glm::eulerAngleY(rotation)
 179                 * glm::eulerAngleXY(surface_tilt.x, surface_tilt.y);
 180         inverse_local =
 181                 glm::eulerAngleYX(-surface_tilt.y, -surface_tilt.x)
 182                 * glm::eulerAngleY(-rotation);
 183 }
 184
 185 void Body::CheckCollision() noexcept {
 186         if (Creatures().size() < 2) return;
 187         collisions.clear();
 188         auto end = Creatures().end();
 189         for (auto i = Creatures().begin(); i != end; ++i) {
 190                 math::AABB i_box((*i)->CollisionBox());
 191                 glm::dmat4 i_mat((*i)->CollisionTransform());
 192                 for (auto j = (i + 1); j != end; ++j) {
 193                         glm::dvec3 diff((*i)->GetSituation().Position() - (*j)->GetSituation().Position());
 194                         double max_dist = ((*i)->Size() + (*j)->Size()) * 1.74;
 195                         if (length2(diff) > max_dist * max_dist) continue;
 196                         math::AABB j_box((*j)->CollisionBox());
 197                         glm::dmat4 j_mat((*j)->CollisionTransform());
 198                         glm::dvec3 normal;
 199                         double depth;
 200                         if (Intersect(i_box, i_mat, j_box, j_mat, normal, depth)) {
 201                                 collisions.push_back({ **i, **j, normal, depth });
 202                         }
 203                 }
 204         }
 205         for (auto &c : collisions) {
 206                 c.A().GetSituation().Move(c.Normal() * (c.Depth() * -0.5));
 207                 c.B().GetSituation().Move(c.Normal() * (c.Depth() * 0.5));
 208                 c.A().GetSituation().Accelerate(c.Normal() * -dot(c.Normal(), c.AVel()));
 209                 c.B().GetSituation().Accelerate(c.Normal() * -dot(c.Normal(), c.BVel()));
 210                 // TODO: notify participants so they can be annoyed
 211         }
 212 }
 213
 214 void Body::AddCreature(creature::Creature *c) {
 215         creatures.push_back(c);
 216 }
 217
 218 void Body::RemoveCreature(creature::Creature *c) {
 219         auto entry = std::find(creatures.begin(), creatures.end(), c);
 220         if (entry != creatures.end()) {
 221                 creatures.erase(entry);
 222         }
 223 }
 224
 225
 226 CreatureCreatureCollision::~CreatureCreatureCollision() {
 227 }
 228
 229 const glm::dvec3 &CreatureCreatureCollision::APos() const noexcept {
 230         return a->GetSituation().Position();
 231 }
 232
 233 const glm::dvec3 &CreatureCreatureCollision::AVel() const noexcept {
 234         return a->GetSituation().Velocity();
 235 }
 236
 237 const glm::dvec3 &CreatureCreatureCollision::BPos() const noexcept {
 238         return b->GetSituation().Position();
 239 }
 240
 241 const glm::dvec3 &CreatureCreatureCollision::BVel() const noexcept {
 242         return b->GetSituation().Velocity();
 243 }
 244
 245
 246 Orbit::Orbit()
 247 : sma(1.0)
 248 , ecc(0.0)
 249 , inc(0.0)
 250 , asc(0.0)
 251 , arg(0.0)
 252 , mna(0.0) {
 253 }
 254
 255 Orbit::~Orbit() {
 256 }
 257
 258 double Orbit::SemiMajorAxis() const noexcept {
 259         return sma;
 260 }
 261
 262 Orbit &Orbit::SemiMajorAxis(double s) noexcept {
 263         sma = s;
 264         return *this;
 265 }
 266
 267 double Orbit::Eccentricity() const noexcept {
 268         return ecc;
 269 }
 270
 271 Orbit &Orbit::Eccentricity(double e) noexcept {
 272         ecc = e;
 273         return *this;
 274 }
 275
 276 double Orbit::Inclination() const noexcept {
 277         return inc;
 278 }
 279
 280 Orbit &Orbit::Inclination(double i) noexcept {
 281         inc = i;
 282         return *this;
 283 }
 284
 285 double Orbit::LongitudeAscending() const noexcept {
 286         return asc;
 287 }
 288
 289 Orbit &Orbit::LongitudeAscending(double l) noexcept {
 290         asc = l;
 291         return *this;
 292 }
 293
 294 double Orbit::ArgumentPeriapsis() const noexcept {
 295         return arg;
 296 }
 297
 298 Orbit &Orbit::ArgumentPeriapsis(double a) noexcept {
 299         arg = a;
 300         return *this;
 301 }
 302
 303 double Orbit::MeanAnomaly() const noexcept {
 304         return mna;
 305 }
 306
 307 Orbit &Orbit::MeanAnomaly(double m) noexcept {
 308         mna = m;
 309         return *this;
 310 }
 311
 312 namespace {
 313
 314 double mean2eccentric(double M, double e) {
 315         double E = M; // eccentric anomaly, solve M = E - e sin E
