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 namespace {
 190
 191 // propagate light from a's edge to b
 192 void edge_light(
 193         Chunk &a, const Chunk::Pos &a_pos,
 194         Chunk &b, const Chunk::Pos &b_pos
 195 ) noexcept {
 196         if (a.GetLight(a_pos) > 1) {
 197                 const BlockType &b_type = b.Type(Chunk::ToIndex(b_pos));
 198                 if (!b_type.block_light) {
 199                         light_queue.emplace(&a, a_pos);
 200                 }
 201                 if (b_type.visible) {
 202                         b.Invalidate();
 203                 }
 204         }
 205 }
 206
 207 }
 208
 209 void Chunk::SetNeighbor(Chunk &other) noexcept {
 210         if (other.position == position + Pos(-1, 0, 0)) {
 211                 if (neighbor[Block::FACE_LEFT] != &other) {
 212                         neighbor[Block::FACE_LEFT] = &other;
 213                         other.neighbor[Block::FACE_RIGHT] = this;
 214                         for (int z = 0; z < depth; ++z) {
 215                                 for (int y = 0; y < height; ++y) {
 216                                         Pos my_pos(0, y, z);
 217                                         Pos other_pos(width - 1, y, z);
 218                                         edge_light(*this, my_pos, other, other_pos);
 219                                         edge_light(other, other_pos, *this, my_pos);
 220                                 }
 221                         }
 222                         work_light();
 223                 }
 224         } else if (other.position == position + Pos(1, 0, 0)) {
 225                 if (neighbor[Block::FACE_RIGHT] != &other) {
 226                         neighbor[Block::FACE_RIGHT] = &other;
 227                         other.neighbor[Block::FACE_LEFT] = this;
 228                         for (int z = 0; z < depth; ++z) {
 229                                 for (int y = 0; y < height; ++y) {
 230                                         Pos my_pos(width - 1, y, z);
 231                                         Pos other_pos(0, y, z);
 232                                         edge_light(*this, my_pos, other, other_pos);
 233                                         edge_light(other, other_pos, *this, my_pos);
 234                                 }
 235                         }
 236                         work_light();
 237                 }
 238         } else if (other.position == position + Pos(0, -1, 0)) {
 239                 if (neighbor[Block::FACE_DOWN] != &other) {
 240                         neighbor[Block::FACE_DOWN] = &other;
 241                         other.neighbor[Block::FACE_UP] = this;
 242                         for (int z = 0; z < depth; ++z) {
 243                                 for (int x = 0; x < width; ++x) {
 244                                         Pos my_pos(x, 0, z);
 245                                         Pos other_pos(x, height - 1, z);
 246                                         edge_light(*this, my_pos, other, other_pos);
 247                                         edge_light(other, other_pos, *this, my_pos);
 248                                 }
 249                         }
 250                         work_light();
 251                 }
 252         } else if (other.position == position + Pos(0, 1, 0)) {
 253                 if (neighbor[Block::FACE_UP] != &other) {
 254                         neighbor[Block::FACE_UP] = &other;
 255                         other.neighbor[Block::FACE_DOWN] = this;
 256                         for (int z = 0; z < depth; ++z) {
 257                                 for (int x = 0; x < width; ++x) {
 258                                         Pos my_pos(x, height - 1, z);
 259                                         Pos other_pos(x, 0, z);
 260                                         edge_light(*this, my_pos, other, other_pos);
 261                                         edge_light(other, other_pos, *this, my_pos);
 262                                 }
 263                         }
 264                         work_light();
 265                 }
 266         } else if (other.position == position + Pos(0, 0, -1)) {
 267                 if (neighbor[Block::FACE_BACK] != &other) {
 268                         neighbor[Block::FACE_BACK] = &other;
 269                         other.neighbor[Block::FACE_FRONT] = this;
 270                         for (int y = 0; y < height; ++y) {
 271                                 for (int x = 0; x < width; ++x) {
 272                                         Pos my_pos(x, y, 0);
