src/world/chunk.cpp

   1 #include "BlockLookup.hpp"
   2 #include "Chunk.hpp"
   3 #include "ChunkLoader.hpp"
   4
   5 #include "Generator.hpp"
   6 #include "WorldCollision.hpp"
   7
   8 #include <algorithm>
   9 #include <iostream>
  10 #include <limits>
  11 #include <queue>
  12
  13
  14 namespace blank {
  15
  16 constexpr int Chunk::width;
  17 constexpr int Chunk::height;
  18 constexpr int Chunk::depth;
  19 constexpr int Chunk::size;
  20
  21
  22 Chunk::Chunk(const BlockTypeRegistry &types) noexcept
  23 : types(&types)
  24 , neighbor{0}
  25 , blocks{}
  26 , light{0}
  27 , model()
  28 , position(0, 0, 0)
  29 , dirty(false) {
  30
  31 }
  32
  33 Chunk::Chunk(Chunk &&other) noexcept
  34 : types(other.types)
  35 , model(std::move(other.model))
  36 , position(other.position)
  37 , dirty(other.dirty) {
  38         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  39         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  40         std::copy(other.light, other.light + sizeof(light), light);
  41 }
  42
  43 Chunk &Chunk::operator =(Chunk &&other) noexcept {
  44         types = other.types;
  45         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  46         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  47         std::copy(other.light, other.light + sizeof(light), light);
  48         model = std::move(other.model);
  49         position = other.position;
  50         dirty = other.dirty;
  51         return *this;
  52 }
  53
  54
  55 namespace {
  56
  57 struct SetNode {
  58
  59         Chunk *chunk;
  60         Chunk::Pos pos;
  61
  62         SetNode(Chunk *chunk, Chunk::Pos pos)
  63         : chunk(chunk), pos(pos) { }
  64
  65         int Get() const noexcept { return chunk->GetLight(pos); }
  66         void Set(int level) noexcept { chunk->SetLight(pos, level); }
  67
  68         bool HasNext(Block::Face face) noexcept {
  69                 const BlockLookup next(chunk, pos, face);
  70                 return next && !next.GetType().block_light;
  71         }
  72         SetNode GetNext(Block::Face face) noexcept {
  73                 const BlockLookup next(chunk, pos, face);
  74                 return SetNode(&next.GetChunk(), next.GetBlockPos());
  75         }
  76
  77 };
  78
  79 struct UnsetNode
  80 : public SetNode {
  81
  82         int level;
  83
  84         UnsetNode(Chunk *chunk, Chunk::Pos pos)
  85         : SetNode(chunk, pos), level(Get()) { }
  86
  87         UnsetNode(const SetNode &set)
  88         : SetNode(set), level(Get()) { }
  89
  90
  91         bool HasNext(Block::Face face) noexcept {
  92                 const BlockLookup next(chunk, pos, face);
  93                 return next;
  94         }
  95         UnsetNode GetNext(Block::Face face) noexcept { return UnsetNode(SetNode::GetNext(face)); }
  96
  97 };
  98
  99 std::queue<SetNode> light_queue;
 100 std::queue<UnsetNode> dark_queue;
 101
 102 void work_light() noexcept {
 103         while (!light_queue.empty()) {
 104                 SetNode node = light_queue.front();
 105                 light_queue.pop();
 106
 107                 int level = node.Get() - 1;
 108                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 109                         if (node.HasNext(Block::Face(face))) {
 110                                 SetNode other = node.GetNext(Block::Face(face));
 111                                 if (other.Get() < level) {
 112                                         other.Set(level);
 113                                         light_queue.emplace(other);
 114                                 }
 115                         }
 116                 }
 117         }
 118 }
 119
 120 void work_dark() noexcept {
 121         while (!dark_queue.empty()) {
 122                 UnsetNode node = dark_queue.front();
 123                 dark_queue.pop();
 124
 125                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 126                         if (node.HasNext(Block::Face(face))) {
 127                                 UnsetNode other = node.GetNext(Block::Face(face));
 128                                 // TODO: if there a light source here with the same level this will err
 129                                 if (other.Get() != 0 && other.Get() < node.level) {
 130                                         other.Set(0);
 131                                         dark_queue.emplace(other);
 132                                 } else {
 133                                         light_queue.emplace(other);
 134                                 }
 135                         }
