src/world/world.cpp

   1 #include "Entity.hpp"
   2 #include "EntityController.hpp"
   3 #include "EntityDerivative.hpp"
   4 #include "EntityState.hpp"
   5 #include "Player.hpp"
   6 #include "World.hpp"
   7
   8 #include "ChunkIndex.hpp"
   9 #include "EntityCollision.hpp"
  10 #include "WorldCollision.hpp"
  11 #include "../app/Assets.hpp"
  12 #include "../graphics/Format.hpp"
  13 #include "../graphics/Viewport.hpp"
  14
  15 #include <algorithm>
  16 #include <cmath>
  17 #include <iostream>
  18 #include <limits>
  19 #include <glm/gtx/euler_angles.hpp>
  20 #include <glm/gtx/io.hpp>
  21 #include <glm/gtx/quaternion.hpp>
  22 #include <glm/gtx/transform.hpp>
  23
  24
  25 namespace blank {
  26
  27 Entity::Entity() noexcept
  28 : ctrl(nullptr)
  29 , model()
  30 , id(-1)
  31 , name("anonymous")
  32 , bounds()
  33 , state()
  34 , heading(0.0f, 0.0f, -1.0f)
  35 , max_vel(5.0f)
  36 , max_force(25.0f)
  37 , ref_count(0)
  38 , world_collision(false)
  39 , dead(false)
  40 , owns_controller(false) {
  41
  42 }
  43
  44 Entity::~Entity() noexcept {
  45         UnsetController();
  46 }
  47
  48 Entity::Entity(const Entity &other) noexcept
  49 : ctrl(other.ctrl)
  50 , model(other.model)
  51 , id(-1)
  52 , name(other.name)
  53 , bounds(other.bounds)
  54 , state(other.state)
  55 , model_transform(1.0f)
  56 , view_transform(1.0f)
  57 , speed(0.0f)
  58 , heading(0.0f, 0.0f, -1.0f)
  59 , max_vel(other.max_vel)
  60 , max_force(other.max_force)
  61 , ref_count(0)
  62 , world_collision(other.world_collision)
  63 , dead(other.dead)
  64 , owns_controller(false) {
  65
  66 }
  67
  68 void Entity::SetController(EntityController *c) noexcept {
  69         UnsetController();
  70         ctrl = c;
  71         owns_controller = true;
  72 }
  73
  74 void Entity::SetController(EntityController &c) noexcept {
  75         UnsetController();
  76         ctrl = &c;
  77         owns_controller = false;
  78 }
  79
  80 void Entity::UnsetController() noexcept {
  81         if (ctrl && owns_controller) {
  82                 delete ctrl;
  83         }
  84         ctrl = nullptr;
  85 }
  86
  87 glm::vec3 Entity::ControlForce(const EntityState &s) const noexcept {
  88         if (HasController()) {
  89                 return GetController().ControlForce(*this, s);
  90         } else {
  91                 return -s.velocity;
  92         }
  93 }
  94
  95 void Entity::Position(const glm::ivec3 &c, const glm::vec3 &b) noexcept {
  96         state.chunk_pos = c;
  97         state.block_pos = b;
  98 }
  99
 100 void Entity::Position(const glm::vec3 &pos) noexcept {
 101         state.block_pos = pos;
 102         state.AdjustPosition();
 103 }
 104
 105 void Entity::TurnHead(float dp, float dy) noexcept {
 106         SetHead(state.pitch + dp, state.yaw + dy);
 107 }
 108
 109 void Entity::SetHead(float p, float y) noexcept {
 110         state.pitch = p;
 111         state.yaw = y;
 112         // TODO: I feel like this could be delayed
 113         UpdateModel();
 114 }
 115
 116 glm::mat4 Entity::Transform(const glm::ivec3 &reference) const noexcept {
 117         return glm::translate(glm::vec3((state.chunk_pos - reference) * Chunk::Extent())) * model_transform;
 118 }
 119
 120 glm::mat4 Entity::ViewTransform(const glm::ivec3 &reference) const noexcept {
 121         return Transform(reference) * view_transform;
 122 }
 123
 124 Ray Entity::Aim(const Chunk::Pos &chunk_offset) const noexcept {
 125         glm::mat4 transform = ViewTransform(chunk_offset);
 126         return Ray{ glm::vec3(transform[3]), -glm::vec3(transform[2]) };
 127 }
 128
 129 void Entity::UpdateModel() noexcept {
 130         state.AdjustHeading();
 131         if (model) {
