src/tree_cmd.cpp

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   4  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file tree_cmd.cpp Handling of tree tiles. */
   9
  10 #include "stdafx.h"
  11 #include "clear_map.h"
  12 #include "landscape.h"
  13 #include "tree_map.h"
  14 #include "viewport_func.h"
  15 #include "command_func.h"
  16 #include "town.h"
  17 #include "genworld.h"
  18 #include "clear_func.h"
  19 #include "company_func.h"
  20 #include "sound_func.h"
  21 #include "water.h"
  22 #include "company_base.h"
  23 #include "core/random_func.hpp"
  24 #include "newgrf_generic.h"
  25
  26 #include "table/strings.h"
  27 #include "table/tree_land.h"
  28 #include "table/clear_land.h"
  29
  30 #include "safeguards.h"
  31
  32 /**
  33  * List of tree placer algorithm.
  34  *
  35  * This enumeration defines all possible tree placer algorithm in the game.
  36  */
  37 enum TreePlacer {
  38         TP_NONE,     ///< No tree placer algorithm
  39         TP_ORIGINAL, ///< The original algorithm
  40         TP_IMPROVED, ///< A 'improved' algorithm
  41 };
  42
  43 /** Where to place trees while in-game? */
  44 enum ExtraTreePlacement {
  45         ETP_NO_SPREAD,           ///< Grow trees on tiles that have them but don't spread to new ones
  46         ETP_SPREAD_RAINFOREST,   ///< Grow trees on tiles that have them, only spread to new ones in rainforests
  47         ETP_SPREAD_ALL,          ///< Grow trees and spread them without restrictions
  48         ETP_NO_GROWTH_NO_SPREAD, ///< Don't grow trees and don't spread them at all
  49 };
  50
  51 /** Determines when to consider building more trees. */
  52 byte _trees_tick_ctr;
  53
  54 static const uint16 DEFAULT_TREE_STEPS = 1000;             ///< Default number of attempts for placing trees.
  55 static const uint16 DEFAULT_RAINFOREST_TREE_STEPS = 15000; ///< Default number of attempts for placing extra trees at rainforest in tropic.
  56 static const uint16 EDITOR_TREE_DIV = 5;                   ///< Game editor tree generation divisor factor.
  57
  58 /**
  59  * Tests if a tile can be converted to MP_TREES
  60  * This is true for clear ground without farms or rocks.
  61  *
  62  * @param tile the tile of interest
  63  * @param allow_desert Allow planting trees on CLEAR_DESERT?
  64  * @return true if trees can be built.
  65  */
  66 static bool CanPlantTreesOnTile(TileIndex tile, bool allow_desert)
  67 {
  68         switch (GetTileType(tile)) {
  69                 case MP_WATER:
  70                         return !IsBridgeAbove(tile) && IsCoast(tile) && !IsSlopeWithOneCornerRaised(GetTileSlope(tile));
  71
  72                 case MP_CLEAR:
  73                         return !IsBridgeAbove(tile) && !IsClearGround(tile, CLEAR_FIELDS) && GetRawClearGround(tile) != CLEAR_ROCKS &&
  74                                (allow_desert || !IsClearGround(tile, CLEAR_DESERT));
  75
  76                 default: return false;
  77         }
  78 }
  79
  80 /**
  81  * Creates a tree tile
  82  * Ground type and density is preserved.
  83  *
  84  * @pre the tile must be suitable for trees.
  85  *
  86  * @param tile where to plant the trees.
