src/world/chunk.cpp

   1 #include "BlockLookup.hpp"
   2 #include "Chunk.hpp"
   3 #include "ChunkIndex.hpp"
   4 #include "ChunkLoader.hpp"
   5 #include "ChunkRenderer.hpp"
   6 #include "ChunkStore.hpp"
   7
   8 #include "Generator.hpp"
   9 #include "WorldCollision.hpp"
  10 #include "../app/Assets.hpp"
  11 #include "../geometry/distance.hpp"
  12 #include "../graphics/BlockLighting.hpp"
  13 #include "../graphics/BlockMesh.hpp"
  14 #include "../graphics/Viewport.hpp"
  15 #include "../io/WorldSave.hpp"
  16
  17 #include <algorithm>
  18 #include <limits>
  19 #include <ostream>
  20 #include <queue>
  21
  22 #include <iostream>
  23 #include <glm/gtx/io.hpp>
  24
  25
  26 namespace blank {
  27
  28 constexpr int Chunk::side;
  29 constexpr int Chunk::size;
  30
  31
  32 Chunk::Chunk(const BlockTypeRegistry &types) noexcept
  33 : types(&types)
  34 , neighbor{0}
  35 , gravity()
  36 , blocks{}
  37 , light{0}
  38 , generated(false)
  39 , lighted(false)
  40 , position(0, 0, 0)
  41 , ref_count(0)
  42 , dirty_mesh(false)
  43 , dirty_save(false) {
  44
  45 }
  46
  47 Chunk::Chunk(Chunk &&other) noexcept
  48 : types(other.types)
  49 , gravity(std::move(other.gravity))
  50 , generated(other.generated)
  51 , lighted(other.lighted)
  52 , position(other.position)
  53 , ref_count(other.ref_count)
  54 , dirty_mesh(other.dirty_mesh)
  55 , dirty_save(other.dirty_save) {
  56         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  57         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  58         std::copy(other.light, other.light + sizeof(light), light);
  59         other.ref_count = 0;
  60 }
  61
  62 Chunk &Chunk::operator =(Chunk &&other) noexcept {
  63         types = other.types;
  64         std::copy(other.neighbor, other.neighbor + sizeof(neighbor), neighbor);
  65         gravity = std::move(other.gravity);
  66         std::copy(other.blocks, other.blocks + sizeof(blocks), blocks);
  67         std::copy(other.light, other.light + sizeof(light), light);
  68         generated = other.generated;
  69         lighted = other.lighted;
  70         position = other.position;
  71         std::swap(ref_count, other.ref_count);
  72         dirty_mesh = other.dirty_save;
  73         dirty_save = other.dirty_save;
  74         return *this;
  75 }
  76
  77
  78 namespace {
  79
  80 struct SetNode {
  81
  82         Chunk *chunk;
  83         RoughLocation::Fine pos;
  84
  85         SetNode(Chunk *chunk, RoughLocation::Fine pos)
  86         : chunk(chunk), pos(pos) { }
  87
  88         int Get() const noexcept { return chunk->GetLight(pos); }
  89         void Set(int level) noexcept { chunk->SetLight(pos, level); }
  90
  91         const BlockType &GetType() const noexcept { return chunk->Type(Chunk::ToIndex(pos)); }
  92
  93         int EmitLevel() const noexcept { return GetType().luminosity; }
  94         bool EmitsLight() const noexcept { return EmitLevel() > 0; }
  95
  96         bool HasNext(Block::Face face) noexcept {
  97                 const BlockType &type = GetType();
  98                 if (type.block_light && !type.luminosity) return false;
  99                 const BlockLookup next(chunk, pos, face);
 100                 return next;
 101         }
 102         SetNode GetNext(Block::Face face) noexcept {
 103                 const BlockLookup next(chunk, pos, face);
 104                 return SetNode(&next.GetChunk(), next.GetBlockPos());
 105         }
 106
 107 };
 108
 109 struct UnsetNode
 110 : public SetNode {
 111
 112         int level;
 113
 114         UnsetNode(Chunk *chunk, RoughLocation::Fine pos)
 115         : SetNode(chunk, pos), level(Get()) { }
 116
 117         UnsetNode(const SetNode &set)
 118         : SetNode(set), level(Get()) { }
 119
 120
 121         bool HasNext(Block::Face face) noexcept {
 122                 const BlockLookup next(chunk, pos, face);
 123                 return next;
 124         }
 125         UnsetNode GetNext(Block::Face face) noexcept { return UnsetNode(SetNode::GetNext(face)); }
 126
 127 };
 128
 129 std::queue<SetNode> light_queue;
 130 std::queue<UnsetNode> dark_queue;
 131
 132 void work_light() noexcept {
 133         while (!light_queue.empty()) {
 134                 SetNode node = light_queue.front();
 135                 light_queue.pop();
 136
 137                 int level = node.Get() - 1;
 138                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 139                         if (node.HasNext(Block::Face(face))) {
 140                                 SetNode other = node.GetNext(Block::Face(face));
 141                                 if (other.Get() < level) {
 142                                         other.Set(level);
 143                                         light_queue.emplace(other);
 144                                 }
 145                         }
 146                 }
 147         }
 148 }
 149
 150 void work_dark() noexcept {
 151         while (!dark_queue.empty()) {
 152                 UnsetNode node = dark_queue.front();
 153                 dark_queue.pop();
 154
 155                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 156                         if (node.HasNext(Block::Face(face))) {
 157                                 UnsetNode other = node.GetNext(Block::Face(face));
 158                                 if (other.Get() != 0 && other.Get() < node.level) {
 159                                         if (other.EmitsLight()) {
 160                                                 other.Set(other.EmitLevel());
 161                                                 light_queue.emplace(other);
 162                                         } else {
 163                                                 other.Set(0);
