src/voxelalgorithms.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "voxelalgorithms.h"
  21 #include "nodedef.h"
  22 #include "mapblock.h"
  23 #include "map.h"
  24
  25 namespace voxalgo
  26 {
  27
  28 /*!
  29  * A direction.
  30  * 0=X+
  31  * 1=Y+
  32  * 2=Z+
  33  * 3=Z-
  34  * 4=Y-
  35  * 5=X-
  36  * 6=no direction
  37  * Two directions are opposite only if their sum is 5.
  38  */
  39 typedef u8 direction;
  40 /*!
  41  * Relative node position.
  42  * This represents a node's position in its map block.
  43  * All coordinates must be between 0 and 15.
  44  */
  45 typedef v3s16 relative_v3;
  46 /*!
  47  * Position of a map block (block coordinates).
  48  * One block_pos unit is as long as 16 node position units.
  49  */
  50 typedef v3s16 mapblock_v3;
  51
  52 //! Contains information about a node whose light is about to change.
  53 struct ChangingLight {
  54         //! Relative position of the node in its map block.
  55         relative_v3 rel_position;
  56         //! Position of the node's block.
  57         mapblock_v3 block_position;
  58         //! Pointer to the node's block.
  59         MapBlock *block = NULL;
  60         /*!
  61          * Direction from the node that caused this node's changing
  62          * to this node.
  63          */
  64         direction source_direction = 6;
  65
  66         ChangingLight() = default;
  67
  68         ChangingLight(relative_v3 rel_pos, mapblock_v3 block_pos,
  69                 MapBlock *b, direction source_dir) :
  70                 rel_position(rel_pos),
  71                 block_position(block_pos),
  72                 block(b),
  73                 source_direction(source_dir)
  74         {}
  75 };
  76
  77 /*!
  78  * A fast, priority queue-like container to contain ChangingLights.
  79  * The ChangingLights are ordered by the given light levels.
  80  * The brightest ChangingLight is returned first.
  81  */
  82 struct LightQueue {
  83         //! For each light level there is a vector.
  84         std::vector<ChangingLight> lights[LIGHT_SUN + 1];
  85         //! Light of the brightest ChangingLight in the queue.
  86         u8 max_light;
  87
  88         /*!
  89          * Creates a LightQueue.
  90          * \param reserve for each light level that many slots are reserved.
  91          */
  92         LightQueue(size_t reserve)
  93         {
  94                 max_light = LIGHT_SUN;
  95                 for (u8 i = 0; i <= LIGHT_SUN; i++) {
  96                         lights[i].reserve(reserve);
  97                 }
  98         }
  99
 100         /*!
 101          * Returns the next brightest ChangingLight and
 102          * removes it from the queue.
 103          * If there were no elements in the queue, the given parameters
 104          * remain unmodified.
 105          * \param light light level of the popped ChangingLight
 106          * \param data the ChangingLight that was popped
 107          * \returns true if there was a ChangingLight in the queue.
 108          */
 109         bool next(u8 &light, ChangingLight &data)
 110         {
 111                 while (lights[max_light].empty()) {
 112                         if (max_light == 0) {
 113                                 return false;
 114                         }
 115                         max_light--;
 116                 }
 117                 light = max_light;
 118                 data = lights[max_light].back();
 119                 lights[max_light].pop_back();
 120                 return true;
 121         }
 122
 123         /*!
 124          * Adds an element to the queue.
 125          * The parameters are the same as in ChangingLight's constructor.
 126          * \param light light level of the ChangingLight
 127          */
 128         inline void push(u8 light, relative_v3 rel_pos,
 129                 mapblock_v3 block_pos, MapBlock *block,
 130                 direction source_dir)
 131         {
 132                 assert(light <= LIGHT_SUN);
 133                 lights[light].emplace_back(rel_pos, block_pos, block, source_dir);
 134         }
 135 };
 136
 137 /*!
 138  * This type of light queue is for unlighting.
 139  * A node can be pushed in it only if its raw light is zero.
 140  * This prevents pushing nodes twice into this queue.
 141  * The light of the pushed ChangingLight must be the
 142  * light of the node before unlighting it.
 143  */
 144 typedef LightQueue UnlightQueue;
 145 /*!
 146  * This type of light queue is for spreading lights.
 147  * While spreading lights, all the nodes in it must
 148  * have the same light as the light level the ChangingLights
 149  * were pushed into this queue with. This prevents unnecessary
 150  * re-pushing of the nodes into the queue.
 151  * If a node doesn't let light trough but emits light, it can be added
 152  * too.
 153  */
 154 typedef LightQueue ReLightQueue;
 155
 156 /*!
 157  * neighbor_dirs[i] points towards
 158  * the direction i.
 159  * See the definition of the type "direction"
 160  */
 161 const static v3s16 neighbor_dirs[6] = {
 162         v3s16(1, 0, 0), // right
 163         v3s16(0, 1, 0), // top
 164         v3s16(0, 0, 1), // back
 165         v3s16(0, 0, -1), // front
 166         v3s16(0, -1, 0), // bottom
 167         v3s16(-1, 0, 0), // left
 168 };
 169
 170 /*!
 171  * Transforms the given map block offset by one node towards
 172  * the specified direction.
 173  * \param dir the direction of the transformation
 174  * \param rel_pos the node's relative position in its map block
 175  * \param block_pos position of the node's block
 176  */
 177 bool step_rel_block_pos(direction dir, relative_v3 &rel_pos,
 178         mapblock_v3 &block_pos)
 179 {
 180         switch (dir) {
 181         case 0:
 182                 if (rel_pos.X < MAP_BLOCKSIZE - 1) {
 183                         rel_pos.X++;
 184                 } else {
 185                         rel_pos.X = 0;
 186                         block_pos.X++;
 187                         return true;
 188                 }
 189                 break;
 190         case 1:
 191                 if (rel_pos.Y < MAP_BLOCKSIZE - 1) {
 192                         rel_pos.Y++;
 193                 } else {
 194                         rel_pos.Y = 0;
 195                         block_pos.Y++;
 196                         return true;
 197                 }
 198                 break;
 199         case 2:
 200                 if (rel_pos.Z < MAP_BLOCKSIZE - 1) {
 201                         rel_pos.Z++;
 202                 } else {
 203                         rel_pos.Z = 0;
 204                         block_pos.Z++;
 205                         return true;
 206                 }
 207                 break;
 208         case 3:
 209                 if (rel_pos.Z > 0) {
 210                         rel_pos.Z--;
 211                 } else {
 212                         rel_pos.Z = MAP_BLOCKSIZE - 1;
 213                         block_pos.Z--;
 214                         return true;
 215                 }
 216                 break;
 217         case 4:
 218                 if (rel_pos.Y > 0) {
 219                         rel_pos.Y--;
 220                 } else {
 221                         rel_pos.Y = MAP_BLOCKSIZE - 1;
 222                         block_pos.Y--;
 223                         return true;
 224                 }
 225                 break;
 226         case 5:
 227                 if (rel_pos.X > 0) {
 228                         rel_pos.X--;
 229                 } else {
 230                         rel_pos.X = MAP_BLOCKSIZE - 1;
 231                         block_pos.X--;
 232                         return true;
 233                 }
 234                 break;
 235         }
 236         return false;
 237 }
 238
 239 /*
 240  * Removes all light that is potentially emitted by the specified
 241  * light sources. These nodes will have zero light.
