src/chunk.cpp

   1 #include "chunk.hpp"
   2
   3 #include "generator.hpp"
   4
   5 #include <algorithm>
   6 #include <limits>
   7 #include <queue>
   8
   9
  10 namespace blank {
  11
  12 constexpr int Chunk::width;
  13 constexpr int Chunk::height;
  14 constexpr int Chunk::depth;
  15 constexpr int Chunk::size;
  16
  17
  18 Chunk::Chunk(const BlockTypeRegistry &types) noexcept
  19 : types(&types)
  20 , neighbor{0}
  21 , blocks{}
  22 , light{0}
  23 , model()
  24 , position(0, 0, 0)
  25 , dirty(false) {
  26
  27 }
  28
  29 Chunk::Chunk(Chunk &&other) noexcept
  30 : types(other.types)
  31 , model(std::move(other.model))
  32 , position(other.position)
  33 , dirty(other.dirty) {
  34         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  35         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  36         std::copy(other.light, other.light + sizeof(light), light);
  37 }
  38
  39 Chunk &Chunk::operator =(Chunk &&other) noexcept {
  40         types = other.types;
  41         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  42         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  43         std::copy(other.light, other.light + sizeof(light), light);
  44         model = std::move(other.model);
  45         position = other.position;
  46         dirty = other.dirty;
  47         return *this;
  48 }
  49
  50
  51 namespace {
  52
  53 struct SetNode {
  54
  55         Chunk *chunk;
  56         Chunk::Pos pos;
  57
  58         SetNode(Chunk *chunk, Chunk::Pos pos)
  59         : chunk(chunk), pos(pos) { }
  60
  61         int Get() const noexcept { return chunk->GetLight(pos); }
  62         void Set(int level) noexcept { chunk->SetLight(pos, level); }
  63
  64         bool HasNext(Block::Face face) noexcept {
  65                 const BlockLookup next(chunk, pos, face);
  66                 return next && !next.GetType().block_light;
  67         }
  68         SetNode GetNext(Block::Face face) noexcept {
  69                 const BlockLookup next(chunk, pos, face);
  70                 return SetNode(&next.GetChunk(), next.GetBlockPos());
  71         }
  72
  73 };
  74
  75 struct UnsetNode
  76 : public SetNode {
  77
  78         int level;
  79
  80         UnsetNode(Chunk *chunk, Chunk::Pos pos)
  81         : SetNode(chunk, pos), level(Get()) { }
  82
  83         UnsetNode(const SetNode &set)
  84         : SetNode(set), level(Get()) { }
  85
  86
  87         bool HasNext(Block::Face face) noexcept {
  88                 const BlockLookup next(chunk, pos, face);
  89                 return next;
  90         }
  91         UnsetNode GetNext(Block::Face face) noexcept { return UnsetNode(SetNode::GetNext(face)); }
  92
  93 };
  94
  95 std::queue<SetNode> light_queue;
  96 std::queue<UnsetNode> dark_queue;
  97
  98 void work_light() noexcept {
  99         while (!light_queue.empty()) {
 100                 SetNode node = light_queue.front();
 101                 light_queue.pop();
 102
 103                 int level = node.Get() - 1;
 104                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 105                         if (node.HasNext(Block::Face(face))) {
 106                                 SetNode other = node.GetNext(Block::Face(face));
 107                                 if (other.Get() < level) {
 108                                         other.Set(level);
 109                                         light_queue.emplace(other);
 110                                 }
 111                         }
 112                 }
 113         }
 114 }
 115
 116 void work_dark() noexcept {
 117         while (!dark_queue.empty()) {
 118                 UnsetNode node = dark_queue.front();
 119                 dark_queue.pop();
 120
 121                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 122                         if (node.HasNext(Block::Face(face))) {
 123                                 UnsetNode other = node.GetNext(Block::Face(face));
 124                                 // TODO: if there a light source here with the same level this will err
 125                                 if (other.Get() != 0 && other.Get() < node.level) {
 126                                         other.Set(0);
 127                                         dark_queue.emplace(other);
 128                                 } else {
 129                                         light_queue.emplace(other);
 130                                 }
 131                         }
 132                 }
 133         }
 134 }
 135
 136 }
 137
 138 void Chunk::SetBlock(int index, const Block &block) noexcept {
 139         const BlockType &old_type = Type(blocks[index]);
 140         const BlockType &new_type = Type(block);
 141
 142         blocks[index] = block;
 143
 144         if (&old_type == &new_type) return;
 145
 146         if (new_type.luminosity > old_type.luminosity) {
 147                 // light added
 148                 SetLight(index, new_type.luminosity);
 149                 light_queue.emplace(this, ToPos(index));
 150                 work_light();