 164                                         }
 165                                         dark_queue.emplace(other);
 166                                 } else {
 167                                         light_queue.emplace(other);
 168                                 }
 169                         }
 170                 }
 171         }
 172 }
 173
 174 }
 175
 176 void Chunk::SetBlock(int index, const Block &block) noexcept {
 177         const BlockType &old_type = Type(blocks[index]);
 178         const BlockType &new_type = Type(block);
 179
 180         blocks[index] = block;
 181         Invalidate();
 182
 183         if (old_type.gravity && !new_type.gravity) {
 184                 gravity.erase(index);
 185         } else if (new_type.gravity && !old_type.gravity) {
 186                 gravity.insert(index);
 187         }
 188
 189         if (!lighted || &old_type == &new_type) return;
 190
 191         if (new_type.luminosity > old_type.luminosity) {
 192                 // light added
 193                 SetLight(index, new_type.luminosity);
 194                 light_queue.emplace(this, ToPos(index));
 195                 work_light();
 196         } else if (new_type.luminosity < old_type.luminosity) {
 197                 // light removed
 198                 dark_queue.emplace(this, ToPos(index));
 199                 SetLight(index, 0);
 200                 work_dark();
 201                 SetLight(index, new_type.luminosity);
 202                 light_queue.emplace(this, ToPos(index));
 203                 work_light();
 204         } else if (new_type.block_light && !old_type.block_light) {
 205                 // obstacle added
 206                 if (GetLight(index) > 0) {
 207                         dark_queue.emplace(this, ToPos(index));
 208                         SetLight(index, 0);
 209                         work_dark();
 210                         work_light();
 211                 }
 212         } else if (!new_type.block_light && old_type.block_light) {
 213                 // obstacle removed
 214                 int level = 0;
 215                 RoughLocation::Fine pos(ToPos(index));
 216                 for (int face = 0; face < Block::FACE_COUNT; ++face) {
 217                         BlockLookup next_block(this, pos, Block::Face(face));
 218                         if (next_block) {
 219                                 level = std::max(level, next_block.GetLight());
 220                         }
 221                 }
 222                 if (level > 1) {
 223                         SetLight(index, level - 1);
 224                         light_queue.emplace(this, pos);
 225                         work_light();
 226                 }
 227         }
 228 }
 229
 230 void Chunk::ScanLights() {
 231         int idx = 0;
 232         RoughLocation::Fine pos(0, 0, 0);
 233         for (; pos.z < side; ++pos.z) {
 234                 for (pos.y = 0; pos.y < side; ++pos.y) {
 235                         for (pos.x = 0; pos.x < side; ++pos.x, ++idx) {
 236                                 const BlockType &type = Type(blocks[idx]);
 237                                 if (type.luminosity) {
 238                                         SetLight(idx, type.luminosity);
 239                                         light_queue.emplace(this, pos);
 240                                 }
 241                         }
 242                 }
 243         }
 244         work_light();
 245         lighted = true;
 246 }
 247
 248 void Chunk::ScanActive() {
 249         gravity.clear();
 250         for (int index = 0; index < size; ++index) {
 251                 if (Type(index).gravity) {
 252                         gravity.insert(gravity.end(), index);
 253                 }
 254         }
 255 }
 256
 257 void Chunk::SetNeighbor(Block::Face face, Chunk &other) noexcept {
 258         neighbor[face] = &other;
 259         other.neighbor[Block::Opposite(face)] = this;
 260 }
 261
 262 void Chunk::Unlink() noexcept {
 263         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 264                 if (neighbor[face]) {
 265                         neighbor[face]->neighbor[Block::Opposite(Block::Face(face))] = nullptr;
 266                         neighbor[face] = nullptr;
 267                 }
 268         }
 269 }
 270
 271
 272 void Chunk::SetLight(int index, int level) noexcept {
 273         if (light[index] != level) {
 274                 light[index] = level;
 275                 Invalidate();
 276         }
 277 }
 278
 279 int Chunk::GetLight(int index) const noexcept {
 280         return light[index];
 281 }
 282
 283 float Chunk::GetVertexLight(const RoughLocation::Fine &pos, const BlockMesh::Position &vtx, const EntityMesh::Normal &norm) const noexcept {
 284         int index = ToIndex(pos);
 285         float light = GetLight(index);
 286
 287         Block::Face direct_face(Block::NormalFace(norm));
 288         // tis okay
 289         BlockLookup direct(const_cast<Chunk *>(this), pos, Block::NormalFace(norm));
 290         if (direct) {
 291                 float direct_light = direct.GetLight();
 292                 if (direct_light > light) {
 293                         light = direct_light;
 294                 }
 295         } else {
 296                 return light;
 297         }
 298
 299         if (Type(BlockAt(index)).luminosity > 0 || direct.GetType().block_light) {
 300                 return light;
 301         }
 302
 303         Block::Face edge[2];
 304         switch (Block::Axis(direct_face)) {
 305                 case 0: // X
 306                         edge[0] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 307                         edge[1] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 308                         break;