  87  * @param treetype The type of the tree
  88  * @param count the number of trees (minus 1)
  89  * @param growth the growth status
  90  */
  91 static void PlantTreesOnTile(TileIndex tile, TreeType treetype, uint count, uint growth)
  92 {
  93         assert(treetype != TREE_INVALID);
  94         assert(CanPlantTreesOnTile(tile, true));
  95
  96         TreeGround ground;
  97         uint density = 3;
  98
  99         switch (GetTileType(tile)) {
 100                 case MP_WATER:
 101                         ground = TREE_GROUND_SHORE;
 102                         break;
 103
 104                 case MP_CLEAR:
 105                         switch (GetClearGround(tile)) {
 106                                 case CLEAR_GRASS:  ground = TREE_GROUND_GRASS;       break;
 107                                 case CLEAR_ROUGH:  ground = TREE_GROUND_ROUGH;       break;
 108                                 case CLEAR_SNOW:   ground = GetRawClearGround(tile) == CLEAR_ROUGH ? TREE_GROUND_ROUGH_SNOW : TREE_GROUND_SNOW_DESERT; break;
 109                                 default:           ground = TREE_GROUND_SNOW_DESERT; break;
 110                         }
 111                         if (GetClearGround(tile) != CLEAR_ROUGH) density = GetClearDensity(tile);
 112                         break;
 113
 114                 default: NOT_REACHED();
 115         }
 116
 117         MakeTree(tile, treetype, count, growth, ground, density);
 118 }
 119
 120 /**
 121  * Get a random TreeType for the given tile based on a given seed
 122  *
 123  * This function returns a random TreeType which can be placed on the given tile.
 124  * The seed for randomness must be less or equal 256, use #GB on the value of Random()
 125  * to get such a value.
 126  *
 127  * @param tile The tile to get a random TreeType from
 128  * @param seed The seed for randomness, must be less or equal 256
 129  * @return The random tree type
 130  */
 131 static TreeType GetRandomTreeType(TileIndex tile, uint seed)
 132 {
 133         switch (_settings_game.game_creation.landscape) {
 134                 case LT_TEMPERATE:
 135                         return (TreeType)(seed * TREE_COUNT_TEMPERATE / 256 + TREE_TEMPERATE);
 136
 137                 case LT_ARCTIC:
 138                         return (TreeType)(seed * TREE_COUNT_SUB_ARCTIC / 256 + TREE_SUB_ARCTIC);
 139
 140                 case LT_TROPIC:
 141                         switch (GetTropicZone(tile)) {
 142                                 case TROPICZONE_NORMAL:  return (TreeType)(seed * TREE_COUNT_SUB_TROPICAL / 256 + TREE_SUB_TROPICAL);
 143                                 case TROPICZONE_DESERT:  return (TreeType)((seed > 12) ? TREE_INVALID : TREE_CACTUS);
 144                                 default:                 return (TreeType)(seed * TREE_COUNT_RAINFOREST / 256 + TREE_RAINFOREST);
 145                         }
 146
 147                 default:
 148                         return (TreeType)(seed * TREE_COUNT_TOYLAND / 256 + TREE_TOYLAND);
 149         }
 150 }
 151
 152 /**
 153  * Make a random tree tile of the given tile
 154  *
 155  * Create a new tree-tile for the given tile. The second parameter is used for
 156  * randomness like type and number of trees.
 157  *
 158  * @param tile The tile to make a tree-tile from
 159  * @param r The randomness value from a Random() value
 160  */
 161 static void PlaceTree(TileIndex tile, uint32 r)
 162 {
 163         TreeType tree = GetRandomTreeType(tile, GB(r, 24, 8));
 164
 165         if (tree != TREE_INVALID) {
 166                 PlantTreesOnTile(tile, tree, GB(r, 22, 2), std::min<byte>(GB(r, 16, 3), 6));
 167
 168                 /* Rerandomize ground, if neither snow nor shore */
 169                 TreeGround ground = GetTreeGround(tile);
 170                 if (ground != TREE_GROUND_SNOW_DESERT && ground != TREE_GROUND_ROUGH_SNOW && ground != TREE_GROUND_SHORE) {
 171                         SetTreeGroundDensity(tile, (TreeGround)GB(r, 28, 1), 3);
 172                 }
 173
 174                 /* Set the counter to a random start value */
 175                 SetTreeCounter(tile, (TreeGround)GB(r, 24, 4));
 176         }
 177 }
 178
 179 /**
 180  * Creates a number of tree groups.
 181  * The number of trees in each group depends on how many trees are actually placed around the given tile.
 182  *
 183  * @param num_groups Number of tree groups to place.