 242  * Returns all nodes whose light became zero but should be re-lighted.
 243  *
 244  * \param bank the light bank in which the procedure operates
 245  * \param from_nodes nodes whose light is removed
 246  * \param light_sources nodes that should be re-lighted
 247  * \param modified_blocks output, all modified map blocks are added to this
 248  */
 249 void unspread_light(Map *map, const NodeDefManager *nodemgr, LightBank bank,
 250         UnlightQueue &from_nodes, ReLightQueue &light_sources,
 251         std::map<v3s16, MapBlock*> &modified_blocks)
 252 {
 253         // Stores data popped from from_nodes
 254         u8 current_light;
 255         ChangingLight current;
 256         // Data of the current neighbor
 257         mapblock_v3 neighbor_block_pos;
 258         relative_v3 neighbor_rel_pos;
 259         // Direction of the brightest neighbor of the node
 260         direction source_dir;
 261         while (from_nodes.next(current_light, current)) {
 262                 // For all nodes that need unlighting
 263
 264                 // There is no brightest neighbor
 265                 source_dir = 6;
 266                 // The current node
 267                 const MapNode &node = current.block->getNodeNoCheck(current.rel_position);
 268                 ContentLightingFlags f = nodemgr->getLightingFlags(node);
 269                 // If the node emits light, it behaves like it had a
 270                 // brighter neighbor.
 271                 u8 brightest_neighbor_light = f.light_source + 1;
 272                 for (direction i = 0; i < 6; i++) {
 273                         //For each neighbor
 274
 275                         // The node that changed this node has already zero light
 276                         // and it can't give light to this node
 277                         if (current.source_direction + i == 5) {
 278                                 continue;
 279                         }
 280                         // Get the neighbor's position and block
 281                         neighbor_rel_pos = current.rel_position;
 282                         neighbor_block_pos = current.block_position;
 283                         MapBlock *neighbor_block;
 284                         if (step_rel_block_pos(i, neighbor_rel_pos, neighbor_block_pos)) {
 285                                 neighbor_block = map->getBlockNoCreateNoEx(neighbor_block_pos);
 286                                 if (neighbor_block == NULL) {
 287                                         current.block->setLightingComplete(bank, i, false);
 288                                         continue;
 289                                 }
 290                         } else {
 291                                 neighbor_block = current.block;
 292                         }
 293                         // Get the neighbor itself
 294                         MapNode neighbor = neighbor_block->getNodeNoCheck(neighbor_rel_pos);
 295                         ContentLightingFlags neighbor_f = nodemgr->getLightingFlags(
 296                                 neighbor.getContent());
 297                         u8 neighbor_light = neighbor.getLightRaw(bank, neighbor_f);
 298                         // If the neighbor has at least as much light as this node, then
 299                         // it won't lose its light, since it should have been added to
 300                         // from_nodes earlier, so its light would be zero.
 301                         if (neighbor_f.light_propagates && neighbor_light < current_light) {
 302                                 // Unlight, but only if the node has light.
 303                                 if (neighbor_light > 0) {
 304                                         neighbor.setLight(bank, 0, neighbor_f);
 305                                         neighbor_block->setNodeNoCheck(neighbor_rel_pos, neighbor);
 306                                         from_nodes.push(neighbor_light, neighbor_rel_pos,
 307                                                 neighbor_block_pos, neighbor_block, i);
 308                                         // The current node was modified earlier, so its block
 309                                         // is in modified_blocks.
 310                                         if (current.block != neighbor_block) {
 311                                                 modified_blocks[neighbor_block_pos] = neighbor_block;
 312                                         }
 313                                 }
 314                         } else {
 315                                 // The neighbor can light up this node.
 316                                 if (neighbor_light < neighbor_f.light_source) {
 317                                         neighbor_light = neighbor_f.light_source;
 318                                 }
 319                                 if (brightest_neighbor_light < neighbor_light) {
 320                                         brightest_neighbor_light = neighbor_light;
 321                                         source_dir = i;
 322                                 }
 323                         }
 324                 }
 325                 // If the brightest neighbor is able to light up this node,
 326                 // then add this node to the output nodes.
 327                 if (brightest_neighbor_light > 1 && f.light_propagates) {
 328                         brightest_neighbor_light--;
 329                         light_sources.push(brightest_neighbor_light, current.rel_position,
 330                                 current.block_position, current.block,
 331                                 (source_dir == 6) ? 6 : 5 - source_dir
 332                                 /* with opposite direction*/);
 333                 }
 334         }
 335 }
 336
 337 /*
 338  * Spreads light from the specified starting nodes.
 339  *
 340  * Before calling this procedure, make sure that all ChangingLights
 341  * in light_sources have as much light on the map as they have in
 342  * light_sources (if the queue contains a node multiple times, the brightest
 343  * occurrence counts).
 344  *
 345  * \param bank the light bank in which the procedure operates
 346  * \param light_sources starting nodes
 347  * \param modified_blocks output, all modified map blocks are added to this
 348  */
 349 void spread_light(Map *map, const NodeDefManager *nodemgr, LightBank bank,
 350         LightQueue &light_sources,
 351         std::map<v3s16, MapBlock*> &modified_blocks)
 352 {
 353         // The light the current node can provide to its neighbors.
 354         u8 spreading_light;
 355         // The ChangingLight for the current node.
 356         ChangingLight current;
 357         // Position of the current neighbor.
 358         mapblock_v3 neighbor_block_pos;
 359         relative_v3 neighbor_rel_pos;
 360         while (light_sources.next(spreading_light, current)) {
 361                 spreading_light--;
 362                 for (direction i = 0; i < 6; i++) {
 363                         // This node can't light up its light source
 364                         if (current.source_direction + i == 5) {
 365                                 continue;
 366                         }
 367                         // Get the neighbor's position and block
 368                         neighbor_rel_pos = current.rel_position;
 369                         neighbor_block_pos = current.block_position;
 370                         MapBlock *neighbor_block;
 371                         if (step_rel_block_pos(i, neighbor_rel_pos, neighbor_block_pos)) {
 372                                 neighbor_block = map->getBlockNoCreateNoEx(neighbor_block_pos);
 373                                 if (neighbor_block == NULL) {
 374                                         current.block->setLightingComplete(bank, i, false);
 375                                         continue;
 376                                 }
 377                         } else {
 378                                 neighbor_block = current.block;
 379                         }
 380                         // Get the neighbor itself
 381                         MapNode neighbor = neighbor_block->getNodeNoCheck(neighbor_rel_pos);
 382                         ContentLightingFlags f = nodemgr->getLightingFlags(neighbor);
 383                         if (f.light_propagates) {
 384                                 // Light up the neighbor, if it has less light than it should.
 385                                 u8 neighbor_light = neighbor.getLightRaw(bank, f);
 386                                 if (neighbor_light < spreading_light) {
 387                                         neighbor.setLight(bank, spreading_light, f);
 388                                         neighbor_block->setNodeNoCheck(neighbor_rel_pos, neighbor);
 389                                         light_sources.push(spreading_light, neighbor_rel_pos,
 390                                                 neighbor_block_pos, neighbor_block, i);
 391                                         // The current node was modified earlier, so its block
 392                                         // is in modified_blocks.