 151         } else if (new_type.luminosity < old_type.luminosity) {
 152                 // light removed
 153                 dark_queue.emplace(this, ToPos(index));
 154                 SetLight(index, 0);
 155                 work_dark();
 156                 SetLight(index, new_type.luminosity);
 157                 light_queue.emplace(this, ToPos(index));
 158                 work_light();
 159         } else if (new_type.block_light && !old_type.block_light) {
 160                 // obstacle added
 161                 if (GetLight(index) > 0) {
 162                         dark_queue.emplace(this, ToPos(index));
 163                         SetLight(index, 0);
 164                         work_dark();
 165                         work_light();
 166                 }
 167         } else if (!new_type.block_light && old_type.block_light) {
 168                 // obstacle removed
 169                 int level = 0;
 170                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 171                         BlockLookup next_block(this, ToPos(index), Block::Face(face));
 172                         if (next_block) {
 173                                 level = std::min(level, next_block.GetLight());
 174                         }
 175                 }
 176                 if (level > 1) {
 177                         SetLight(index, level - 1);
 178                         light_queue.emplace(this, ToPos(index));
 179                         work_light();
 180                 }
 181         }
 182 }
 183
 184 void Chunk::SetNeighbor(Chunk &other) noexcept {
 185         if (other.position == position + Pos(-1, 0, 0)) {
 186                 if (neighbor[Block::FACE_LEFT] != &other) {
 187                         neighbor[Block::FACE_LEFT] = &other;
 188                         other.neighbor[Block::FACE_RIGHT] = this;
 189                         for (int z = 0; z < depth; ++z) {
 190                                 for (int y = 0; y < height; ++y) {
 191                                         Pos my_pos(0, y, z);
 192                                         Pos other_pos(width - 1, y, z);
 193                                         if (GetLight(my_pos) > 0) {
 194                                                 light_queue.emplace(this, my_pos);
 195                                         }
 196                                         if (other.GetLight(other_pos) > 0) {
 197                                                 light_queue.emplace(&other, other_pos);
 198                                         }
 199                                 }
 200                         }
 201                         work_light();
 202                 }
 203         } else if (other.position == position + Pos(1, 0, 0)) {
 204                 if (neighbor[Block::FACE_RIGHT] != &other) {
 205                         neighbor[Block::FACE_RIGHT] = &other;
 206                         other.neighbor[Block::FACE_LEFT] = this;
 207                         for (int z = 0; z < depth; ++z) {
 208                                 for (int y = 0; y < height; ++y) {
 209                                         Pos my_pos(width - 1, y, z);
 210                                         Pos other_pos(0, y, z);
 211                                         if (GetLight(my_pos) > 0) {
 212                                                 light_queue.emplace(this, my_pos);
 213                                         }
 214                                         if (other.GetLight(other_pos) > 0) {
 215                                                 light_queue.emplace(&other, other_pos);
 216                                         }
 217                                 }
 218                         }
 219                         work_light();
 220                 }
 221         } else if (other.position == position + Pos(0, -1, 0)) {
 222                 if (neighbor[Block::FACE_DOWN] != &other) {
 223                         neighbor[Block::FACE_DOWN] = &other;
 224                         other.neighbor[Block::FACE_UP] = this;
 225                         for (int z = 0; z < depth; ++z) {
 226                                 for (int x = 0; x < width; ++x) {
 227                                         Pos my_pos(x, 0, z);
 228                                         Pos other_pos(x, height - 1, z);
 229                                         if (GetLight(my_pos) > 0) {
 230                                                 light_queue.emplace(this, my_pos);
 231                                         }
 232                                         if (other.GetLight(other_pos) > 0) {
 233                                                 light_queue.emplace(&other, other_pos);
 234                                         }
 235                                 }
 236                         }
 237                         work_light();
 238                 }
 239         } else if (other.position == position + Pos(0, 1, 0)) {
 240                 if (neighbor[Block::FACE_UP] != &other) {
 241                         neighbor[Block::FACE_UP] = &other;