 184  */
 185 static void PlaceTreeGroups(uint num_groups)
 186 {
 187         do {
 188                 TileIndex center_tile = RandomTile();
 189
 190                 for (uint i = 0; i < DEFAULT_TREE_STEPS; i++) {
 191                         uint32 r = Random();
 192                         int x = GB(r, 0, 5) - 16;
 193                         int y = GB(r, 8, 5) - 16;
 194                         uint dist = abs(x) + abs(y);
 195                         TileIndex cur_tile = TileAddWrap(center_tile, x, y);
 196
 197                         IncreaseGeneratingWorldProgress(GWP_TREE);
 198
 199                         if (cur_tile != INVALID_TILE && dist <= 13 && CanPlantTreesOnTile(cur_tile, true)) {
 200                                 PlaceTree(cur_tile, r);
 201                         }
 202                 }
 203
 204         } while (--num_groups);
 205 }
 206
 207 /**
 208  * Place a tree at the same height as an existing tree.
 209  *
 210  * Add a new tree around the given tile which is at the same
 211  * height or at some offset (2 units) of it.
 212  *
 213  * @param tile The base tile to add a new tree somewhere around
 214  * @param height The height (like the one from the tile)
 215  */
 216 static void PlaceTreeAtSameHeight(TileIndex tile, int height)
 217 {
 218         for (uint i = 0; i < DEFAULT_TREE_STEPS; i++) {
 219                 uint32 r = Random();
 220                 int x = GB(r, 0, 5) - 16;
 221                 int y = GB(r, 8, 5) - 16;
 222                 TileIndex cur_tile = TileAddWrap(tile, x, y);
 223                 if (cur_tile == INVALID_TILE) continue;
 224
 225                 /* Keep in range of the existing tree */
 226                 if (abs(x) + abs(y) > 16) continue;
 227
 228                 /* Clear tile, no farm-tiles or rocks */
 229                 if (!CanPlantTreesOnTile(cur_tile, true)) continue;
 230
 231                 /* Not too much height difference */
 232                 if (Delta(GetTileZ(cur_tile), height) > 2) continue;
 233
 234                 /* Place one tree and quit */
 235                 PlaceTree(cur_tile, r);
 236                 break;
 237         }
 238 }
 239
 240 /**
 241  * Place some trees randomly
 242  *
 243  * This function just place some trees randomly on the map.
 244  */
 245 void PlaceTreesRandomly()
 246 {
 247         int i, j, ht;
 248
 249         i = ScaleByMapSize(DEFAULT_TREE_STEPS);
 250         if (_game_mode == GM_EDITOR) i /= EDITOR_TREE_DIV;
 251         do {
 252                 uint32 r = Random();
 253                 TileIndex tile = RandomTileSeed(r);
 254
 255                 IncreaseGeneratingWorldProgress(GWP_TREE);
 256
 257                 if (CanPlantTreesOnTile(tile, true)) {
 258                         PlaceTree(tile, r);
 259                         if (_settings_game.game_creation.tree_placer != TP_IMPROVED) continue;
 260
 261                         /* Place a number of trees based on the tile height.
 262                          *  This gives a cool effect of multiple trees close together.
 263                          *  It is almost real life ;) */
 264                         ht = GetTileZ(tile);
 265                         /* The higher we get, the more trees we plant */
 266                         j = GetTileZ(tile) * 2;
 267                         /* Above snowline more trees! */
 268                         if (_settings_game.game_creation.landscape == LT_ARCTIC && ht > GetSnowLine()) j *= 3;
 269                         while (j--) {
 270                                 PlaceTreeAtSameHeight(tile, ht);
 271                         }
 272                 }
 273         } while (--i);
 274
 275         /* place extra trees at rainforest area */
 276         if (_settings_game.game_creation.landscape == LT_TROPIC) {
 277                 i = ScaleByMapSize(DEFAULT_RAINFOREST_TREE_STEPS);
 278                 if (_game_mode == GM_EDITOR) i /= EDITOR_TREE_DIV;
 279
 280                 do {
 281                         uint32 r = Random();
 282                         TileIndex tile = RandomTileSeed(r);
 283
 284                         IncreaseGeneratingWorldProgress(GWP_TREE);
 285
 286                         if (GetTropicZone(tile) == TROPICZONE_RAINFOREST && CanPlantTreesOnTile(tile, false)) {
 287                                 PlaceTree(tile, r);
 288                         }
 289                 } while (--i);
 290         }
 291 }
 292
 293 /**
 294  * Place some trees in a radius around a tile.