 273                                         Pos other_pos(x, y, depth - 1);
 274                                         edge_light(*this, my_pos, other, other_pos);
 275                                         edge_light(other, other_pos, *this, my_pos);
 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                                         edge_light(*this, my_pos, other, other_pos);
 289                                         edge_light(other, other_pos, *this, my_pos);
 290                                 }
 291                         }
 292                         work_light();
 293                 }
 294         }
 295 }
 296
 297 void Chunk::ClearNeighbors() noexcept {
 298         for (int i = 0; i < Block::FACE_COUNT; ++i) {
 299                 neighbor[i] = nullptr;
 300         }
 301 }
 302
 303 void Chunk::Unlink() noexcept {
 304         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 305                 if (neighbor[face]) {
 306                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = nullptr;
 307                 }
 308         }
 309 }
 310
 311 void Chunk::Relink() noexcept {
 312         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 313                 if (neighbor[face]) {
 314                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = this;
 315                 }
 316         }
 317 }
 318
 319
 320 void Chunk::SetLight(int index, int level) noexcept {
 321         if (light[index] != level) {
 322                 light[index] = level;
 323                 Invalidate();
 324         }
 325 }
 326
 327 int Chunk::GetLight(int index) const noexcept {
 328         return light[index];
 329 }
 330
 331 float Chunk::GetVertexLight(const Pos &pos, const BlockModel::Position &vtx, const Model::Normal &norm) const noexcept {
 332         int index = ToIndex(pos);
 333         float light = GetLight(index);
 334
 335         Block::Face direct_face(Block::NormalFace(norm));
 336         // tis okay
 337         BlockLookup direct(const_cast<Chunk *>(this), pos, Block::NormalFace(norm));
 338         if (direct) {
 339                 float direct_light = direct.GetLight();
 340                 if (direct_light > light) {
 341                         light = direct_light;
 342                 }
 343         } else {
 344                 return light;
 345         }
 346
 347         if (Type(BlockAt(index)).luminosity > 0 || direct.GetType().block_light) {
 348                 return light;
 349         }
 350
 351         Block::Face edge[2];
 352         switch (Block::Axis(direct_face)) {
 353                 case 0: // X
 354                         edge[0] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 355                         edge[1] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 356                         break;
 357                 case 1: // Y
 358                         edge[0] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 359                         edge[1] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 360                         break;
 361                 case 2: // Z
 362                         edge[0] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 363                         edge[1] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 364                         break;
 365         }
 366
 367         int num = 1;
 368         int occlusion = 0;
 369
 370         BlockLookup next[2] = {
 371                 direct.Next(edge[0]),
 372                 direct.Next(edge[1]),
 373         };
 374
 375         if (next[0]) {
 376                 if (next[0].GetType().block_light) {
 377                         ++occlusion;
 378                 } else {
 379                         light += next[0].GetLight();
 380                         ++num;
 381                 }
 382         }
 383         if (next[1]) {
 384                 if (next[1].GetType().block_light) {
 385                         ++occlusion;
 386                 } else {
 387                         light += next[1].GetLight();
 388                         ++num;
 389                 }
 390         }
 391         if (occlusion < 2) {
 392                 if (next[0]) {
 393                         BlockLookup corner = next[0].Next(edge[1]);
 394                         if (corner) {
 395                                 if (corner.GetType().block_light) {
 396                                         ++occlusion;
 397                                 } else {
 398                                         light += corner.GetLight();
 399                                         ++num;