 242                         other.neighbor[Block::FACE_DOWN] = this;
 243                         for (int z = 0; z < depth; ++z) {
 244                                 for (int x = 0; x < width; ++x) {
 245                                         Pos my_pos(x, height - 1, z);
 246                                         Pos other_pos(x, 0, z);
 247                                         if (GetLight(my_pos) > 0) {
 248                                                 light_queue.emplace(this, my_pos);
 249                                         }
 250                                         if (other.GetLight(other_pos) > 0) {
 251                                                 light_queue.emplace(&other, other_pos);
 252                                         }
 253                                 }
 254                         }
 255                         work_light();
 256                 }
 257         } else if (other.position == position + Pos(0, 0, -1)) {
 258                 if (neighbor[Block::FACE_BACK] != &other) {
 259                         neighbor[Block::FACE_BACK] = &other;
 260                         other.neighbor[Block::FACE_FRONT] = this;
 261                         for (int y = 0; y < height; ++y) {
 262                                 for (int x = 0; x < width; ++x) {
 263                                         Pos my_pos(x, y, 0);
 264                                         Pos other_pos(x, y, depth - 1);
 265                                         if (GetLight(my_pos) > 0) {
 266                                                 light_queue.emplace(this, my_pos);
 267                                         }
 268                                         if (other.GetLight(other_pos) > 0) {
 269                                                 light_queue.emplace(&other, other_pos);
 270                                         }
 271                                 }
 272                         }
 273                         work_light();
 274                 }
 275         } else if (other.position == position + Pos(0, 0, 1)) {
 276                 if (neighbor[Block::FACE_FRONT] != &other) {
 277                         neighbor[Block::FACE_FRONT] = &other;
 278                         other.neighbor[Block::FACE_BACK] = this;
 279                         for (int y = 0; y < height; ++y) {
 280                                 for (int x = 0; x < width; ++x) {
 281                                         Pos my_pos(x, y, depth - 1);
 282                                         Pos other_pos(x, y, 0);
 283                                         if (GetLight(my_pos) > 0) {
 284                                                 light_queue.emplace(this, my_pos);
 285                                         }
 286                                         if (other.GetLight(other_pos) > 0) {
 287                                                 light_queue.emplace(&other, other_pos);
 288                                         }
 289                                 }
 290                         }
 291                         work_light();
 292                 }
 293         }
 294 }
 295
 296 void Chunk::ClearNeighbors() noexcept {
 297         for (int i = 0; i < Block::FACE_COUNT; ++i) {
 298                 neighbor[i] = nullptr;
 299         }
 300 }
 301
 302 void Chunk::Unlink() noexcept {
 303         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 304                 if (neighbor[face]) {
 305                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = nullptr;
 306                 }
 307         }
 308 }
 309
 310 void Chunk::Relink() noexcept {
 311         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 312                 if (neighbor[face]) {
 313                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = this;
 314                 }
 315         }
 316 }
 317
 318
 319 void Chunk::SetLight(int index, int level) noexcept {
 320         if (light[index] != level) {
 321                 light[index] = level;
 322                 Invalidate();
 323         }
 324 }
 325
 326 int Chunk::GetLight(int index) const noexcept {
 327         return light[index];
 328 }
 329
 330 float Chunk::GetVertexLight(const Pos &pos, const BlockModel::Position &vtx, const Model::Normal &norm) const noexcept {
 331         int index = ToIndex(pos);
 332         float light = GetLight(index);
 333
 334         Block::Face direct_face(Block::NormalFace(norm));
 335         // tis okay
 336         BlockLookup direct(const_cast<Chunk *>(this), pos, Block::NormalFace(norm));
 337         if (direct) {
 338                 float direct_light = direct.GetLight();
 339                 if (direct_light > light) {
 340                         light = direct_light;
 341                 }
 342         } else {
 343                 return light;
 344         }
 345
 346         if (Type(BlockAt(index)).luminosity > 0 || direct.GetType().block_light) {
 347                 return light;
 348         }
 349
 350         Block::Face edge[2];
 351         switch (Block::Axis(direct_face)) {