 393                                         if (current.block != neighbor_block) {
 394                                                 modified_blocks[neighbor_block_pos] = neighbor_block;
 395                                         }
 396                                 }
 397                         }
 398                 }
 399         }
 400 }
 401
 402 struct SunlightPropagationUnit{
 403         v2s16 relative_pos;
 404         bool is_sunlit;
 405
 406         SunlightPropagationUnit(v2s16 relpos, bool sunlit):
 407                 relative_pos(relpos),
 408                 is_sunlit(sunlit)
 409         {}
 410 };
 411
 412 struct SunlightPropagationData{
 413         std::vector<SunlightPropagationUnit> data;
 414         v3s16 target_block;
 415 };
 416
 417 /*!
 418  * Returns true if the node gets sunlight from the
 419  * node above it.
 420  *
 421  * \param pos position of the node.
 422  */
 423 bool is_sunlight_above(Map *map, v3s16 pos, const NodeDefManager *ndef)
 424 {
 425         bool sunlight = true;
 426         mapblock_v3 source_block_pos;
 427         relative_v3 source_rel_pos;
 428         getNodeBlockPosWithOffset(pos + v3s16(0, 1, 0), source_block_pos,
 429                 source_rel_pos);
 430         // If the node above has sunlight, this node also can get it.
 431         MapBlock *source_block = map->getBlockNoCreateNoEx(source_block_pos);
 432         if (source_block == NULL) {
 433                 // But if there is no node above, then use heuristics
 434                 MapBlock *node_block = map->getBlockNoCreateNoEx(getNodeBlockPos(pos));
 435                 if (node_block == NULL) {
 436                         sunlight = false;
 437                 } else {
 438                         sunlight = !node_block->getIsUnderground();
 439                 }
 440         } else {
 441                 MapNode above = source_block->getNodeNoCheck(source_rel_pos);
 442                 if (above.getContent() == CONTENT_IGNORE) {
 443                         // Trust heuristics
 444                         if (source_block->getIsUnderground()) {
 445                                 sunlight = false;
 446                         }
 447                 } else {
 448                         ContentLightingFlags above_f = ndef->getLightingFlags(above);
 449                         if (above.getLight(LIGHTBANK_DAY, above_f) != LIGHT_SUN) {
 450                                 // If the node above doesn't have sunlight, this
 451                                 // node is in shadow.
 452                                 sunlight = false;
 453                         }
 454                 }
 455         }
 456         return sunlight;
 457 }
 458
 459 static const LightBank banks[] = { LIGHTBANK_DAY, LIGHTBANK_NIGHT };
 460
 461 void update_lighting_nodes(Map *map,
 462         const std::vector<std::pair<v3s16, MapNode>> &oldnodes,
 463         std::map<v3s16, MapBlock*> &modified_blocks)
 464 {
 465         const NodeDefManager *ndef = map->getNodeDefManager();
 466         // For node getter functions
 467         bool is_valid_position;
 468
 469         // Process each light bank separately
 470         for (LightBank bank : banks) {
 471                 UnlightQueue disappearing_lights(256);
 472                 ReLightQueue light_sources(256);
 473                 // Nodes that are brighter than the brightest modified node was
 474                 // won't change, since they didn't get their light from a
 475                 // modified node.
 476                 u8 min_safe_light = 0;
 477                 for (auto it = oldnodes.cbegin(); it < oldnodes.cend(); ++it) {
 478                         u8 old_light = it->second.getLight(bank, ndef->getLightingFlags(it->second));
 479                         if (old_light > min_safe_light) {
 480                                 min_safe_light = old_light;
 481                         }
 482                 }
 483                 // If only one node changed, even nodes with the same brightness
 484                 // didn't get their light from the changed node.
 485                 if (oldnodes.size() > 1) {
 486                         min_safe_light++;
 487                 }
 488                 // For each changed node process sunlight and initialize
 489                 for (auto it = oldnodes.cbegin(); it < oldnodes.cend(); ++it) {
 490                         // Get position and block of the changed node
 491                         v3s16 p = it->first;
 492                         relative_v3 rel_pos;
 493                         mapblock_v3 block_pos;
 494                         getNodeBlockPosWithOffset(p, block_pos, rel_pos);
 495                         MapBlock *block = map->getBlockNoCreateNoEx(block_pos);
 496                         if (block == NULL) {
 497                                 continue;
 498                         }
 499                         // Get the new node
 500                         MapNode n = block->getNodeNoCheck(rel_pos);
 501
 502                         // Light of the old node
 503                         u8 old_light = it->second.getLight(bank, ndef->getLightingFlags(it->second));
 504
 505                         // Add the block of the added node to modified_blocks
 506                         modified_blocks[block_pos] = block;
 507
 508                         // Get new light level of the node
 509                         u8 new_light = 0;
 510                         ContentLightingFlags f = ndef->getLightingFlags(n);
 511                         if (f.light_propagates) {
 512                                 if (bank == LIGHTBANK_DAY && f.sunlight_propagates
 513                                         && is_sunlight_above(map, p, ndef)) {
 514                                         new_light = LIGHT_SUN;
 515                                 } else {
 516                                         new_light = f.light_source;
 517                                         for (const v3s16 &neighbor_dir : neighbor_dirs) {
 518                                                 v3s16 p2 = p + neighbor_dir;
 519                                                 MapNode n2 = map->getNode(p2, &is_valid_position);
 520                                                 if (is_valid_position) {
 521                                                         u8 spread = n2.getLight(bank, ndef->getLightingFlags(n2));
 522                                                         // If it is sure that the neighbor won't be
 523                                                         // unlighted, its light can spread to this node.
 524                                                         if (spread > new_light && spread >= min_safe_light) {
 525                                                                 new_light = spread - 1;
 526                                                         }
 527                                                 }
 528                                         }
 529                                 }
 530                         } else {
 531                                 // If this is an opaque node, it still can emit light.
 532                                 new_light = f.light_source;
 533                         }
 534
 535                         if (new_light > 0) {
 536                                 light_sources.push(new_light, rel_pos, block_pos, block, 6);
 537                         }
 538
 539                         if (new_light < old_light) {
 540                                 // The node became opaque or doesn't provide as much
 541                                 // light as the previous one, so it must be unlighted.
 542
 543                                 // Add to unlight queue
 544                                 n.setLight(bank, 0, f);
 545                                 block->setNodeNoCheck(rel_pos, n);
 546                                 disappearing_lights.push(old_light, rel_pos, block_pos, block,
 547                                         6);
 548
 549                                 // Remove sunlight, if there was any
 550                                 if (bank == LIGHTBANK_DAY && old_light == LIGHT_SUN) {
 551                                         for (s16 y = p.Y - 1;; y--) {
 552                                                 v3s16 n2pos(p.X, y, p.Z);
 553
 554                                                 MapNode n2;
 555
 556                                                 n2 = map->getNode(n2pos, &is_valid_position);
 557                                                 if (!is_valid_position)
 558                                                         break;
 559
 560                                                 // If this node doesn't have sunlight, the nodes below
 561                                                 // it don't have too.
 562                                                 ContentLightingFlags f2 = ndef->getLightingFlags(n2);
 563                                                 if (n2.getLight(LIGHTBANK_DAY, f2) != LIGHT_SUN) {
 564                                                         break;
 565                                                 }
 566                                                 // Remove sunlight and add to unlight queue.
