src/chunk.cpp

   1 #include "chunk.hpp"
   2
   3 #include "generator.hpp"
   4
   5 #include <limits>
   6 #include <queue>
   7 #include <glm/gtx/transform.hpp>
   8
   9
  10 namespace blank {
  11
  12 Chunk::Chunk(const BlockTypeRegistry &types)
  13 : types(&types)
  14 , neighbor{ 0, 0, 0, 0, 0, 0 }
  15 , blocks()
  16 , model()
  17 , position(0, 0, 0)
  18 , dirty(false) {
  19
  20 }
  21
  22 Chunk::Chunk(Chunk &&other)
  23 : types(other.types)
  24 , blocks(std::move(other.blocks))
  25 , model(std::move(other.model))
  26 , dirty(other.dirty) {
  27         for (size_t i = 0; i < Block::FACE_COUNT; ++i) {
  28                 neighbor[i] = other.neighbor[i];
  29         }
  30 }
  31
  32 Chunk &Chunk::operator =(Chunk &&other) {
  33         types = other.types;
  34         for (size_t i = 0; i < Block::FACE_COUNT; ++i) {
  35                 neighbor[i] = other.neighbor[i];
  36         }
  37         blocks = std::move(other.blocks);
  38         model = std::move(other.model);
  39         dirty = other.dirty;
  40         return *this;
  41 }
  42
  43
  44 void Chunk::SetNeighbor(Chunk &other) {
  45         if (other.position == position - Pos(-1, 0, 0)) {
  46                 neighbor[Block::FACE_LEFT] = &other;
  47                 other.neighbor[Block::FACE_RIGHT] = this;
  48         } else if (other.position == position - Pos(1, 0, 0)) {
  49                 neighbor[Block::FACE_RIGHT] = &other;
  50                 other.neighbor[Block::FACE_LEFT] = this;
  51         } else if (other.position == position - Pos(0, -1, 0)) {
  52                 neighbor[Block::FACE_DOWN] = &other;
  53                 other.neighbor[Block::FACE_UP] = this;
  54         } else if (other.position == position - Pos(0, 1, 0)) {
  55                 neighbor[Block::FACE_UP] = &other;
  56                 other.neighbor[Block::FACE_DOWN] = this;
  57         } else if (other.position == position - Pos(0, 0, -1)) {
  58                 neighbor[Block::FACE_BACK] = &other;
  59                 other.neighbor[Block::FACE_FRONT] = this;
  60         } else if (other.position == position - Pos(0, 0, 1)) {
  61                 neighbor[Block::FACE_FRONT] = &other;
  62                 other.neighbor[Block::FACE_BACK] = this;
  63         }
  64 }
  65
  66 void Chunk::ClearNeighbors() {
  67         for (int i = 0; i < Block::FACE_COUNT; ++i) {
  68                 neighbor[i] = nullptr;
  69         }
  70 }
  71
  72 void Chunk::Unlink() {
  73         if (neighbor[Block::FACE_UP]) {
  74                 neighbor[Block::FACE_UP]->neighbor[Block::FACE_DOWN] = nullptr;
  75         }
  76         if (neighbor[Block::FACE_DOWN]) {
  77                 neighbor[Block::FACE_DOWN]->neighbor[Block::FACE_UP] = nullptr;
  78         }
  79         if (neighbor[Block::FACE_LEFT]) {
  80                 neighbor[Block::FACE_LEFT]->neighbor[Block::FACE_RIGHT] = nullptr;
  81         }
  82         if (neighbor[Block::FACE_RIGHT]) {
  83                 neighbor[Block::FACE_RIGHT]->neighbor[Block::FACE_LEFT] = nullptr;
  84         }
  85         if (neighbor[Block::FACE_FRONT]) {
  86                 neighbor[Block::FACE_FRONT]->neighbor[Block::FACE_BACK] = nullptr;
  87         }
  88         if (neighbor[Block::FACE_BACK]) {
  89                 neighbor[Block::FACE_BACK]->neighbor[Block::FACE_FRONT] = nullptr;
  90         }
  91 }
  92
  93 void Chunk::Relink() {
  94         if (neighbor[Block::FACE_UP]) {
  95                 neighbor[Block::FACE_UP]->neighbor[Block::FACE_DOWN] = this;
  96         }
  97         if (neighbor[Block::FACE_DOWN]) {
  98                 neighbor[Block::FACE_DOWN]->neighbor[Block::FACE_UP] = this;
  99         }
 100         if (neighbor[Block::FACE_LEFT]) {
 101                 neighbor[Block::FACE_LEFT]->neighbor[Block::FACE_RIGHT] = this;
 102         }
 103         if (neighbor[Block::FACE_RIGHT]) {
 104                 neighbor[Block::FACE_RIGHT]->neighbor[Block::FACE_LEFT] = this;
 105         }
 106         if (neighbor[Block::FACE_FRONT]) {
 107                 neighbor[Block::FACE_FRONT]->neighbor[Block::FACE_BACK] = this;
 108         }
