src/chunk.cpp

   1 #include "chunk.hpp"
   2
   3 #include "generator.hpp"
   4
   5 #include <algorithm>
   6 #include <limits>
   7 #include <queue>
   8 #include <glm/gtx/transform.hpp>
   9
  10
  11 namespace blank {
  12
  13 Chunk::Chunk(const BlockTypeRegistry &types)
  14 : types(&types)
  15 , neighbor{0}
  16 , blocks{}
  17 , light{0}
  18 , model()
  19 , position(0, 0, 0)
  20 , dirty(false) {
  21
  22 }
  23
  24 Chunk::Chunk(Chunk &&other)
  25 : types(other.types)
  26 , model(std::move(other.model))
  27 , position(other.position)
  28 , dirty(other.dirty) {
  29         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  30         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  31         std::copy(other.light, other.light + sizeof(light), light);
  32 }
  33
  34 Chunk &Chunk::operator =(Chunk &&other) {
  35         types = other.types;
  36         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  37         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  38         std::copy(other.light, other.light + sizeof(light), light);
  39         model = std::move(other.model);
  40         position = other.position;
  41         dirty = other.dirty;
  42         return *this;
  43 }
  44
  45
  46 namespace {
  47
  48 struct SetNode {
  49
  50         Chunk *chunk;
  51         Chunk::Pos pos;
  52
  53         SetNode(Chunk *chunk, Chunk::Pos pos)
  54         : chunk(chunk), pos(pos) { }
  55
  56         int Get() const { return chunk->GetLight(pos); }
  57         void Set(int level) { chunk->SetLight(pos, level); }
  58
  59         bool HasNext(Block::Face face) {
  60                 const BlockLookup next(chunk, pos, face);
  61                 return next && !next.GetType().block_light;
  62         }
  63         SetNode GetNext(Block::Face face) {
  64                 const BlockLookup next(chunk, pos, face);
  65                 return SetNode(&next.GetChunk(), next.GetBlockPos());
  66         }
  67
  68 };
  69
  70 struct UnsetNode
  71 : public SetNode {
  72
  73         int level;
  74
  75         UnsetNode(Chunk *chunk, Chunk::Pos pos)
  76         : SetNode(chunk, pos), level(Get()) { }
  77
  78         UnsetNode(const SetNode &set)
  79         : SetNode(set), level(Get()) { }
  80
  81
  82         bool HasNext(Block::Face face) {
  83                 const BlockLookup next(chunk, pos, face);
  84                 return next;
  85         }
  86         UnsetNode GetNext(Block::Face face) { return UnsetNode(SetNode::GetNext(face)); }
  87
  88 };
  89
  90 std::queue<SetNode> light_queue;
  91 std::queue<UnsetNode> dark_queue;
  92
  93 void work_light() {
  94         while (!light_queue.empty()) {
  95                 SetNode node = light_queue.front();
  96                 light_queue.pop();
  97
  98                 int level = node.Get() - 1;
  99                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 100                         if (node.HasNext(Block::Face(face))) {
 101                                 SetNode other = node.GetNext(Block::Face(face));
 102                                 if (other.Get() < level) {
 103                                         other.Set(level);
 104                                         light_queue.emplace(other);
 105                                 }
 106                         }
 107                 }
 108         }
 109 }
 110
 111 void work_dark() {
 112         while (!dark_queue.empty()) {
 113                 UnsetNode node = dark_queue.front();
 114                 dark_queue.pop();
 115
 116                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 117                         if (node.HasNext(Block::Face(face))) {
 118                                 UnsetNode other = node.GetNext(Block::Face(face));
 119                                 // TODO: if there a light source here with the same level this will err
 120                                 if (other.Get() != 0 && other.Get() < node.level) {
 121                                         other.Set(0);
 122                                         dark_queue.emplace(other);
 123                                 } else {
 124                                         light_queue.emplace(other);
 125                                 }
 126                         }
 127                 }
 128         }
 129 }
 130
 131 }
 132
 133 void Chunk::SetBlock(int index, const Block &block) {
 134         const BlockType &old_type = Type(blocks[index]);
 135         const BlockType &new_type = Type(block);
 136
 137         blocks[index] = block;
 138
 139         if (&old_type == &new_type) return;
