src/world/chunk.cpp

   1 #include "BlockLookup.hpp"
   2 #include "Chunk.hpp"
   3 #include "ChunkLoader.hpp"
   4
   5 #include "Generator.hpp"
   6
   7 #include <algorithm>
   8 #include <limits>
   9 #include <queue>
  10
  11
  12 namespace blank {
  13
  14 constexpr int Chunk::width;
  15 constexpr int Chunk::height;
  16 constexpr int Chunk::depth;
  17 constexpr int Chunk::size;
  18
  19
  20 Chunk::Chunk(const BlockTypeRegistry &types) noexcept
  21 : types(&types)
  22 , neighbor{0}
  23 , blocks{}
  24 , light{0}
  25 , model()
  26 , position(0, 0, 0)
  27 , dirty(false) {
  28
  29 }
  30
  31 Chunk::Chunk(Chunk &&other) noexcept
  32 : types(other.types)
  33 , model(std::move(other.model))
  34 , position(other.position)
  35 , dirty(other.dirty) {
  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 }
  40
  41 Chunk &Chunk::operator =(Chunk &&other) noexcept {
  42         types = other.types;
  43         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  44         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  45         std::copy(other.light, other.light + sizeof(light), light);
  46         model = std::move(other.model);
  47         position = other.position;
  48         dirty = other.dirty;
  49         return *this;
  50 }
  51
  52
  53 namespace {
  54
  55 struct SetNode {
  56
  57         Chunk *chunk;
  58         Chunk::Pos pos;
  59
  60         SetNode(Chunk *chunk, Chunk::Pos pos)
  61         : chunk(chunk), pos(pos) { }
  62
  63         int Get() const noexcept { return chunk->GetLight(pos); }
  64         void Set(int level) noexcept { chunk->SetLight(pos, level); }
  65
  66         bool HasNext(Block::Face face) noexcept {
  67                 const BlockLookup next(chunk, pos, face);
  68                 return next && !next.GetType().block_light;
  69         }
  70         SetNode GetNext(Block::Face face) noexcept {
  71                 const BlockLookup next(chunk, pos, face);
  72                 return SetNode(&next.GetChunk(), next.GetBlockPos());
  73         }
  74
  75 };
  76
  77 struct UnsetNode
  78 : public SetNode {
  79
  80         int level;
  81
  82         UnsetNode(Chunk *chunk, Chunk::Pos pos)
  83         : SetNode(chunk, pos), level(Get()) { }
  84
  85         UnsetNode(const SetNode &set)
  86         : SetNode(set), level(Get()) { }
  87
  88
  89         bool HasNext(Block::Face face) noexcept {
  90                 const BlockLookup next(chunk, pos, face);
  91                 return next;
  92         }
  93         UnsetNode GetNext(Block::Face face) noexcept { return UnsetNode(SetNode::GetNext(face)); }
  94
  95 };
  96
  97 std::queue<SetNode> light_queue;
  98 std::queue<UnsetNode> dark_queue;
  99
 100 void work_light() noexcept {
 101         while (!light_queue.empty()) {
 102                 SetNode node = light_queue.front();
 103                 light_queue.pop();
 104
 105                 int level = node.Get() - 1;
 106                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 107                         if (node.HasNext(Block::Face(face))) {
 108                                 SetNode other = node.GetNext(Block::Face(face));
 109                                 if (other.Get() < level) {
 110                                         other.Set(level);
 111                                         light_queue.emplace(other);
 112                                 }
 113                         }
 114                 }
 115         }
 116 }
 117
 118 void work_dark() noexcept {
 119         while (!dark_queue.empty()) {
 120                 UnsetNode node = dark_queue.front();
 121                 dark_queue.pop();
 122
 123                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 124                         if (node.HasNext(Block::Face(face))) {
 125                                 UnsetNode other = node.GetNext(Block::Face(face));
 126                                 // TODO: if there a light source here with the same level this will err
 127                                 if (other.Get() != 0 && other.Get() < node.level) {
 128                                         other.Set(0);
 129                                         dark_queue.emplace(other);
 130                                 } else {
 131                                         light_queue.emplace(other);
 132                                 }
 133                         }
 134                 }
 135         }
 136 }
 137
 138 }
 139
 140 void Chunk::SetBlock(int index, const Block &block) noexcept {
 141         const BlockType &old_type = Type(blocks[index]);
 142         const BlockType &new_type = Type(block);
 143
 144         blocks[index] = block;
 145
 146         if (&old_type == &new_type) return;
 147
 148         if (new_type.luminosity > old_type.luminosity) {
 149                 // light added
 150                 SetLight(index, new_type.luminosity);
 151                 light_queue.emplace(this, ToPos(index));
 152                 work_light();
 153         } else if (new_type.luminosity < old_type.luminosity) {