 567                                                 n2.setLight(LIGHTBANK_DAY, 0, f2);
 568                                                 map->setNode(n2pos, n2);
 569                                                 relative_v3 rel_pos2;
 570                                                 mapblock_v3 block_pos2;
 571                                                 getNodeBlockPosWithOffset(n2pos, block_pos2, rel_pos2);
 572                                                 MapBlock *block2 = map->getBlockNoCreateNoEx(
 573                                                         block_pos2);
 574                                                 disappearing_lights.push(LIGHT_SUN, rel_pos2,
 575                                                         block_pos2, block2,
 576                                                         4 /* The node above caused the change */);
 577                                         }
 578                                 }
 579                         } else if (new_light > old_light) {
 580                                 // It is sure that the node provides more light than the previous
 581                                 // one, unlighting is not necessary.
 582                                 // Propagate sunlight
 583                                 if (bank == LIGHTBANK_DAY && new_light == LIGHT_SUN) {
 584                                         for (s16 y = p.Y - 1;; y--) {
 585                                                 v3s16 n2pos(p.X, y, p.Z);
 586
 587                                                 MapNode n2;
 588
 589                                                 n2 = map->getNode(n2pos, &is_valid_position);
 590                                                 if (!is_valid_position)
 591                                                         break;
 592
 593                                                 // This should not happen, but if the node has sunlight
 594                                                 // then the iteration should stop.
 595                                                 ContentLightingFlags f2 = ndef->getLightingFlags(n2);
 596                                                 if (n2.getLight(LIGHTBANK_DAY, f2) == LIGHT_SUN) {
 597                                                         break;
 598                                                 }
 599                                                 // If the node terminates sunlight, stop.
 600                                                 if (!f2.sunlight_propagates) {
 601                                                         break;
 602                                                 }
 603                                                 relative_v3 rel_pos2;
 604                                                 mapblock_v3 block_pos2;
 605                                                 getNodeBlockPosWithOffset(n2pos, block_pos2, rel_pos2);
 606                                                 MapBlock *block2 = map->getBlockNoCreateNoEx(
 607                                                         block_pos2);
 608                                                 // Mark node for lighting.
 609                                                 light_sources.push(LIGHT_SUN, rel_pos2, block_pos2,
 610                                                         block2, 4);
 611                                         }
 612                                 }
 613                         }
 614
 615                 }
 616                 // Remove lights
 617                 unspread_light(map, ndef, bank, disappearing_lights, light_sources,
 618                         modified_blocks);
 619                 // Initialize light values for light spreading.
 620                 for (u8 i = 0; i <= LIGHT_SUN; i++) {
 621                         const std::vector<ChangingLight> &lights = light_sources.lights[i];
 622                         for (std::vector<ChangingLight>::const_iterator it = lights.begin();
 623                                         it < lights.end(); ++it) {
 624                                 MapNode n = it->block->getNodeNoCheck(it->rel_position);
 625                                 n.setLight(bank, i, ndef->getLightingFlags(n));
 626                                 it->block->setNodeNoCheck(it->rel_position, n);
 627                         }
 628                 }
 629                 // Spread lights.
 630                 spread_light(map, ndef, bank, light_sources, modified_blocks);
 631         }
 632 }
 633
 634 /*!
 635  * Borders of a map block in relative node coordinates.
 636  * Compatible with type 'direction'.
 637  */
 638 const VoxelArea block_borders[] = {
 639         VoxelArea(v3s16(15, 0, 0), v3s16(15, 15, 15)), //X+
 640         VoxelArea(v3s16(0, 15, 0), v3s16(15, 15, 15)), //Y+
 641         VoxelArea(v3s16(0, 0, 15), v3s16(15, 15, 15)), //Z+
 642         VoxelArea(v3s16(0, 0, 0), v3s16(15, 15, 0)),   //Z-
 643         VoxelArea(v3s16(0, 0, 0), v3s16(15, 0, 15)),   //Y-
 644         VoxelArea(v3s16(0, 0, 0), v3s16(0, 15, 15))    //X-
 645 };
 646
 647 /*!
 648  * Returns true if:
 649  * -the node has unloaded neighbors
 650  * -the node doesn't have light
 651  * -the node's light is the same as the maximum of
 652  * its light source and its brightest neighbor minus one.
 653  * .
 654  */
 655 bool is_light_locally_correct(Map *map, const NodeDefManager *ndef,
 656         LightBank bank, v3s16 pos)
 657 {
 658         bool is_valid_position;
 659         MapNode n = map->getNode(pos, &is_valid_position);
 660         ContentLightingFlags f = ndef->getLightingFlags(n);
 661         if (!f.has_light) {
 662                 return true;
 663         }
 664         u8 light = n.getLight(bank, f);
 665         assert(f.light_source <= LIGHT_MAX);
 666         u8 brightest_neighbor = f.light_source + 1;
 667         for (const v3s16 &neighbor_dir : neighbor_dirs) {
 668                 MapNode n2 = map->getNode(pos + neighbor_dir,
 669                         &is_valid_position);
 670                 u8 light2 = n2.getLight(bank, ndef->getLightingFlags(n2));
 671                 if (brightest_neighbor < light2) {
 672                         brightest_neighbor = light2;
 673                 }
 674         }
 675         assert(light <= LIGHT_SUN);
 676         return brightest_neighbor == light + 1;
 677 }
 678
 679 void update_block_border_lighting(Map *map, MapBlock *block,
 680         std::map<v3s16, MapBlock*> &modified_blocks)
 681 {
 682         const NodeDefManager *ndef = map->getNodeDefManager();
 683         for (LightBank bank : banks) {
 684                 // Since invalid light is not common, do not allocate
 685                 // memory if not needed.
 686                 UnlightQueue disappearing_lights(0);
 687                 ReLightQueue light_sources(0);
 688                 // Get incorrect lights
 689                 for (direction d = 0; d < 6; d++) {
 690                         // For each direction
 691                         // Get neighbor block
 692                         v3s16 otherpos = block->getPos() + neighbor_dirs[d];
 693                         MapBlock *other = map->getBlockNoCreateNoEx(otherpos);
 694                         if (other == NULL) {
 695                                 continue;
 696                         }
 697                         // Only update if lighting was not completed.