 140
 141         if (new_type.luminosity > old_type.luminosity) {
 142                 // light added
 143                 SetLight(index, new_type.luminosity);
 144                 light_queue.emplace(this, ToPos(index));
 145                 work_light();
 146         } else if (new_type.luminosity < old_type.luminosity) {
 147                 // light removed
 148                 dark_queue.emplace(this, ToPos(index));
 149                 SetLight(index, 0);
 150                 work_dark();
 151                 SetLight(index, new_type.luminosity);
 152                 light_queue.emplace(this, ToPos(index));
 153                 work_light();
 154         } else if (new_type.block_light && !old_type.block_light) {
 155                 // obstacle added
 156                 if (GetLight(index) > 0) {
 157                         dark_queue.emplace(this, ToPos(index));
 158                         SetLight(index, 0);
 159                         work_dark();
 160                         work_light();
 161                 }
 162         } else if (!new_type.block_light && old_type.block_light) {
 163                 // obstacle removed
 164                 int level = 0;
 165                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 166                         BlockLookup next_block(this, ToPos(index), Block::Face(face));
 167                         if (next_block) {
 168                                 level = std::min(level, next_block.GetLight());
 169                         }
 170                 }
 171                 if (level > 1) {
 172                         SetLight(index, level - 1);
 173                         light_queue.emplace(this, ToPos(index));
 174                         work_light();
 175                 }
 176         }
 177 }
 178
 179 void Chunk::SetNeighbor(Chunk &other) {
 180         if (other.position == position + Pos(-1, 0, 0)) {
 181                 if (neighbor[Block::FACE_LEFT] != &other) {
 182                         neighbor[Block::FACE_LEFT] = &other;
 183                         other.neighbor[Block::FACE_RIGHT] = this;
 184                         for (int z = 0; z < Depth(); ++z) {
 185                                 for (int y = 0; y < Height(); ++y) {
 186                                         Pos my_pos(0, y, z);
 187                                         Pos other_pos(Width() - 1, y, z);
 188                                         if (GetLight(my_pos) > 0) {
 189                                                 light_queue.emplace(this, my_pos);
 190                                         }
 191                                         if (other.GetLight(other_pos) > 0) {
 192                                                 light_queue.emplace(&other, other_pos);
 193                                         }
 194                                 }
 195                         }
 196                         work_light();
 197                 }
 198         } else if (other.position == position + Pos(1, 0, 0)) {
 199                 if (neighbor[Block::FACE_RIGHT] != &other) {
 200                         neighbor[Block::FACE_RIGHT] = &other;
 201                         other.neighbor[Block::FACE_LEFT] = this;
 202                         for (int z = 0; z < Depth(); ++z) {
 203                                 for (int y = 0; y < Height(); ++y) {
 204                                         Pos my_pos(Width() - 1, y, z);
 205                                         Pos other_pos(0, y, z);
 206                                         if (GetLight(my_pos) > 0) {
 207                                                 light_queue.emplace(this, my_pos);
 208                                         }
 209                                         if (other.GetLight(other_pos) > 0) {
 210                                                 light_queue.emplace(&other, other_pos);
 211                                         }
 212                                 }
 213                         }
 214                         work_light();
 215                 }
 216         } else if (other.position == position + Pos(0, -1, 0)) {
 217                 if (neighbor[Block::FACE_DOWN] != &other) {
 218                         neighbor[Block::FACE_DOWN] = &other;
 219                         other.neighbor[Block::FACE_UP] = this;
 220                         for (int z = 0; z < Depth(); ++z) {
 221                                 for (int x = 0; x < Width(); ++x) {
 222                                         Pos my_pos(x, 0, z);
 223                                         Pos other_pos(x, Height() - 1, z);