 136                 }
 137         }
 138 }
 139
 140 }
 141
 142 void Chunk::SetBlock(int index, const Block &block) noexcept {
 143         const BlockType &old_type = Type(blocks[index]);
 144         const BlockType &new_type = Type(block);
 145
 146         blocks[index] = block;
 147
 148         if (&old_type == &new_type) return;
 149
 150         if (new_type.luminosity > old_type.luminosity) {
 151                 // light added
 152                 SetLight(index, new_type.luminosity);
 153                 light_queue.emplace(this, ToPos(index));
 154                 work_light();
 155         } else if (new_type.luminosity < old_type.luminosity) {
 156                 // light removed
 157                 dark_queue.emplace(this, ToPos(index));
 158                 SetLight(index, 0);
 159                 work_dark();
 160                 SetLight(index, new_type.luminosity);
 161                 light_queue.emplace(this, ToPos(index));
 162                 work_light();
 163         } else if (new_type.block_light && !old_type.block_light) {
 164                 // obstacle added
 165                 if (GetLight(index) > 0) {
 166                         dark_queue.emplace(this, ToPos(index));
 167                         SetLight(index, 0);
 168                         work_dark();
 169                         work_light();
 170                 }
 171         } else if (!new_type.block_light && old_type.block_light) {
 172                 // obstacle removed
 173                 int level = 0;
 174                 Pos pos(ToPos(index));
 175                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 176                         BlockLookup next_block(this, pos, Block::Face(face));
 177                         if (next_block) {
 178                                 level = std::max(level, next_block.GetLight());
 179                         }
 180                 }
 181                 if (level > 1) {
 182                         SetLight(index, level - 1);
 183                         light_queue.emplace(this, pos);
 184                         work_light();
 185                 }
 186         }
 187 }
 188
 189 void Chunk::SetNeighbor(Chunk &other) noexcept {
 190         if (other.position == position + Pos(-1, 0, 0)) {
 191                 if (neighbor[Block::FACE_LEFT] != &other) {
 192                         neighbor[Block::FACE_LEFT] = &other;
 193                         other.neighbor[Block::FACE_RIGHT] = this;
 194                         for (int z = 0; z < depth; ++z) {
 195                                 for (int y = 0; y < height; ++y) {
 196                                         Pos my_pos(0, y, z);
 197                                         Pos other_pos(width - 1, y, z);
 198                                         if (GetLight(my_pos) > 0) {
 199                                                 light_queue.emplace(this, my_pos);
 200                                         }
 201                                         if (other.GetLight(other_pos) > 0) {
 202                                                 light_queue.emplace(&other, other_pos);
 203                                         }
 204                                 }
 205                         }
 206                         work_light();
 207                 }
 208         } else if (other.position == position + Pos(1, 0, 0)) {
 209                 if (neighbor[Block::FACE_RIGHT] != &other) {
 210                         neighbor[Block::FACE_RIGHT] = &other;
 211                         other.neighbor[Block::FACE_LEFT] = this;
 212                         for (int z = 0; z < depth; ++z) {
 213                                 for (int y = 0; y < height; ++y) {
 214                                         Pos my_pos(width - 1, y, z);
 215                                         Pos other_pos(0, y, z);
 216                                         if (GetLight(my_pos) > 0) {
 217                                                 light_queue.emplace(this, my_pos);
 218                                         }
 219                                         if (other.GetLight(other_pos) > 0) {
 220                                                 light_queue.emplace(&other, other_pos);
 221                                         }
 222                                 }
 223                         }
 224                         work_light();
 225                 }
 226         } else if (other.position == position + Pos(0, -1, 0)) {
 227                 if (neighbor[Block::FACE_DOWN] != &other) {
 228                         neighbor[Block::FACE_DOWN] = &other;
