src/world/world.cpp

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