 224                                         if (GetLight(my_pos) > 0) {
 225                                                 light_queue.emplace(this, my_pos);
 226                                         }
 227                                         if (other.GetLight(other_pos) > 0) {
 228                                                 light_queue.emplace(&other, other_pos);
 229                                         }
 230                                 }
 231                         }
 232                         work_light();
 233                 }
 234         } else if (other.position == position + Pos(0, 1, 0)) {
 235                 if (neighbor[Block::FACE_UP] != &other) {
 236                         neighbor[Block::FACE_UP] = &other;
 237                         other.neighbor[Block::FACE_DOWN] = this;
 238                         for (int z = 0; z < Depth(); ++z) {
 239                                 for (int x = 0; x < Width(); ++x) {
 240                                         Pos my_pos(x, Height() - 1, z);
 241                                         Pos other_pos(x, 0, z);
 242                                         if (GetLight(my_pos) > 0) {
 243                                                 light_queue.emplace(this, my_pos);
 244                                         }
 245                                         if (other.GetLight(other_pos) > 0) {
 246                                                 light_queue.emplace(&other, other_pos);
 247                                         }
 248                                 }
 249                         }
 250                         work_light();
 251                 }
 252         } else if (other.position == position + Pos(0, 0, -1)) {
 253                 if (neighbor[Block::FACE_BACK] != &other) {
 254                         neighbor[Block::FACE_BACK] = &other;
 255                         other.neighbor[Block::FACE_FRONT] = this;
 256                         for (int y = 0; y < Height(); ++y) {
 257                                 for (int x = 0; x < Width(); ++x) {
 258                                         Pos my_pos(x, y, 0);
 259                                         Pos other_pos(x, y, Depth() - 1);
 260                                         if (GetLight(my_pos) > 0) {
 261                                                 light_queue.emplace(this, my_pos);
 262                                         }
 263                                         if (other.GetLight(other_pos) > 0) {
 264                                                 light_queue.emplace(&other, other_pos);
 265                                         }
 266                                 }
 267                         }
 268                         work_light();
 269                 }
 270         } else if (other.position == position + Pos(0, 0, 1)) {
 271                 if (neighbor[Block::FACE_FRONT] != &other) {
 272                         neighbor[Block::FACE_FRONT] = &other;
 273                         other.neighbor[Block::FACE_BACK] = this;
 274                         for (int y = 0; y < Height(); ++y) {
 275                                 for (int x = 0; x < Width(); ++x) {
 276                                         Pos my_pos(x, y, Depth() - 1);
 277                                         Pos other_pos(x, y, 0);
 278                                         if (GetLight(my_pos) > 0) {
 279                                                 light_queue.emplace(this, my_pos);
 280                                         }
 281                                         if (other.GetLight(other_pos) > 0) {
 282                                                 light_queue.emplace(&other, other_pos);
 283                                         }
 284                                 }
 285                         }
 286                         work_light();
 287                 }
 288         }
 289 }
 290
 291 void Chunk::ClearNeighbors() {
 292         for (int i = 0; i < Block::FACE_COUNT; ++i) {
 293                 neighbor[i] = nullptr;
 294         }
 295 }
 296
 297 void Chunk::Unlink() {
 298         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 299                 if (neighbor[face]) {
 300                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = nullptr;
 301                 }
 302         }
 303 }
 304
 305 void Chunk::Relink() {
 306         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 307                 if (neighbor[face]) {
 308                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = this;
 309                 }
 310         }
 311 }
 312
 313