 698                         if (block->isLightingComplete(bank, d) &&
 699                                         other->isLightingComplete(bank, 5 - d))
 700                                 continue;
 701                         // Reset flags
 702                         block->setLightingComplete(bank, d, true);
 703                         other->setLightingComplete(bank, 5 - d, true);
 704                         // The two blocks and their connecting surfaces
 705                         MapBlock *blocks[] = {block, other};
 706                         VoxelArea areas[] = {block_borders[d], block_borders[5 - d]};
 707                         // For both blocks
 708                         for (u8 blocknum = 0; blocknum < 2; blocknum++) {
 709                                 MapBlock *b = blocks[blocknum];
 710                                 VoxelArea a = areas[blocknum];
 711                                 // For all nodes
 712                                 for (s32 x = a.MinEdge.X; x <= a.MaxEdge.X; x++)
 713                                 for (s32 z = a.MinEdge.Z; z <= a.MaxEdge.Z; z++)
 714                                 for (s32 y = a.MinEdge.Y; y <= a.MaxEdge.Y; y++) {
 715                                         MapNode n = b->getNodeNoCheck(x, y, z);
 716                                         ContentLightingFlags f = ndef->getLightingFlags(n);
 717                                         u8 light = n.getLight(bank, f);
 718                                         // Sunlight is fixed
 719                                         if (light < LIGHT_SUN) {
 720                                                 // Unlight if not correct
 721                                                 if (!is_light_locally_correct(map, ndef, bank,
 722                                                                 v3s16(x, y, z) + b->getPosRelative())) {
 723                                                         // Initialize for unlighting
 724                                                         n.setLight(bank, 0, ndef->getLightingFlags(n));
 725                                                         b->setNodeNoCheck(x, y, z, n);
 726                                                         modified_blocks[b->getPos()]=b;
 727                                                         disappearing_lights.push(light,
 728                                                                 relative_v3(x, y, z), b->getPos(), b,
 729                                                                 6);
 730                                                 }
 731                                         }
 732                                 }
 733                         }
 734                 }
 735                 // Remove lights
 736                 unspread_light(map, ndef, bank, disappearing_lights, light_sources,
 737                         modified_blocks);
 738                 // Initialize light values for light spreading.
 739                 for (u8 i = 0; i <= LIGHT_SUN; i++) {
 740                         const std::vector<ChangingLight> &lights = light_sources.lights[i];
 741                         for (std::vector<ChangingLight>::const_iterator it = lights.begin();
 742                                         it < lights.end(); ++it) {
 743                                 MapNode n = it->block->getNodeNoCheck(it->rel_position);
 744                                 n.setLight(bank, i, ndef->getLightingFlags(n));
 745                                 it->block->setNodeNoCheck(it->rel_position, n);
 746                         }
 747                 }
 748                 // Spread lights.
 749                 spread_light(map, ndef, bank, light_sources, modified_blocks);
 750         }
 751 }
 752
 753 /*!
 754  * Resets the lighting of the given VoxelManipulator to
 755  * complete darkness and full sunlight.
 756  * Operates in one map sector.
 757  *
 758  * \param offset contains the least x and z node coordinates
 759  * of the map sector.
 760  * \param light incoming sunlight, light[x][z] is true if there
 761  * is sunlight above the voxel manipulator at the given x-z coordinates.
 762  * The array's indices are relative node coordinates in the sector.
 763  * After the procedure returns, this contains outgoing light at
 764  * the bottom of the voxel manipulator.
 765  */
 766 void fill_with_sunlight(MMVManip *vm, const NodeDefManager *ndef, v2s16 offset,
 767         bool light[MAP_BLOCKSIZE][MAP_BLOCKSIZE])
 768 {
 769         // Distance in array between two nodes on top of each other.
 770         s16 ystride = vm->m_area.getExtent().X;
 771         // Cache the ignore node.
 772         MapNode ignore = MapNode(CONTENT_IGNORE);
 773         // For each column of nodes:
 774         for (s16 z = 0; z < MAP_BLOCKSIZE; z++)
 775         for (s16 x = 0; x < MAP_BLOCKSIZE; x++) {
 776                 // Position of the column on the map.
 777                 v2s16 realpos = offset + v2s16(x, z);
 778                 // Array indices in the voxel manipulator
 779                 s32 maxindex = vm->m_area.index(realpos.X, vm->m_area.MaxEdge.Y,
 780                         realpos.Y);
 781                 s32 minindex = vm->m_area.index(realpos.X, vm->m_area.MinEdge.Y,
 782                         realpos.Y);
 783                 // True if the current node has sunlight.
 784                 bool lig = light[z][x];
 785                 // For each node, downwards:
 786                 for (s32 i = maxindex; i >= minindex; i -= ystride) {
 787                         MapNode *n;
 788                         if (vm->m_flags[i] & VOXELFLAG_NO_DATA)
 789                                 n = &ignore;
 790                         else
 791                                 n = &vm->m_data[i];
 792                         // Ignore IGNORE nodes, these are not generated yet.
 793                         if(n->getContent() == CONTENT_IGNORE)
 794                                 continue;
 795                         ContentLightingFlags f = ndef->getLightingFlags(*n);
 796                         if (lig && !f.sunlight_propagates)
 797                                 // Sunlight is stopped.
 798                                 lig = false;
 799                         // Reset light
 800                         n->setLight(LIGHTBANK_DAY, lig ? 15 : 0, f);
 801                         n->setLight(LIGHTBANK_NIGHT, 0, f);
 802                 }
 803                 // Output outgoing light.
 804                 light[z][x] = lig;
 805         }
 806 }
 807
 808 /*!
 809  * Returns incoming sunlight for one map block.
 810  * If block above is not found, it is loaded.
 811  *
 812  * \param pos position of the map block that gets the sunlight.
 813  * \param light incoming sunlight, light[z][x] is true if there
 814  * is sunlight above the block at the given z-x relative
 815  * node coordinates.
 816  */
 817 void is_sunlight_above_block(Map *map, mapblock_v3 pos,
 818         const NodeDefManager *ndef, bool light[MAP_BLOCKSIZE][MAP_BLOCKSIZE])
 819 {
 820         mapblock_v3 source_block_pos = pos + v3s16(0, 1, 0);
 821         // Get or load source block.
 822         // It might take a while to load, but correcting incorrect
 823         // sunlight may be even slower.
 824         MapBlock *source_block = map->emergeBlock(source_block_pos, false);
 825         // Trust only generated blocks.
 826         if (source_block == NULL || !source_block->isGenerated()) {
 827                 // But if there is no block above, then use heuristics
 828                 bool sunlight = true;
 829                 MapBlock *node_block = map->getBlockNoCreateNoEx(pos);
 830                 if (node_block == NULL)
 831                         // This should not happen.
 832                         sunlight = false;
 833                 else
 834                         sunlight = !node_block->getIsUnderground();
 835                 for (s16 z = 0; z < MAP_BLOCKSIZE; z++)
 836                 for (s16 x = 0; x < MAP_BLOCKSIZE; x++)
 837                         light[z][x] = sunlight;
 838         } else {
 839                 // For each column:
 840                 for (s16 z = 0; z < MAP_BLOCKSIZE; z++)
 841                 for (s16 x = 0; x < MAP_BLOCKSIZE; x++) {
 842                         // Get the bottom block.
 843                         MapNode above = source_block->getNodeNoCheck(x, 0, z);
 844                         ContentLightingFlags above_f = ndef->getLightingFlags(above);
 845                         light[z][x] = above.getLight(LIGHTBANK_DAY, above_f) == LIGHT_SUN;
 846                 }
 847         }
 848 }
 849
 850 /*!
 851  * Propagates sunlight down in a given map block.
 852  *
 853  * \param data contains incoming sunlight and shadow and
 854  * the coordinates of the target block.
 855  * \param unlight propagated shadow is inserted here
 856  * \param relight propagated sunlight is inserted here
 857  *
 858  * \returns true if the block was modified, false otherwise.
 859  */
 860 bool propagate_block_sunlight(Map *map, const NodeDefManager *ndef,
 861         SunlightPropagationData *data, UnlightQueue *unlight, ReLightQueue *relight)
 862 {
 863         bool modified = false;
 864         // Get the block.