 352                 case 0: // X
 353                         edge[0] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 354                         edge[1] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 355                         break;
 356                 case 1: // Y
 357                         edge[0] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 358                         edge[1] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 359                         break;
 360                 case 2: // Z
 361                         edge[0] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 362                         edge[1] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 363                         break;
 364         }
 365
 366         int num = 1;
 367         int occlusion = 0;
 368
 369         BlockLookup next[2] = {
 370                 direct.Next(edge[0]),
 371                 direct.Next(edge[1]),
 372         };
 373
 374         if (next[0]) {
 375                 if (next[0].GetType().block_light) {
 376                         ++occlusion;
 377                 } else {
 378                         light += next[0].GetLight();
 379                         ++num;
 380                 }
 381         }
 382         if (next[1]) {
 383                 if (next[1].GetType().block_light) {
 384                         ++occlusion;
 385                 } else {
 386                         light += next[1].GetLight();
 387                         ++num;
 388                 }
 389         }
 390         if (occlusion < 2) {
 391                 if (next[0]) {
 392                         BlockLookup corner = next[0].Next(edge[1]);
 393                         if (corner) {
 394                                 if (corner.GetType().block_light) {
 395                                         ++occlusion;
 396                                 } else {
 397                                         light += corner.GetLight();
 398                                         ++num;
 399                                 }
 400                         }
 401                 } else if (next[1]) {
 402                         BlockLookup corner = next[1].Next(edge[0]);
 403                         if (corner) {
 404                                 if (corner.GetType().block_light) {
 405                                         ++occlusion;
 406                                 } else {
 407                                         light += corner.GetLight();
 408                                         ++num;
 409                                 }
 410                         }
 411                 }
 412         } else {
 413                 ++occlusion;
 414         }
 415
 416         return (light / num) - (occlusion * 0.8f);
 417 }
 418
 419
 420 bool Chunk::IsSurface(const Pos &pos) const noexcept {
 421         const Block &block = BlockAt(pos);
 422         if (!Type(block).visible) {
 423                 return false;
 424         }
 425         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 426                 BlockLookup next = BlockLookup(const_cast<Chunk *>(this), pos, Block::Face(face));
 427                 if (!next || !next.GetType().visible) {
 428                         return true;
 429                 }
 430         }
 431         return false;
 432 }
 433
 434
 435 void Chunk::Draw() noexcept {
 436         if (dirty) {
 437                 Update();
 438         }
 439         model.Draw();
 440 }
 441
 442
 443 bool Chunk::Intersection(
 444         const Ray &ray,
 445         const glm::mat4 &M,
 446         int &blkid,
 447         float &dist,
 448         glm::vec3 &normal
 449 ) const noexcept {
 450         // TODO: should be possible to heavily optimize this
 451         int idx = 0;
 452         blkid = -1;
 453         dist = std::numeric_limits<float>::infinity();
 454         for (int z = 0; z < depth; ++z) {
 455                 for (int y = 0; y < height; ++y) {
 456                         for (int x = 0; x < width; ++x, ++idx) {
 457                                 const BlockType &type = Type(idx);
 458                                 if (!type.visible) {
 459                                         continue;
 460                                 }
 461                                 float cur_dist;
 462                                 glm::vec3 cur_norm;
 463                                 if (type.shape->Intersects(ray, M * ToTransform(Pos(x, y, z), idx), cur_dist, cur_norm)) {
 464                                         if (cur_dist < dist) {
 465                                                 blkid = idx;
 466                                                 dist = cur_dist;
 467                                                 normal = cur_norm;
 468                                         }
 469                                 }
 470                         }
 471                 }
 472         }
 473
 474         if (blkid < 0) {
 475                 return false;
 476         } else {
 477                 normal = glm::vec3(BlockAt(blkid).Transform() * glm::vec4(normal, 0.0f));