 229                         other.neighbor[Block::FACE_UP] = this;
 230                         for (int z = 0; z < depth; ++z) {
 231                                 for (int x = 0; x < width; ++x) {
 232                                         Pos my_pos(x, 0, z);
 233                                         Pos other_pos(x, height - 1, z);
 234                                         if (GetLight(my_pos) > 0) {
 235                                                 light_queue.emplace(this, my_pos);
 236                                         }
 237                                         if (other.GetLight(other_pos) > 0) {
 238                                                 light_queue.emplace(&other, other_pos);
 239                                         }
 240                                 }
 241                         }
 242                         work_light();
 243                 }
 244         } else if (other.position == position + Pos(0, 1, 0)) {
 245                 if (neighbor[Block::FACE_UP] != &other) {
 246                         neighbor[Block::FACE_UP] = &other;
 247                         other.neighbor[Block::FACE_DOWN] = this;
 248                         for (int z = 0; z < depth; ++z) {
 249                                 for (int x = 0; x < width; ++x) {
 250                                         Pos my_pos(x, height - 1, z);
 251                                         Pos other_pos(x, 0, z);
 252                                         if (GetLight(my_pos) > 0) {
 253                                                 light_queue.emplace(this, my_pos);
 254                                         }
 255                                         if (other.GetLight(other_pos) > 0) {
 256                                                 light_queue.emplace(&other, other_pos);
 257                                         }
 258                                 }
 259                         }
 260                         work_light();
 261                 }
 262         } else if (other.position == position + Pos(0, 0, -1)) {
 263                 if (neighbor[Block::FACE_BACK] != &other) {
 264                         neighbor[Block::FACE_BACK] = &other;
 265                         other.neighbor[Block::FACE_FRONT] = this;
 266                         for (int y = 0; y < height; ++y) {
 267                                 for (int x = 0; x < width; ++x) {
 268                                         Pos my_pos(x, y, 0);
 269                                         Pos other_pos(x, y, depth - 1);
 270                                         if (GetLight(my_pos) > 0) {
 271                                                 light_queue.emplace(this, my_pos);
 272                                         }
 273                                         if (other.GetLight(other_pos) > 0) {
 274                                                 light_queue.emplace(&other, other_pos);
 275                                         }
 276                                 }
 277                         }
 278                         work_light();
 279                 }
 280         } else if (other.position == position + Pos(0, 0, 1)) {
 281                 if (neighbor[Block::FACE_FRONT] != &other) {
 282                         neighbor[Block::FACE_FRONT] = &other;
 283                         other.neighbor[Block::FACE_BACK] = this;
 284                         for (int y = 0; y < height; ++y) {
 285                                 for (int x = 0; x < width; ++x) {
 286                                         Pos my_pos(x, y, depth - 1);
 287                                         Pos other_pos(x, y, 0);
 288                                         if (GetLight(my_pos) > 0) {
 289                                                 light_queue.emplace(this, my_pos);
 290                                         }
 291                                         if (other.GetLight(other_pos) > 0) {
 292                                                 light_queue.emplace(&other, other_pos);
 293                                         }
 294                                 }
 295                         }
 296                         work_light();
 297                 }
 298         }
 299 }
 300
 301 void Chunk::ClearNeighbors() noexcept {
 302         for (int i = 0; i < Block::FACE_COUNT; ++i) {
 303                 neighbor[i] = nullptr;
 304         }
 305 }
 306
 307 void Chunk::Unlink() noexcept {
 308         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 309                 if (neighbor[face]) {
 310                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = nullptr;
