src/chunk.cpp

   1 #include "chunk.hpp"
   2
   3 #include "generator.hpp"
   4
   5 #include <limits>
   6 #include <glm/gtx/transform.hpp>
   7
   8
   9 namespace {
  10
  11 blank::Model::Buffer buf;
  12
  13 }
  14
  15 namespace blank {
  16
  17 Chunk::Chunk(const BlockTypeRegistry &types)
  18 : types(&types)
  19 , neighbor{ 0, 0, 0, 0, 0, 0 }
  20 , blocks()
  21 , model()
  22 , position(0, 0, 0)
  23 , dirty(false) {
  24
  25 }
  26
  27 Chunk::Chunk(Chunk &&other)
  28 : types(other.types)
  29 , blocks(std::move(other.blocks))
  30 , model(std::move(other.model))
  31 , dirty(other.dirty) {
  32         for (size_t i = 0; i < Block::FACE_COUNT; ++i) {
  33                 neighbor[i] = other.neighbor[i];
  34         }
  35 }
  36
  37 Chunk &Chunk::operator =(Chunk &&other) {
  38         types = other.types;
  39         for (size_t i = 0; i < Block::FACE_COUNT; ++i) {
  40                 neighbor[i] = other.neighbor[i];
  41         }
  42         blocks = std::move(other.blocks);
  43         model = std::move(other.model);
  44         dirty = other.dirty;
  45         return *this;
  46 }
  47
  48
  49 void Chunk::SetNeighbor(Chunk &other) {
  50         if (other.position == position - Pos(-1, 0, 0)) {
  51                 neighbor[Block::FACE_LEFT] = &other;
  52                 other.neighbor[Block::FACE_RIGHT] = this;
  53         } else if (other.position == position - Pos(1, 0, 0)) {
  54                 neighbor[Block::FACE_RIGHT] = &other;
  55                 other.neighbor[Block::FACE_LEFT] = this;
  56         } else if (other.position == position - Pos(0, -1, 0)) {
  57                 neighbor[Block::FACE_DOWN] = &other;
  58                 other.neighbor[Block::FACE_UP] = this;
  59         } else if (other.position == position - Pos(0, 1, 0)) {
  60                 neighbor[Block::FACE_UP] = &other;
  61                 other.neighbor[Block::FACE_DOWN] = this;
  62         } else if (other.position == position - Pos(0, 0, -1)) {
  63                 neighbor[Block::FACE_BACK] = &other;
  64                 other.neighbor[Block::FACE_FRONT] = this;
  65         } else if (other.position == position - Pos(0, 0, 1)) {
  66                 neighbor[Block::FACE_FRONT] = &other;
  67                 other.neighbor[Block::FACE_BACK] = this;
  68         }
  69 }
  70
  71 void Chunk::ClearNeighbors() {
  72         for (int i = 0; i < Block::FACE_COUNT; ++i) {
  73                 neighbor[i] = nullptr;
  74         }
  75 }
  76
  77 void Chunk::Unlink() {
  78         if (neighbor[Block::FACE_UP]) {
  79                 neighbor[Block::FACE_UP]->neighbor[Block::FACE_DOWN] = nullptr;
  80         }
  81         if (neighbor[Block::FACE_DOWN]) {
  82                 neighbor[Block::FACE_DOWN]->neighbor[Block::FACE_UP] = nullptr;
  83         }
  84         if (neighbor[Block::FACE_LEFT]) {
  85                 neighbor[Block::FACE_LEFT]->neighbor[Block::FACE_RIGHT] = nullptr;
  86         }
  87         if (neighbor[Block::FACE_RIGHT]) {
  88                 neighbor[Block::FACE_RIGHT]->neighbor[Block::FACE_LEFT] = nullptr;
  89         }
  90         if (neighbor[Block::FACE_FRONT]) {
  91                 neighbor[Block::FACE_FRONT]->neighbor[Block::FACE_BACK] = nullptr;
  92         }
  93         if (neighbor[Block::FACE_BACK]) {
  94                 neighbor[Block::FACE_BACK]->neighbor[Block::FACE_FRONT] = nullptr;
  95         }
  96 }
  97
  98 void Chunk::Relink() {
  99         if (neighbor[Block::FACE_UP]) {
 100                 neighbor[Block::FACE_UP]->neighbor[Block::FACE_DOWN] = this;
 101         }
 102         if (neighbor[Block::FACE_DOWN]) {
 103                 neighbor[Block::FACE_DOWN]->neighbor[Block::FACE_UP] = this;
 104         }
 105         if (neighbor[Block::FACE_LEFT]) {
 106                 neighbor[Block::FACE_LEFT]->neighbor[Block::FACE_RIGHT] = this;
 107         }
 108         if (neighbor[Block::FACE_RIGHT]) {
 109                 neighbor[Block::FACE_RIGHT]->neighbor[Block::FACE_LEFT] = this;
 110         }
 111         if (neighbor[Block::FACE_FRONT]) {
 112                 neighbor[Block::FACE_FRONT]->neighbor[Block::FACE_BACK] = this;
 113         }
 114         if (neighbor[Block::FACE_BACK]) {
 115                 neighbor[Block::FACE_BACK]->neighbor[Block::FACE_FRONT] = this;
 116         }
 117 }
 118
 119
 120 void Chunk::Allocate() {
 121         blocks.resize(Size());
 122 }
 123
 124
 125 void Chunk::Draw() {
 126         if (dirty) {
 127                 Update();
 128         }
 129         model.Draw();
 130 }
 131
 132