 132                 Part::State &body_state = model.BodyState();
 133                 Part::State &eyes_state = model.EyesState();
 134                 if (&body_state != &eyes_state) {
 135                         body_state.orientation = glm::quat(glm::vec3(0.0f, state.yaw, 0.0f));
 136                         eyes_state.orientation = glm::quat(glm::vec3(state.pitch, 0.0f, 0.0f));
 137                 } else {
 138                         eyes_state.orientation = glm::quat(glm::vec3(state.pitch, state.yaw, 0.0f));
 139                 }
 140         }
 141 }
 142
 143 void Entity::Update(float dt) {
 144         UpdateTransforms();
 145         UpdateHeading();
 146         if (HasController()) {
 147                 GetController().Update(*this, dt);
 148         }
 149 }
 150
 151 void Entity::UpdateTransforms() noexcept {
 152         // model transform is the one given by current state
 153         model_transform = state.Transform(state.chunk_pos);
 154         // view transform is either the model's eyes transform or,
 155         // should the entity have no model, the pitch (yaw already is
 156         // in model transform)
 157         if (model) {
 158                 view_transform = model.EyesTransform();
 159         } else {
 160                 view_transform = glm::eulerAngleX(state.pitch);
 161         }
 162 }
 163
 164 void Entity::UpdateHeading() noexcept {
 165         speed = length(Velocity());
 166         if (speed > std::numeric_limits<float>::epsilon()) {
 167                 heading = Velocity() / speed;
 168         } else {
 169                 speed = 0.0f;
 170                 // use -Z (forward axis) of local view transform
 171                 heading = -glm::vec3(view_transform[2]);
 172         }
 173 }
 174
 175
 176 EntityController::~EntityController() {
 177
 178 }
 179
 180 bool EntityController::MaxOutForce(
 181         glm::vec3 &out,
 182         const glm::vec3 &add,
 183         float max
 184 ) noexcept {
 185         if (iszero(add) || any(isnan(add))) {
 186                 return false;
 187         }
 188         float current = iszero(out) ? 0.0f : length(out);
 189         float remain = max - current;
 190         if (remain <= 0.0f) {
 191                 return true;
 192         }
 193         float additional = length(add);
 194         if (additional > remain) {
 195                 out += normalize(add) * remain;
 196                 return true;
 197         } else {
 198                 out += add;
 199                 return false;
 200         }
 201 }
 202
 203
 204 EntityState::EntityState()
 205 : chunk_pos(0)
 206 , block_pos(0.0f)
 207 , velocity(0.0f)
 208 , orient(1.0f, 0.0f, 0.0f, 0.0f)
 209 , pitch(0.0f)
 210 , yaw(0.0f) {
 211
 212 }
 213
 214 void EntityState::AdjustPosition() noexcept {
 215         while (block_pos.x >= Chunk::width) {
 216                 block_pos.x -= Chunk::width;
 217                 ++chunk_pos.x;
 218         }
 219         while (block_pos.x < 0) {
 220                 block_pos.x += Chunk::width;
 221                 --chunk_pos.x;
 222         }
 223         while (block_pos.y >= Chunk::height) {
 224                 block_pos.y -= Chunk::height;
 225                 ++chunk_pos.y;
 226         }
 227         while (block_pos.y < 0) {
 228                 block_pos.y += Chunk::height;
 229                 --chunk_pos.y;
 230         }
 231         while (block_pos.z >= Chunk::depth) {
 232                 block_pos.z -= Chunk::depth;
 233                 ++chunk_pos.z;
 234         }
 235         while (block_pos.z < 0) {
 236                 block_pos.z += Chunk::depth;
 237                 --chunk_pos.z;
 238         }
 239 }
 240
 241 void EntityState::AdjustHeading() noexcept {