 314 void Chunk::SetLight(int index, int level) {
 315         if (light[index] != level) {
 316                 light[index] = level;
 317                 Invalidate();
 318         }
 319 }
 320
 321 int Chunk::GetLight(int index) const {
 322         return light[index];
 323 }
 324
 325 float Chunk::GetVertexLight(int index, const BlockModel::Position &vtx, const Model::Normal &norm) const {
 326         float light = GetLight(index);
 327         Chunk::Pos pos(ToPos(index));
 328
 329         Block::Face direct_face(Block::NormalFace(norm));
 330         // tis okay
 331         BlockLookup direct(const_cast<Chunk *>(this), pos, Block::NormalFace(norm));
 332         if (direct) {
 333                 float direct_light = direct.GetLight();
 334                 if (direct_light > light) {
 335                         light = direct_light;
 336                 }
 337         }
 338
 339         // cheap alternative until AO etc are implemented
 340         // to tell the faces apart
 341
 342         if (direct_face == Block::FACE_LEFT || direct_face == Block::FACE_RIGHT) {
 343                 light -= 0.2;
 344         } else if (direct_face == Block::FACE_FRONT || direct_face == Block::FACE_BACK) {
 345                 light -= 0.4;
 346         }
 347
 348         return light;
 349 }
 350
 351
 352 bool Chunk::IsSurface(const Pos &pos) const {
 353         const Block &block = BlockAt(pos);
 354         if (!Type(block).visible) {
 355                 return false;
 356         }
 357         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 358                 BlockLookup next = BlockLookup(const_cast<Chunk *>(this), pos, Block::Face(face));
 359                 if (!next || !next.GetType().visible) {
 360                         return true;
 361                 }
 362         }
 363         return false;
 364 }
 365
 366
 367 void Chunk::Draw() {
 368         if (dirty) {
 369                 Update();
 370         }
 371         model.Draw();
 372 }
 373
 374
 375 bool Chunk::Intersection(
 376         const Ray &ray,
 377         const glm::mat4 &M,
 378         int &blkid,
 379         float &dist,
 380         glm::vec3 &normal
 381 ) const {
 382         // TODO: should be possible to heavily optimize this
 383         int id = 0;
 384         blkid = -1;
 385         dist = std::numeric_limits<float>::infinity();
 386         for (int z = 0; z < Depth(); ++z) {
 387                 for (int y = 0; y < Height(); ++y) {
 388                         for (int x = 0; x < Width(); ++x, ++id) {
 389                                 if (!Type(blocks[id]).visible) {
 390                                         continue;
 391                                 }
 392                                 float cur_dist;
 393                                 glm::vec3 cur_norm;
 394                                 if (Type(blocks[id]).shape->Intersects(ray, M * ToTransform(id), cur_dist, cur_norm)) {
 395                                         if (cur_dist < dist) {
 396                                                 blkid = id;
 397                                                 dist = cur_dist;
 398                                                 normal = cur_norm;
 399                                         }
 400                                 }
 401                         }
 402                 }
 403         }
 404
 405         if (blkid < 0) {
 406                 return false;
 407         } else {
 408                 normal = glm::vec3(BlockAt(blkid).Transform() * glm::vec4(normal, 0.0f));
 409                 return true;
 410         }
 411 }
 412
 413 void Chunk::Position(const Pos &pos) {
 414         position = pos;
 415 }
 416
 417 glm::mat4 Chunk::Transform(const Pos &offset) const {
 418         return glm::translate((position - offset) * Extent());
 419 }
 420
 421
 422 namespace {
 423
 424 BlockModel::Buffer buf;
 425
 426 }
 427
 428 void Chunk::CheckUpdate() {
 429         if (dirty) {
 430                 Update();
 431         }
 432 }
 433
 434 void Chunk::Update() {
 435         int vtx_count = 0, idx_count = 0;
 436         for (const auto &block : blocks) {
 437                 const Shape *shape = Type(block).shape;
 438                 vtx_count += shape->VertexCount();
 439                 idx_count += shape->VertexIndexCount();
 440         }
 441         buf.Clear();
 442         buf.Reserve(vtx_count, idx_count);
 443
 444         BlockModel::Index vtx_counter = 0;
 445         for (size_t i = 0; i < Size(); ++i) {
 446                 const BlockType &type = Type(blocks[i]);
 447
 448                 if (!type.visible || Obstructed(i).All()) continue;