 309                 case 1: // Y
 310                         edge[0] = (vtx.z - pos.z) > 0.5f ? Block::FACE_FRONT : Block::FACE_BACK;
 311                         edge[1] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 312                         break;
 313                 case 2: // Z
 314                         edge[0] = (vtx.x - pos.x) > 0.5f ? Block::FACE_RIGHT : Block::FACE_LEFT;
 315                         edge[1] = (vtx.y - pos.y) > 0.5f ? Block::FACE_UP : Block::FACE_DOWN;
 316                         break;
 317         }
 318
 319         int num = 1;
 320         int occlusion = 0;
 321
 322         BlockLookup next[2] = {
 323                 direct.Next(edge[0]),
 324                 direct.Next(edge[1]),
 325         };
 326
 327         if (next[0]) {
 328                 if (next[0].GetType().block_light) {
 329                         ++occlusion;
 330                 } else {
 331                         light += next[0].GetLight();
 332                         ++num;
 333                 }
 334         }
 335         if (next[1]) {
 336                 if (next[1].GetType().block_light) {
 337                         ++occlusion;
 338                 } else {
 339                         light += next[1].GetLight();
 340                         ++num;
 341                 }
 342         }
 343         if (occlusion < 2) {
 344                 if (next[0]) {
 345                         BlockLookup corner = next[0].Next(edge[1]);
 346                         if (corner) {
 347                                 if (corner.GetType().block_light) {
 348                                         ++occlusion;
 349                                 } else {
 350                                         light += corner.GetLight();
 351                                         ++num;
 352                                 }
 353                         }
 354                 } else if (next[1]) {
 355                         BlockLookup corner = next[1].Next(edge[0]);
 356                         if (corner) {
 357                                 if (corner.GetType().block_light) {
 358                                         ++occlusion;
 359                                 } else {
 360                                         light += corner.GetLight();
 361                                         ++num;
 362                                 }
 363                         }
 364                 }
 365         } else {
 366                 ++occlusion;
 367         }
 368
 369         return (light / num) - (occlusion * 0.8f);
 370 }
 371
 372
 373 glm::vec3 Chunk::GravityAt(const ExactLocation &coords) const noexcept {
 374         glm::vec3 grav(0.0f);
 375         for (int index : gravity) {
 376                 RoughLocation::Fine block_pos(ToPos(index));
 377                 ExactLocation block_coords(position, ToCoords(block_pos));
 378                 // trust that block type hasn't changed
 379                 grav += Type(index).gravity->GetGravity(
 380                         coords.Difference(block_coords).Absolute(),
 381                         ToTransform(block_pos, index));
 382         }
 383         return grav;
 384 }
 385
 386
 387 bool Chunk::IsSurface(const RoughLocation::Fine &pos) const noexcept {
 388         const Block &block = BlockAt(pos);
 389         if (!Type(block).visible) {
 390                 return false;
 391         }
 392         for (int face = 0; face < Block::FACE_COUNT; ++face) {
 393                 BlockLookup next = BlockLookup(const_cast<Chunk *>(this), pos, Block::Face(face));
 394                 if (!next || !next.GetType().visible) {
 395                         return true;
 396                 }
 397         }
 398         return false;
 399 }
 400
 401
 402 bool Chunk::Intersection(
 403         const Ray &ray,
 404         const ExactLocation::Coarse &reference,
 405         WorldCollision &coll
 406 ) noexcept {
 407         int idx = 0;
 408         coll.chunk = this;
 409         coll.block = -1;
 410         coll.depth = std::numeric_limits<float>::infinity();
 411         for (int z = 0; z < side; ++z) {
 412                 for (int y = 0; y < side; ++y) {
 413                         for (int x = 0; x < side; ++x, ++idx) {
 414                                 const BlockType &type = Type(idx);
 415                                 if (!type.collision || !type.shape) {
 416                                         continue;
 417                                 }
 418                                 float cur_dist;
 419                                 glm::vec3 cur_norm;
 420                                 if (type.shape->Intersects(ray, ToTransform(reference, RoughLocation::Fine(x, y, z), idx), cur_dist, cur_norm)) {
 421                                         if (cur_dist < coll.depth) {
 422                                                 coll.block = idx;
 423                                                 coll.depth = cur_dist;
 424                                                 coll.normal = cur_norm;
 425                                         }
 426                                 }
 427                         }
 428                 }
 429         }
 430
 431         if (coll.block < 0) {
 432                 return false;
 433         } else {
 434                 coll.normal = glm::vec3(BlockAt(coll.block).Transform() * glm::vec4(coll.normal, 0.0f));
 435                 return true;
 436         }
 437 }
 438
 439 bool Chunk::Intersection(
 440         const AABB &box,
 441         const glm::mat4 &Mbox,
 442         const glm::mat4 &Mchunk,
 443         std::vector<WorldCollision> &col
 444 ) noexcept {
 445         bool any = false;
 446         float penetration;
 447         glm::vec3 normal;
 448