 316         // limit to 100 steps to prevent deadlocks in impossible situations
 317         for (int i = 0; i < 100; ++i) {
 318                 double dE = (E - e * sin(E) - M) / (1 - e * cos(E));
 319                 E -= dE;
 320                 if (abs(dE) < 1.0e-6) break;
 321         }
 322         return E;
 323 }
 324
 325 }
 326
 327 glm::dmat4 Orbit::Matrix(double t) const noexcept {
 328         double M = mna + t;
 329         double E = mean2eccentric(M, ecc);
 330
 331         // coordinates in orbital plane, P=x, Q=-z
 332         double P = sma * (cos(E) - ecc);
 333         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 334
 335         return glm::yawPitchRoll(asc, inc, arg) * glm::translate(glm::dvec3(P, 0.0, -Q));
 336 }
 337
 338 glm::dmat4 Orbit::InverseMatrix(double t) const noexcept {
 339         double M = mna + t;
 340         double E = mean2eccentric(M, ecc);
 341         double P = sma * (cos(E) - ecc);
 342         double Q = sma * sin(E) * sqrt(1 - (ecc * ecc));
 343         return glm::translate(glm::dvec3(-P, 0.0, Q)) * glm::transpose(glm::yawPitchRoll(asc, inc, arg));
 344 }
 345
 346
 347 Planet::Planet(int sidelength)
 348 : Body()
 349 , sidelength(sidelength)
 350 , tiles(TilesTotal())
 351 , vao() {
 352         Radius(double(sidelength) / 2.0);
 353 }
 354
 355 Planet::~Planet() {
 356 }
 357
 358 const TileType &Planet::TypeAt(int srf, int x, int y) const {
 359         return GetSimulation().TileTypes()[TileAt(srf, x, y).type];
 360 }
 361
 362 glm::ivec2 Planet::SurfacePosition(int srf, const glm::dvec3 &pos) const noexcept {
 363         return glm::ivec2(
 364                 PositionToTile(pos[(srf + 0) % 3]),
 365                 PositionToTile(pos[(srf + 1) % 3]));
 366 }
 367
 368 double Planet::SurfaceElevation(int srf, const glm::dvec3 &pos) const noexcept {
 369         return srf < 3
 370                 ? pos[(srf + 2) % 3] - Radius()
 371                 : -pos[(srf + 2) % 3] - Radius();
 372 }
 373
 374 glm::dvec3 Planet::TileCenter(int srf, int x, int y, double e) const noexcept {
 375         glm::dvec3 center(0.0f);
 376         center[(srf + 0) % 3] = x + 0.5 - Radius();
 377         center[(srf + 1) % 3] = y + 0.5 - Radius();
 378         center[(srf + 2) % 3] = srf < 3 ? (Radius() + e) : -(Radius() + e);
 379         return center;
 380 }
 381
 382 void Planet::BuildVAO(const Set<TileType> &ts) {
 383         vao.reset(new graphics::SimpleVAO<Attributes, unsigned int>);
 384         vao->Bind();
 385         vao->BindAttributes();
 386         vao->EnableAttribute(0);
 387         vao->EnableAttribute(1);
 388         vao->AttributePointer<glm::vec3>(0, false, offsetof(Attributes, position));
 389         vao->AttributePointer<glm::vec3>(1, false, offsetof(Attributes, tex_coord));
 390         vao->ReserveAttributes(TilesTotal() * 4, GL_STATIC_DRAW);
 391         {
 392                 auto attrib = vao->MapAttributes(GL_WRITE_ONLY);
 393                 float offset = Radius();
 394
 395                 // srf  0  1  2  3  4  5
 396                 //  up +Z +X +Y -Z -X -Y
 397
 398                 for (int index = 0, surface = 0; surface < 6; ++surface) {
 399                         for (int y = 0; y < sidelength; ++y) {
 400                                 for (int x = 0; x < sidelength; ++x, ++index) {
 401                                         float tex = ts[TileAt(surface, x, y).type].texture;
 402                                         const float tex_v_begin = surface < 3 ? 1.0f : 0.0f;
 403                                         const float tex_v_end = surface < 3 ? 0.0f : 1.0f;
 404                                         attrib[4 * index + 0].position[(surface + 0) % 3] = x + 0 - offset;
 405                                         attrib[4 * index + 0].position[(surface + 1) % 3] = y + 0 - offset;
 406                                         attrib[4 * index + 0].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 407                                         attrib[4 * index + 0].tex_coord[0] = 0.0f;
 408                                         attrib[4 * index + 0].tex_coord[1] = tex_v_begin;
 409                                         attrib[4 * index + 0].tex_coord[2] = tex;
 410
 411                                         attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
 412                                         attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