 109         if (neighbor[Block::FACE_BACK]) {
 110                 neighbor[Block::FACE_BACK]->neighbor[Block::FACE_FRONT] = this;
 111         }
 112 }
 113
 114
 115 namespace {
 116
 117 struct SetNode {
 118
 119         Chunk *chunk;
 120         Chunk::Pos pos;
 121
 122         SetNode(Chunk *chunk, Chunk::Pos pos)
 123         : chunk(chunk), pos(pos) { }
 124
 125         int Get() const { return chunk->GetLight(pos); }
 126         void Set(int level) { chunk->SetLight(pos, level); }
 127
 128         bool HasNext(Block::Face face) {
 129                 const Block *next = chunk->FindNext(pos, face);
 130                 return next && !chunk->Type(*next).block_light;
 131         }
 132         SetNode GetNext(Block::Face face) {
 133                 Chunk::Pos next_pos(pos + Block::FaceNormal(face));
 134                 if (Chunk::InBounds(next_pos)) {
 135                         return SetNode(chunk, next_pos);
 136                 } else {
 137                         return SetNode(&chunk->GetNeighbor(face), next_pos - (Block::FaceNormal(face) * Chunk::Extent()));
 138                 }
 139         }
 140
 141 };
 142
 143 struct UnsetNode
 144 : public SetNode {
 145
 146         int level;
 147
 148         UnsetNode(Chunk *chunk, Chunk::Pos pos)
 149         : SetNode(chunk, pos), level(Get()) { }
 150
 151         UnsetNode(const SetNode &set)
 152         : SetNode(set), level(Get()) { }
 153
 154         UnsetNode GetNext(Block::Face face) { return UnsetNode(SetNode::GetNext(face)); }
 155
 156 };
 157
 158 std::queue<SetNode> light_queue;
 159 std::queue<UnsetNode> dark_queue;
 160
 161 void work_light() {
 162         while (!light_queue.empty()) {
 163                 SetNode node = light_queue.front();
 164                 light_queue.pop();
 165
 166                 int level = node.Get() - 1;
 167                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 168                         if (node.HasNext(Block::Face(face))) {
 169                                 SetNode other = node.GetNext(Block::Face(face));
 170                                 if (other.Get() < level) {
 171                                         other.Set(level);
 172                                         light_queue.emplace(other);
 173                                 }
 174                         }
 175                 }
 176         }
 177 }
 178
 179 void work_dark() {
 180         while (!dark_queue.empty()) {
 181                 UnsetNode node = dark_queue.front();
 182                 dark_queue.pop();
 183
 184                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 185                         if (node.HasNext(Block::Face(face))) {
 186                                 UnsetNode other = node.GetNext(Block::Face(face));
 187                                 // TODO: if there a light source here with the same level this will err
 188                                 if (other.Get() != 0 && other.Get() < node.level) {
 189                                         other.Set(0);
 190                                         dark_queue.emplace(other);
 191                                 } else {
 192                                         light_queue.emplace(other);
 193                                 }
 194                         }
 195                 }
 196         }
 197         work_light();
 198 }
 199
 200 }
 201
 202 void Chunk::SetBlock(int index, const Block &block) {
 203         const BlockType &old_type = Type(blocks[index]);
 204         const BlockType &new_type = Type(block);
 205
 206         blocks[index] = block;
 207
 208         if (&old_type == &new_type) return;
 209
 210         if (new_type.luminosity > 0) {
 211                 if (GetLight(index) < new_type.luminosity) {
 212                         SetLight(index, new_type.luminosity);
 213                         light_queue.emplace(this, ToPos(index));
 214                         work_light();
 215                 }
 216         } else if (new_type.block_light && GetLight(index) != 0) {
 217                 SetLight(index, 0);
 218                 dark_queue.emplace(this, ToPos(index));