 449         if (!blank::Intersection(box, Mbox, Bounds(), Mchunk, penetration, normal)) {
 450                 return false;
 451         }
 452
 453         // box's origin relative to the chunk
 454         const glm::vec3 box_coords(Mbox[3] - Mchunk[3]);
 455         const float box_rad = box.OriginRadius();
 456
 457         // assume a bounding radius of 2 for blocks
 458         constexpr float block_rad = 2.0f;
 459         const float bb_radius = box_rad + block_rad;
 460
 461         const RoughLocation::Fine begin(max(
 462                 RoughLocation::Fine(0),
 463                 RoughLocation::Fine(floor(box_coords - bb_radius))
 464         ));
 465         const RoughLocation::Fine end(min(
 466                 RoughLocation::Fine(side - 1),
 467                 RoughLocation::Fine(ceil(box_coords + bb_radius))
 468         ) - 1);
 469
 470         for (RoughLocation::Fine pos(begin); pos.z < end.y; ++pos.z) {
 471                 for (pos.y = begin.y; pos.y < end.y; ++pos.y) {
 472                         for (pos.x = begin.x; pos.x < end.x; ++pos.x) {
 473                                 int idx = ToIndex(pos);
 474                                 const BlockType &type = Type(idx);
 475                                 if (!type.collision || !type.shape) {
 476                                         continue;
 477                                 }
 478                                 if (type.shape->Intersects(Mchunk * ToTransform(pos, idx), box, Mbox, penetration, normal)) {
 479                                         col.emplace_back(this, idx, penetration, normal);
 480                                         any = true;
 481                                 }
 482                         }
 483                 }
 484         }
 485         return any;
 486 }
 487
 488 bool Chunk::Intersection(
 489         const Entity &entity,
 490         const glm::mat4 &Mentity,
 491         const glm::mat4 &Mchunk,
 492         std::vector<WorldCollision> &col
 493 ) noexcept {
 494         // entity's origin relative to the chunk
 495         const glm::vec3 entity_coords(Mentity[3] - Mchunk[3]);
 496         const float ec_radius = entity.Radius() + Radius();
 497
 498         if (distance2(entity_coords, Center()) > ec_radius * ec_radius) {
 499                 return false;
 500         }
 501
 502         bool any = false;
 503         float penetration;
 504         glm::vec3 normal;
 505
 506         // assume a bounding radius of 2 for blocks
 507         constexpr float block_rad = 2.0f;
 508         const float eb_radius = entity.Radius() + block_rad;
 509
 510         const RoughLocation::Fine begin(max(
 511                 RoughLocation::Fine(0),
 512                 RoughLocation::Fine(floor(entity_coords - eb_radius))
 513         ));
 514         const RoughLocation::Fine end(min(
 515                 RoughLocation::Fine(side),
 516                 RoughLocation::Fine(ceil(entity_coords + eb_radius))
 517         ));
 518
 519         for (RoughLocation::Fine pos(begin); pos.z < end.z; ++pos.z) {
 520                 for (pos.y = begin.y; pos.y < end.y; ++pos.y) {
 521                         for (pos.x = begin.x; pos.x < end.x; ++pos.x) {
 522                                 int idx = ToIndex(pos);
 523                                 const BlockType &type = Type(idx);
 524                                 if (!type.collision || !type.shape) {
 525                                         continue;
 526                                 }
 527                                 if (type.shape->Intersects(Mchunk * ToTransform(pos, idx), entity.Bounds(), Mentity, penetration, normal)) {
 528                                         col.emplace_back(this, idx, penetration, normal);
 529                                         any = true;
 530                                 }
 531                         }
 532                 }
 533         }
 534         return any;
 535 }
 536
 537
 538 namespace {
 539
 540 BlockMesh::Buffer buf;
 541
 542 }
 543
 544 void Chunk::Update(BlockMesh &model) noexcept {
 545         int vtx_count = 0, idx_count = 0;
 546         for (const auto &block : blocks) {
 547                 const BlockType &type = Type(block);
 548                 if (type.visible && type.shape) {
 549                         vtx_count += type.shape->VertexCount();
 550                         idx_count += type.shape->IndexCount();
 551                 }
 552         }
 553         buf.Clear();
 554         buf.Reserve(vtx_count, idx_count);
 555
 556         if (idx_count > 0) {
 557                 int idx = 0;
 558                 BlockMesh::Index vtx_counter = 0;
 559                 for (size_t z = 0; z < side; ++z) {
 560                         for (size_t y = 0; y < side; ++y) {
 561                                 for (size_t x = 0; x < side; ++x, ++idx) {
 562                                         const BlockType &type = Type(BlockAt(idx));
 563                                         const RoughLocation::Fine pos(x, y, z);
 564
 565                                         if (!type.visible || !type.shape || Obstructed(pos).All()) continue;
 566
 567                                         type.FillBlockMesh(buf, ToTransform(pos, idx), vtx_counter);
 568                                         size_t vtx_begin = vtx_counter;
 569                                         vtx_counter += type.shape->VertexCount();
 570
 571                                         for (size_t vtx = vtx_begin; vtx < vtx_counter; ++vtx) {
 572                                                 buf.lights.emplace_back(GetVertexLight(
 573                                                         pos,
 574                                                         buf.vertices[vtx],