 865         MapBlock *block = map->getBlockNoCreateNoEx(data->target_block);
 866         if (block == NULL) {
 867                 // The work is done if the block does not contain data.
 868                 data->data.clear();
 869                 return false;
 870         }
 871         // For each changing column of nodes:
 872         size_t index;
 873         for (index = 0; index < data->data.size(); index++) {
 874                 SunlightPropagationUnit it = data->data[index];
 875                 // Relative position of the currently inspected node.
 876                 relative_v3 current_pos(it.relative_pos.X, MAP_BLOCKSIZE - 1,
 877                         it.relative_pos.Y);
 878                 if (it.is_sunlit) {
 879                         // Propagate sunlight.
 880                         // For each node downwards:
 881                         for (; current_pos.Y >= 0; current_pos.Y--) {
 882                                 MapNode n = block->getNodeNoCheck(current_pos);
 883                                 ContentLightingFlags f = ndef->getLightingFlags(n);
 884                                 if (n.getLightRaw(LIGHTBANK_DAY, f) < LIGHT_SUN
 885                                                 && f.sunlight_propagates) {
 886                                         // This node gets sunlight.
 887                                         n.setLight(LIGHTBANK_DAY, LIGHT_SUN, f);
 888                                         block->setNodeNoCheck(current_pos, n);
 889                                         modified = true;
 890                                         relight->push(LIGHT_SUN, current_pos, data->target_block,
 891                                                 block, 4);
 892                                 } else {
 893                                         // Light already valid, propagation stopped.
 894                                         break;
 895                                 }
 896                         }
 897                 } else {
 898                         // Propagate shadow.
 899                         // For each node downwards:
 900                         for (; current_pos.Y >= 0; current_pos.Y--) {
 901                                 MapNode n = block->getNodeNoCheck(current_pos);
 902                                 ContentLightingFlags f = ndef->getLightingFlags(n);
 903                                 if (n.getLightRaw(LIGHTBANK_DAY, f) == LIGHT_SUN) {
 904                                         // The sunlight is no longer valid.
 905                                         n.setLight(LIGHTBANK_DAY, 0, f);
 906                                         block->setNodeNoCheck(current_pos, n);
 907                                         modified = true;
 908                                         unlight->push(LIGHT_SUN, current_pos, data->target_block,
 909                                                 block, 4);
 910                                 } else {
 911                                         // Reached shadow, propagation stopped.
 912                                         break;
 913                                 }
 914                         }
 915                 }
 916                 if (current_pos.Y >= 0) {
 917                         // Propagation stopped, remove from data.
 918                         data->data[index] = data->data.back();
 919                         data->data.pop_back();
 920                         index--;
 921                 }
 922         }
 923         return modified;
 924 }
 925
 926 /*!
 927  * Borders of a map block in relative node coordinates.
 928  * The areas do not overlap.
 929  * Compatible with type 'direction'.
 930  */
 931 const VoxelArea block_pad[] = {
 932         VoxelArea(v3s16(15, 0, 0), v3s16(15, 15, 15)), //X+
 933         VoxelArea(v3s16(1, 15, 0), v3s16(14, 15, 15)), //Y+
 934         VoxelArea(v3s16(1, 1, 15), v3s16(14, 14, 15)), //Z+
 935         VoxelArea(v3s16(1, 1, 0), v3s16(14, 14, 0)),   //Z-
 936         VoxelArea(v3s16(1, 0, 0), v3s16(14, 0, 15)),   //Y-
 937         VoxelArea(v3s16(0, 0, 0), v3s16(0, 15, 15))    //X-
 938 };
 939
 940 /*!
 941  * The common part of bulk light updates - it is always executed.
 942  * The procedure takes the nodes that should be unlit, and the
 943  * full modified area.
 944  *
 945  * The procedure handles the correction of all lighting except
 946  * direct sunlight spreading.
 947  *
 948  * \param minblock least coordinates of the changed area in block
 949  * coordinates
 950  * \param maxblock greatest coordinates of the changed area in block
 951  * coordinates
 952  * \param unlight the first queue is for day light, the second is for
 953  * night light. Contains all nodes on the borders that need to be unlit.
 954  * \param relight the first queue is for day light, the second is for
 955  * night light. Contains nodes that were not modified, but got sunlight
 956  * because the changes.
 957  * \param modified_blocks the procedure adds all modified blocks to
 958  * this map
 959  */
 960 void finish_bulk_light_update(Map *map, mapblock_v3 minblock,
 961         mapblock_v3 maxblock, UnlightQueue unlight[2], ReLightQueue relight[2],
 962         std::map<v3s16, MapBlock*> *modified_blocks)
 963 {
 964         const NodeDefManager *ndef = map->getNodeDefManager();
 965
 966         // --- STEP 1: Do unlighting
 967
 968         for (size_t bank = 0; bank < 2; bank++) {
 969                 LightBank b = banks[bank];
 970                 unspread_light(map, ndef, b, unlight[bank], relight[bank],
 971                         *modified_blocks);
 972         }
 973
 974         // --- STEP 2: Get all newly inserted light sources
 975
 976         // For each block:
 977         v3s16 blockpos;
 978         v3s16 relpos;
 979         for (blockpos.X = minblock.X; blockpos.X <= maxblock.X; blockpos.X++)
 980         for (blockpos.Y = minblock.Y; blockpos.Y <= maxblock.Y; blockpos.Y++)
 981         for (blockpos.Z = minblock.Z; blockpos.Z <= maxblock.Z; blockpos.Z++) {
 982                 MapBlock *block = map->getBlockNoCreateNoEx(blockpos);
 983                 if (!block)
 984                         // Skip not existing blocks
 985                         continue;
 986                 // For each node in the block:
 987                 for (relpos.X = 0; relpos.X < MAP_BLOCKSIZE; relpos.X++)
 988                 for (relpos.Z = 0; relpos.Z < MAP_BLOCKSIZE; relpos.Z++)
 989                 for (relpos.Y = 0; relpos.Y < MAP_BLOCKSIZE; relpos.Y++) {
 990                         MapNode node = block->getNodeNoCheck(relpos.X, relpos.Y, relpos.Z);
 991                         ContentLightingFlags f = ndef->getLightingFlags(node);
 992
 993                         // For each light bank
 994                         for (size_t b = 0; b < 2; b++) {
 995                                 LightBank bank = banks[b];
 996                                 u8 light = f.has_light ?
 997                                         node.getLight(bank, f):
 998                                         f.light_source;
 999                                 if (light > 1)
1000                                         relight[b].push(light, relpos, blockpos, block, 6);
1001                         } // end of banks
1002                 } // end of nodes
1003         } // end of blocks
1004
1005         // --- STEP 3: do light spreading
1006
1007         // For each light bank:
1008         for (size_t b = 0; b < 2; b++) {
1009                 LightBank bank = banks[b];
1010                 // Sunlight is already initialized.
1011                 u8 maxlight = (b == 0) ? LIGHT_MAX : LIGHT_SUN;
1012                 // Initialize light values for light spreading.