 413                                         attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 414                                         attrib[4 * index + 1].tex_coord[0] = 0.0f;
 415                                         attrib[4 * index + 1].tex_coord[1] = tex_v_end;
 416                                         attrib[4 * index + 1].tex_coord[2] = tex;
 417
 418                                         attrib[4 * index + 2].position[(surface + 0) % 3] = x + 1 - offset;
 419                                         attrib[4 * index + 2].position[(surface + 1) % 3] = y + 0 - offset;
 420                                         attrib[4 * index + 2].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 421                                         attrib[4 * index + 2].tex_coord[0] = 1.0f;
 422                                         attrib[4 * index + 2].tex_coord[1] = tex_v_begin;
 423                                         attrib[4 * index + 2].tex_coord[2] = tex;
 424
 425                                         attrib[4 * index + 3].position[(surface + 0) % 3] = x + 1 - offset;
 426                                         attrib[4 * index + 3].position[(surface + 1) % 3] = y + 1 - offset;
 427                                         attrib[4 * index + 3].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
 428                                         attrib[4 * index + 3].tex_coord[0] = 1.0f;
 429                                         attrib[4 * index + 3].tex_coord[1] = tex_v_end;
 430                                         attrib[4 * index + 3].tex_coord[2] = tex;
 431                                 }
 432                         }
 433                 }
 434         }
 435         vao->BindElements();
 436         vao->ReserveElements(TilesTotal() * 6, GL_STATIC_DRAW);
 437         {
 438                 auto element = vao->MapElements(GL_WRITE_ONLY);
 439                 int index = 0;
 440                 for (int surface = 0; surface < 3; ++surface) {
 441                         for (int y = 0; y < sidelength; ++y) {
 442                                 for (int x = 0; x < sidelength; ++x, ++index) {
 443                                         element[6 * index + 0] = 4 * index + 0;
 444                                         element[6 * index + 1] = 4 * index + 2;
 445                                         element[6 * index + 2] = 4 * index + 1;
 446                                         element[6 * index + 3] = 4 * index + 1;
 447                                         element[6 * index + 4] = 4 * index + 2;
 448                                         element[6 * index + 5] = 4 * index + 3;
 449                                 }
 450                         }
 451                 }
 452                 for (int surface = 3; surface < 6; ++surface) {
 453                         for (int y = 0; y < sidelength; ++y) {
 454                                 for (int x = 0; x < sidelength; ++x, ++index) {
 455                                         element[6 * index + 0] = 4 * index + 0;
 456                                         element[6 * index + 1] = 4 * index + 1;
 457                                         element[6 * index + 2] = 4 * index + 2;
 458                                         element[6 * index + 3] = 4 * index + 2;
 459                                         element[6 * index + 4] = 4 * index + 1;
 460                                         element[6 * index + 5] = 4 * index + 3;
 461                                 }
 462                         }
 463                 }
 464         }
 465         vao->Unbind();
 466 }
 467
 468 void Planet::Draw(app::Assets &assets, graphics::Viewport &viewport) {
 469         if (!vao) return;
 470
 471         vao->Bind();
 472         const glm::mat4 &MV = assets.shaders.planet_surface.MV();
 473         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, 1.0f, 0.0f)));
 474         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 0);
 475         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(1.0f, 0.0f, 0.0f, 0.0f)));
 476         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 1);
 477         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 1.0f, 0.0f, 0.0f)));
 478         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 2);
 479         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, 0.0f, -1.0f, 0.0f)));
 480         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 3);