 478                 return true;
 479         }
 480 }
 481
 482
 483 namespace {
 484
 485 BlockModel::Buffer buf;
 486
 487 }
 488
 489 void Chunk::CheckUpdate() noexcept {
 490         if (dirty) {
 491                 Update();
 492         }
 493 }
 494
 495 void Chunk::Update() noexcept {
 496         int vtx_count = 0, idx_count = 0;
 497         for (const auto &block : blocks) {
 498                 const Shape *shape = Type(block).shape;
 499                 vtx_count += shape->VertexCount();
 500                 idx_count += shape->VertexIndexCount();
 501         }
 502         buf.Clear();
 503         buf.Reserve(vtx_count, idx_count);
 504
 505         int idx = 0;
 506         BlockModel::Index vtx_counter = 0;
 507         for (size_t z = 0; z < depth; ++z) {
 508                 for (size_t y = 0; y < height; ++y) {
 509                         for (size_t x = 0; x < width; ++x, ++idx) {
 510                                 const BlockType &type = Type(BlockAt(idx));
 511                                 const Pos pos(x, y, z);
 512
 513                                 if (!type.visible || Obstructed(pos).All()) continue;
 514
 515                                 type.FillBlockModel(buf, ToTransform(pos, idx), vtx_counter);
 516                                 size_t vtx_begin = vtx_counter;
 517                                 vtx_counter += type.shape->VertexCount();
 518
 519                                 for (size_t vtx = vtx_begin; vtx < vtx_counter; ++vtx) {
 520                                         buf.lights.emplace_back(GetVertexLight(
 521                                                 pos,
 522                                                 buf.vertices[vtx],
 523                                                 type.shape->VertexNormal(vtx - vtx_begin, BlockAt(idx).Transform())
 524                                         ));
 525                                 }
 526                         }
 527                 }
 528         }
 529
 530         model.Update(buf);
 531         dirty = false;
 532 }
 533
 534 Block::FaceSet Chunk::Obstructed(const Pos &pos) const noexcept {
 535         Block::FaceSet result;
 536
 537         for (int f = 0; f < Block::FACE_COUNT; ++f) {
 538                 Block::Face face = Block::Face(f);
 539                 BlockLookup next(const_cast<Chunk *>(this), pos, face);
 540                 if (next && next.GetType().FaceFilled(next.GetBlock(), Block::Opposite(face))) {
 541                         result.Set(face);
 542                 }
 543         }
 544
 545         return result;
 546 }
 547
 548 glm::mat4 Chunk::ToTransform(const Pos &pos, int idx) const noexcept {
 549         return glm::translate(ToCoords(pos)) * BlockAt(idx).Transform();
 550 }
 551
 552
 553 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p) noexcept
 554 : chunk(c), pos(p) {
 555         while (pos.x >= Chunk::width) {
 556                 if (chunk->HasNeighbor(Block::FACE_RIGHT)) {
 557                         chunk = &chunk->GetNeighbor(Block::FACE_RIGHT);
 558                         pos.x -= Chunk::width;
 559                 } else {
 560                         chunk = nullptr;
 561                         return;
 562                 }
 563         }
 564         while (pos.x < 0) {
 565                 if (chunk->HasNeighbor(Block::FACE_LEFT)) {
 566                         chunk = &chunk->GetNeighbor(Block::FACE_LEFT);
 567                         pos.x += Chunk::width;
 568                 } else {
 569                         chunk = nullptr;
 570                         return;
 571                 }
 572         }
 573         while (pos.y >= Chunk::height) {
 574                 if (chunk->HasNeighbor(Block::FACE_UP)) {
 575                         chunk = &chunk->GetNeighbor(Block::FACE_UP);
 576                         pos.y -= Chunk::height;
 577                 } else {
 578                         chunk = nullptr;
 579                         return;
 580                 }
 581         }
 582         while (pos.y < 0) {
 583                 if (chunk->HasNeighbor(Block::FACE_DOWN)) {
 584                         chunk = &chunk->GetNeighbor(Block::FACE_DOWN);
 585                         pos.y += Chunk::height;
 586                 } else {
 587                         chunk = nullptr;
 588                         return;
 589                 }
 590         }
 591         while (pos.z >= Chunk::depth) {
 592                 if (chunk->HasNeighbor(Block::FACE_FRONT)) {
 593                         chunk = &chunk->GetNeighbor(Block::FACE_FRONT);
 594                         pos.z -= Chunk::depth;
 595                 } else {
 596                         chunk = nullptr;
 597                         return;
 598                 }
 599         }
 600         while (pos.z < 0) {
 601                 if (chunk->HasNeighbor(Block::FACE_BACK)) {
 602                         chunk = &chunk->GetNeighbor(Block::FACE_BACK);
 603                         pos.z += Chunk::depth;
 604                 } else {
 605                         chunk = nullptr;
 606                         return;