 133 bool Chunk::Intersection(
 134         const Ray &ray,
 135         const glm::mat4 &M,
 136         int &blkid,
 137         float &dist,
 138         glm::vec3 &normal
 139 ) const {
 140         // TODO: should be possible to heavily optimize this
 141         int id = 0;
 142         blkid = -1;
 143         dist = std::numeric_limits<float>::infinity();
 144         for (int z = 0; z < Depth(); ++z) {
 145                 for (int y = 0; y < Height(); ++y) {
 146                         for (int x = 0; x < Width(); ++x, ++id) {
 147                                 if (!Type(blocks[id]).visible) {
 148                                         continue;
 149                                 }
 150                                 float cur_dist;
 151                                 glm::vec3 cur_norm;
 152                                 if (Type(blocks[id]).shape->Intersects(ray, M * ToTransform(id), cur_dist, cur_norm)) {
 153                                         if (cur_dist < dist) {
 154                                                 blkid = id;
 155                                                 dist = cur_dist;
 156                                                 normal = cur_norm;
 157                                         }
 158                                 }
 159                         }
 160                 }
 161         }
 162
 163         if (blkid < 0) {
 164                 return false;
 165         } else {
 166                 normal = glm::vec3(BlockAt(blkid).Transform() * glm::vec4(normal, 0.0f));
 167                 return true;
 168         }
 169 }
 170
 171 void Chunk::Position(const Pos &pos) {
 172         position = pos;
 173 }
 174
 175 glm::mat4 Chunk::Transform(const Pos &offset) const {
 176         return glm::translate((position - offset) * Extent());
 177 }
 178
 179
 180 void Chunk::CheckUpdate() {
 181         if (dirty) {
 182                 Update();
 183         }
 184 }
 185
 186 void Chunk::Update() {
 187         int vtx_count = 0, idx_count = 0;
 188         for (const auto &block : blocks) {
 189                 const Shape *shape = Type(block).shape;
 190                 vtx_count += shape->VertexCount();
 191                 idx_count += shape->VertexIndexCount();
 192         }
 193         buf.Clear();
 194         buf.Reserve(vtx_count, idx_count);
 195
 196         Model::Index vtx_counter = 0;
 197         for (size_t i = 0; i < Size(); ++i) {
 198                 const BlockType &type = Type(blocks[i]);
 199
 200                 if (!type.visible || Obstructed(i)) continue;
 201
 202                 type.FillModel(buf, ToTransform(i), vtx_counter);
 203                 vtx_counter += type.shape->VertexCount();
 204         }
 205
 206         model.Update(buf);
 207         dirty = false;
 208 }
 209
 210 bool Chunk::Obstructed(int idx) const {
 211         Chunk::Pos pos(ToPos(idx));
 212
 213         Chunk::Pos left_pos(pos + Chunk::Pos(-1, 0, 0));
 214         const Block *left_block = nullptr;
 215         if (InBounds(left_pos)) {
 216                 left_block = &BlockAt(left_pos);
 217         } else if (HasNeighbor(Block::FACE_LEFT)) {
 218                 left_pos += Chunk::Pos(Width(), 0, 0);
 219                 left_block = &GetNeighbor(Block::FACE_LEFT).BlockAt(left_pos);
 220         } else {
 221                 return false;
 222         }
 223         if (!Type(*left_block).FaceFilled(*left_block, Block::FACE_RIGHT)) {
 224                 return false;
 225         }
 226
 227         Chunk::Pos right_pos(pos + Chunk::Pos(1, 0, 0));
 228         const Block *right_block = nullptr;
 229         if (InBounds(right_pos)) {
 230                 right_block = &BlockAt(right_pos);
 231         } else if (HasNeighbor(Block::FACE_RIGHT)) {
 232                 right_pos += Chunk::Pos(-Width(), 0, 0);
 233                 right_block = &GetNeighbor(Block::FACE_RIGHT).BlockAt(right_pos);
 234         } else {
 235                 return false;
 236         }
 237         if (!Type(*right_block).FaceFilled(*right_block, Block::FACE_LEFT)) {
 238                 return false;
 239         }
 240
 241         Chunk::Pos down_pos(pos + Chunk::Pos(0, -1, 0));
 242         const Block *down_block = nullptr;
 243         if (InBounds(down_pos)) {
 244                 down_block = &BlockAt(down_pos);
 245         } else if (HasNeighbor(Block::FACE_DOWN)) {
 246                 down_pos += Chunk::Pos(0, Height(), 0);
 247                 down_block = &GetNeighbor(Block::FACE_DOWN).BlockAt(down_pos);
 248         } else {
 249                 return false;