 481         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(-1.0f, 0.0f, 0.0f, 0.0f)));
 482         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 4);
 483         assets.shaders.planet_surface.SetNormal(glm::vec3(MV * glm::vec4(0.0f, -1.0f, 0.0f, 0.0f)));
 484         vao->DrawTriangles(TilesPerSurface() * 6, TilesPerSurface() * 6 * 5);
 485 }
 486
 487
 488 void GenerateEarthlike(const Set<TileType> &tiles, Planet &p) noexcept {
 489         math::SimplexNoise elevation_gen(0);
 490         math::SimplexNoise variation_gen(45623752346);
 491
 492         const int ice = tiles["ice"].id;
 493         const int ocean = tiles["ocean"].id;
 494         const int water = tiles["water"].id;
 495         const int sand = tiles["sand"].id;
 496         const int grass = tiles["grass"].id;
 497         const int tundra = tiles["tundra"].id;
 498         const int taiga = tiles["taiga"].id;
 499         const int desert = tiles["desert"].id;
 500         const int mntn = tiles["mountain"].id;
 501         const int algae = tiles["algae"].id;
 502         const int forest = tiles["forest"].id;
 503         const int jungle = tiles["jungle"].id;
 504         const int rock = tiles["rock"].id;
 505         const int wheat = tiles["wheat"].id;
 506
 507         constexpr double ocean_thresh = -0.2;
 508         constexpr double water_thresh = 0.0;
 509         constexpr double beach_thresh = 0.05;
 510         constexpr double highland_thresh = 0.4;
 511         constexpr double mountain_thresh = 0.5;
 512
 513         const glm::dvec3 axis(glm::dvec4(0.0, 1.0, 0.0, 0.0) * glm::eulerAngleXY(p.SurfaceTilt().x, p.SurfaceTilt().y));
 514         const double cap_thresh = std::abs(std::cos(p.AxialTilt().x));
 515         const double equ_thresh = std::abs(std::sin(p.AxialTilt().x)) / 2.0;
 516         const double fzone_start = equ_thresh - (equ_thresh - cap_thresh) / 3.0;
 517         const double fzone_end = cap_thresh + (equ_thresh - cap_thresh) / 3.0;
 518
 519         for (int surface = 0; surface <= 5; ++surface) {
 520                 for (int y = 0; y < p.SideLength(); ++y) {
 521                         for (int x = 0; x < p.SideLength(); ++x) {
 522                                 glm::dvec3 to_tile = p.TileCenter(surface, x, y);
 523                                 double near_axis = std::abs(glm::dot(glm::normalize(to_tile), axis));
 524                                 if (near_axis > cap_thresh) {
 525                                         p.TileAt(surface, x, y).type = ice;
 526                                         continue;
 527                                 }
 528                                 float elevation = math::OctaveNoise(
 529                                         elevation_gen,
 530                                         to_tile / p.Radius(),
 531                                         3,   // octaves
 532                                         0.5, // persistence
 533                                         5 / p.Radius(), // frequency
 534                                         2,   // amplitude
 535                                         2    // growth
 536                                 );
 537                                 float variation = math::OctaveNoise(
 538                                         variation_gen,
 539                                         to_tile / p.Radius(),
 540                                         3,   // octaves
 541                                         0.5, // persistence
 542                                         16 / p.Radius(), // frequency
 543                                         2,   // amplitude
 544                                         2    // growth
 545                                 );
 546                                 if (elevation < ocean_thresh) {
 547                                         p.TileAt(surface, x, y).type = ocean;
 548                                 } else if (elevation < water_thresh) {
 549                                         if (variation > 0.3) {
 550                                                 p.TileAt(surface, x, y).type = algae;
 551                                         } else {
 552                                                 p.TileAt(surface, x, y).type = water;
 553                                         }
 554                                 } else if (elevation < beach_thresh) {
 555                                         p.TileAt(surface, x, y).type = sand;