 311                 }
 312         }
 313 }
 314
 315 void Chunk::Relink() noexcept {
 316         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 317                 if (neighbor[face]) {
 318                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = this;
 319                 }
 320         }
 321 }
 322
 323
 324 void Chunk::SetLight(int index, int level) noexcept {
 325         if (light[index] != level) {
 326                 light[index] = level;
 327                 Invalidate();
 328         }
 329 }
 330
 331 int Chunk::GetLight(int index) const noexcept {
 332         return light[index];
 333 }
 334
 335 float Chunk::GetVertexLight(const Pos &pos, const BlockModel::Position &vtx, const Model::Normal &norm) const noexcept {
 336         int index = ToIndex(pos);
 337         float light = GetLight(index);
 338
 339         Block::Face direct_face(Block::NormalFace(norm));
 340         // tis okay
 341         BlockLookup direct(const_cast<Chunk *>(this), pos, Block::NormalFace(norm));
 342         if (direct) {
 343                 float direct_light = direct.GetLight();
 344                 if (direct_light > light) {
 345                         light = direct_light;
 346                 }
 347         } else {
 348                 return light;
 349         }
 350
 351         if (Type(BlockAt(index)).luminosity > 0 || direct.GetType().block_light) {
 352                 return light;
 353         }
 354
 355         Block::Face edge[2];
 356         switch (Block::Axis(direct_face)) {
 357                 case 0: // X
 358                         edge[0] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 359                         edge[1] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 360                         break;
 361                 case 1: // Y
 362                         edge[0] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 363                         edge[1] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 364                         break;
 365                 case 2: // Z
 366                         edge[0] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 367                         edge[1] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 368                         break;
 369         }
 370
 371         int num = 1;
 372         int occlusion = 0;
 373
 374         BlockLookup next[2] = {
 375                 direct.Next(edge[0]),
 376                 direct.Next(edge[1]),
 377         };
 378
 379         if (next[0]) {
 380                 if (next[0].GetType().block_light) {
 381                         ++occlusion;
 382                 } else {
 383                         light += next[0].GetLight();
 384                         ++num;
 385                 }
 386         }
 387         if (next[1]) {
 388                 if (next[1].GetType().block_light) {
 389                         ++occlusion;
 390                 } else {
 391                         light += next[1].GetLight();
 392                         ++num;
 393                 }
 394         }
 395         if (occlusion < 2) {
 396                 if (next[0]) {
 397                         BlockLookup corner = next[0].Next(edge[1]);
 398                         if (corner) {
 399                                 if (corner.GetType().block_light) {
 400                                         ++occlusion;
 401                                 } else {
 402                                         light += corner.GetLight();
 403                                         ++num;
 404                                 }
 405                         }
 406                 } else if (next[1]) {
 407                         BlockLookup corner = next[1].Next(edge[0]);
 408                         if (corner) {
 409                                 if (corner.GetType().block_light) {
 410                                         ++occlusion;
 411                                 } else {
 412                                         light += corner.GetLight();
 413                                         ++num;
 414                                 }
 415                         }
 416                 }
 417         } else {
 418                 ++occlusion;
 419         }
 420
 421         return (light / num) - (occlusion * 0.8f);
 422 }
 423
 424
 425 bool Chunk::IsSurface(const Pos &pos) const noexcept {
 426         const Block &block = BlockAt(pos);
 427         if (!Type(block).visible) {
 428                 return false;
 429         }
 430         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 431                 BlockLookup next = BlockLookup(const_cast<Chunk *>(this), pos, Block::Face(face));