 242         glm::clamp(pitch, -PI_0p5, PI_0p5);
 243         while (yaw > PI) {
 244                 yaw -= PI_2p0;
 245         }
 246         while (yaw < -PI) {
 247                 yaw += PI_2p0;
 248         }
 249 }
 250
 251 glm::mat4 EntityState::Transform(const glm::ivec3 &reference) const noexcept {
 252         const glm::vec3 translation = RelativePosition(reference);
 253         glm::mat4 transform(toMat4(orient));
 254         transform[3] = glm::vec4(translation, 1.0f);
 255         return transform;
 256 }
 257
 258
 259 Player::Player(Entity &e, ChunkIndex &c)
 260 : entity(e)
 261 , chunks(c)
 262 , inv_slot(0) {
 263
 264 }
 265
 266 Player::~Player() {
 267
 268 }
 269
 270 bool Player::SuitableSpawn(BlockLookup &spawn_block) const noexcept {
 271         if (!spawn_block || spawn_block.GetType().collide_block) {
 272                 return false;
 273         }
 274
 275         BlockLookup head_block(spawn_block.Next(Block::FACE_UP));
 276         if (!head_block || head_block.GetType().collide_block) {
 277                 return false;
 278         }
 279
 280         return true;
 281 }
 282
 283 void Player::Update(int dt) {
 284         chunks.Rebase(entity.ChunkCoords());
 285 }
 286
 287
 288 World::World(const BlockTypeRegistry &types, const Config &config)
 289 : config(config)
 290 , block_type(types)
 291 , chunks(types)
 292 , players()
 293 , entities()
 294 , light_direction(config.light_direction)
 295 , fog_density(config.fog_density) {
 296
 297 }
 298
 299 World::~World() {
 300
 301 }
 302
 303
 304 Player *World::AddPlayer(const std::string &name) {
 305         for (Player &p : players) {
 306                 if (p.Name() == name) {
 307                         return nullptr;
 308                 }
 309         }
 310         Entity &entity = AddEntity();
 311         entity.Name(name);
 312         entity.Bounds({ { -0.4f, -0.9f, -0.4f }, { 0.4f, 0.9f, 0.4f } });
 313         entity.WorldCollidable(true);
 314         ChunkIndex &index = chunks.MakeIndex(entity.ChunkCoords(), 6);
 315         players.emplace_back(entity, index);
 316         return &players.back();
 317 }
 318
 319 Player *World::AddPlayer(const std::string &name, std::uint32_t id) {
 320         for (Player &p : players) {
 321                 if (p.Name() == name) {
 322                         return nullptr;
 323                 }
 324         }
 325         Entity *entity = AddEntity(id);
 326         if (!entity) {
 327                 return nullptr;
 328         }
 329         entity->Name(name);
 330         entity->Bounds({ { -0.4f, -0.9f, -0.4f }, { 0.4f, 0.9f, 0.4f } });
 331         entity->WorldCollidable(true);
 332         ChunkIndex &index = chunks.MakeIndex(entity->ChunkCoords(), 6);
 333         players.emplace_back(*entity, index);
 334         return &players.back();
 335 }
 336
 337 Entity &World::AddEntity() {
 338         if (entities.empty()) {
 339                 entities.emplace_back();
 340                 entities.back().ID(1);
 341                 return entities.back();
 342         }
 343         if (entities.back().ID() < std::numeric_limits<std::uint32_t>::max()) {
 344                 std::uint32_t id = entities.back().ID() + 1;
 345                 entities.emplace_back();
 346                 entities.back().ID(id);
 347                 return entities.back();
 348         }
 349         std::uint32_t id = 1;
 350         auto position = entities.begin();
 351         auto end = entities.end();
 352         while (position != end && position->ID() == id) {
 353                 ++id;
 354                 ++position;
 355         }
 356         auto entity = entities.emplace(position);
 357         entity->ID(id);
 358         return *entity;
 359 }