 154                 // light removed
 155                 dark_queue.emplace(this, ToPos(index));
 156                 SetLight(index, 0);
 157                 work_dark();
 158                 SetLight(index, new_type.luminosity);
 159                 light_queue.emplace(this, ToPos(index));
 160                 work_light();
 161         } else if (new_type.block_light && !old_type.block_light) {
 162                 // obstacle added
 163                 if (GetLight(index) > 0) {
 164                         dark_queue.emplace(this, ToPos(index));
 165                         SetLight(index, 0);
 166                         work_dark();
 167                         work_light();
 168                 }
 169         } else if (!new_type.block_light && old_type.block_light) {
 170                 // obstacle removed
 171                 int level = 0;
 172                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 173                         BlockLookup next_block(this, ToPos(index), Block::Face(face));
 174                         if (next_block) {
 175                                 level = std::min(level, next_block.GetLight());
 176                         }
 177                 }
 178                 if (level > 1) {
 179                         SetLight(index, level - 1);
 180                         light_queue.emplace(this, ToPos(index));
 181                         work_light();
 182                 }
 183         }
 184 }
 185
 186 void Chunk::SetNeighbor(Chunk &other) noexcept {
 187         if (other.position == position + Pos(-1, 0, 0)) {
 188                 if (neighbor[Block::FACE_LEFT] != &other) {
 189                         neighbor[Block::FACE_LEFT] = &other;
 190                         other.neighbor[Block::FACE_RIGHT] = this;
 191                         for (int z = 0; z < depth; ++z) {
 192                                 for (int y = 0; y < height; ++y) {
 193                                         Pos my_pos(0, y, z);
 194                                         Pos other_pos(width - 1, y, z);
 195                                         if (GetLight(my_pos) > 0) {
 196                                                 light_queue.emplace(this, my_pos);
 197                                         }
 198                                         if (other.GetLight(other_pos) > 0) {
 199                                                 light_queue.emplace(&other, other_pos);
 200                                         }
 201                                 }
 202                         }
 203                         work_light();
 204                 }
 205         } else if (other.position == position + Pos(1, 0, 0)) {
 206                 if (neighbor[Block::FACE_RIGHT] != &other) {
 207                         neighbor[Block::FACE_RIGHT] = &other;
 208                         other.neighbor[Block::FACE_LEFT] = this;
 209                         for (int z = 0; z < depth; ++z) {
 210                                 for (int y = 0; y < height; ++y) {
 211                                         Pos my_pos(width - 1, y, z);
 212                                         Pos other_pos(0, y, z);
 213                                         if (GetLight(my_pos) > 0) {
 214                                                 light_queue.emplace(this, my_pos);
 215                                         }
 216                                         if (other.GetLight(other_pos) > 0) {
 217                                                 light_queue.emplace(&other, other_pos);
 218                                         }
 219                                 }
 220                         }
 221                         work_light();
 222                 }
 223         } else if (other.position == position + Pos(0, -1, 0)) {
 224                 if (neighbor[Block::FACE_DOWN] != &other) {
 225                         neighbor[Block::FACE_DOWN] = &other;
 226                         other.neighbor[Block::FACE_UP] = this;
 227                         for (int z = 0; z < depth; ++z) {
 228                                 for (int x = 0; x < width; ++x) {
 229                                         Pos my_pos(x, 0, z);
 230                                         Pos other_pos(x, height - 1, z);
 231                                         if (GetLight(my_pos) > 0) {
 232                                                 light_queue.emplace(this, my_pos);
 233                                         }
 234                                         if (other.GetLight(other_pos) > 0) {
 235                                                 light_queue.emplace(&other, other_pos);
 236                                         }
 237                                 }
 238                         }
 239                         work_light();
 240                 }
 241         } else if (other.position == position + Pos(0, 1, 0)) {
 242                 if (neighbor[Block::FACE_UP] != &other) {
 243                         neighbor[Block::FACE_UP] = &other;
 244                         other.neighbor[Block::FACE_DOWN] = this;