 432                 if (!next || !next.GetType().visible) {
 433                         return true;
 434                 }
 435         }
 436         return false;
 437 }
 438
 439
 440 void Chunk::Draw() noexcept {
 441         if (dirty) {
 442                 Update();
 443         }
 444         model.Draw();
 445 }
 446
 447
 448 bool Chunk::Intersection(
 449         const Ray &ray,
 450         const glm::mat4 &M,
 451         int &blkid,
 452         float &dist,
 453         glm::vec3 &normal
 454 ) const noexcept {
 455         int idx = 0;
 456         blkid = -1;
 457         dist = std::numeric_limits<float>::infinity();
 458         for (int z = 0; z < depth; ++z) {
 459                 for (int y = 0; y < height; ++y) {
 460                         for (int x = 0; x < width; ++x, ++idx) {
 461                                 const BlockType &type = Type(idx);
 462                                 if (!type.visible) {
 463                                         continue;
 464                                 }
 465                                 float cur_dist;
 466                                 glm::vec3 cur_norm;
 467                                 if (type.shape->Intersects(ray, M * ToTransform(Pos(x, y, z), idx), cur_dist, cur_norm)) {
 468                                         if (cur_dist < dist) {
 469                                                 blkid = idx;
 470                                                 dist = cur_dist;
 471                                                 normal = cur_norm;
 472                                         }
 473                                 }
 474                         }
 475                 }
 476         }
 477
 478         if (blkid < 0) {
 479                 return false;
 480         } else {
 481                 normal = glm::vec3(BlockAt(blkid).Transform() * glm::vec4(normal, 0.0f));
 482                 return true;
 483         }
 484 }
 485
 486 bool Chunk::Intersection(
 487         const AABB &box,
 488         const glm::mat4 &Mbox,
 489         const glm::mat4 &Mchunk,
 490         std::vector<WorldCollision> &col
 491 ) const noexcept {
 492         bool any = false;
 493         float penetration;
 494         glm::vec3 normal;
 495
 496         if (!blank::Intersection(box, Mbox, Bounds(), Mchunk, penetration, normal)) {
 497                 return false;
 498         }
 499         for (int idx = 0, z = 0; z < depth; ++z) {
 500                 for (int y = 0; y < height; ++y) {
 501                         for (int x = 0; x < width; ++x, ++idx) {
 502                                 const BlockType &type = Type(idx);
 503                                 if (!type.visible) {
 504                                         continue;
 505                                 }
 506                                 if (type.shape->Intersects(Mchunk * ToTransform(Pos(x, y, z), idx), box, Mbox, penetration, normal)) {
 507                                         col.emplace_back(this, idx, penetration, normal);
 508                                         any = true;
 509                                 }
 510                         }
 511                 }
 512         }
 513         return any;
 514 }
 515
 516
 517 namespace {
 518
 519 BlockModel::Buffer buf;
 520
 521 }
 522
 523 void Chunk::CheckUpdate() noexcept {
 524         if (dirty) {
 525                 Update();
 526         }
 527 }
 528
 529 void Chunk::Update() noexcept {
 530         int vtx_count = 0, idx_count = 0;
 531         for (const auto &block : blocks) {
 532                 const Shape *shape = Type(block).shape;
 533                 vtx_count += shape->VertexCount();
 534                 idx_count += shape->VertexIndexCount();
 535         }
 536         buf.Clear();
 537         buf.Reserve(vtx_count, idx_count);
 538
 539         int idx = 0;
 540         BlockModel::Index vtx_counter = 0;
 541         for (size_t z = 0; z < depth; ++z) {
 542                 for (size_t y = 0; y < height; ++y) {
 543                         for (size_t x = 0; x < width; ++x, ++idx) {
 544                                 const BlockType &type = Type(BlockAt(idx));
 545                                 const Pos pos(x, y, z);
 546
 547                                 if (!type.visible || Obstructed(pos).All()) continue;
 548
 549                                 type.FillBlockModel(buf, ToTransform(pos, idx), vtx_counter);
 550                                 size_t vtx_begin = vtx_counter;
 551                                 vtx_counter += type.shape->VertexCount();