 219                 work_dark();
 220         } else if (old_type.block_light && !new_type.block_light) {
 221                 int level = 0;
 222                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 223                         Pos next_pos(ToPos(index) + Block::FaceNormal(Block::Face(face)));
 224                         int next_level = 0;
 225                         if (InBounds(next_pos)) {
 226                                 next_level = GetLight(next_pos);
 227                         } else {
 228                                 if (HasNeighbor(Block::Face(face))) {
 229                                         next_pos -= (Block::FaceNormal(Block::Face(face)) * Chunk::Extent());
 230                                         next_level = GetNeighbor(Block::Face(face)).GetLight(next_pos);
 231                                 }
 232                         }
 233                         if (level < next_level) {
 234                                 level = next_level;
 235                         }
 236                 }
 237                 if (level > 1) {
 238                         SetLight(index, level - 1);
 239                         light_queue.emplace(this, ToPos(index));
 240                         work_light();
 241                 }
 242         }
 243 }
 244
 245 const Block *Chunk::FindNext(const Pos &pos, Block::Face face) const {
 246         Pos next_pos(pos + Block::FaceNormal(face));
 247         if (InBounds(next_pos)) {
 248                 return &BlockAt(pos + Block::FaceNormal(face));
 249         } else if (HasNeighbor(face)) {
 250                 return &GetNeighbor(face).BlockAt(next_pos - (Block::FaceNormal(face) * Extent()));
 251         } else {
 252                 return nullptr;
 253         }
 254 }
 255
 256
 257 void Chunk::SetLight(int index, int level) {
 258         light[index] = level;
 259 }
 260
 261 int Chunk::GetLight(int index) const {
 262         return light[index];
 263 }
 264
 265
 266 bool Chunk::IsSurface(const Pos &pos) const {
 267         const Block &block = BlockAt(pos);
 268         if (!Type(block).visible) {
 269                 return false;
 270         }
 271         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 272                 const Block *next = FindNext(pos, Block::Face(face));
 273                 if (!next || !Type(*next).visible) {
 274                         return true;
 275                 }
 276         }
 277         return false;
 278 }
 279
 280
 281 void Chunk::Allocate() {
 282         blocks.resize(Size(), Block(0));
 283         light.resize(Size(), 0);
 284 }
 285
 286
 287 void Chunk::Draw() {
 288         if (dirty) {
 289                 Update();
 290         }
 291         model.Draw();
 292 }
 293
 294
 295 bool Chunk::Intersection(
 296         const Ray &ray,
 297         const glm::mat4 &M,
 298         int &blkid,
 299         float &dist,
 300         glm::vec3 &normal
 301 ) const {
 302         // TODO: should be possible to heavily optimize this
 303         int id = 0;
 304         blkid = -1;
 305         dist = std::numeric_limits<float>::infinity();
 306         for (int z = 0; z < Depth(); ++z) {
 307                 for (int y = 0; y < Height(); ++y) {
 308                         for (int x = 0; x < Width(); ++x, ++id) {
 309                                 if (!Type(blocks[id]).visible) {
 310                                         continue;
 311                                 }
 312                                 float cur_dist;
 313                                 glm::vec3 cur_norm;
 314                                 if (Type(blocks[id]).shape->Intersects(ray, M * ToTransform(id), cur_dist, cur_norm)) {
 315                                         if (cur_dist < dist) {
 316                                                 blkid = id;
 317                                                 dist = cur_dist;
 318                                                 normal = cur_norm;
 319                                         }
 320                                 }
 321                         }
 322                 }