 245                         for (int z = 0; z < depth; ++z) {
 246                                 for (int x = 0; x < width; ++x) {
 247                                         Pos my_pos(x, height - 1, z);
 248                                         Pos other_pos(x, 0, z);
 249                                         if (GetLight(my_pos) > 0) {
 250                                                 light_queue.emplace(this, my_pos);
 251                                         }
 252                                         if (other.GetLight(other_pos) > 0) {
 253                                                 light_queue.emplace(&other, other_pos);
 254                                         }
 255                                 }
 256                         }
 257                         work_light();
 258                 }
 259         } else if (other.position == position + Pos(0, 0, -1)) {
 260                 if (neighbor[Block::FACE_BACK] != &other) {
 261                         neighbor[Block::FACE_BACK] = &other;
 262                         other.neighbor[Block::FACE_FRONT] = this;
 263                         for (int y = 0; y < height; ++y) {
 264                                 for (int x = 0; x < width; ++x) {
 265                                         Pos my_pos(x, y, 0);
 266                                         Pos other_pos(x, y, depth - 1);
 267                                         if (GetLight(my_pos) > 0) {
 268                                                 light_queue.emplace(this, my_pos);
 269                                         }
 270                                         if (other.GetLight(other_pos) > 0) {
 271                                                 light_queue.emplace(&other, other_pos);
 272                                         }
 273                                 }
 274                         }
 275                         work_light();
 276                 }
 277         } else if (other.position == position + Pos(0, 0, 1)) {
 278                 if (neighbor[Block::FACE_FRONT] != &other) {
 279                         neighbor[Block::FACE_FRONT] = &other;
 280                         other.neighbor[Block::FACE_BACK] = this;
 281                         for (int y = 0; y < height; ++y) {
 282                                 for (int x = 0; x < width; ++x) {
 283                                         Pos my_pos(x, y, depth - 1);
 284                                         Pos other_pos(x, y, 0);
 285                                         if (GetLight(my_pos) > 0) {
 286                                                 light_queue.emplace(this, my_pos);
 287                                         }
 288                                         if (other.GetLight(other_pos) > 0) {
 289                                                 light_queue.emplace(&other, other_pos);
 290                                         }
 291                                 }
 292                         }
 293                         work_light();
 294                 }
 295         }
 296 }
 297
 298 void Chunk::ClearNeighbors() noexcept {
 299         for (int i = 0; i < Block::FACE_COUNT; ++i) {
 300                 neighbor[i] = nullptr;
 301         }
 302 }
 303
 304 void Chunk::Unlink() noexcept {
 305         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 306                 if (neighbor[face]) {
 307                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = nullptr;
 308                 }
 309         }
 310 }
 311
 312 void Chunk::Relink() noexcept {
 313         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 314                 if (neighbor[face]) {
 315                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = this;
 316                 }
 317         }
 318 }
 319
 320
 321 void Chunk::SetLight(int index, int level) noexcept {
 322         if (light[index] != level) {
 323                 light[index] = level;
 324                 Invalidate();
 325         }
 326 }
 327
 328 int Chunk::GetLight(int index) const noexcept {
 329         return light[index];
 330 }
 331
 332 float Chunk::GetVertexLight(const Pos &pos, const BlockModel::Position &vtx, const Model::Normal &norm) const noexcept {
 333         int index = ToIndex(pos);
 334         float light = GetLight(index);
 335
 336         Block::Face direct_face(Block::NormalFace(norm));
 337         // tis okay
 338         BlockLookup direct(const_cast<Chunk *>(this), pos, Block::NormalFace(norm));
 339         if (direct) {
 340                 float direct_light = direct.GetLight();
 341                 if (direct_light > light) {
 342                         light = direct_light;
 343                 }
 344         } else {
 345                 return light;
 346         }
 347
 348         if (Type(BlockAt(index)).luminosity > 0 || direct.GetType().block_light) {
 349                 return light;
 350         }
 351
 352         Block::Face edge[2];
 353         switch (Block::Axis(direct_face)) {
 354                 case 0: // X