1013                 for (u8 i = 0; i <= maxlight; i++) {
1014                         const std::vector<ChangingLight> &lights = relight[b].lights[i];
1015                         for (std::vector<ChangingLight>::const_iterator it = lights.begin();
1016                                         it < lights.end(); ++it) {
1017                                 MapNode n = it->block->getNodeNoCheck(it->rel_position);
1018                                 n.setLight(bank, i, ndef->getLightingFlags(n));
1019                                 it->block->setNodeNoCheck(it->rel_position, n);
1020                         }
1021                 }
1022                 // Spread lights.
1023                 spread_light(map, ndef, bank, relight[b], *modified_blocks);
1024         }
1025 }
1026
1027 void blit_back_with_light(Map *map, MMVManip *vm,
1028         std::map<v3s16, MapBlock*> *modified_blocks)
1029 {
1030         const NodeDefManager *ndef = map->getNodeDefManager();
1031         mapblock_v3 minblock = getNodeBlockPos(vm->m_area.MinEdge);
1032         mapblock_v3 maxblock = getNodeBlockPos(vm->m_area.MaxEdge);
1033         // First queue is for day light, second is for night light.
1034         UnlightQueue unlight[] = { UnlightQueue(256), UnlightQueue(256) };
1035         ReLightQueue relight[] = { ReLightQueue(256), ReLightQueue(256) };
1036         // Will hold sunlight data.
1037         bool lights[MAP_BLOCKSIZE][MAP_BLOCKSIZE];
1038         SunlightPropagationData data;
1039
1040         // --- STEP 1: reset everything to sunlight
1041
1042         // For each map block:
1043         for (s16 x = minblock.X; x <= maxblock.X; x++)
1044         for (s16 z = minblock.Z; z <= maxblock.Z; z++) {
1045                 // Extract sunlight above.
1046                 is_sunlight_above_block(map, v3s16(x, maxblock.Y, z), ndef, lights);
1047                 v2s16 offset(x, z);
1048                 offset *= MAP_BLOCKSIZE;
1049                 // Reset the voxel manipulator.
1050                 fill_with_sunlight(vm, ndef, offset, lights);
1051                 // Copy sunlight data
1052                 data.target_block = v3s16(x, minblock.Y - 1, z);
1053                 for (s16 z = 0; z < MAP_BLOCKSIZE; z++)
1054                 for (s16 x = 0; x < MAP_BLOCKSIZE; x++)
1055                         data.data.emplace_back(v2s16(x, z), lights[z][x]);
1056                 // Propagate sunlight and shadow below the voxel manipulator.
1057                 while (!data.data.empty()) {
1058                         if (propagate_block_sunlight(map, ndef, &data, &unlight[0],
1059                                         &relight[0]))
1060                                 (*modified_blocks)[data.target_block] =
1061                                         map->getBlockNoCreateNoEx(data.target_block);
1062                         // Step downwards.
1063                         data.target_block.Y--;
1064                 }
1065         }
1066
1067         // --- STEP 2: Get nodes from borders to unlight
1068         v3s16 blockpos;
1069         v3s16 relpos;
1070
1071         // In case there are unloaded holes in the voxel manipulator
1072         // unlight each block.
1073         // For each block:
1074         for (blockpos.X = minblock.X; blockpos.X <= maxblock.X; blockpos.X++)
1075         for (blockpos.Y = minblock.Y; blockpos.Y <= maxblock.Y; blockpos.Y++)
1076         for (blockpos.Z = minblock.Z; blockpos.Z <= maxblock.Z; blockpos.Z++) {
1077                 MapBlock *block = map->getBlockNoCreateNoEx(blockpos);
1078                 if (!block)
1079                         // Skip not existing blocks.
1080                         continue;
1081                 v3s16 offset = block->getPosRelative();
1082                 // For each border of the block:
1083                 for (const VoxelArea &a : block_pad) {
1084                         // For each node of the border:
1085                         for (relpos.X = a.MinEdge.X; relpos.X <= a.MaxEdge.X; relpos.X++)
1086                         for (relpos.Z = a.MinEdge.Z; relpos.Z <= a.MaxEdge.Z; relpos.Z++)
1087                         for (relpos.Y = a.MinEdge.Y; relpos.Y <= a.MaxEdge.Y; relpos.Y++) {
1088
1089                                 // Get old and new node
1090                                 MapNode oldnode = block->getNodeNoCheck(relpos);
1091                                 ContentLightingFlags oldf = ndef->getLightingFlags(oldnode);
1092                                 MapNode newnode = vm->getNodeNoExNoEmerge(relpos + offset);
1093                                 ContentLightingFlags newf = ndef->getLightingFlags(newnode);
1094
1095                                 // For each light bank
1096                                 for (size_t b = 0; b < 2; b++) {
1097                                         LightBank bank = banks[b];
1098                                         u8 oldlight = oldf.has_light ?
1099                                                 oldnode.getLight(bank, oldf):
1100                                                 LIGHT_SUN; // no light information, force unlighting
1101                                         u8 newlight = newf.has_light ?
1102                                                 newnode.getLight(bank, newf):
1103                                                 newf.light_source;
1104                                         // If the new node is dimmer, unlight.
1105                                         if (oldlight > newlight) {
1106                                                 unlight[b].push(
1107                                                         oldlight, relpos, blockpos, block, 6);
1108                                         }
1109                                 } // end of banks
1110                         } // end of nodes
1111                 } // end of borders
1112         } // end of blocks
1113
1114         // --- STEP 3: All information extracted, overwrite
1115
1116         vm->blitBackAll(modified_blocks, true);
1117
1118         // --- STEP 4: Finish light update
1119
1120         finish_bulk_light_update(map, minblock, maxblock, unlight, relight,
1121                 modified_blocks);
1122 }
1123
1124 /*!
1125  * Resets the lighting of the given map block to
1126  * complete darkness and full sunlight.
1127  *
1128  * \param light incoming sunlight, light[x][z] is true if there
1129  * is sunlight above the map block at the given x-z coordinates.
1130  * The array's indices are relative node coordinates in the block.
1131  * After the procedure returns, this contains outgoing light at
1132  * the bottom of the map block.
1133  */
1134 void fill_with_sunlight(MapBlock *block, const NodeDefManager *ndef,
1135         bool light[MAP_BLOCKSIZE][MAP_BLOCKSIZE])
1136 {
1137         // For each column of nodes:
1138         for (s16 z = 0; z < MAP_BLOCKSIZE; z++)
1139         for (s16 x = 0; x < MAP_BLOCKSIZE; x++) {
1140                 // True if the current node has sunlight.
1141                 bool lig = light[z][x];
1142                 // For each node, downwards:
1143                 for (s16 y = MAP_BLOCKSIZE - 1; y >= 0; y--) {
1144                         MapNode n = block->getNodeNoCheck(x, y, z);
1145                         // Ignore IGNORE nodes, these are not generated yet.
1146                         if (n.getContent() == CONTENT_IGNORE)
1147                                 continue;
1148                         ContentLightingFlags f = ndef->getLightingFlags(n);
1149                         if (lig && !f.sunlight_propagates) {
1150                                 // Sunlight is stopped.
1151                                 lig = false;
1152                         }
1153                         // Reset light
1154                         n.setLight(LIGHTBANK_DAY, lig ? 15 : 0, f);
1155                         n.setLight(LIGHTBANK_NIGHT, 0, f);
1156                         block->setNodeNoCheck(x, y, z, n);
1157                 }
1158                 // Output outgoing light.