 360
 361 Entity *World::AddEntity(std::uint32_t id) {
 362         if (entities.empty() || entities.back().ID() < id) {
 363                 entities.emplace_back();
 364                 entities.back().ID(id);
 365                 return &entities.back();
 366         }
 367
 368         auto position = entities.begin();
 369         auto end = entities.end();
 370         while (position != end && position->ID() < id) {
 371                 ++position;
 372         }
 373         if (position != end && position->ID() == id) {
 374                 return nullptr;
 375         }
 376         auto entity = entities.emplace(position);
 377         entity->ID(id);
 378         return &*entity;
 379 }
 380
 381 Entity &World::ForceAddEntity(std::uint32_t id) {
 382         if (entities.empty() || entities.back().ID() < id) {
 383                 entities.emplace_back();
 384                 entities.back().ID(id);
 385                 return entities.back();
 386         }
 387
 388         auto position = entities.begin();
 389         auto end = entities.end();
 390         while (position != end && position->ID() < id) {
 391                 ++position;
 392         }
 393         if (position != end && position->ID() == id) {
 394                 return *position;
 395         }
 396         auto entity = entities.emplace(position);
 397         entity->ID(id);
 398         return *entity;
 399 }
 400
 401
 402 namespace {
 403
 404 struct Candidate {
 405         Chunk *chunk;
 406         float dist;
 407 };
 408
 409 bool CandidateLess(const Candidate &a, const Candidate &b) {
 410         return a.dist < b.dist;
 411 }
 412
 413 std::vector<Candidate> candidates;
 414
 415 }
 416
 417 bool World::Intersection(
 418         const Ray &ray,
 419         const glm::mat4 &M,
 420         const Chunk::Pos &reference,
 421         WorldCollision &coll
 422 ) {
 423         candidates.clear();
 424
 425         for (Chunk &cur_chunk : chunks) {
 426                 float cur_dist;
 427                 if (cur_chunk.Intersection(ray, M * cur_chunk.Transform(reference), cur_dist)) {
 428                         candidates.push_back({ &cur_chunk, cur_dist });
 429                 }
 430         }
 431
 432         if (candidates.empty()) return false;
 433
 434         std::sort(candidates.begin(), candidates.end(), CandidateLess);
 435
 436         coll.chunk = nullptr;
 437         coll.block = -1;
 438         coll.depth = std::numeric_limits<float>::infinity();
 439
 440         for (Candidate &cand : candidates) {
 441                 if (cand.dist > coll.depth) continue;
 442                 WorldCollision cur_coll;
 443                 if (cand.chunk->Intersection(ray, M * cand.chunk->Transform(reference), cur_coll)) {
 444                         if (cur_coll.depth < coll.depth) {
 445                                 coll = cur_coll;
 446                         }
 447                 }
 448         }
 449
 450         return coll.chunk;
 451 }
 452
 453 bool World::Intersection(
 454         const Ray &ray,
 455         const glm::mat4 &M,
 456         const Entity &reference,
 457         EntityCollision &coll
 458 ) {
 459         coll.entity = nullptr;
 460         coll.depth = std::numeric_limits<float>::infinity();
 461         for (Entity &cur_entity : entities) {
 462                 if (&cur_entity == &reference) {
 463                         continue;
 464                 }
 465                 float cur_dist;
 466                 glm::vec3 cur_normal;
 467                 if (blank::Intersection(ray, cur_entity.Bounds(), M * cur_entity.Transform(reference.ChunkCoords()), &cur_dist, &cur_normal)) {
 468                         // TODO: fine grained check goes here? maybe?