 607                 }
 608         }
 609 }
 610
 611 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p, Block::Face face) noexcept
 612 : chunk(c), pos(p) {
 613         pos += Block::FaceNormal(face);
 614         if (!Chunk::InBounds(pos)) {
 615                 pos -= Block::FaceNormal(face) * Chunk::Extent();
 616                 chunk = &chunk->GetNeighbor(face);
 617         }
 618 }
 619
 620
 621 ChunkLoader::ChunkLoader(const Config &config, const BlockTypeRegistry &reg, const Generator &gen) noexcept
 622 : base(0, 0, 0)
 623 , reg(reg)
 624 , gen(gen)
 625 , loaded()
 626 , to_generate()
 627 , to_free()
 628 , load_dist(config.load_dist)
 629 , unload_dist(config.unload_dist) {
 630
 631 }
 632
 633 namespace {
 634
 635 struct ChunkLess {
 636
 637         explicit ChunkLess(const Chunk::Pos &base) noexcept
 638         : base(base) { }
 639
 640         bool operator ()(const Chunk::Pos &a, const Chunk::Pos &b) const noexcept {
 641                 Chunk::Pos da(base - a);
 642                 Chunk::Pos db(base - b);
 643                 return
 644                         da.x * da.x + da.y * da.y + da.z * da.z <
 645                         db.x * db.x + db.y * db.y + db.z * db.z;
 646         }
 647
 648         Chunk::Pos base;
 649
 650 };
 651
 652 }
 653
 654 void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 655         for (int z = from.z; z < to.z; ++z) {
 656                 for (int y = from.y; y < to.y; ++y) {
 657                         for (int x = from.x; x < to.x; ++x) {
 658                                 Chunk::Pos pos(x, y, z);
 659                                 if (Known(pos)) {
 660                                         continue;
 661                                 } else if (pos == base) {
 662                                         Generate(pos);
 663
 664                                 //      light testing
 665                                 //      for (int i = 0; i < 16; ++i) {
 666                                 //              for (int j = 0; j < 16; ++j) {
 667                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j,  0 }, Block(1));
 668                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j, 15 }, Block(1));
 669                                 //                      loaded.back().SetBlock(Chunk::Pos{  0, j,  i }, Block(1));
 670                                 //                      loaded.back().SetBlock(Chunk::Pos{ 15, j,  i }, Block(1));
 671                                 //              }
 672                                 //      }
 673                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0,  1 }, Block(13));
 674                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0,  1 }, Block(13));
 675                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0, 14 }, Block(13));
 676                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0, 14 }, Block(13));
 677                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15,  1 }, Block(13));
 678                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15,  1 }, Block(13));
 679                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15, 14 }, Block(13));
 680                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15, 14 }, Block(13));
 681                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7,  0 }, Block(13));
 682                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7,  0 }, Block(13));
 683                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8,  0 }, Block(13));
 684                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8,  0 }, Block(13));
 685                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7, 15 }, Block(13));
 686                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7, 15 }, Block(13));
 687                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8, 15 }, Block(13));
 688                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8, 15 }, Block(13));
 689                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  7 }, Block(13));
 690                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  8 }, Block(13));
 691                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  7 }, Block(13));
 692                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  8 }, Block(13));
 693                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  7 }, Block(13));
 694                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  8 }, Block(13));
 695                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  7 }, Block(13));
 696                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  8 }, Block(13));
 697                                 //      loaded.back().Invalidate();
 698                                 //      loaded.back().CheckUpdate();
 699
 700                                 //      orientation testing
 701                                 //      for (int i = 0; i < Block::FACE_COUNT; ++i) {