 449
 450                 type.FillBlockModel(buf, ToTransform(i), vtx_counter);
 451                 size_t vtx_begin = vtx_counter;
 452                 vtx_counter += type.shape->VertexCount();
 453
 454                 for (size_t vtx = vtx_begin; vtx < vtx_counter; ++vtx) {
 455                         buf.lights.emplace_back(GetVertexLight(
 456                                 i,
 457                                 buf.vertices[vtx],
 458                                 type.shape->VertexNormal(vtx - vtx_begin, blocks[i].Transform())
 459                         ));
 460                 }
 461         }
 462
 463         model.Update(buf);
 464         dirty = false;
 465 }
 466
 467 Block::FaceSet Chunk::Obstructed(int idx) const {
 468         Chunk::Pos pos(ToPos(idx));
 469         Block::FaceSet result;
 470
 471         for (int f = 0; f < Block::FACE_COUNT; ++f) {
 472                 Block::Face face = Block::Face(f);
 473                 BlockLookup next(const_cast<Chunk *>(this), pos, face);
 474                 if (next && next.GetType().FaceFilled(next.GetBlock(), Block::Opposite(face))) {
 475                         result.Set(face);
 476                 }
 477         }
 478
 479         return result;
 480 }
 481
 482 glm::mat4 Chunk::ToTransform(int idx) const {
 483         return glm::translate(glm::mat4(1.0f), ToCoords(idx)) * blocks[idx].Transform();
 484 }
 485
 486
 487 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p)
 488 : chunk(c), pos(p) {
 489         while (pos.x >= Chunk::Width()) {
 490                 if (chunk->HasNeighbor(Block::FACE_RIGHT)) {
 491                         chunk = &chunk->GetNeighbor(Block::FACE_RIGHT);
 492                         pos.x -= Chunk::Width();
 493                 } else {
 494                         chunk = nullptr;
 495                         return;
 496                 }
 497         }
 498         while (pos.x < 0) {
 499                 if (chunk->HasNeighbor(Block::FACE_LEFT)) {
 500                         chunk = &chunk->GetNeighbor(Block::FACE_LEFT);
 501                         pos.x += Chunk::Width();
 502                 } else {
 503                         chunk = nullptr;
 504                         return;
 505                 }
 506         }
 507         while (pos.y >= Chunk::Height()) {
 508                 if (chunk->HasNeighbor(Block::FACE_UP)) {
 509                         chunk = &chunk->GetNeighbor(Block::FACE_UP);
 510                         pos.y -= Chunk::Height();
 511                 } else {
 512                         chunk = nullptr;
 513                         return;
 514                 }
 515         }
 516         while (pos.y < 0) {
 517                 if (chunk->HasNeighbor(Block::FACE_DOWN)) {
 518                         chunk = &chunk->GetNeighbor(Block::FACE_DOWN);
 519                         pos.y += Chunk::Height();
 520                 } else {
 521                         chunk = nullptr;
 522                         return;
 523                 }
 524         }
 525         while (pos.z >= Chunk::Depth()) {
 526                 if (chunk->HasNeighbor(Block::FACE_FRONT)) {
 527                         chunk = &chunk->GetNeighbor(Block::FACE_FRONT);
 528                         pos.z -= Chunk::Depth();
 529                 } else {
 530                         chunk = nullptr;
 531                         return;
 532                 }
 533         }
 534         while (pos.z < 0) {
 535                 if (chunk->HasNeighbor(Block::FACE_BACK)) {
 536                         chunk = &chunk->GetNeighbor(Block::FACE_BACK);
 537                         pos.z += Chunk::Depth();
 538                 } else {
 539                         chunk = nullptr;
 540                         return;
 541                 }
 542         }
 543 }
 544
 545 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p, Block::Face face)
 546 : chunk(c), pos(p) {
 547         pos += Block::FaceNormal(face);
 548         if (!Chunk::InBounds(pos)) {
 549                 pos -= Block::FaceNormal(face) * Chunk::Extent();
 550                 chunk = &chunk->GetNeighbor(face);
 551         }
 552 }
 553
 554
 555 ChunkLoader::ChunkLoader(const Config &config, const BlockTypeRegistry &reg, const Generator &gen)
 556 : base(0, 0, 0)
 557 , reg(reg)
 558 , gen(gen)
 559 , loaded()
 560 , to_generate()
 561 , to_free()
 562 , load_dist(config.load_dist)
 563 , unload_dist(config.unload_dist) {
 564
 565 }
 566
 567 namespace {
 568
 569 struct ChunkLess {
 570
 571         explicit ChunkLess(const Chunk::Pos &base)
 572         : base(base) { }
 573