 250         }
 251         if (!Type(*down_block).FaceFilled(*down_block, Block::FACE_UP)) {
 252                 return false;
 253         }
 254
 255         Chunk::Pos up_pos(pos + Chunk::Pos(0, 1, 0));
 256         const Block *up_block = nullptr;
 257         if (InBounds(up_pos)) {
 258                 up_block = &BlockAt(up_pos);
 259         } else if (HasNeighbor(Block::FACE_UP)) {
 260                 up_pos += Chunk::Pos(0, -Height(), 0);
 261                 up_block = &GetNeighbor(Block::FACE_UP).BlockAt(up_pos);
 262         } else {
 263                 return false;
 264         }
 265         if (!Type(*up_block).FaceFilled(*up_block, Block::FACE_DOWN)) {
 266                 return false;
 267         }
 268
 269         Chunk::Pos back_pos(pos + Chunk::Pos(0, 0, -1));
 270         const Block *back_block = nullptr;
 271         if (InBounds(back_pos)) {
 272                 back_block = &BlockAt(back_pos);
 273         } else if (HasNeighbor(Block::FACE_BACK)) {
 274                 back_pos += Chunk::Pos(0, 0, Depth());
 275                 back_block = &GetNeighbor(Block::FACE_BACK).BlockAt(back_pos);
 276         } else {
 277                 return false;
 278         }
 279         if (!Type(*back_block).FaceFilled(*back_block, Block::FACE_FRONT)) {
 280                 return false;
 281         }
 282
 283         Chunk::Pos front_pos(pos + Chunk::Pos(0, 0, 1));
 284         const Block *front_block = nullptr;
 285         if (InBounds(front_pos)) {
 286                 front_block = &BlockAt(front_pos);
 287         } else if (HasNeighbor(Block::FACE_FRONT)) {
 288                 front_pos += Chunk::Pos(0, 0, -Depth());
 289                 front_block = &GetNeighbor(Block::FACE_FRONT).BlockAt(front_pos);
 290         } else {
 291                 return false;
 292         }
 293         if (!Type(*front_block).FaceFilled(*front_block, Block::FACE_BACK)) {
 294                 return false;
 295         }
 296
 297         return true;
 298 }
 299
 300 glm::mat4 Chunk::ToTransform(int idx) const {
 301         return glm::translate(glm::mat4(1.0f), ToCoords(idx)) * blocks[idx].Transform();
 302 }
 303
 304
 305 ChunkLoader::ChunkLoader(const BlockTypeRegistry &reg, const Generator &gen)
 306 : base(0, 0, 0)
 307 , reg(reg)
 308 , gen(gen)
 309 , loaded()
 310 , to_generate()
 311 , to_free()
 312 , load_dist(4)
 313 , unload_dist(5) {
 314
 315 }
 316
 317 namespace {
 318
 319 struct ChunkLess {
 320
 321         explicit ChunkLess(const Chunk::Pos &base)
 322         : base(base) { }
 323
 324         bool operator ()(const Chunk::Pos &a, const Chunk::Pos &b) const {
 325                 Chunk::Pos da(base - a);
 326                 Chunk::Pos db(base - b);
 327                 return
 328                         da.x * da.x + da.y * da.y + da.z * da.z <
 329                         db.x * db.x + db.y * db.y + db.z * db.z;
 330         }
 331
 332         Chunk::Pos base;
 333
 334 };
 335
 336 }
 337
 338 void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
 339         for (int z = from.z; z < to.z; ++z) {
 340                 for (int y = from.y; y < to.y; ++y) {
 341                         for (int x = from.x; x < to.x; ++x) {
 342                                 Chunk::Pos pos(x, y, z);
 343                                 if (Known(pos)) {
 344                                         continue;
 345                                 } else if (pos == base) {
 346                                         Generate(pos);
 347
 348                                 //      orientation testing
 349                                 //      for (int i = 0; i < Block::FACE_COUNT; ++i) {
 350                                 //              for (int j = 0; j < Block::TURN_COUNT; ++j) {
 351                                 //                      loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
 352                                 //              }
 353                                 //      }
 354                                 //      loaded.back().Invalidate();
 355                                 //      loaded.back().CheckUpdate();
 356                                 } else {
 357                                         to_generate.emplace_back(pos);
 358                                 }
 359                         }
 360                 }
 361         }
 362         to_generate.sort(ChunkLess(base));
 363 }
 364
 365 Chunk &ChunkLoader::Generate(const Chunk::Pos &pos) {
 366         loaded.emplace_back(reg);
 367         Chunk &chunk = loaded.back();