 355                         edge[0] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 356                         edge[1] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 357                         break;
 358                 case 1: // Y
 359                         edge[0] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 360                         edge[1] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 361                         break;
 362                 case 2: // Z
 363                         edge[0] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 364                         edge[1] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 365                         break;
 366         }
 367
 368         int num = 1;
 369         int occlusion = 0;
 370
 371         BlockLookup next[2] = {
 372                 direct.Next(edge[0]),
 373                 direct.Next(edge[1]),
 374         };
 375
 376         if (next[0]) {
 377                 if (next[0].GetType().block_light) {
 378                         ++occlusion;
 379                 } else {
 380                         light += next[0].GetLight();
 381                         ++num;
 382                 }
 383         }
 384         if (next[1]) {
 385                 if (next[1].GetType().block_light) {
 386                         ++occlusion;
 387                 } else {
 388                         light += next[1].GetLight();
 389                         ++num;
 390                 }
 391         }
 392         if (occlusion < 2) {
 393                 if (next[0]) {
 394                         BlockLookup corner = next[0].Next(edge[1]);
 395                         if (corner) {
 396                                 if (corner.GetType().block_light) {
 397                                         ++occlusion;
 398                                 } else {
 399                                         light += corner.GetLight();
 400                                         ++num;
 401                                 }
 402                         }
 403                 } else if (next[1]) {
 404                         BlockLookup corner = next[1].Next(edge[0]);
 405                         if (corner) {
 406                                 if (corner.GetType().block_light) {
 407                                         ++occlusion;
 408                                 } else {
 409                                         light += corner.GetLight();
 410                                         ++num;
 411                                 }
 412                         }
 413                 }
 414         } else {
 415                 ++occlusion;
 416         }
 417
 418         return (light / num) - (occlusion * 0.8f);
 419 }
 420
 421
 422 bool Chunk::IsSurface(const Pos &pos) const noexcept {
 423         const Block &block = BlockAt(pos);
 424         if (!Type(block).visible) {
 425                 return false;
 426         }
 427         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 428                 BlockLookup next = BlockLookup(const_cast<Chunk *>(this), pos, Block::Face(face));
 429                 if (!next || !next.GetType().visible) {
 430                         return true;
 431                 }
 432         }
 433         return false;
 434 }
 435
 436
 437 void Chunk::Draw() noexcept {
 438         if (dirty) {
 439                 Update();
 440         }
 441         model.Draw();
 442 }
 443
 444
 445 bool Chunk::Intersection(
 446         const Ray &ray,
 447         const glm::mat4 &M,
 448         int &blkid,
 449         float &dist,
 450         glm::vec3 &normal
 451 ) const noexcept {
 452         // TODO: should be possible to heavily optimize this
 453         int idx = 0;
 454         blkid = -1;
 455         dist = std::numeric_limits<float>::infinity();
 456         for (int z = 0; z < depth; ++z) {
 457                 for (int y = 0; y < height; ++y) {
 458                         for (int x = 0; x < width; ++x, ++idx) {
 459                                 const BlockType &type = Type(idx);
 460                                 if (!type.visible) {
 461                                         continue;
 462                                 }
 463                                 float cur_dist;
 464                                 glm::vec3 cur_norm;
 465                                 if (type.shape->Intersects(ray, M * ToTransform(Pos(x, y, z), idx), cur_dist, cur_norm)) {
 466                                         if (cur_dist < dist) {
 467                                                 blkid = idx;
 468                                                 dist = cur_dist;
 469                                                 normal = cur_norm;
 470                                         }
 471                                 }
 472                         }
 473                 }
 474         }
 475
 476         if (blkid < 0) {
 477                 return false;
 478         } else {
 479                 normal = glm::vec3(BlockAt(blkid).Transform() * glm::vec4(normal, 0.0f));
 480                 return true;