 323         }
 324
 325         if (blkid < 0) {
 326                 return false;
 327         } else {
 328                 normal = glm::vec3(BlockAt(blkid).Transform() * glm::vec4(normal, 0.0f));
 329                 return true;
 330         }
 331 }
 332
 333 void Chunk::Position(const Pos &pos) {
 334         position = pos;
 335 }
 336
 337 glm::mat4 Chunk::Transform(const Pos &offset) const {
 338         return glm::translate((position - offset) * Extent());
 339 }
 340
 341
 342 namespace {
 343
 344 Model::Buffer buf;
 345
 346 }
 347
 348 void Chunk::CheckUpdate() {
 349         if (dirty) {
 350                 Update();
 351         }
 352 }
 353
 354 void Chunk::Update() {
 355         int vtx_count = 0, idx_count = 0;
 356         for (const auto &block : blocks) {
 357                 const Shape *shape = Type(block).shape;
 358                 vtx_count += shape->VertexCount();
 359                 idx_count += shape->VertexIndexCount();
 360         }
 361         buf.Clear();
 362         buf.Reserve(vtx_count, idx_count);
 363
 364         Model::Index vtx_counter = 0;
 365         for (size_t i = 0; i < Size(); ++i) {
 366                 const BlockType &type = Type(blocks[i]);
 367
 368                 if (!type.visible || Obstructed(i)) continue;
 369
 370                 type.FillModel(buf, ToTransform(i), vtx_counter);
 371                 vtx_counter += type.shape->VertexCount();
 372         }
 373
 374         model.Update(buf);
 375         dirty = false;
 376 }
 377
 378 bool Chunk::Obstructed(int idx) const {
 379         Chunk::Pos pos(ToPos(idx));
 380
 381         Chunk::Pos left_pos(pos + Chunk::Pos(-1, 0, 0));
 382         const Block *left_block = nullptr;
 383         if (InBounds(left_pos)) {
 384                 left_block = &BlockAt(left_pos);
 385         } else if (HasNeighbor(Block::FACE_LEFT)) {
 386                 left_pos += Chunk::Pos(Width(), 0, 0);
 387                 left_block = &GetNeighbor(Block::FACE_LEFT).BlockAt(left_pos);
 388         } else {
 389                 return false;
 390         }
 391         if (!Type(*left_block).FaceFilled(*left_block, Block::FACE_RIGHT)) {
 392                 return false;
 393         }
 394
 395         Chunk::Pos right_pos(pos + Chunk::Pos(1, 0, 0));
 396         const Block *right_block = nullptr;
 397         if (InBounds(right_pos)) {
 398                 right_block = &BlockAt(right_pos);
 399         } else if (HasNeighbor(Block::FACE_RIGHT)) {
 400                 right_pos += Chunk::Pos(-Width(), 0, 0);
 401                 right_block = &GetNeighbor(Block::FACE_RIGHT).BlockAt(right_pos);
 402         } else {
 403                 return false;
 404         }
 405         if (!Type(*right_block).FaceFilled(*right_block, Block::FACE_LEFT)) {
 406                 return false;
 407         }
 408
 409         Chunk::Pos down_pos(pos + Chunk::Pos(0, -1, 0));
 410         const Block *down_block = nullptr;
 411         if (InBounds(down_pos)) {
 412                 down_block = &BlockAt(down_pos);
 413         } else if (HasNeighbor(Block::FACE_DOWN)) {
 414                 down_pos += Chunk::Pos(0, Height(), 0);
 415                 down_block = &GetNeighbor(Block::FACE_DOWN).BlockAt(down_pos);
 416         } else {
 417                 return false;
 418         }
 419         if (!Type(*down_block).FaceFilled(*down_block, Block::FACE_UP)) {
 420                 return false;
 421         }
 422
 423         Chunk::Pos up_pos(pos + Chunk::Pos(0, 1, 0));
 424         const Block *up_block = nullptr;
 425         if (InBounds(up_pos)) {
 426                 up_block = &BlockAt(up_pos);
 427         } else if (HasNeighbor(Block::FACE_UP)) {
 428                 up_pos += Chunk::Pos(0, -Height(), 0);
 429                 up_block = &GetNeighbor(Block::FACE_UP).BlockAt(up_pos);
 430         } else {
 431                 return false;
 432         }
 433         if (!Type(*up_block).FaceFilled(*up_block, Block::FACE_DOWN)) {
 434                 return false;
 435         }
 436
 437         Chunk::Pos back_pos(pos + Chunk::Pos(0, 0, -1));
 438         const Block *back_block = nullptr;