 575                                                         type.shape->VertexNormal(vtx - vtx_begin, BlockAt(idx).Transform())
 576                                                 ));
 577                                         }
 578                                 }
 579                         }
 580                 }
 581         }
 582
 583         model.Update(buf);
 584         ClearMesh();
 585 }
 586
 587 Block::FaceSet Chunk::Obstructed(const RoughLocation::Fine &pos) const noexcept {
 588         Block::FaceSet result;
 589
 590         for (int f = 0; f < Block::FACE_COUNT; ++f) {
 591                 Block::Face face = Block::Face(f);
 592                 BlockLookup next(const_cast<Chunk *>(this), pos, face);
 593                 if (next && next.GetType().FaceFilled(next.GetBlock(), Block::Opposite(face))) {
 594                         result.Set(face);
 595                 }
 596         }
 597
 598         return result;
 599 }
 600
 601 glm::mat4 Chunk::ToTransform(const RoughLocation::Fine &pos, int idx) const noexcept {
 602         return glm::translate(ToCoords(pos)) * BlockAt(idx).Transform();
 603 }
 604
 605 glm::mat4 Chunk::ToTransform(const ExactLocation::Coarse &ref, const RoughLocation::Fine &pos, int idx) const noexcept {
 606         return glm::translate(ExactLocation::Fine((position - ref) * ExactLocation::Extent()) + ToCoords(pos)) * BlockAt(idx).Transform();
 607 }
 608
 609
 610 BlockLookup::BlockLookup(Chunk *c, const RoughLocation::Fine &p) noexcept
 611 : chunk(c), pos(p) {
 612         while (pos.x >= Chunk::side) {
 613                 if (chunk->HasNeighbor(Block::FACE_RIGHT)) {
 614                         chunk = &chunk->GetNeighbor(Block::FACE_RIGHT);
 615                         pos.x -= Chunk::side;
 616                 } else {
 617                         chunk = nullptr;
 618                         return;
 619                 }
 620         }
 621         while (pos.x < 0) {
 622                 if (chunk->HasNeighbor(Block::FACE_LEFT)) {
 623                         chunk = &chunk->GetNeighbor(Block::FACE_LEFT);
 624                         pos.x += Chunk::side;
 625                 } else {
 626                         chunk = nullptr;
 627                         return;
 628                 }
 629         }
 630         while (pos.y >= Chunk::side) {
 631                 if (chunk->HasNeighbor(Block::FACE_UP)) {
 632                         chunk = &chunk->GetNeighbor(Block::FACE_UP);
 633                         pos.y -= Chunk::side;
 634                 } else {
 635                         chunk = nullptr;
 636                         return;
 637                 }
 638         }
 639         while (pos.y < 0) {
 640                 if (chunk->HasNeighbor(Block::FACE_DOWN)) {
 641                         chunk = &chunk->GetNeighbor(Block::FACE_DOWN);
 642                         pos.y += Chunk::side;
 643                 } else {
 644                         chunk = nullptr;
 645                         return;
 646                 }
 647         }
 648         while (pos.z >= Chunk::side) {
 649                 if (chunk->HasNeighbor(Block::FACE_FRONT)) {
 650                         chunk = &chunk->GetNeighbor(Block::FACE_FRONT);
 651                         pos.z -= Chunk::side;
 652                 } else {
 653                         chunk = nullptr;
 654                         return;
 655                 }
 656         }
 657         while (pos.z < 0) {
 658                 if (chunk->HasNeighbor(Block::FACE_BACK)) {
 659                         chunk = &chunk->GetNeighbor(Block::FACE_BACK);
 660                         pos.z += Chunk::side;
 661                 } else {
 662                         chunk = nullptr;
 663                         return;
 664                 }
 665         }
 666 }
 667
 668 BlockLookup::BlockLookup(Chunk *c, const RoughLocation::Fine &p, Block::Face face) noexcept
 669 : chunk(c), pos(p) {
 670         pos += Block::FaceNormal(face);
 671         if (!Chunk::InBounds(pos)) {
 672                 pos -= Block::FaceNormal(face) * ExactLocation::Extent();
 673                 chunk = &chunk->GetNeighbor(face);
 674         }
 675 }
 676
 677
 678 ChunkLoader::ChunkLoader(
 679         ChunkStore &store,
 680         const Generator &gen,
 681         const WorldSave &save
 682 ) noexcept
 683 : store(store)
 684 , gen(gen)
 685 , save(save) {
 686
 687 }
 688
 689 void ChunkLoader::Update(int dt) {
 690         // check if there's chunks waiting to be loaded
 691         // load until one of load or generation limits was hit
 692         constexpr int max_load = 10;
 693         constexpr int max_gen = 1;
 694         int loaded = 0;
 695         int generated = 0;
 696         while (loaded < max_load && generated < max_gen && store.HasMissing()) {
 697                 if (LoadOne()) {
 698                         ++generated;
 699                 } else {
 700                         ++loaded;
 701                 }
 702         }
 703
 704         // store a few chunks as well
 705         constexpr int max_save = 10;
 706         int saved = 0;
 707         for (Chunk &chunk : store) {
 708                 if (chunk.ShouldUpdateSave()) {
 709                         save.Write(chunk);
 710                         ++saved;
 711                         if (saved >= max_save) {
 712                                 break;
 713                         }
 714                 }
 715         }
 716 }
 717
 718 int ChunkLoader::ToLoad() const noexcept {
 719         return store.EstimateMissing();
 720 }
 721
 722 bool ChunkLoader::LoadOne() {
 723         if (!store.HasMissing()) return false;
 724
 725         ExactLocation::Coarse pos = store.NextMissing();
 726         Chunk *chunk = store.Allocate(pos);
 727         if (!chunk) {
 728                 // chunk store corrupted?