 574         bool operator ()(const Chunk::Pos &a, const Chunk::Pos &b) const {
 575                 Chunk::Pos da(base - a);
 576                 Chunk::Pos db(base - b);
 577                 return
 578                         da.x * da.x + da.y * da.y + da.z * da.z <
 579                         db.x * db.x + db.y * db.y + db.z * db.z;
 580         }
 581
 582         Chunk::Pos base;
 583
 584 };
 585
 586 }
 587
 588 void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 589         for (int z = from.z; z < to.z; ++z) {
 590                 for (int y = from.y; y < to.y; ++y) {
 591                         for (int x = from.x; x < to.x; ++x) {
 592                                 Chunk::Pos pos(x, y, z);
 593                                 if (Known(pos)) {
 594                                         continue;
 595                                 } else if (pos == base) {
 596                                         Generate(pos);
 597
 598                                 //      light testing
 599                                 //      for (int i = 0; i < 16; ++i) {
 600                                 //              for (int j = 0; j < 16; ++j) {
 601                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j,  0 }, Block(1));
 602                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j, 15 }, Block(1));
 603                                 //                      loaded.back().SetBlock(Chunk::Pos{  0, j,  i }, Block(1));
 604                                 //                      loaded.back().SetBlock(Chunk::Pos{ 15, j,  i }, Block(1));
 605                                 //              }
 606                                 //      }
 607                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0,  1 }, Block(13));
 608                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0,  1 }, Block(13));
 609                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0, 14 }, Block(13));
 610                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0, 14 }, Block(13));
 611                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15,  1 }, Block(13));
 612                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15,  1 }, Block(13));
 613                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15, 14 }, Block(13));
 614                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15, 14 }, Block(13));
 615                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7,  0 }, Block(13));
 616                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7,  0 }, Block(13));
 617                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8,  0 }, Block(13));
 618                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8,  0 }, Block(13));
 619                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7, 15 }, Block(13));
 620                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7, 15 }, Block(13));
 621                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8, 15 }, Block(13));
 622                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8, 15 }, Block(13));
 623                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  7 }, Block(13));
 624                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  8 }, Block(13));
 625                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  7 }, Block(13));
 626                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  8 }, Block(13));
 627                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  7 }, Block(13));
 628                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  8 }, Block(13));
 629                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  7 }, Block(13));
 630                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  8 }, Block(13));
 631                                 //      loaded.back().Invalidate();
 632                                 //      loaded.back().CheckUpdate();
 633
 634                                 //      orientation testing
 635                                 //      for (int i = 0; i < Block::FACE_COUNT; ++i) {
 636                                 //              for (int j = 0; j < Block::TURN_COUNT; ++j) {
 637                                 //                      loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
 638                                 //              }
 639                                 //      }
 640                                 //      loaded.back().Invalidate();