 439         if (InBounds(back_pos)) {
 440                 back_block = &BlockAt(back_pos);
 441         } else if (HasNeighbor(Block::FACE_BACK)) {
 442                 back_pos += Chunk::Pos(0, 0, Depth());
 443                 back_block = &GetNeighbor(Block::FACE_BACK).BlockAt(back_pos);
 444         } else {
 445                 return false;
 446         }
 447         if (!Type(*back_block).FaceFilled(*back_block, Block::FACE_FRONT)) {
 448                 return false;
 449         }
 450
 451         Chunk::Pos front_pos(pos + Chunk::Pos(0, 0, 1));
 452         const Block *front_block = nullptr;
 453         if (InBounds(front_pos)) {
 454                 front_block = &BlockAt(front_pos);
 455         } else if (HasNeighbor(Block::FACE_FRONT)) {
 456                 front_pos += Chunk::Pos(0, 0, -Depth());
 457                 front_block = &GetNeighbor(Block::FACE_FRONT).BlockAt(front_pos);
 458         } else {
 459                 return false;
 460         }
 461         if (!Type(*front_block).FaceFilled(*front_block, Block::FACE_BACK)) {
 462                 return false;
 463         }
 464
 465         return true;
 466 }
 467
 468 glm::mat4 Chunk::ToTransform(int idx) const {
 469         return glm::translate(glm::mat4(1.0f), ToCoords(idx)) * blocks[idx].Transform();
 470 }
 471
 472
 473 ChunkLoader::ChunkLoader(const BlockTypeRegistry &reg, const Generator &gen)
 474 : base(0, 0, 0)
 475 , reg(reg)
 476 , gen(gen)
 477 , loaded()
 478 , to_generate()
 479 , to_free()
 480 , load_dist(6)
 481 , unload_dist(8) {
 482
 483 }
 484
 485 namespace {
 486
 487 struct ChunkLess {
 488
 489         explicit ChunkLess(const Chunk::Pos &base)
 490         : base(base) { }
 491
 492         bool operator ()(const Chunk::Pos &a, const Chunk::Pos &b) const {
 493                 Chunk::Pos da(base - a);
 494                 Chunk::Pos db(base - b);
 495                 return
 496                         da.x * da.x + da.y * da.y + da.z * da.z <
 497                         db.x * db.x + db.y * db.y + db.z * db.z;
 498         }
 499
 500         Chunk::Pos base;
 501
 502 };
 503
 504 }
 505
 506 void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 507         for (int z = from.z; z < to.z; ++z) {
 508                 for (int y = from.y; y < to.y; ++y) {
 509                         for (int x = from.x; x < to.x; ++x) {
 510                                 Chunk::Pos pos(x, y, z);
 511                                 if (Known(pos)) {
 512                                         continue;
 513                                 } else if (pos == base) {
 514                                         Generate(pos);
 515
 516                                 //      orientation testing
 517                                 //      for (int i = 0; i < Block::FACE_COUNT; ++i) {
 518                                 //              for (int j = 0; j < Block::TURN_COUNT; ++j) {
 519                                 //                      loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
 520                                 //              }
 521                                 //      }
 522                                 //      loaded.back().Invalidate();
 523                                 //      loaded.back().CheckUpdate();
 524                                 } else {
 525                                         to_generate.emplace_back(pos);
 526                                 }
 527                         }
 528                 }
 529         }
 530         to_generate.sort(ChunkLess(base));
 531 }
 532
 533 Chunk &ChunkLoader::Generate(const Chunk::Pos &pos) {
 534         loaded.emplace_back(reg);
 535         Chunk &chunk = loaded.back();
 536         chunk.Position(pos);
 537         Insert(chunk);
 538         gen(chunk);
 539         return chunk;
 540 }
 541
 542 void ChunkLoader::Insert(Chunk &chunk) {
 543         for (Chunk &other : loaded) {
 544                 chunk.SetNeighbor(other);
 545         }
 546 }
 547
 548 void ChunkLoader::Remove(Chunk &chunk) {
 549         chunk.Unlink();
 550 }
 551
 552 Chunk *ChunkLoader::Loaded(const Chunk::Pos &pos) {
