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         state.orient = glm::quat(glm::vec3(0.0f, state.yaw, 0.0f));
 132         if (model) {
 133                 model.EyesState().orientation = glm::quat(glm::vec3(state.pitch, 0.0f, 0.0f));
 134         }
 135 }
 136
 137 void Entity::Update(float dt) {
 138         UpdateTransforms();
 139         UpdateHeading();
 140         if (HasController()) {
 141                 GetController().Update(*this, dt);
 142         }
 143 }
 144
 145 void Entity::UpdateTransforms() noexcept {
 146         // model transform is the one given by current state
 147         model_transform = state.Transform(state.chunk_pos);
 148         // view transform is either the model's eyes transform or,
 149         // should the entity have no model, the pitch (yaw already is
 150         // in model transform)
 151         if (model) {
 152                 view_transform = model.EyesTransform();
 153         } else {
 154                 view_transform = glm::eulerAngleX(state.pitch);
 155         }
 156 }
 157
 158 void Entity::UpdateHeading() noexcept {
 159         speed = length(Velocity());
 160         if (speed > std::numeric_limits<float>::epsilon()) {
 161                 heading = Velocity() / speed;
 162         } else {
 163                 speed = 0.0f;
 164                 // use -Z (forward axis) of model transform (our "chest")
 165                 heading = -glm::vec3(model_transform[2]);
 166         }
 167 }
 168
 169
 170 EntityController::~EntityController() {
 171
 172 }
 173
 174 bool EntityController::MaxOutForce(
 175         glm::vec3 &out,
 176         const glm::vec3 &add,
 177         float max
 178 ) noexcept {
 179         if (iszero(add) || any(isnan(add))) {
 180                 return false;
 181         }
 182         float current = iszero(out) ? 0.0f : length(out);
 183         float remain = max - current;
 184         if (remain <= 0.0f) {
 185                 return true;
 186         }
 187         float additional = length(add);
 188         if (additional > remain) {
 189                 out += normalize(add) * remain;
 190                 return true;
 191         } else {
 192                 out += add;
 193                 return false;
 194         }
 195 }
 196
 197
 198 EntityState::EntityState()
 199 : chunk_pos(0)
 200 , block_pos(0.0f)
 201 , velocity(0.0f)
 202 , orient(1.0f, 0.0f, 0.0f, 0.0f)
 203 , pitch(0.0f)
 204 , yaw(0.0f) {
 205
 206 }
 207
 208 void EntityState::AdjustPosition() noexcept {
 209         while (block_pos.x >= Chunk::width) {
 210                 block_pos.x -= Chunk::width;
 211                 ++chunk_pos.x;
 212         }
 213         while (block_pos.x < 0) {
 214                 block_pos.x += Chunk::width;
 215                 --chunk_pos.x;
 216         }
 217         while (block_pos.y >= Chunk::height) {
 218                 block_pos.y -= Chunk::height;
 219                 ++chunk_pos.y;
 220         }
 221         while (block_pos.y < 0) {
 222                 block_pos.y += Chunk::height;
 223                 --chunk_pos.y;
 224         }
 225         while (block_pos.z >= Chunk::depth) {
 226                 block_pos.z -= Chunk::depth;
 227                 ++chunk_pos.z;
 228         }
 229         while (block_pos.z < 0) {
 230                 block_pos.z += Chunk::depth;
 231                 --chunk_pos.z;
 232         }
 233 }
 234
 235 void EntityState::AdjustHeading() noexcept {
 236         glm::clamp(pitch, -PI_0p5, PI_0p5);
 237         while (yaw > PI) {
 238                 yaw -= PI_2p0;
 239         }
 240         while (yaw < -PI) {
 241                 yaw += PI_2p0;