 481         }
 482 }
 483
 484
 485 namespace {
 486
 487 BlockModel::Buffer buf;
 488
 489 }
 490
 491 void Chunk::CheckUpdate() noexcept {
 492         if (dirty) {
 493                 Update();
 494         }
 495 }
 496
 497 void Chunk::Update() noexcept {
 498         int vtx_count = 0, idx_count = 0;
 499         for (const auto &block : blocks) {
 500                 const Shape *shape = Type(block).shape;
 501                 vtx_count += shape->VertexCount();
 502                 idx_count += shape->VertexIndexCount();
 503         }
 504         buf.Clear();
 505         buf.Reserve(vtx_count, idx_count);
 506
 507         int idx = 0;
 508         BlockModel::Index vtx_counter = 0;
 509         for (size_t z = 0; z < depth; ++z) {
 510                 for (size_t y = 0; y < height; ++y) {
 511                         for (size_t x = 0; x < width; ++x, ++idx) {
 512                                 const BlockType &type = Type(BlockAt(idx));
 513                                 const Pos pos(x, y, z);
 514
 515                                 if (!type.visible || Obstructed(pos).All()) continue;
 516
 517                                 type.FillBlockModel(buf, ToTransform(pos, idx), vtx_counter);
 518                                 size_t vtx_begin = vtx_counter;
 519                                 vtx_counter += type.shape->VertexCount();
 520
 521                                 for (size_t vtx = vtx_begin; vtx < vtx_counter; ++vtx) {
 522                                         buf.lights.emplace_back(GetVertexLight(
 523                                                 pos,
 524                                                 buf.vertices[vtx],
 525                                                 type.shape->VertexNormal(vtx - vtx_begin, BlockAt(idx).Transform())
 526                                         ));
 527                                 }
 528                         }
 529                 }
 530         }
 531
 532         model.Update(buf);
 533         dirty = false;
 534 }
 535
 536 Block::FaceSet Chunk::Obstructed(const Pos &pos) const noexcept {
 537         Block::FaceSet result;
 538
 539         for (int f = 0; f < Block::FACE_COUNT; ++f) {
 540                 Block::Face face = Block::Face(f);
 541                 BlockLookup next(const_cast<Chunk *>(this), pos, face);
 542                 if (next && next.GetType().FaceFilled(next.GetBlock(), Block::Opposite(face))) {
 543                         result.Set(face);
 544                 }
 545         }
 546
 547         return result;
 548 }
 549
 550 glm::mat4 Chunk::ToTransform(const Pos &pos, int idx) const noexcept {
 551         return glm::translate(ToCoords(pos)) * BlockAt(idx).Transform();
 552 }
 553
 554
 555 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p) noexcept
 556 : chunk(c), pos(p) {
 557         while (pos.x >= Chunk::width) {
 558                 if (chunk->HasNeighbor(Block::FACE_RIGHT)) {
 559                         chunk = &chunk->GetNeighbor(Block::FACE_RIGHT);
 560                         pos.x -= Chunk::width;
 561                 } else {
 562                         chunk = nullptr;
 563                         return;
 564                 }
 565         }
 566         while (pos.x < 0) {
 567                 if (chunk->HasNeighbor(Block::FACE_LEFT)) {
 568                         chunk = &chunk->GetNeighbor(Block::FACE_LEFT);
 569                         pos.x += Chunk::width;
 570                 } else {
 571                         chunk = nullptr;
 572                         return;
 573                 }
 574         }
 575         while (pos.y >= Chunk::height) {
 576                 if (chunk->HasNeighbor(Block::FACE_UP)) {
 577                         chunk = &chunk->GetNeighbor(Block::FACE_UP);
 578                         pos.y -= Chunk::height;
 579                 } else {
 580                         chunk = nullptr;
 581                         return;
 582                 }
 583         }
 584         while (pos.y < 0) {
 585                 if (chunk->HasNeighbor(Block::FACE_DOWN)) {
 586                         chunk = &chunk->GetNeighbor(Block::FACE_DOWN);
 587                         pos.y += Chunk::height;
 588                 } else {
 589                         chunk = nullptr;
 590                         return;
 591                 }
 592         }
 593         while (pos.z >= Chunk::depth) {
 594                 if (chunk->HasNeighbor(Block::FACE_FRONT)) {
 595                         chunk = &chunk->GetNeighbor(Block::FACE_FRONT);
 596                         pos.z -= Chunk::depth;
 597                 } else {
 598                         chunk = nullptr;
 599                         return;
 600                 }
 601         }
 602         while (pos.z < 0) {
 603                 if (chunk->HasNeighbor(Block::FACE_BACK)) {
 604                         chunk = &chunk->GetNeighbor(Block::FACE_BACK);
 605                         pos.z += Chunk::depth;
 606                 } else {
 607                         chunk = nullptr;
 608                         return;