 556                                 } else if (elevation < highland_thresh) {
 557                                         if (near_axis < equ_thresh) {
 558                                                 if (variation > 0.6) {
 559                                                         p.TileAt(surface, x, y).type = grass;
 560                                                 } else if (variation > 0.2) {
 561                                                         p.TileAt(surface, x, y).type = sand;
 562                                                 } else {
 563                                                         p.TileAt(surface, x, y).type = desert;
 564                                                 }
 565                                         } else if (near_axis < fzone_start) {
 566                                                 if (variation > 0.4) {
 567                                                         p.TileAt(surface, x, y).type = forest;
 568                                                 } else if (variation < -0.5) {
 569                                                         p.TileAt(surface, x, y).type = jungle;
 570                                                 } else if (variation > -0.02 && variation < 0.02) {
 571                                                         p.TileAt(surface, x, y).type = wheat;
 572                                                 } else {
 573                                                         p.TileAt(surface, x, y).type = grass;
 574                                                 }
 575                                         } else if (near_axis < fzone_end) {
 576                                                 p.TileAt(surface, x, y).type = tundra;
 577                                         } else {
 578                                                 p.TileAt(surface, x, y).type = taiga;
 579                                         }
 580                                 } else if (elevation < mountain_thresh) {
 581                                         if (variation > 0.3) {
 582                                                 p.TileAt(surface, x, y).type = mntn;
 583                                         } else {
 584                                                 p.TileAt(surface, x, y).type = rock;
 585                                         }
 586                                 } else {
 587                                         p.TileAt(surface, x, y).type = mntn;
 588                                 }
 589                         }
 590                 }
 591         }
 592         p.BuildVAO(tiles);
 593 }
 594
 595 void GenerateTest(const Set<TileType> &tiles, Planet &p) noexcept {
 596         for (int surface = 0; surface <= 5; ++surface) {
 597                 for (int y = 0; y < p.SideLength(); ++y) {
 598                         for (int x = 0; x < p.SideLength(); ++x) {
 599                                 if (x == p.SideLength() / 2 && y == p.SideLength() / 2) {
 600                                         p.TileAt(surface, x, y).type = surface;
 601                                 } else {
 602                                         p.TileAt(surface, x, y).type = (x == p.SideLength()/2) + (y == p.SideLength()/2) + 6;
 603                                 }
 604                         }
 605                 }
 606         }
 607         p.BuildVAO(tiles);
 608 }
 609
 610
 611 Sun::Sun()
 612 : Body() {
 613 }
 614
 615 Sun::~Sun() {
 616 }
 617
 618
 619 std::vector<TileType::Yield>::const_iterator TileType::FindResource(int r) const {
 620         auto yield = resources.cbegin();
 621         for (; yield != resources.cend(); ++yield) {
 622                 if (yield->resource == r) {
 623                         break;
 624                 }
 625         }
 626         return yield;
 627 }
 628
 629 std::vector<TileType::Yield>::const_iterator TileType::FindBestResource(const creature::Composition &comp) const {
 630         auto best = resources.cend();
 631         double best_value = 0.0;
 632         for (auto yield = resources.cbegin(); yield != resources.cend(); ++yield) {
 633                 double value = comp.Get(yield->resource);
 634                 if (value > best_value) {
 635                         best = yield;
 636                         best_value = value;
 637                 }
 638         }
 639         return best;
 640 }
 641
 642 }
 643 }