 400                                 }
 401                         }
 402                 } else if (next[1]) {
 403                         BlockLookup corner = next[1].Next(edge[0]);
 404                         if (corner) {
 405                                 if (corner.GetType().block_light) {
 406                                         ++occlusion;
 407                                 } else {
 408                                         light += corner.GetLight();
 409                                         ++num;
 410                                 }
 411                         }
 412                 }
 413         } else {
 414                 ++occlusion;
 415         }
 416
 417         return (light / num) - (occlusion * 0.8f);
 418 }
 419
 420
 421 bool Chunk::IsSurface(const Pos &pos) const noexcept {
 422         const Block &block = BlockAt(pos);
 423         if (!Type(block).visible) {
 424                 return false;
 425         }
 426         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 427                 BlockLookup next = BlockLookup(const_cast<Chunk *>(this), pos, Block::Face(face));
 428                 if (!next || !next.GetType().visible) {
 429                         return true;
 430                 }
 431         }
 432         return false;
 433 }
 434
 435
 436 void Chunk::Draw() noexcept {
 437         if (dirty) {
 438                 Update();
 439         }
 440         model.Draw();
 441 }
 442
 443
 444 bool Chunk::Intersection(
 445         const Ray &ray,
 446         const glm::mat4 &M,
 447         int &blkid,
 448         float &dist,
 449         glm::vec3 &normal
 450 ) const noexcept {
 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 bool Chunk::Intersection(
 483         const AABB &box,
 484         const glm::mat4 &Mbox,
 485         const glm::mat4 &Mchunk,
 486         std::vector<WorldCollision> &col
 487 ) const noexcept {
 488         bool any = false;
 489         float penetration;
 490         glm::vec3 normal;
 491
 492         if (!blank::Intersection(box, Mbox, Bounds(), Mchunk, penetration, normal)) {
 493                 return false;
 494         }
 495         for (int idx = 0, z = 0; z < depth; ++z) {
 496                 for (int y = 0; y < height; ++y) {
 497                         for (int x = 0; x < width; ++x, ++idx) {
 498                                 const BlockType &type = Type(idx);
 499                                 if (!type.collision) {
 500                                         continue;
 501                                 }
 502                                 if (type.shape->Intersects(Mchunk * ToTransform(Pos(x, y, z), idx), box, Mbox, penetration, normal)) {
 503                                         col.emplace_back(this, idx, penetration, normal);
 504                                         any = true;
 505                                 }
 506                         }
 507                 }
 508         }
 509         return any;
 510 }
 511
 512
 513 namespace {
 514
 515 BlockModel::Buffer buf;
 516
 517 }
 518
 519 void Chunk::CheckUpdate() noexcept {
 520         if (dirty) {
 521                 Update();
 522         }
 523 }
 524
 525 void Chunk::Update() noexcept {
 526         int vtx_count = 0, idx_count = 0;
 527         for (const auto &block : blocks) {
 528                 const Shape *shape = Type(block).shape;
 529                 vtx_count += shape->VertexCount();
 530                 idx_count += shape->VertexIndexCount();
 531         }
 532         buf.Clear();
 533         buf.Reserve(vtx_count, idx_count);
 534
 535         int idx = 0;
 536         BlockModel::Index vtx_counter = 0;
 537         for (size_t z = 0; z < depth; ++z) {
 538                 for (size_t y = 0; y < height; ++y) {
 539                         for (size_t x = 0; x < width; ++x, ++idx) {
 540                                 const BlockType &type = Type(BlockAt(idx));
 541                                 const Pos pos(x, y, z);
 542
 543                                 if (!type.visible || Obstructed(pos).All()) continue;
 544
 545                                 type.FillBlockModel(buf, ToTransform(pos, idx), vtx_counter);
 546                                 size_t vtx_begin = vtx_counter;
 547                                 vtx_counter += type.shape->VertexCount();
 548
 549                                 for (size_t vtx = vtx_begin; vtx < vtx_counter; ++vtx) {
 550                                         buf.lights.emplace_back(GetVertexLight(
 551                                                 pos,