 729                 return false;
 730         }
 731
 732         bool generated = false;
 733         if (save.Exists(pos)) {
 734                 save.Read(*chunk);
 735         } else {
 736                 gen(*chunk);
 737                 generated = true;
 738         }
 739
 740         ChunkIndex *index = store.ClosestIndex(pos);
 741         if (!index) {
 742                 return generated;
 743         }
 744
 745         ExactLocation::Coarse begin(pos - ExactLocation::Coarse(1));
 746         ExactLocation::Coarse end(pos + ExactLocation::Coarse(2));
 747         for (ExactLocation::Coarse iter(begin); iter.z < end.z; ++iter.z) {
 748                 for (iter.y = begin.y; iter.y < end.y; ++iter.y) {
 749                         for (iter.x = begin.x; iter.x < end.x; ++iter.x) {
 750                                 if (index->IsBorder(iter)) continue;
 751                                 Chunk *light_chunk = index->Get(iter);
 752                                 if (!light_chunk) continue;
 753                                 if (index->HasAllSurrounding(iter)) {
 754                                         if (!light_chunk->Lighted()) {
 755                                                 light_chunk->ScanLights();
 756                                         } else {
 757                                                 light_chunk->InvalidateMesh();
 758                                         }
 759                                 }
 760                         }
 761                 }
 762         }
 763
 764         return generated;
 765 }
 766
 767 void ChunkLoader::LoadN(std::size_t n) {
 768         std::size_t end = std::min(n, std::size_t(ToLoad()));
 769         for (std::size_t i = 0; i < end && store.HasMissing(); ++i) {
 770                 LoadOne();
 771         }
 772 }
 773
 774
 775 ChunkRenderer::ChunkRenderer(ChunkIndex &index)
 776 : index(index)
 777 , models(index.TotalChunks())
 778 , block_tex()
 779 , fog_density(0.0f) {
 780
 781 }
 782
 783 ChunkRenderer::~ChunkRenderer() {
 784
 785 }
 786
 787 int ChunkRenderer::MissingChunks() const noexcept {
 788         return index.MissingChunks();
 789 }
 790
 791 void ChunkRenderer::LoadTextures(const AssetLoader &loader, const ResourceIndex &tex_index) {
 792         block_tex.Bind();
 793         loader.LoadTextures(tex_index, block_tex);
 794         block_tex.FilterNearest();
 795 }
 796
 797 void ChunkRenderer::Update(int dt) {
 798         for (int i = 0, updates = 0; updates < dt && i < index.TotalChunks(); ++i) {
 799                 if (!index[i]) continue;
 800                 if (!index[i]->Lighted() && index.HasAllSurrounding(index[i]->Position())) {
 801                         index[i]->ScanLights();
 802                 }
 803                 if (index[i]->ShouldUpdateMesh()) {
 804                         index[i]->Update(models[i]);
 805                         ++updates;
 806                 }
 807         }
 808 }
 809
 810 void ChunkRenderer::Render(Viewport &viewport) {
 811         BlockLighting &chunk_prog = viewport.ChunkProgram();
 812         chunk_prog.SetTexture(block_tex);
 813         chunk_prog.SetFogDensity(fog_density);
 814
 815         Frustum frustum(transpose(chunk_prog.GetVP()));
 816         AABB box;
 817
 818         for (int i = 0; i < index.TotalChunks(); ++i) {
 819                 if (!index[i]) continue;
 820                 box.min = (index[i]->Position() - index.Base()) * ExactLocation::Extent();
 821                 box.max = box.min + ExactLocation::FExtent();
 822
 823                 if (!CullTest(box, frustum)) {
 824                         if (index[i]->ShouldUpdateMesh()) {
 825                                 index[i]->Update(models[i]);
 826                         }
 827                         if (!models[i].Empty()) {
 828                                 chunk_prog.SetM(index[i]->Transform(index.Base()));
 829                                 models[i].Draw();
 830                         }
 831                 }
 832         }
 833 }
 834
 835
 836 ChunkIndex::ChunkIndex(ChunkStore &store, const ExactLocation::Coarse &base, int extent)
 837 : store(store)
 838 , base(base)
 839 , extent(extent)
 840 , side_length(2 * extent + 1)
 841 , total_length(side_length * side_length * side_length)
 842 , total_indexed(0)
 843 , last_missing(0)
 844 , stride(1, side_length, side_length * side_length)
 845 , chunks(total_length, nullptr) {
 846         Scan();
 847 }
 848
 849 ChunkIndex::~ChunkIndex() {
 850         Clear();
 851 }
 852
 853 bool ChunkIndex::InRange(const ExactLocation::Coarse &pos) const noexcept {
 854         return Distance(pos) <= extent;
 855 }
 856
 857 bool ChunkIndex::IsBorder(const ExactLocation::Coarse &pos) const noexcept {
 858         return Distance(pos) == extent;
 859 }
 860
 861 int ChunkIndex::Distance(const ExactLocation::Coarse &pos) const noexcept {
 862         return manhattan_radius(pos - base);
 863 }
 864
 865 bool ChunkIndex::HasAllSurrounding(const ExactLocation::Coarse &pos) const noexcept {
 866         ExactLocation::Coarse begin(pos - ExactLocation::Coarse(1));
 867         ExactLocation::Coarse end(pos + ExactLocation::Coarse(2));
 868         for (ExactLocation::Coarse iter(begin); iter.z < end.z; ++iter.z) {
 869                 for (iter.y = begin.y; iter.y < end.y; ++iter.y) {