 609                 }
 610         }
 611 }
 612
 613 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p, Block::Face face) noexcept
 614 : chunk(c), pos(p) {
 615         pos += Block::FaceNormal(face);
 616         if (!Chunk::InBounds(pos)) {
 617                 pos -= Block::FaceNormal(face) * Chunk::Extent();
 618                 chunk = &chunk->GetNeighbor(face);
 619         }
 620 }
 621
 622
 623 ChunkLoader::ChunkLoader(const Config &config, const BlockTypeRegistry &reg, const Generator &gen) noexcept
 624 : base(0, 0, 0)
 625 , reg(reg)
 626 , gen(gen)
 627 , loaded()
 628 , to_generate()
 629 , to_free()
 630 , load_dist(config.load_dist)
 631 , unload_dist(config.unload_dist) {
 632
 633 }
 634
 635 namespace {
 636
 637 struct ChunkLess {
 638
 639         explicit ChunkLess(const Chunk::Pos &base) noexcept
 640         : base(base) { }
 641
 642         bool operator ()(const Chunk::Pos &a, const Chunk::Pos &b) const noexcept {
 643                 Chunk::Pos da(base - a);
 644                 Chunk::Pos db(base - b);
 645                 return
 646                         da.x * da.x + da.y * da.y + da.z * da.z <
 647                         db.x * db.x + db.y * db.y + db.z * db.z;
 648         }
 649
 650         Chunk::Pos base;
 651
 652 };
 653
 654 }
 655
 656 void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 657         for (int z = from.z; z < to.z; ++z) {
 658                 for (int y = from.y; y < to.y; ++y) {
 659                         for (int x = from.x; x < to.x; ++x) {
 660                                 Chunk::Pos pos(x, y, z);
 661                                 if (Known(pos)) {
 662                                         continue;
 663                                 } else if (pos == base) {
 664                                         Generate(pos);
 665
 666                                 //      light testing
 667                                 //      for (int i = 0; i < 16; ++i) {
 668                                 //              for (int j = 0; j < 16; ++j) {
 669                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j,  0 }, Block(1));
 670                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j, 15 }, Block(1));
 671                                 //                      loaded.back().SetBlock(Chunk::Pos{  0, j,  i }, Block(1));
 672                                 //                      loaded.back().SetBlock(Chunk::Pos{ 15, j,  i }, Block(1));
 673                                 //              }
 674                                 //      }
 675                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0,  1 }, Block(13));
 676                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0,  1 }, Block(13));
 677                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0, 14 }, Block(13));
 678                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0, 14 }, Block(13));
 679                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15,  1 }, Block(13));
 680                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15,  1 }, Block(13));
 681                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15, 14 }, Block(13));
 682                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15, 14 }, Block(13));
 683                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7,  0 }, Block(13));
 684                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7,  0 }, Block(13));
 685                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8,  0 }, Block(13));
 686                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8,  0 }, Block(13));
 687                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7, 15 }, Block(13));
 688                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7, 15 }, Block(13));
 689                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8, 15 }, Block(13));
 690                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8, 15 }, Block(13));
 691                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  7 }, Block(13));
 692                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  8 }, Block(13));
 693                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  7 }, Block(13));
 694                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  8 }, Block(13));
 695                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  7 }, Block(13));
 696                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  8 }, Block(13));
 697                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  7 }, Block(13));
 698                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  8 }, Block(13));
 699                                 //      loaded.back().Invalidate();
 700                                 //      loaded.back().CheckUpdate();
 701
 702                                 //      orientation testing
 703                                 //      for (int i = 0; i < Block::FACE_COUNT; ++i) {