 242         }
 243 }
 244
 245 glm::mat4 EntityState::Transform(const glm::ivec3 &reference) const noexcept {
 246         const glm::vec3 translation = RelativePosition(reference);
 247         glm::mat4 transform(toMat4(orient));
 248         transform[3] = glm::vec4(translation, 1.0f);
 249         return transform;
 250 }
 251
 252
 253 Player::Player(Entity &e, ChunkIndex &c)
 254 : entity(e)
 255 , chunks(c)
 256 , inv_slot(0) {
 257
 258 }
 259
 260 Player::~Player() {
 261
 262 }
 263
 264 bool Player::SuitableSpawn(BlockLookup &spawn_block) const noexcept {
 265         if (!spawn_block || spawn_block.GetType().collide_block) {
 266                 return false;
 267         }
 268
 269         BlockLookup head_block(spawn_block.Next(Block::FACE_UP));
 270         if (!head_block || head_block.GetType().collide_block) {
 271                 return false;
 272         }
 273
 274         return true;
 275 }
 276
 277 void Player::Update(int dt) {
 278         chunks.Rebase(entity.ChunkCoords());
 279 }
 280
 281
 282 World::World(const BlockTypeRegistry &types, const Config &config)
 283 : config(config)
 284 , block_type(types)
 285 , chunks(types)
 286 , players()
 287 , entities()
 288 , light_direction(config.light_direction)
 289 , fog_density(config.fog_density) {
 290
 291 }
 292
 293 World::~World() {
 294
 295 }
 296
 297
 298 Player *World::AddPlayer(const std::string &name) {
 299         for (Player &p : players) {
 300                 if (p.Name() == name) {
 301                         return nullptr;
 302                 }
 303         }
 304         Entity &entity = AddEntity();
 305         entity.Name(name);
 306         entity.Bounds({ { -0.4f, -0.9f, -0.4f }, { 0.4f, 0.9f, 0.4f } });
 307         entity.WorldCollidable(true);
 308         ChunkIndex &index = chunks.MakeIndex(entity.ChunkCoords(), 6);
 309         players.emplace_back(entity, index);
 310         return &players.back();
 311 }
 312
 313 Player *World::AddPlayer(const std::string &name, std::uint32_t id) {
 314         for (Player &p : players) {
 315                 if (p.Name() == name) {
 316                         return nullptr;
 317                 }
 318         }
 319         Entity *entity = AddEntity(id);
 320         if (!entity) {
 321                 return nullptr;
 322         }
 323         entity->Name(name);
 324         entity->Bounds({ { -0.4f, -0.9f, -0.4f }, { 0.4f, 0.9f, 0.4f } });
 325         entity->WorldCollidable(true);
 326         ChunkIndex &index = chunks.MakeIndex(entity->ChunkCoords(), 6);
 327         players.emplace_back(*entity, index);
 328         return &players.back();
 329 }
 330
 331 Entity &World::AddEntity() {
 332         if (entities.empty()) {
 333                 entities.emplace_back();
 334                 entities.back().ID(1);
 335                 return entities.back();
 336         }
 337         if (entities.back().ID() < std::numeric_limits<std::uint32_t>::max()) {
 338                 std::uint32_t id = entities.back().ID() + 1;
 339                 entities.emplace_back();
 340                 entities.back().ID(id);
 341                 return entities.back();
 342         }
 343         std::uint32_t id = 1;
 344         auto position = entities.begin();
 345         auto end = entities.end();
 346         while (position != end && position->ID() == id) {
 347                 ++id;
 348                 ++position;
 349         }
 350         auto entity = entities.emplace(position);
 351         entity->ID(id);
 352         return *entity;
 353 }
 354
 355 Entity *World::AddEntity(std::uint32_t id) {
 356         if (entities.empty() || entities.back().ID() < id) {