 552
 553                                 for (size_t vtx = vtx_begin; vtx < vtx_counter; ++vtx) {
 554                                         buf.lights.emplace_back(GetVertexLight(
 555                                                 pos,
 556                                                 buf.vertices[vtx],
 557                                                 type.shape->VertexNormal(vtx - vtx_begin, BlockAt(idx).Transform())
 558                                         ));
 559                                 }
 560                         }
 561                 }
 562         }
 563
 564         model.Update(buf);
 565         dirty = false;
 566 }
 567
 568 Block::FaceSet Chunk::Obstructed(const Pos &pos) const noexcept {
 569         Block::FaceSet result;
 570
 571         for (int f = 0; f < Block::FACE_COUNT; ++f) {
 572                 Block::Face face = Block::Face(f);
 573                 BlockLookup next(const_cast<Chunk *>(this), pos, face);
 574                 if (next && next.GetType().FaceFilled(next.GetBlock(), Block::Opposite(face))) {
 575                         result.Set(face);
 576                 }
 577         }
 578
 579         return result;
 580 }
 581
 582 glm::mat4 Chunk::ToTransform(const Pos &pos, int idx) const noexcept {
 583         return glm::translate(ToCoords(pos)) * BlockAt(idx).Transform();
 584 }
 585
 586
 587 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p) noexcept
 588 : chunk(c), pos(p) {
 589         while (pos.x >= Chunk::width) {
 590                 if (chunk->HasNeighbor(Block::FACE_RIGHT)) {
 591                         chunk = &chunk->GetNeighbor(Block::FACE_RIGHT);
 592                         pos.x -= Chunk::width;
 593                 } else {
 594                         chunk = nullptr;
 595                         return;
 596                 }
 597         }
 598         while (pos.x < 0) {
 599                 if (chunk->HasNeighbor(Block::FACE_LEFT)) {
 600                         chunk = &chunk->GetNeighbor(Block::FACE_LEFT);
 601                         pos.x += Chunk::width;
 602                 } else {
 603                         chunk = nullptr;
 604                         return;
 605                 }
 606         }
 607         while (pos.y >= Chunk::height) {
 608                 if (chunk->HasNeighbor(Block::FACE_UP)) {
 609                         chunk = &chunk->GetNeighbor(Block::FACE_UP);
 610                         pos.y -= Chunk::height;
 611                 } else {
 612                         chunk = nullptr;
 613                         return;
 614                 }
 615         }
 616         while (pos.y < 0) {
 617                 if (chunk->HasNeighbor(Block::FACE_DOWN)) {
 618                         chunk = &chunk->GetNeighbor(Block::FACE_DOWN);
 619                         pos.y += Chunk::height;
 620                 } else {
 621                         chunk = nullptr;
 622                         return;
 623                 }
 624         }
 625         while (pos.z >= Chunk::depth) {
 626                 if (chunk->HasNeighbor(Block::FACE_FRONT)) {
 627                         chunk = &chunk->GetNeighbor(Block::FACE_FRONT);
 628                         pos.z -= Chunk::depth;
 629                 } else {
 630                         chunk = nullptr;
 631                         return;
 632                 }
 633         }
 634         while (pos.z < 0) {
 635                 if (chunk->HasNeighbor(Block::FACE_BACK)) {
 636                         chunk = &chunk->GetNeighbor(Block::FACE_BACK);
 637                         pos.z += Chunk::depth;
 638                 } else {
 639                         chunk = nullptr;
 640                         return;
 641                 }
 642         }
 643 }
 644
 645 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p, Block::Face face) noexcept
 646 : chunk(c), pos(p) {
 647         pos += Block::FaceNormal(face);
 648         if (!Chunk::InBounds(pos)) {
 649                 pos -= Block::FaceNormal(face) * Chunk::Extent();
 650                 chunk = &chunk->GetNeighbor(face);
 651         }
 652 }
 653
 654
 655 ChunkLoader::ChunkLoader(const Config &config, const BlockTypeRegistry &reg, const Generator &gen) noexcept
 656 : base(0, 0, 0)
 657 , reg(reg)
 658 , gen(gen)
 659 , loaded()
 660 , to_generate()
 661 , to_free()
 662 , gen_timer(config.gen_limit)
 663 , load_dist(config.load_dist)
 664 , unload_dist(config.unload_dist) {
 665         gen_timer.Start();
 666 }
 667
 668 namespace {
 669
 670 struct ChunkLess {
 671
 672         explicit ChunkLess(const Chunk::Pos &base) noexcept