 552                                                 buf.vertices[vtx],
 553                                                 type.shape->VertexNormal(vtx - vtx_begin, BlockAt(idx).Transform())
 554                                         ));
 555                                 }
 556                         }
 557                 }
 558         }
 559
 560         model.Update(buf);
 561         dirty = false;
 562 }
 563
 564 Block::FaceSet Chunk::Obstructed(const Pos &pos) const noexcept {
 565         Block::FaceSet result;
 566
 567         for (int f = 0; f < Block::FACE_COUNT; ++f) {
 568                 Block::Face face = Block::Face(f);
 569                 BlockLookup next(const_cast<Chunk *>(this), pos, face);
 570                 if (next && next.GetType().FaceFilled(next.GetBlock(), Block::Opposite(face))) {
 571                         result.Set(face);
 572                 }
 573         }
 574
 575         return result;
 576 }
 577
 578 glm::mat4 Chunk::ToTransform(const Pos &pos, int idx) const noexcept {
 579         return glm::translate(ToCoords(pos)) * BlockAt(idx).Transform();
 580 }
 581
 582
 583 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p) noexcept
 584 : chunk(c), pos(p) {
 585         while (pos.x >= Chunk::width) {
 586                 if (chunk->HasNeighbor(Block::FACE_RIGHT)) {
 587                         chunk = &chunk->GetNeighbor(Block::FACE_RIGHT);
 588                         pos.x -= Chunk::width;
 589                 } else {
 590                         chunk = nullptr;
 591                         return;
 592                 }
 593         }
 594         while (pos.x < 0) {
 595                 if (chunk->HasNeighbor(Block::FACE_LEFT)) {
 596                         chunk = &chunk->GetNeighbor(Block::FACE_LEFT);
 597                         pos.x += Chunk::width;
 598                 } else {
 599                         chunk = nullptr;
 600                         return;
 601                 }
 602         }
 603         while (pos.y >= Chunk::height) {
 604                 if (chunk->HasNeighbor(Block::FACE_UP)) {
 605                         chunk = &chunk->GetNeighbor(Block::FACE_UP);
 606                         pos.y -= Chunk::height;
 607                 } else {
 608                         chunk = nullptr;
 609                         return;
 610                 }
 611         }
 612         while (pos.y < 0) {
 613                 if (chunk->HasNeighbor(Block::FACE_DOWN)) {
 614                         chunk = &chunk->GetNeighbor(Block::FACE_DOWN);
 615                         pos.y += Chunk::height;
 616                 } else {
 617                         chunk = nullptr;
 618                         return;
 619                 }
 620         }
 621         while (pos.z >= Chunk::depth) {
 622                 if (chunk->HasNeighbor(Block::FACE_FRONT)) {
 623                         chunk = &chunk->GetNeighbor(Block::FACE_FRONT);
 624                         pos.z -= Chunk::depth;
 625                 } else {
 626                         chunk = nullptr;
 627                         return;
 628                 }
 629         }
 630         while (pos.z < 0) {
 631                 if (chunk->HasNeighbor(Block::FACE_BACK)) {
 632                         chunk = &chunk->GetNeighbor(Block::FACE_BACK);
 633                         pos.z += Chunk::depth;
 634                 } else {
 635                         chunk = nullptr;
 636                         return;
 637                 }
 638         }
 639 }
 640
 641 BlockLookup::BlockLookup(Chunk *c, const Chunk::Pos &p, Block::Face face) noexcept
 642 : chunk(c), pos(p) {
 643         pos += Block::FaceNormal(face);
 644         if (!Chunk::InBounds(pos)) {
 645                 pos -= Block::FaceNormal(face) * Chunk::Extent();
 646                 chunk = &chunk->GetNeighbor(face);
 647         }
 648 }
 649
 650
 651 ChunkLoader::ChunkLoader(const Config &config, const BlockTypeRegistry &reg, const Generator &gen) noexcept
 652 : base(0, 0, 0)
 653 , reg(reg)
 654 , gen(gen)
 655 , loaded()
 656 , to_generate()
 657 , to_free()
 658 , gen_timer(config.gen_limit)
 659 , load_dist(config.load_dist)
 660 , unload_dist(config.unload_dist) {
 661         gen_timer.Start();
 662 }
 663
 664 namespace {
 665
 666 struct ChunkLess {
 667
 668         explicit ChunkLess(const Chunk::Pos &base) noexcept
 669         : base(base) { }
 670
 671         bool operator ()(const Chunk::Pos &a, const Chunk::Pos &b) const noexcept {
 672                 Chunk::Pos da(base - a);
 673                 Chunk::Pos db(base - b);