 357                 entities.emplace_back();
 358                 entities.back().ID(id);
 359                 return &entities.back();
 360         }
 361
 362         auto position = entities.begin();
 363         auto end = entities.end();
 364         while (position != end && position->ID() < id) {
 365                 ++position;
 366         }
 367         if (position != end && position->ID() == id) {
 368                 return nullptr;
 369         }
 370         auto entity = entities.emplace(position);
 371         entity->ID(id);
 372         return &*entity;
 373 }
 374
 375 Entity &World::ForceAddEntity(std::uint32_t id) {
 376         if (entities.empty() || entities.back().ID() < id) {
 377                 entities.emplace_back();
 378                 entities.back().ID(id);
 379                 return entities.back();
 380         }
 381
 382         auto position = entities.begin();
 383         auto end = entities.end();
 384         while (position != end && position->ID() < id) {
 385                 ++position;
 386         }
 387         if (position != end && position->ID() == id) {
 388                 return *position;
 389         }
 390         auto entity = entities.emplace(position);
 391         entity->ID(id);
 392         return *entity;
 393 }
 394
 395
 396 namespace {
 397
 398 struct Candidate {
 399         Chunk *chunk;
 400         float dist;
 401 };
 402
 403 bool CandidateLess(const Candidate &a, const Candidate &b) {
 404         return a.dist < b.dist;
 405 }
 406
 407 std::vector<Candidate> candidates;
 408
 409 }
 410
 411 bool World::Intersection(
 412         const Ray &ray,
 413         const glm::mat4 &M,
 414         const Chunk::Pos &reference,
 415         WorldCollision &coll
 416 ) {
 417         candidates.clear();
 418
 419         for (Chunk &cur_chunk : chunks) {
 420                 float cur_dist;
 421                 if (cur_chunk.Intersection(ray, M * cur_chunk.Transform(reference), cur_dist)) {
 422                         candidates.push_back({ &cur_chunk, cur_dist });
 423                 }
 424         }
 425
 426         if (candidates.empty()) return false;
 427
 428         std::sort(candidates.begin(), candidates.end(), CandidateLess);
 429
 430         coll.chunk = nullptr;
 431         coll.block = -1;
 432         coll.depth = std::numeric_limits<float>::infinity();
 433
 434         for (Candidate &cand : candidates) {
 435                 if (cand.dist > coll.depth) continue;
 436                 WorldCollision cur_coll;
 437                 if (cand.chunk->Intersection(ray, M * cand.chunk->Transform(reference), cur_coll)) {
 438                         if (cur_coll.depth < coll.depth) {
 439                                 coll = cur_coll;
 440                         }
 441                 }
 442         }
 443
 444         return coll.chunk;
 445 }
 446
 447 bool World::Intersection(
 448         const Ray &ray,
 449         const glm::mat4 &M,
 450         const Entity &reference,
 451         EntityCollision &coll
 452 ) {
 453         coll.entity = nullptr;
 454         coll.depth = std::numeric_limits<float>::infinity();
 455         for (Entity &cur_entity : entities) {
 456                 if (&cur_entity == &reference) {
 457                         continue;
 458                 }
 459                 float cur_dist;
 460                 glm::vec3 cur_normal;
 461                 if (blank::Intersection(ray, cur_entity.Bounds(), M * cur_entity.Transform(reference.ChunkCoords()), &cur_dist, &cur_normal)) {
 462                         // TODO: fine grained check goes here? maybe?