 673         : base(base) { }
 674
 675         bool operator ()(const Chunk::Pos &a, const Chunk::Pos &b) const noexcept {
 676                 Chunk::Pos da(base - a);
 677                 Chunk::Pos db(base - b);
 678                 return
 679                         da.x * da.x + da.y * da.y + da.z * da.z <
 680                         db.x * db.x + db.y * db.y + db.z * db.z;
 681         }
 682
 683         Chunk::Pos base;
 684
 685 };
 686
 687 }
 688
 689 void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 690         for (int z = from.z; z < to.z; ++z) {
 691                 for (int y = from.y; y < to.y; ++y) {
 692                         for (int x = from.x; x < to.x; ++x) {
 693                                 Chunk::Pos pos(x, y, z);
 694                                 if (Known(pos)) {
 695                                         continue;
 696                                 } else if (pos == base) {
 697                                         Generate(pos);
 698
 699                                 //      light testing
 700                                 //      for (int i = 0; i < 16; ++i) {
 701                                 //              for (int j = 0; j < 16; ++j) {
 702                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j,  0 }, Block(1));
 703                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j, 15 }, Block(1));
 704                                 //                      loaded.back().SetBlock(Chunk::Pos{  0, j,  i }, Block(1));
 705                                 //                      loaded.back().SetBlock(Chunk::Pos{ 15, j,  i }, Block(1));
 706                                 //              }
 707                                 //      }
 708                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0,  1 }, Block(13));
 709                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0,  1 }, Block(13));
 710                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0, 14 }, Block(13));
 711                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0, 14 }, Block(13));
 712                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15,  1 }, Block(13));
 713                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15,  1 }, Block(13));
 714                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15, 14 }, Block(13));
 715                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15, 14 }, Block(13));
 716                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7,  0 }, Block(13));
 717                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7,  0 }, Block(13));
 718                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8,  0 }, Block(13));
 719                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8,  0 }, Block(13));
 720                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7, 15 }, Block(13));
 721                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7, 15 }, Block(13));
 722                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8, 15 }, Block(13));
 723                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8, 15 }, Block(13));
 724                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  7 }, Block(13));
 725                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  8 }, Block(13));
 726                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  7 }, Block(13));
 727                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  8 }, Block(13));
 728                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  7 }, Block(13));
 729                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  8 }, Block(13));
 730                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  7 }, Block(13));
 731                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  8 }, Block(13));
 732                                 //      loaded.back().Invalidate();
 733                                 //      loaded.back().CheckUpdate();
 734
 735                                 //      orientation testing
 736                                 //      for (int i = 0; i < Block::FACE_COUNT; ++i) {
 737                                 //              for (int j = 0; j < Block::TURN_COUNT; ++j) {
 738                                 //                      loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
 739                                 //              }
 740                                 //      }
 741                                 //      loaded.back().Invalidate();