1159                 light[z][x] = lig;
1160         }
1161 }
1162
1163 void repair_block_light(Map *map, MapBlock *block,
1164         std::map<v3s16, MapBlock*> *modified_blocks)
1165 {
1166         if (!block)
1167                 return;
1168         const NodeDefManager *ndef = map->getNodeDefManager();
1169         // First queue is for day light, second is for night light.
1170         UnlightQueue unlight[] = { UnlightQueue(256), UnlightQueue(256) };
1171         ReLightQueue relight[] = { ReLightQueue(256), ReLightQueue(256) };
1172         // Will hold sunlight data.
1173         bool lights[MAP_BLOCKSIZE][MAP_BLOCKSIZE];
1174         SunlightPropagationData data;
1175
1176         // --- STEP 1: reset everything to sunlight
1177
1178         mapblock_v3 blockpos = block->getPos();
1179         (*modified_blocks)[blockpos] = block;
1180         // For each map block:
1181         // Extract sunlight above.
1182         is_sunlight_above_block(map, blockpos, ndef, lights);
1183         // Reset the voxel manipulator.
1184         fill_with_sunlight(block, ndef, lights);
1185         // Copy sunlight data
1186         data.target_block = v3s16(blockpos.X, blockpos.Y - 1, blockpos.Z);
1187         for (s16 z = 0; z < MAP_BLOCKSIZE; z++)
1188         for (s16 x = 0; x < MAP_BLOCKSIZE; x++) {
1189                 data.data.emplace_back(v2s16(x, z), lights[z][x]);
1190         }
1191         // Propagate sunlight and shadow below the voxel manipulator.
1192         while (!data.data.empty()) {
1193                 if (propagate_block_sunlight(map, ndef, &data, &unlight[0],
1194                                 &relight[0]))
1195                         (*modified_blocks)[data.target_block] =
1196                                 map->getBlockNoCreateNoEx(data.target_block);
1197                 // Step downwards.
1198                 data.target_block.Y--;
1199         }
1200
1201         // --- STEP 2: Get nodes from borders to unlight
1202
1203         // For each border of the block:
1204         for (const VoxelArea &a : block_pad) {
1205                 v3s16 relpos;
1206                 // For each node of the border:
1207                 for (relpos.X = a.MinEdge.X; relpos.X <= a.MaxEdge.X; relpos.X++)
1208                 for (relpos.Z = a.MinEdge.Z; relpos.Z <= a.MaxEdge.Z; relpos.Z++)
1209                 for (relpos.Y = a.MinEdge.Y; relpos.Y <= a.MaxEdge.Y; relpos.Y++) {
1210
1211                         // Get node
1212                         MapNode node = block->getNodeNoCheck(relpos);
1213                         ContentLightingFlags f = ndef->getLightingFlags(node);
1214                         // For each light bank
1215                         for (size_t b = 0; b < 2; b++) {
1216                                 LightBank bank = banks[b];
1217                                 u8 light = f.has_light ?
1218                                         node.getLight(bank, f):
1219                                         f.light_source;
1220                                 // If the new node is dimmer than sunlight, unlight.
1221                                 // (if it has maximal light, it is pointless to remove
1222                                 // surrounding light, as it can only become brighter)
1223                                 if (LIGHT_SUN > light) {
1224                                         unlight[b].push(
1225                                                 LIGHT_SUN, relpos, blockpos, block, 6);
1226                                 }
1227                         } // end of banks
1228                 } // end of nodes
1229         } // end of borders
1230
1231         // STEP 3: Remove and spread light
1232
1233         finish_bulk_light_update(map, blockpos, blockpos, unlight, relight,
1234                 modified_blocks);
1235 }
1236
1237 VoxelLineIterator::VoxelLineIterator(const v3f &start_position, const v3f &line_vector) :
1238         m_start_position(start_position),
1239         m_line_vector(line_vector)
1240 {
1241         m_current_node_pos = floatToInt(m_start_position, 1);
1242         m_start_node_pos = m_current_node_pos;
1243         m_last_index = getIndex(floatToInt(start_position + line_vector, 1));
1244
1245         if (m_line_vector.X > 0) {
1246                 m_next_intersection_multi.X = (floorf(m_start_position.X - 0.5) + 1.5
1247                         - m_start_position.X) / m_line_vector.X;
1248                 m_intersection_multi_inc.X = 1 / m_line_vector.X;
1249         } else if (m_line_vector.X < 0) {
1250                 m_next_intersection_multi.X = (floorf(m_start_position.X - 0.5)
1251                         - m_start_position.X + 0.5) / m_line_vector.X;
1252                 m_intersection_multi_inc.X = -1 / m_line_vector.X;
1253                 m_step_directions.X = -1;
1254         }
1255
1256         if (m_line_vector.Y > 0) {
1257                 m_next_intersection_multi.Y = (floorf(m_start_position.Y - 0.5) + 1.5
1258                         - m_start_position.Y) / m_line_vector.Y;
1259                 m_intersection_multi_inc.Y = 1 / m_line_vector.Y;
1260         } else if (m_line_vector.Y < 0) {
1261                 m_next_intersection_multi.Y = (floorf(m_start_position.Y - 0.5)
1262                         - m_start_position.Y + 0.5) / m_line_vector.Y;
1263                 m_intersection_multi_inc.Y = -1 / m_line_vector.Y;
1264                 m_step_directions.Y = -1;
1265         }
1266
1267         if (m_line_vector.Z > 0) {
1268                 m_next_intersection_multi.Z = (floorf(m_start_position.Z - 0.5) + 1.5
1269                         - m_start_position.Z) / m_line_vector.Z;
1270                 m_intersection_multi_inc.Z = 1 / m_line_vector.Z;
1271         } else if (m_line_vector.Z < 0) {
1272                 m_next_intersection_multi.Z = (floorf(m_start_position.Z - 0.5)
1273                         - m_start_position.Z + 0.5) / m_line_vector.Z;
1274                 m_intersection_multi_inc.Z = -1 / m_line_vector.Z;
1275                 m_step_directions.Z = -1;
1276         }
1277 }
1278
1279 void VoxelLineIterator::next()
1280 {
1281         m_current_index++;
1282         if ((m_next_intersection_multi.X < m_next_intersection_multi.Y)
1283                         && (m_next_intersection_multi.X < m_next_intersection_multi.Z)) {
1284                 m_next_intersection_multi.X += m_intersection_multi_inc.X;
1285                 m_current_node_pos.X += m_step_directions.X;
1286         } else if ((m_next_intersection_multi.Y < m_next_intersection_multi.Z)) {
1287                 m_next_intersection_multi.Y += m_intersection_multi_inc.Y;
1288                 m_current_node_pos.Y += m_step_directions.Y;
1289         } else {
1290                 m_next_intersection_multi.Z += m_intersection_multi_inc.Z;
1291                 m_current_node_pos.Z += m_step_directions.Z;
1292         }
1293 }
1294
1295 s16 VoxelLineIterator::getIndex(v3s16 voxel){
1296         return
1297                 abs(voxel.X - m_start_node_pos.X) +
1298                 abs(voxel.Y - m_start_node_pos.Y) +
1299                 abs(voxel.Z - m_start_node_pos.Z);
1300 }
1301
1302 } // namespace voxalgo
1303