 702                                 //              for (int j = 0; j < Block::TURN_COUNT; ++j) {
 703                                 //                      loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
 704                                 //              }
 705                                 //      }
 706                                 //      loaded.back().Invalidate();
 707                                 //      loaded.back().CheckUpdate();
 708                                 } else {
 709                                         to_generate.emplace_back(pos);
 710                                 }
 711                         }
 712                 }
 713         }
 714         to_generate.sort(ChunkLess(base));
 715 }
 716
 717 Chunk &ChunkLoader::Generate(const Chunk::Pos &pos) {
 718         loaded.emplace_back(reg);
 719         Chunk &chunk = loaded.back();
 720         chunk.Position(pos);
 721         gen(chunk);
 722         Insert(chunk);
 723         return chunk;
 724 }
 725
 726 void ChunkLoader::Insert(Chunk &chunk) noexcept {
 727         for (Chunk &other : loaded) {
 728                 chunk.SetNeighbor(other);
 729         }
 730 }
 731
 732 void ChunkLoader::Remove(Chunk &chunk) noexcept {
 733         chunk.Unlink();
 734 }
 735
 736 Chunk *ChunkLoader::Loaded(const Chunk::Pos &pos) noexcept {
 737         for (Chunk &chunk : loaded) {
 738                 if (chunk.Position() == pos) {
 739                         return &chunk;
 740                 }
 741         }
 742         return nullptr;
 743 }
 744
 745 bool ChunkLoader::Queued(const Chunk::Pos &pos) noexcept {
 746         for (const Chunk::Pos &chunk : to_generate) {
 747                 if (chunk == pos) {
 748                         return true;
 749                 }
 750         }
 751         return nullptr;
 752 }
 753
 754 bool ChunkLoader::Known(const Chunk::Pos &pos) noexcept {
 755         if (Loaded(pos)) return true;
 756         return Queued(pos);
 757 }
 758
 759 Chunk &ChunkLoader::ForceLoad(const Chunk::Pos &pos) {
 760         Chunk *chunk = Loaded(pos);
 761         if (chunk) {
 762                 return *chunk;
 763         }
 764
 765         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end; ++iter) {
 766                 if (*iter == pos) {
 767                         to_generate.erase(iter);
 768                         break;
 769                 }
 770         }
 771
 772         return Generate(pos);
 773 }
 774
 775 void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 776         if (new_base == base) {
 777                 return;
 778         }
 779         base = new_base;
 780
 781         // unload far away chunks
 782         for (auto iter(loaded.begin()), end(loaded.end()); iter != end;) {
 783                 if (std::abs(base.x - iter->Position().x) > unload_dist
 784                                 || std::abs(base.y - iter->Position().y) > unload_dist
 785                                 || std::abs(base.z - iter->Position().z) > unload_dist) {
 786                         auto saved = iter;
 787                         Remove(*saved);
 788                         ++iter;
 789                         to_free.splice(to_free.end(), loaded, saved);
 790                 } else {
 791                         ++iter;
 792                 }
 793         }
 794         // abort far away queued chunks
 795         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end;) {
 796                 if (std::abs(base.x - iter->x) > unload_dist
 797                                 || std::abs(base.y - iter->y) > unload_dist
 798                                 || std::abs(base.z - iter->z) > unload_dist) {
 799                         iter = to_generate.erase(iter);
 800                 } else {
 801                         ++iter;
 802                 }
 803         }
 804         // add missing new chunks
 805         GenerateSurrounding(base);
 806 }
 807
 808 void ChunkLoader::GenerateSurrounding(const Chunk::Pos &pos) {
 809         const Chunk::Pos offset(load_dist, load_dist, load_dist);
 810         Generate(pos - offset, pos + offset);
 811 }
 812
 813 void ChunkLoader::Update() {
 814         if (to_generate.empty()) {
 815                 return;
 816         }
 817
 818         Chunk::Pos pos(to_generate.front());
 819         to_generate.pop_front();
 820
 821         for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
 822                 if (iter->Position() == pos) {
 823                         iter->Relink();
 824                         loaded.splice(loaded.end(), to_free, iter);
 825                         return;
 826                 }
 827         }
 828
 829         if (to_free.empty()) {
 830                 loaded.emplace_back(reg);
 831         } else {
 832                 to_free.front().ClearNeighbors();
 833                 loaded.splice(loaded.end(), to_free, to_free.begin());
 834         }
 835         Chunk &chunk = loaded.back();
 836         chunk.Position(pos);
 837         gen(chunk);
 838         Insert(chunk);
 839 }
 840
 841 }