 704                                 //              for (int j = 0; j < Block::TURN_COUNT; ++j) {
 705                                 //                      loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
 706                                 //              }
 707                                 //      }
 708                                 //      loaded.back().Invalidate();
 709                                 //      loaded.back().CheckUpdate();
 710                                 } else {
 711                                         to_generate.emplace_back(pos);
 712                                 }
 713                         }
 714                 }
 715         }
 716         to_generate.sort(ChunkLess(base));
 717 }
 718
 719 Chunk &ChunkLoader::Generate(const Chunk::Pos &pos) {
 720         loaded.emplace_back(reg);
 721         Chunk &chunk = loaded.back();
 722         chunk.Position(pos);
 723         gen(chunk);
 724         Insert(chunk);
 725         return chunk;
 726 }
 727
 728 void ChunkLoader::Insert(Chunk &chunk) noexcept {
 729         for (Chunk &other : loaded) {
 730                 chunk.SetNeighbor(other);
 731         }
 732 }
 733
 734 void ChunkLoader::Remove(Chunk &chunk) noexcept {
 735         chunk.Unlink();
 736 }
 737
 738 Chunk *ChunkLoader::Loaded(const Chunk::Pos &pos) noexcept {
 739         for (Chunk &chunk : loaded) {
 740                 if (chunk.Position() == pos) {
 741                         return &chunk;
 742                 }
 743         }
 744         return nullptr;
 745 }
 746
 747 bool ChunkLoader::Queued(const Chunk::Pos &pos) noexcept {
 748         for (const Chunk::Pos &chunk : to_generate) {
 749                 if (chunk == pos) {
 750                         return true;
 751                 }
 752         }
 753         return nullptr;
 754 }
 755
 756 bool ChunkLoader::Known(const Chunk::Pos &pos) noexcept {
 757         if (Loaded(pos)) return true;
 758         return Queued(pos);
 759 }
 760
 761 Chunk &ChunkLoader::ForceLoad(const Chunk::Pos &pos) {
 762         Chunk *chunk = Loaded(pos);
 763         if (chunk) {
 764                 return *chunk;
 765         }
 766
 767         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end; ++iter) {
 768                 if (*iter == pos) {
 769                         to_generate.erase(iter);
 770                         break;
 771                 }
 772         }
 773
 774         return Generate(pos);
 775 }
 776
 777 void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 778         if (new_base == base) {
 779                 return;
 780         }
 781         base = new_base;
 782
 783         // unload far away chunks
 784         for (auto iter(loaded.begin()), end(loaded.end()); iter != end;) {
 785                 if (std::abs(base.x - iter->Position().x) > unload_dist
 786                                 || std::abs(base.y - iter->Position().y) > unload_dist
 787                                 || std::abs(base.z - iter->Position().z) > unload_dist) {
 788                         auto saved = iter;
 789                         Remove(*saved);
 790                         ++iter;
 791                         to_free.splice(to_free.end(), loaded, saved);
 792                 } else {
 793                         ++iter;
 794                 }
 795         }
 796         // abort far away queued chunks
 797         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end;) {
 798                 if (std::abs(base.x - iter->x) > unload_dist
 799                                 || std::abs(base.y - iter->y) > unload_dist
 800                                 || std::abs(base.z - iter->z) > unload_dist) {
 801                         iter = to_generate.erase(iter);
 802                 } else {
 803                         ++iter;
 804                 }
 805         }
 806         // add missing new chunks
 807         GenerateSurrounding(base);
 808 }
 809
 810 void ChunkLoader::GenerateSurrounding(const Chunk::Pos &pos) {
 811         const Chunk::Pos offset(load_dist, load_dist, load_dist);
 812         Generate(pos - offset, pos + offset);
 813 }
 814
 815 void ChunkLoader::Update() {
 816         if (to_generate.empty()) {
 817                 return;
 818         }
 819
 820         Chunk::Pos pos(to_generate.front());
 821         to_generate.pop_front();
 822
 823         for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
 824                 if (iter->Position() == pos) {
 825                         iter->Relink();
 826                         loaded.splice(loaded.end(), to_free, iter);
 827                         return;
 828                 }
 829         }
 830
 831         if (to_free.empty()) {
 832                 loaded.emplace_back(reg);
 833         } else {
 834                 to_free.front().ClearNeighbors();
 835                 loaded.splice(loaded.end(), to_free, to_free.begin());
 836         }
 837         Chunk &chunk = loaded.back();
 838         chunk.Position(pos);
 839         gen(chunk);
 840         Insert(chunk);
 841 }
 842
 843 }