 674                 return
 675                         da.x * da.x + da.y * da.y + da.z * da.z <
 676                         db.x * db.x + db.y * db.y + db.z * db.z;
 677         }
 678
 679         Chunk::Pos base;
 680
 681 };
 682
 683 }
 684
 685 void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 686         for (int z = from.z; z < to.z; ++z) {
 687                 for (int y = from.y; y < to.y; ++y) {
 688                         for (int x = from.x; x < to.x; ++x) {
 689                                 Chunk::Pos pos(x, y, z);
 690                                 if (Known(pos)) {
 691                                         continue;
 692                                 } else if (pos == base) {
 693                                         Generate(pos);
 694
 695                                 //      light testing
 696                                 //      for (int i = 0; i < 16; ++i) {
 697                                 //              for (int j = 0; j < 16; ++j) {
 698                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j,  0 }, Block(1));
 699                                 //                      loaded.back().SetBlock(Chunk::Pos{  i, j, 15 }, Block(1));
 700                                 //                      loaded.back().SetBlock(Chunk::Pos{  0, j,  i }, Block(1));
 701                                 //                      loaded.back().SetBlock(Chunk::Pos{ 15, j,  i }, Block(1));
 702                                 //              }
 703                                 //      }
 704                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0,  1 }, Block(13));
 705                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0,  1 }, Block(13));
 706                                 //      loaded.back().SetBlock(Chunk::Pos{  1,  0, 14 }, Block(13));
 707                                 //      loaded.back().SetBlock(Chunk::Pos{ 14,  0, 14 }, Block(13));
 708                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15,  1 }, Block(13));
 709                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15,  1 }, Block(13));
 710                                 //      loaded.back().SetBlock(Chunk::Pos{  1, 15, 14 }, Block(13));
 711                                 //      loaded.back().SetBlock(Chunk::Pos{ 14, 15, 14 }, Block(13));
 712                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7,  0 }, Block(13));
 713                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7,  0 }, Block(13));
 714                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8,  0 }, Block(13));
 715                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8,  0 }, Block(13));
 716                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  7, 15 }, Block(13));
 717                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  7, 15 }, Block(13));
 718                                 //      loaded.back().SetBlock(Chunk::Pos{  7,  8, 15 }, Block(13));
 719                                 //      loaded.back().SetBlock(Chunk::Pos{  8,  8, 15 }, Block(13));
 720                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  7 }, Block(13));
 721                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  7,  8 }, Block(13));
 722                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  7 }, Block(13));
 723                                 //      loaded.back().SetBlock(Chunk::Pos{  0,  8,  8 }, Block(13));
 724                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  7 }, Block(13));
 725                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  7,  8 }, Block(13));
 726                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  7 }, Block(13));
 727                                 //      loaded.back().SetBlock(Chunk::Pos{ 15,  8,  8 }, Block(13));
 728                                 //      loaded.back().Invalidate();
 729                                 //      loaded.back().CheckUpdate();
 730
 731                                 //      orientation testing
 732                                 //      for (int i = 0; i < Block::FACE_COUNT; ++i) {
 733                                 //              for (int j = 0; j < Block::TURN_COUNT; ++j) {
 734                                 //                      loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
 735                                 //              }
 736                                 //      }
 737                                 //      loaded.back().Invalidate();