 870                         for (iter.x = begin.x; iter.x < end.x; ++iter.x) {
 871                                 if (!Get(iter)) return false;
 872                         }
 873                 }
 874         }
 875         return true;
 876 }
 877
 878 int ChunkIndex::IndexOf(const ExactLocation::Coarse &pos) const noexcept {
 879         ExactLocation::Coarse mod_pos(
 880                 GetCol(pos.x),
 881                 GetCol(pos.y),
 882                 GetCol(pos.z)
 883         );
 884         return mod_pos.x * stride.x
 885                 +  mod_pos.y * stride.y
 886                 +  mod_pos.z * stride.z;
 887 }
 888
 889 ExactLocation::Coarse ChunkIndex::PositionOf(int i) const noexcept {
 890         ExactLocation::Coarse zero_pos(
 891                 (i / stride.x) % side_length,
 892                 (i / stride.y) % side_length,
 893                 (i / stride.z) % side_length
 894         );
 895         ExactLocation::Coarse zero_base(
 896                 GetCol(base.x),
 897                 GetCol(base.y),
 898                 GetCol(base.z)
 899         );
 900         ExactLocation::Coarse base_relative(zero_pos - zero_base);
 901         if (base_relative.x > extent) base_relative.x -= side_length;
 902         else if (base_relative.x < -extent) base_relative.x += side_length;
 903         if (base_relative.y > extent) base_relative.y -= side_length;
 904         else if (base_relative.y < -extent) base_relative.y += side_length;
 905         if (base_relative.z > extent) base_relative.z -= side_length;
 906         else if (base_relative.z < -extent) base_relative.z += side_length;
 907         return base + base_relative;
 908 }
 909
 910 Chunk *ChunkIndex::Get(const ExactLocation::Coarse &pos) noexcept {
 911         if (InRange(pos)) {
 912                 return chunks[IndexOf(pos)];
 913         } else {
 914                 return nullptr;
 915         }
 916 }
 917
 918 const Chunk *ChunkIndex::Get(const ExactLocation::Coarse &pos) const noexcept {
 919         if (InRange(pos)) {
 920                 return chunks[IndexOf(pos)];
 921         } else {
 922                 return nullptr;
 923         }
 924 }
 925
 926 void ChunkIndex::Rebase(const ExactLocation::Coarse &new_base) {
 927         if (new_base == base) return;
 928
 929         ExactLocation::Coarse diff(new_base - base);
 930
 931         if (manhattan_radius(diff) > extent) {
 932                 // that's more than half, so probably not worth shifting
 933                 base = new_base;
 934                 Clear();
 935                 Scan();
 936                 store.Clean();
 937                 return;
 938         }
 939
 940         while (diff.x > 0) {
 941                 Shift(Block::FACE_RIGHT);
 942                 --diff.x;
 943         }
 944         while (diff.x < 0) {
 945                 Shift(Block::FACE_LEFT);
 946                 ++diff.x;
 947         }
 948         while (diff.y > 0) {
 949                 Shift(Block::FACE_UP);
 950                 --diff.y;
 951         }
 952         while (diff.y < 0) {
 953                 Shift(Block::FACE_DOWN);
 954                 ++diff.y;
 955         }
 956         while (diff.z > 0) {
 957                 Shift(Block::FACE_FRONT);
 958                 --diff.z;
 959         }
 960         while (diff.z < 0) {
 961                 Shift(Block::FACE_BACK);
 962                 ++diff.z;
 963         }
 964         store.Clean();
 965 }
 966
 967 int ChunkIndex::GetCol(int c) const noexcept {
 968         c %= side_length;
 969         if (c < 0) c += side_length;
 970         return c;
 971 }
 972
 973 void ChunkIndex::Shift(Block::Face f) {
 974         int a_axis = Block::Axis(f);
 975         int b_axis = (a_axis + 1) % 3;
 976         int c_axis = (a_axis + 2) % 3;
 977         int dir = Block::Direction(f);
 978         base[a_axis] += dir;
 979         int a = GetCol(base[a_axis] + (extent * dir));
 980         int a_stride = a * stride[a_axis];
 981         for (int b = 0; b < side_length; ++b) {
 982                 int b_stride = b * stride[b_axis];
 983                 for (int c = 0; c < side_length; ++c) {
 984                         int bc_stride = b_stride + c * stride[c_axis];
 985                         int index = a_stride + bc_stride;
 986                         Unset(index);
 987                         int neighbor = ((a - dir + side_length) % side_length) * stride[a_axis] + bc_stride;
 988                         if (chunks[neighbor] && chunks[neighbor]->HasNeighbor(f)) {
 989                                 Set(index, chunks[neighbor]->GetNeighbor(f));
 990                         }
 991                 }
 992         }
 993 }
 994
 995 void ChunkIndex::Clear() noexcept {
 996         for (int i = 0; i < total_length && total_indexed > 0; ++i) {
 997                 Unset(i);
 998         }
 999 }
1000
1001 void ChunkIndex::Scan() noexcept {
1002         for (Chunk &chunk : store) {
1003                 Register(chunk);
1004         }
1005 }
1006
1007 void ChunkIndex::Register(Chunk &chunk) noexcept {
1008         if (InRange(chunk.Position())) {
1009                 Set(IndexOf(chunk.Position()), chunk);
1010         }
1011 }
1012
1013 void ChunkIndex::Set(int index, Chunk &chunk) noexcept {
1014         Unset(index);
1015         chunks[index] = &chunk;
1016         chunk.Ref();
1017         ++total_indexed;