 742                                 //      loaded.back().CheckUpdate();
 743                                 } else {
 744                                         to_generate.emplace_back(pos);
 745                                 }
 746                         }
 747                 }
 748         }
 749         to_generate.sort(ChunkLess(base));
 750 }
 751
 752 Chunk &ChunkLoader::Generate(const Chunk::Pos &pos) {
 753         loaded.emplace_back(reg);
 754         Chunk &chunk = loaded.back();
 755         chunk.Position(pos);
 756         gen(chunk);
 757         Insert(chunk);
 758         return chunk;
 759 }
 760
 761 void ChunkLoader::Insert(Chunk &chunk) noexcept {
 762         for (Chunk &other : loaded) {
 763                 chunk.SetNeighbor(other);
 764         }
 765 }
 766
 767 void ChunkLoader::Remove(Chunk &chunk) noexcept {
 768         chunk.Unlink();
 769 }
 770
 771 Chunk *ChunkLoader::Loaded(const Chunk::Pos &pos) noexcept {
 772         for (Chunk &chunk : loaded) {
 773                 if (chunk.Position() == pos) {
 774                         return &chunk;
 775                 }
 776         }
 777         return nullptr;
 778 }
 779
 780 bool ChunkLoader::Queued(const Chunk::Pos &pos) noexcept {
 781         for (const Chunk::Pos &chunk : to_generate) {
 782                 if (chunk == pos) {
 783                         return true;
 784                 }
 785         }
 786         return false;
 787 }
 788
 789 bool ChunkLoader::Known(const Chunk::Pos &pos) noexcept {
 790         if (Loaded(pos)) return true;
 791         return Queued(pos);
 792 }
 793
 794 Chunk &ChunkLoader::ForceLoad(const Chunk::Pos &pos) {
 795         Chunk *chunk = Loaded(pos);
 796         if (chunk) {
 797                 return *chunk;
 798         }
 799
 800         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end; ++iter) {
 801                 if (*iter == pos) {
 802                         to_generate.erase(iter);
 803                         break;
 804                 }
 805         }
 806
 807         return Generate(pos);
 808 }
 809
 810 bool ChunkLoader::OutOfRange(const Chunk::Pos &pos) const noexcept {
 811         return std::abs(base.x - pos.x) > unload_dist
 812                         || std::abs(base.y - pos.y) > unload_dist
 813                         || std::abs(base.z - pos.z) > unload_dist;
 814 }
 815
 816 void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 817         if (new_base == base) {
 818                 return;
 819         }
 820         base = new_base;
 821
 822         // unload far away chunks
 823         for (auto iter(loaded.begin()), end(loaded.end()); iter != end;) {
 824                 if (OutOfRange(*iter)) {
 825                         auto saved = iter;
 826                         Remove(*saved);
 827                         ++iter;
 828                         to_free.splice(to_free.end(), loaded, saved);
 829                 } else {
 830                         ++iter;
 831                 }
 832         }
 833         // abort far away queued chunks
 834         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end;) {
 835                 if (OutOfRange(*iter)) {
 836                         iter = to_generate.erase(iter);
 837                 } else {
 838                         ++iter;
 839                 }
 840         }
 841         // add missing new chunks
 842         GenerateSurrounding(base);
 843 }
 844
 845 void ChunkLoader::GenerateSurrounding(const Chunk::Pos &pos) {
 846         const Chunk::Pos offset(load_dist, load_dist, load_dist);
 847         Generate(pos - offset, pos + offset);
 848 }
 849
 850 void ChunkLoader::Update(int dt) {
 851         gen_timer.Update(dt);
 852         if (!gen_timer.Hit() || to_generate.empty()) {
 853                 return;
 854         }
 855
 856         Chunk::Pos pos(to_generate.front());
 857         to_generate.pop_front();
 858
 859         for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
 860                 if (iter->Position() == pos) {
 861                         iter->Relink();
 862                         loaded.splice(loaded.end(), to_free, iter);
 863                 }
 864         }
 865
 866         if (to_free.empty()) {
 867                 loaded.emplace_back(reg);
 868         } else {
 869                 to_free.front().ClearNeighbors();
 870                 loaded.splice(loaded.end(), to_free, to_free.begin());
 871         }
 872         Chunk &chunk = loaded.back();
 873         chunk.Position(pos);
 874         gen(chunk);
 875         Insert(chunk);
 876 }
 877
 878 }