 641                                 //      loaded.back().CheckUpdate();
 642                                 } else {
 643                                         to_generate.emplace_back(pos);
 644                                 }
 645                         }
 646                 }
 647         }
 648         to_generate.sort(ChunkLess(base));
 649 }
 650
 651 Chunk &ChunkLoader::Generate(const Chunk::Pos &pos) {
 652         loaded.emplace_back(reg);
 653         Chunk &chunk = loaded.back();
 654         chunk.Position(pos);
 655         gen(chunk);
 656         Insert(chunk);
 657         return chunk;
 658 }
 659
 660 void ChunkLoader::Insert(Chunk &chunk) {
 661         for (Chunk &other : loaded) {
 662                 chunk.SetNeighbor(other);
 663         }
 664 }
 665
 666 void ChunkLoader::Remove(Chunk &chunk) {
 667         chunk.Unlink();
 668 }
 669
 670 Chunk *ChunkLoader::Loaded(const Chunk::Pos &pos) {
 671         for (Chunk &chunk : loaded) {
 672                 if (chunk.Position() == pos) {
 673                         return &chunk;
 674                 }
 675         }
 676         return nullptr;
 677 }
 678
 679 bool ChunkLoader::Queued(const Chunk::Pos &pos) {
 680         for (const Chunk::Pos &chunk : to_generate) {
 681                 if (chunk == pos) {
 682                         return true;
 683                 }
 684         }
 685         return nullptr;
 686 }
 687
 688 bool ChunkLoader::Known(const Chunk::Pos &pos) {
 689         if (Loaded(pos)) return true;
 690         return Queued(pos);
 691 }
 692
 693 Chunk &ChunkLoader::ForceLoad(const Chunk::Pos &pos) {
 694         Chunk *chunk = Loaded(pos);
 695         if (chunk) {
 696                 return *chunk;
 697         }
 698
 699         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end; ++iter) {
 700                 if (*iter == pos) {
 701                         to_generate.erase(iter);
 702                         break;
 703                 }
 704         }
 705
 706         return Generate(pos);
 707 }
 708
 709 void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 710         if (new_base == base) {
 711                 return;
 712         }
 713         base = new_base;
 714
 715         // unload far away chunks
 716         for (auto iter(loaded.begin()), end(loaded.end()); iter != end;) {
 717                 if (std::abs(base.x - iter->Position().x) > unload_dist
 718                                 || std::abs(base.y - iter->Position().y) > unload_dist
 719                                 || std::abs(base.z - iter->Position().z) > unload_dist) {
 720                         auto saved = iter;
 721                         Remove(*saved);
 722                         ++iter;
 723                         to_free.splice(to_free.end(), loaded, saved);
 724                 } else {
 725                         ++iter;
 726                 }
 727         }
 728         // abort far away queued chunks
 729         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end;) {
 730                 if (std::abs(base.x - iter->x) > unload_dist
 731                                 || std::abs(base.y - iter->y) > unload_dist
 732                                 || std::abs(base.z - iter->z) > unload_dist) {
 733                         iter = to_generate.erase(iter);
 734                 } else {
 735                         ++iter;
 736                 }
 737         }
 738         // add missing new chunks
 739         GenerateSurrounding(base);
 740 }
 741
 742 void ChunkLoader::GenerateSurrounding(const Chunk::Pos &pos) {
 743         const Chunk::Pos offset(load_dist, load_dist, load_dist);
 744         Generate(pos - offset, pos + offset);
 745 }
 746
 747 void ChunkLoader::Update() {
 748         if (to_generate.empty()) {
 749                 return;
 750         }
 751
 752         Chunk::Pos pos(to_generate.front());
 753         to_generate.pop_front();
 754
 755         for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
 756                 if (iter->Position() == pos) {
 757                         iter->Relink();
 758                         loaded.splice(loaded.end(), to_free, iter);
 759                         return;
 760                 }
 761         }
 762
 763         if (to_free.empty()) {
 764                 loaded.emplace_back(reg);
 765         } else {
 766                 to_free.front().ClearNeighbors();
 767                 loaded.splice(loaded.end(), to_free, to_free.begin());
 768         }
 769         Chunk &chunk = loaded.back();
 770         chunk.Position(pos);
 771         gen(chunk);
 772         Insert(chunk);
 773 }
 774
 775 }