1018 }
1019
1020 void ChunkIndex::Unset(int index) noexcept {
1021         if (chunks[index]) {
1022                 chunks[index]->UnRef();
1023                 chunks[index] = nullptr;
1024                 --total_indexed;
1025         }
1026 }
1027
1028 ExactLocation::Coarse ChunkIndex::NextMissing() noexcept {
1029         if (MissingChunks() > 0) {
1030                 int roundtrip = last_missing;
1031                 last_missing = (last_missing + 1) % total_length;
1032                 while (chunks[last_missing]) {
1033                         last_missing = (last_missing + 1) % total_length;
1034                         if (last_missing == roundtrip) {
1035                                 break;
1036                         }
1037                 }
1038         }
1039         return PositionOf(last_missing);
1040 }
1041
1042
1043 ChunkStore::ChunkStore(const BlockTypeRegistry &types)
1044 : types(types)
1045 , loaded()
1046 , free()
1047 , indices() {
1048
1049 }
1050
1051 ChunkStore::~ChunkStore() {
1052
1053 }
1054
1055 ChunkIndex &ChunkStore::MakeIndex(const ExactLocation::Coarse &pos, int extent) {
1056         indices.emplace_back(*this, pos, extent);
1057         return indices.back();
1058 }
1059
1060 void ChunkStore::UnregisterIndex(ChunkIndex &index) {
1061         for (auto i = indices.begin(), end = indices.end(); i != end; ++i) {
1062                 if (&*i == &index) {
1063                         indices.erase(i);
1064                         return;
1065                 } else {
1066                         ++i;
1067                 }
1068         }
1069 }
1070
1071 ChunkIndex *ChunkStore::ClosestIndex(const ExactLocation::Coarse &pos) {
1072         ChunkIndex *closest_index = nullptr;
1073         int closest_distance = std::numeric_limits<int>::max();
1074
1075         for (ChunkIndex &index : indices) {
1076                 int distance = index.Distance(pos);
1077                 if (distance < closest_distance) {
1078                         closest_index = &index;
1079                         closest_distance = distance;
1080                 }
1081         }
1082
1083         return closest_index;
1084 }
1085
1086 Chunk *ChunkStore::Get(const ExactLocation::Coarse &pos) noexcept {
1087         for (ChunkIndex &index : indices) {
1088                 Chunk *chunk = index.Get(pos);
1089                 if (chunk) {
1090                         return chunk;
1091                 }
1092         }
1093         return nullptr;
1094 }
1095
1096 const Chunk *ChunkStore::Get(const ExactLocation::Coarse &pos) const noexcept {
1097         for (const ChunkIndex &index : indices) {
1098                 const Chunk *chunk = index.Get(pos);
1099                 if (chunk) {
1100                         return chunk;
1101                 }
1102         }
1103         return nullptr;
1104 }
1105
1106 Chunk *ChunkStore::Allocate(const ExactLocation::Coarse &pos) {
1107         Chunk *chunk = Get(pos);
1108         if (chunk) {
1109                 return chunk;
1110         }
1111         if (free.empty()) {
1112                 loaded.emplace(loaded.begin(), types);
1113         } else {
1114                 loaded.splice(loaded.begin(), free, free.begin());
1115                 loaded.front().Unlink();
1116         }
1117         chunk = &loaded.front();
1118         chunk->Position(pos);
1119         for (ChunkIndex &index : indices) {
1120                 if (index.InRange(pos)) {
1121                         index.Register(*chunk);
1122                 }
1123         }
1124         for (int i = 0; i < Block::FACE_COUNT; ++i) {
1125                 Block::Face face = Block::Face(i);
1126                 ExactLocation::Coarse neighbor_pos(pos + Block::FaceNormal(face));
1127                 Chunk *neighbor = Get(neighbor_pos);
1128                 if (neighbor) {
1129                         chunk->SetNeighbor(face, *neighbor);
1130                 }
1131         }
1132         return chunk;
1133 }
1134
1135 bool ChunkStore::HasMissing() const noexcept {
1136         for (const ChunkIndex &index : indices) {
1137                 if (index.MissingChunks() > 0) {
1138                         return true;
1139                 }
1140         }
1141         return false;
1142 }
1143
1144 int ChunkStore::EstimateMissing() const noexcept {
1145         int missing = 0;
1146         for (const ChunkIndex &index : indices) {
1147                 missing += index.MissingChunks();
1148         }
1149         return missing;
1150 }
1151
1152 ExactLocation::Coarse ChunkStore::NextMissing() noexcept {
1153         for (ChunkIndex &index : indices) {
1154                 if (index.MissingChunks()) {
1155                         return index.NextMissing();
1156                 }
1157         }
1158         return ExactLocation::Coarse(0, 0, 0);
1159 }
1160
1161 void ChunkStore::Clean() {
1162         for (auto i = loaded.begin(), end = loaded.end(); i != end;) {
1163                 if (i->Referenced() || i->ShouldUpdateSave()) {
1164                         ++i;
1165                 } else {
1166                         auto chunk = i;
1167                         ++i;
1168                         free.splice(free.end(), loaded, chunk);
1169                         chunk->Unlink();
1170                         chunk->InvalidateMesh();
1171                 }
1172         }
1173 }
1174
1175 }