 469                         if (cur_dist < coll.depth) {
 470                                 coll.entity = &cur_entity;
 471                                 coll.depth = cur_dist;
 472                                 coll.normal = cur_normal;
 473                         }
 474                 }
 475         }
 476
 477         return coll.entity;
 478 }
 479
 480 bool World::Intersection(const Entity &e, const EntityState &s, std::vector<WorldCollision> &col) {
 481         AABB box = e.Bounds();
 482         Chunk::Pos reference = s.chunk_pos;
 483         glm::mat4 M = s.Transform(reference);
 484         return Intersection(box, M, reference, col);
 485 }
 486
 487 bool World::Intersection(
 488         const AABB &box,
 489         const glm::mat4 &M,
 490         const glm::ivec3 &reference,
 491         std::vector<WorldCollision> &col
 492 ) {
 493         bool any = false;
 494         for (Chunk &cur_chunk : chunks) {
 495                 if (manhattan_radius(cur_chunk.Position() - reference) > 1) {
 496                         // chunk is not one of the 3x3x3 surrounding the entity
 497                         // since there's no entity which can extent over 16 blocks, they can be skipped
 498                         continue;
 499                 }
 500                 if (cur_chunk.Intersection(box, M, cur_chunk.Transform(reference), col)) {
 501                         any = true;
 502                 }
 503         }
 504         return any;
 505 }
 506
 507 void World::Update(int dt) {
 508         float fdt(dt * 0.001f);
 509         for (Entity &entity : entities) {
 510                 Update(entity, fdt);
 511         }
 512         for (Entity &entity : entities) {
 513                 entity.Update(fdt);
 514         }
 515         for (Player &player : players) {
 516                 player.Update(dt);
 517         }
 518         for (auto iter = entities.begin(), end = entities.end(); iter != end;) {
 519                 if (iter->CanRemove()) {
 520                         iter = RemoveEntity(iter);
 521                 } else {
 522                         ++iter;
 523                 }
 524         }
 525 }
 526
 527 void World::Update(Entity &entity, float dt) {
 528         EntityState state(entity.GetState());
 529
 530         EntityDerivative a(CalculateStep(entity, state, 0.0f, EntityDerivative()));
 531         EntityDerivative b(CalculateStep(entity, state, dt * 0.5f, a));
 532         EntityDerivative c(CalculateStep(entity, state, dt * 0.5f, b));
 533         EntityDerivative d(CalculateStep(entity, state, dt, c));
 534
 535         EntityDerivative f;
 536         constexpr float sixth = 1.0f / 6.0f;
 537         f.position = sixth * ((a.position + 2.0f * (b.position + c.position)) + d.position);
 538         f.velocity = sixth * ((a.velocity + 2.0f * (b.velocity + c.velocity)) + d.velocity);
 539
 540         state.block_pos += f.position * dt;
 541         state.velocity += f.velocity * dt;
 542         state.AdjustPosition();
 543
 544         entity.SetState(state);
 545 }
 546
 547 EntityDerivative World::CalculateStep(
 548         const Entity &entity,
 549         const EntityState &cur,
 550         float dt,
 551         const EntityDerivative &delta
 552 ) {
 553         EntityState next(cur);
 554         next.block_pos += delta.position * dt;
 555         next.velocity += delta.velocity * dt;
 556         next.AdjustPosition();
 557
 558         if (dot(next.velocity, next.velocity) > entity.MaxVelocity() * entity.MaxVelocity()) {
 559                 next.velocity = normalize(next.velocity) * entity.MaxVelocity();
 560         }
 561
 562         EntityDerivative out;
 563         out.position = next.velocity;
 564         out.velocity = CalculateForce(entity, next); // by mass = 1kg
 565         return out;
 566 }
 567
 568 glm::vec3 World::CalculateForce(
 569         const Entity &entity,
 570         const EntityState &state
 571 ) {
 572         glm::vec3 force(ControlForce(entity, state) + CollisionForce(entity, state) + Gravity(entity, state));
 573         if (dot(force, force) > entity.MaxControlForce() * entity.MaxControlForce()) {
 574                 return normalize(force) * entity.MaxControlForce();
 575         } else {