 463                         if (cur_dist < coll.depth) {
 464                                 coll.entity = &cur_entity;
 465                                 coll.depth = cur_dist;
 466                                 coll.normal = cur_normal;
 467                         }
 468                 }
 469         }
 470
 471         return coll.entity;
 472 }
 473
 474 bool World::Intersection(const Entity &e, const EntityState &s, std::vector<WorldCollision> &col) {
 475         AABB box = e.Bounds();
 476         Chunk::Pos reference = s.chunk_pos;
 477         glm::mat4 M = s.Transform(reference);
 478         return Intersection(box, M, reference, col);
 479 }
 480
 481 bool World::Intersection(
 482         const AABB &box,
 483         const glm::mat4 &M,
 484         const glm::ivec3 &reference,
 485         std::vector<WorldCollision> &col
 486 ) {
 487         bool any = false;
 488         for (Chunk &cur_chunk : chunks) {
 489                 if (manhattan_radius(cur_chunk.Position() - reference) > 1) {
 490                         // chunk is not one of the 3x3x3 surrounding the entity
 491                         // since there's no entity which can extent over 16 blocks, they can be skipped
 492                         continue;
 493                 }
 494                 if (cur_chunk.Intersection(box, M, cur_chunk.Transform(reference), col)) {
 495                         any = true;
 496                 }
 497         }
 498         return any;
 499 }
 500
 501 void World::Update(int dt) {
 502         float fdt(dt * 0.001f);
 503         for (Entity &entity : entities) {
 504                 Update(entity, fdt);
 505         }
 506         for (Entity &entity : entities) {
 507                 entity.Update(fdt);
 508         }
 509         for (Player &player : players) {
 510                 player.Update(dt);
 511         }
 512         for (auto iter = entities.begin(), end = entities.end(); iter != end;) {
 513                 if (iter->CanRemove()) {
 514                         iter = RemoveEntity(iter);
 515                 } else {
 516                         ++iter;
 517                 }
 518         }
 519 }
 520
 521 void World::Update(Entity &entity, float dt) {
 522         EntityState state(entity.GetState());
 523
 524         EntityDerivative a(CalculateStep(entity, state, 0.0f, EntityDerivative()));
 525         EntityDerivative b(CalculateStep(entity, state, dt * 0.5f, a));
 526         EntityDerivative c(CalculateStep(entity, state, dt * 0.5f, b));
 527         EntityDerivative d(CalculateStep(entity, state, dt, c));
 528
 529         EntityDerivative f;
 530         constexpr float sixth = 1.0f / 6.0f;
 531         f.position = sixth * ((a.position + 2.0f * (b.position + c.position)) + d.position);
 532         f.velocity = sixth * ((a.velocity + 2.0f * (b.velocity + c.velocity)) + d.velocity);
 533
 534         state.block_pos += f.position * dt;
 535         state.velocity += f.velocity * dt;
 536         state.AdjustPosition();
 537
 538         entity.SetState(state);
 539 }
 540
 541 EntityDerivative World::CalculateStep(
 542         const Entity &entity,
 543         const EntityState &cur,
 544         float dt,
 545         const EntityDerivative &delta
 546 ) {
 547         EntityState next(cur);
 548         next.block_pos += delta.position * dt;
 549         next.velocity += delta.velocity * dt;
 550         next.AdjustPosition();
 551
 552         if (dot(next.velocity, next.velocity) > entity.MaxVelocity() * entity.MaxVelocity()) {
 553                 next.velocity = normalize(next.velocity) * entity.MaxVelocity();
 554         }
 555
 556         EntityDerivative out;
 557         out.position = next.velocity;
 558         out.velocity = CalculateForce(entity, next); // by mass = 1kg
 559         return out;
 560 }
 561
 562 glm::vec3 World::CalculateForce(
 563         const Entity &entity,
 564         const EntityState &state
 565 ) {
 566         glm::vec3 force(ControlForce(entity, state) + CollisionForce(entity, state) + Gravity(entity, state));
 567         if (dot(force, force) > entity.MaxControlForce() * entity.MaxControlForce()) {
 568                 return normalize(force) * entity.MaxControlForce();
 569         } else {
 570                 return force;
 571         }
 572 }
 573
 574 glm::vec3 World::ControlForce(
 575         const Entity &entity,
 576         const EntityState &state
 577 ) {
 578         return entity.ControlForce(state);
 579 }
 580
 581 namespace {
 582
 583 std::vector<WorldCollision> col;
 584
 585 }
 586
 587 glm::vec3 World::CollisionForce(