 553         for (Chunk &chunk : loaded) {
 554                 if (chunk.Position() == pos) {
 555                         return &chunk;
 556                 }
 557         }
 558         return nullptr;
 559 }
 560
 561 bool ChunkLoader::Queued(const Chunk::Pos &pos) {
 562         for (const Chunk::Pos &chunk : to_generate) {
 563                 if (chunk == pos) {
 564                         return true;
 565                 }
 566         }
 567         return nullptr;
 568 }
 569
 570 bool ChunkLoader::Known(const Chunk::Pos &pos) {
 571         if (Loaded(pos)) return true;
 572         return Queued(pos);
 573 }
 574
 575 Chunk &ChunkLoader::ForceLoad(const Chunk::Pos &pos) {
 576         Chunk *chunk = Loaded(pos);
 577         if (chunk) {
 578                 return *chunk;
 579         }
 580
 581         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end; ++iter) {
 582                 if (*iter == pos) {
 583                         to_generate.erase(iter);
 584                         break;
 585                 }
 586         }
 587
 588         return Generate(pos);
 589 }
 590
 591 void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 592         if (new_base == base) {
 593                 return;
 594         }
 595         base = new_base;
 596
 597         // unload far away chunks
 598         for (auto iter(loaded.begin()), end(loaded.end()); iter != end;) {
 599                 if (std::abs(base.x - iter->Position().x) > unload_dist
 600                                 || std::abs(base.y - iter->Position().y) > unload_dist
 601                                 || std::abs(base.z - iter->Position().z) > unload_dist) {
 602                         auto saved = iter;
 603                         Remove(*saved);
 604                         ++iter;
 605                         to_free.splice(to_free.end(), loaded, saved);
 606                 } else {
 607                         ++iter;
 608                 }
 609         }
 610         // abort far away queued chunks
 611         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end;) {
 612                 if (std::abs(base.x - iter->x) > unload_dist
 613                                 || std::abs(base.y - iter->y) > unload_dist
 614                                 || std::abs(base.z - iter->z) > unload_dist) {
 615                         iter = to_generate.erase(iter);
 616                 } else {
 617                         ++iter;
 618                 }
 619         }
 620         // add missing new chunks
 621         const Chunk::Pos offset(load_dist, load_dist, load_dist);
 622         Generate(base - offset, base + offset);
 623 }
 624
 625 void ChunkLoader::Update() {
 626         bool reused = false;
 627         if (!to_generate.empty()) {
 628                 Chunk::Pos pos(to_generate.front());
 629
 630                 for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
 631                         if (iter->Position() == pos) {
 632                                 iter->Relink();
 633                                 loaded.splice(loaded.end(), to_free, iter);
 634                                 reused = true;
 635                                 break;
 636                         }
 637                 }
 638
 639                 if (!reused) {
 640                         if (to_free.empty()) {
 641                                 loaded.emplace_back(reg);
 642                         } else {
 643                                 to_free.front().ClearNeighbors();
 644                                 loaded.splice(loaded.end(), to_free, to_free.begin());
 645                                 reused = true;
 646                         }
 647                         Chunk &chunk = loaded.back();
 648                         chunk.Position(pos);
 649                         Insert(chunk);
 650                         gen(chunk);
 651                 }
 652                 to_generate.pop_front();
 653         }
 654
 655         if (!reused && !to_free.empty()) {
 656                 to_free.pop_front();
 657         }
 658 }
 659
 660 }