 576                 return force;
 577         }
 578 }
 579
 580 glm::vec3 World::ControlForce(
 581         const Entity &entity,
 582         const EntityState &state
 583 ) {
 584         return entity.ControlForce(state);
 585 }
 586
 587 namespace {
 588
 589 std::vector<WorldCollision> col;
 590
 591 }
 592
 593 glm::vec3 World::CollisionForce(
 594         const Entity &entity,
 595         const EntityState &state
 596 ) {
 597         col.clear();
 598         if (entity.WorldCollidable() && Intersection(entity, state, col)) {
 599                 // determine displacement for each cardinal axis and move entity accordingly
 600                 glm::vec3 min_pen(0.0f);
 601                 glm::vec3 max_pen(0.0f);
 602                 for (const WorldCollision &c : col) {
 603                         if (!c.Blocks()) continue;
 604                         glm::vec3 local_pen(c.normal * c.depth);
 605                         // swap if neccessary (normal may point away from the entity)
 606                         if (dot(c.normal, state.RelativePosition(c.ChunkPos()) - c.BlockCoords()) > 0) {
 607                                 local_pen *= -1;
 608                         }
 609                         min_pen = min(min_pen, local_pen);
 610                         max_pen = max(max_pen, local_pen);
 611                 }
 612                 glm::vec3 correction(0.0f);
 613                 // only apply correction for axes where penetration is only in one direction
 614                 for (std::size_t i = 0; i < 3; ++i) {
 615                         if (min_pen[i] < -std::numeric_limits<float>::epsilon()) {
 616                                 if (max_pen[i] < std::numeric_limits<float>::epsilon()) {
 617                                         correction[i] = -min_pen[i];
 618                                 }
 619                         } else {
 620                                 correction[i] = -max_pen[i];
 621                         }
 622                 }
 623                 // correction may be zero in which case normalize() returns NaNs
 624                 if (dot(correction, correction) < std::numeric_limits<float>::epsilon()) {
 625                         return glm::vec3(0.0f);
 626                 }
 627                 glm::vec3 normal(normalize(correction));
 628                 glm::vec3 normal_velocity(normal * dot(state.velocity, normal));
 629                 // apply force proportional to penetration
 630                 // use velocity projected onto normal as damper
 631                 constexpr float k = 1000.0f; // spring constant
 632                 constexpr float b = 10.0f; // damper constant
 633                 const glm::vec3 x(-correction); // endpoint displacement from equilibrium in m
 634                 const glm::vec3 v(normal_velocity); // relative velocity between endpoints in m/s
 635                 return (((-k) * x) - (b * v)); // times 1kg/s, in kg*m/s²
 636         } else {
 637                 return glm::vec3(0.0f);
 638         }
 639 }
 640
 641 glm::vec3 World::Gravity(
 642         const Entity &entity,
 643         const EntityState &state
 644 ) {
 645         return glm::vec3(0.0f);
 646 }
 647
 648 World::EntityHandle World::RemoveEntity(EntityHandle &eh) {
 649         // check for player
 650         for (auto player = players.begin(), end = players.end(); player != end;) {
 651                 if (&player->GetEntity() == &*eh) {
 652                         chunks.UnregisterIndex(player->GetChunks());
 653                         player = players.erase(player);
 654                         end = players.end();
 655                 } else {
 656                         ++player;
 657                 }
 658         }
 659         return entities.erase(eh);
 660 }
 661
 662
 663 void World::Render(Viewport &viewport) {
 664         DirectionalLighting &entity_prog = viewport.EntityProgram();
 665         entity_prog.SetLightDirection(light_direction);
 666         entity_prog.SetFogDensity(fog_density);
 667
 668         for (Entity &entity : entities) {
 669                 entity.Render(entity.Transform(players.front().GetEntity().ChunkCoords()), entity_prog);
 670         }
 671 }
 672
 673 }