 368         chunk.Position(pos);
 369         Insert(chunk);
 370         gen(chunk);
 371         return chunk;
 372 }
 373
 374 void ChunkLoader::Insert(Chunk &chunk) {
 375         for (Chunk &other : loaded) {
 376                 chunk.SetNeighbor(other);
 377         }
 378 }
 379
 380 void ChunkLoader::Remove(Chunk &chunk) {
 381         chunk.Unlink();
 382 }
 383
 384 Chunk *ChunkLoader::Loaded(const Chunk::Pos &pos) {
 385         for (Chunk &chunk : loaded) {
 386                 if (chunk.Position() == pos) {
 387                         return &chunk;
 388                 }
 389         }
 390         return nullptr;
 391 }
 392
 393 bool ChunkLoader::Queued(const Chunk::Pos &pos) {
 394         for (const Chunk::Pos &chunk : to_generate) {
 395                 if (chunk == pos) {
 396                         return true;
 397                 }
 398         }
 399         return nullptr;
 400 }
 401
 402 bool ChunkLoader::Known(const Chunk::Pos &pos) {
 403         if (Loaded(pos)) return true;
 404         return Queued(pos);
 405 }
 406
 407 Chunk &ChunkLoader::ForceLoad(const Chunk::Pos &pos) {
 408         Chunk *chunk = Loaded(pos);
 409         if (chunk) {
 410                 return *chunk;
 411         }
 412
 413         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end; ++iter) {
 414                 if (*iter == pos) {
 415                         to_generate.erase(iter);
 416                         break;
 417                 }
 418         }
 419
 420         return Generate(pos);
 421 }
 422
 423 void ChunkLoader::Rebase(const Chunk::Pos &new_base) {
 424         if (new_base == base) {
 425                 return;
 426         }
 427         base = new_base;
 428
 429         // unload far away chunks
 430         for (auto iter(loaded.begin()), end(loaded.end()); iter != end;) {
 431                 if (std::abs(base.x - iter->Position().x) > unload_dist
 432                                 || std::abs(base.y - iter->Position().y) > unload_dist
 433                                 || std::abs(base.z - iter->Position().z) > unload_dist) {
 434                         auto saved = iter;
 435                         Remove(*saved);
 436                         ++iter;
 437                         to_free.splice(to_free.end(), loaded, saved);
 438                 } else {
 439                         ++iter;
 440                 }
 441         }
 442         // abort far away queued chunks
 443         for (auto iter(to_generate.begin()), end(to_generate.end()); iter != end;) {
 444                 if (std::abs(base.x - iter->x) > unload_dist
 445                                 || std::abs(base.y - iter->y) > unload_dist
 446                                 || std::abs(base.z - iter->z) > unload_dist) {
 447                         iter = to_generate.erase(iter);
 448                 } else {
 449                         ++iter;
 450                 }
 451         }
 452         // add missing new chunks
 453         const Chunk::Pos offset(load_dist, load_dist, load_dist);
 454         Generate(base - offset, base + offset);
 455 }
 456
 457 void ChunkLoader::Update() {
 458         bool reused = false;
 459         if (!to_generate.empty()) {
 460                 Chunk::Pos pos(to_generate.front());
 461
 462                 for (auto iter(to_free.begin()), end(to_free.end()); iter != end; ++iter) {
 463                         if (iter->Position() == pos) {
 464                                 iter->Relink();
 465                                 loaded.splice(loaded.end(), to_free, iter);
 466                                 reused = true;
 467                                 break;
 468                         }
 469                 }
 470
 471                 if (!reused) {
 472                         if (to_free.empty()) {
 473                                 loaded.emplace_back(reg);
 474                         } else {
 475                                 to_free.front().ClearNeighbors();
 476                                 loaded.splice(loaded.end(), to_free, to_free.begin());
 477                                 reused = true;
 478                         }
 479                         Chunk &chunk = loaded.back();
 480                         chunk.Position(pos);
 481                         Insert(chunk);
 482                         gen(chunk);
 483                 }
 484                 to_generate.pop_front();
 485         }
 486
 487         if (!reused && !to_free.empty()) {
 488                 to_free.pop_front();
 489         }
 490 }
 491
 492 }