 738                                 //      loaded.back().CheckUpdate();
 739                                 } else {
 740                                         to_generate.emplace_back(pos);
 741                                 }
 742                         }
 743                 }
 744         }
 745         to_generate.sort(ChunkLess(base));
 746 }
 747
 748 Chunk &ChunkLoader::Generate(const Chunk::Pos &pos) {
 749         loaded.emplace_back(reg);
 750         Chunk &chunk = loaded.back();
 751         chunk.Position(pos);
 752         gen(chunk);
 753         Insert(chunk);
 754         return chunk;
 755 }
 756
 757 void ChunkLoader::Insert(Chunk &chunk) noexcept {
 758         for (Chunk &other : loaded) {
 759                 chunk.SetNeighbor(other);
 760         }
 761 }
 762
 763 void ChunkLoader::Remove(Chunk &chunk) noexcept {
 764         chunk.Unlink();
 765 }
 766
 767 Chunk *ChunkLoader::Loaded(const Chunk::Pos &pos) noexcept {
 768         for (Chunk &chunk : loaded) {
 769                 if (chunk.Position() == pos) {
 770                         return &chunk;
 771                 }
 772         }
 773         return nullptr;
 774 }
 775
 776 bool ChunkLoader::Queued(const Chunk::Pos &pos) noexcept {
 777         for (const Chunk::Pos &chunk : to_generate) {
 778                 if (chunk == pos) {
 779                         return true;
 780                 }
 781         }
 782         return false;
 783 }
 784
 785 bool ChunkLoader::Known(const Chunk::Pos &pos) noexcept {
 786         if (Loaded(pos)) return true;
 787         return Queued(pos);
 788 }
 789
 790 Chunk &ChunkLoader::ForceLoad(const Chunk::Pos &pos) {
 791         Chunk *chunk = Loaded(pos);
 792         if (chunk) {
 793                 return *chunk;
 794         }
 795
 796         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end; ++iter) {
 797                 if (*iter == pos) {
 798                         to_generate.erase(iter);
 799                         break;
 800                 }
 801         }
 802
 803         return Generate(pos);
 804 }
 805
 806 bool ChunkLoader::OutOfRange(const Chunk::Pos &pos) const noexcept {
 807         return std::abs(base.x - pos.x) > unload_dist
 808                         || std::abs(base.y - pos.y) > unload_dist
 809                         || std::abs(base.z - pos.z) > unload_dist;
 810 }
 811
 812 void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 813         if (new_base == base) {
 814                 return;
 815         }
 816         base = new_base;
 817
 818         // unload far away chunks
 819         for (auto iter(loaded.begin()), end(loaded.end()); iter != end;) {
 820                 if (OutOfRange(*iter)) {
 821                         auto saved = iter;
 822                         Remove(*saved);
 823                         ++iter;
 824                         to_free.splice(to_free.end(), loaded, saved);
 825                 } else {
 826                         ++iter;
 827                 }
 828         }
 829         // abort far away queued chunks
 830         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end;) {
 831                 if (OutOfRange(*iter)) {
 832                         iter = to_generate.erase(iter);
 833                 } else {
 834                         ++iter;
 835                 }
 836         }
 837         // add missing new chunks
 838         GenerateSurrounding(base);
 839 }
 840
 841 void ChunkLoader::GenerateSurrounding(const Chunk::Pos &pos) {
 842         const Chunk::Pos offset(load_dist, load_dist, load_dist);
 843         Generate(pos - offset, pos + offset);
 844 }
 845
 846 void ChunkLoader::Update(int dt) {
 847         gen_timer.Update(dt);
 848         if (!gen_timer.Hit() || to_generate.empty()) {
 849                 return;
 850         }
 851
 852         Chunk::Pos pos(to_generate.front());
 853         to_generate.pop_front();
 854
 855         for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
 856                 if (iter->Position() == pos) {
 857                         iter->Relink();
 858                         loaded.splice(loaded.end(), to_free, iter);
 859                 }
 860         }
 861
 862         if (to_free.empty()) {
 863                 loaded.emplace_back(reg);
 864         } else {
 865                 to_free.front().ClearNeighbors();
 866                 loaded.splice(loaded.end(), to_free, to_free.begin());
 867         }
 868         Chunk &chunk = loaded.back();
 869         chunk.Position(pos);
 870         gen(chunk);
 871         Insert(chunk);
 872 }
 873
 874 }