 588         const Entity &entity,
 589         const EntityState &state
 590 ) {
 591         col.clear();
 592         if (entity.WorldCollidable() && Intersection(entity, state, col)) {
 593                 // determine displacement for each cardinal axis and move entity accordingly
 594                 glm::vec3 min_pen(0.0f);
 595                 glm::vec3 max_pen(0.0f);
 596                 for (const WorldCollision &c : col) {
 597                         if (!c.Blocks()) continue;
 598                         glm::vec3 local_pen(c.normal * c.depth);
 599                         // swap if neccessary (normal may point away from the entity)
 600                         if (dot(c.normal, state.RelativePosition(c.ChunkPos()) - c.BlockCoords()) > 0) {
 601                                 local_pen *= -1;
 602                         }
 603                         min_pen = min(min_pen, local_pen);
 604                         max_pen = max(max_pen, local_pen);
 605                 }
 606                 glm::vec3 correction(0.0f);
 607                 // only apply correction for axes where penetration is only in one direction
 608                 for (std::size_t i = 0; i < 3; ++i) {
 609                         if (min_pen[i] < -std::numeric_limits<float>::epsilon()) {
 610                                 if (max_pen[i] < std::numeric_limits<float>::epsilon()) {
 611                                         correction[i] = -min_pen[i];
 612                                 }
 613                         } else {
 614                                 correction[i] = -max_pen[i];
 615                         }
 616                 }
 617                 // correction may be zero in which case normalize() returns NaNs
 618                 if (dot(correction, correction) < std::numeric_limits<float>::epsilon()) {
 619                         return glm::vec3(0.0f);
 620                 }
 621                 glm::vec3 normal(normalize(correction));
 622                 glm::vec3 normal_velocity(normal * dot(state.velocity, normal));
 623                 // apply force proportional to penetration
 624                 // use velocity projected onto normal as damper
 625                 constexpr float k = 1000.0f; // spring constant
 626                 constexpr float b = 10.0f; // damper constant
 627                 const glm::vec3 x(-correction); // endpoint displacement from equilibrium in m
 628                 const glm::vec3 v(normal_velocity); // relative velocity between endpoints in m/s
 629                 return (((-k) * x) - (b * v)); // times 1kg/s, in kg*m/s²
 630         } else {
 631                 return glm::vec3(0.0f);
 632         }
 633 }
 634
 635 glm::vec3 World::Gravity(
 636         const Entity &entity,
 637         const EntityState &state
 638 ) {
 639         return glm::vec3(0.0f);
 640 }
 641
 642 World::EntityHandle World::RemoveEntity(EntityHandle &eh) {
 643         // check for player
 644         for (auto player = players.begin(), end = players.end(); player != end;) {
 645                 if (&player->GetEntity() == &*eh) {
 646                         chunks.UnregisterIndex(player->GetChunks());
 647                         player = players.erase(player);
 648                         end = players.end();
 649                 } else {
 650                         ++player;
 651                 }
 652         }
 653         return entities.erase(eh);
 654 }
 655
 656
 657 void World::Render(Viewport &viewport) {
 658         DirectionalLighting &entity_prog = viewport.EntityProgram();
 659         entity_prog.SetLightDirection(light_direction);
 660         entity_prog.SetFogDensity(fog_density);
 661
 662         for (Entity &entity : entities) {
 663                 glm::mat4 M(entity.Transform(players.front().GetEntity().ChunkCoords()));
 664                 if (!CullTest(entity.Bounds(), entity_prog.GetVP() * M)) {
 665                         entity.Render(M, entity_prog);
 666                 }
 667         }
 668 }
 669
 670 namespace {
 671
 672 PrimitiveMesh::Buffer debug_buf;
 673
 674 }
 675
 676 void World::RenderDebug(Viewport &viewport) {
 677         PrimitiveMesh debug_mesh;
 678         PlainColor &prog = viewport.WorldColorProgram();
 679         for (const Entity &entity : entities) {
 680                 debug_buf.OutlineBox(entity.Bounds(), glm::vec4(1.0f, 0.0f, 0.0f, 1.0f));
 681                 debug_mesh.Update(debug_buf);
 682                 prog.SetM(entity.Transform(players.front().GetEntity().ChunkCoords()));
 683                 debug_mesh.DrawLines();
 684         }
 685 }
 686
 687 }