 295  * The trees are placed in an quasi-normal distribution around the indicated tile, meaning that while
 296  * the radius does define a square, the distribution inside the square will be roughly circular.
 297  * @note This function the interactive RNG and must only be used in editor and map generation.
 298  * @param tile      Tile to place trees around.
 299  * @param treetype  Type of trees to place. Must be a valid tree type for the climate.
 300  * @param radius    Maximum distance (on each axis) from tile to place trees.
 301  * @param count     Maximum number of trees to place.
 302  * @return Number of trees actually placed.
 303  */
 304 uint PlaceTreeGroupAroundTile(TileIndex tile, TreeType treetype, uint radius, uint count)
 305 {
 306         assert(treetype < TREE_TOYLAND + TREE_COUNT_TOYLAND);
 307         const bool allow_desert = treetype == TREE_CACTUS;
 308         uint planted = 0;
 309
 310         for (; count > 0; count--) {
 311                 /* Simple quasi-normal distribution with range [-radius; radius) */
 312                 auto mkcoord = [&]() -> int32 {
 313                         const uint32 rand = InteractiveRandom();
 314                         const int32 dist = GB<int32>(rand, 0, 8) + GB<int32>(rand, 8, 8) + GB<int32>(rand, 16, 8) + GB<int32>(rand, 24, 8);
 315                         const int32 scu = dist * radius / 512;
 316                         return scu - radius;
 317                 };
 318                 const int32 xofs = mkcoord();
 319                 const int32 yofs = mkcoord();
 320                 const TileIndex tile_to_plant = TileAddWrap(tile, xofs, yofs);
 321                 if (tile_to_plant != INVALID_TILE) {
 322                         if (IsTileType(tile_to_plant, MP_TREES) && GetTreeCount(tile_to_plant) < 4) {
 323                                 AddTreeCount(tile_to_plant, 1);
 324                                 SetTreeGrowth(tile_to_plant, 0);
 325                                 MarkTileDirtyByTile(tile_to_plant, 0);
 326                                 planted++;
 327                         } else if (CanPlantTreesOnTile(tile_to_plant, allow_desert)) {
 328                                 PlantTreesOnTile(tile_to_plant, treetype, 0, 3);
 329                                 MarkTileDirtyByTile(tile_to_plant, 0);
 330                                 planted++;
 331                         }
 332                 }
 333         }
 334
 335         return planted;
 336 }
 337
 338 /**
 339  * Place new trees.
 340  *
 341  * This function takes care of the selected tree placer algorithm and
 342  * place randomly the trees for a new game.
 343  */
 344 void GenerateTrees()
 345 {
 346         uint i, total;
 347
 348         if (_settings_game.game_creation.tree_placer == TP_NONE) return;
 349
 350         switch (_settings_game.game_creation.tree_placer) {
 351                 case TP_ORIGINAL: i = _settings_game.game_creation.landscape == LT_ARCTIC ? 15 : 6; break;
 352                 case TP_IMPROVED: i = _settings_game.game_creation.landscape == LT_ARCTIC ?  4 : 2; break;
 353                 default: NOT_REACHED();
 354         }
 355
 356         total = ScaleByMapSize(DEFAULT_TREE_STEPS);
 357         if (_settings_game.game_creation.landscape == LT_TROPIC) total += ScaleByMapSize(DEFAULT_RAINFOREST_TREE_STEPS);
 358         total *= i;
 359         uint num_groups = (_settings_game.game_creation.landscape != LT_TOYLAND) ? ScaleByMapSize(GB(Random(), 0, 5) + 25) : 0;
 360         total += num_groups * DEFAULT_TREE_STEPS;
 361         SetGeneratingWorldProgress(GWP_TREE, total);
 362
 363         if (num_groups != 0) PlaceTreeGroups(num_groups);
 364
 365         for (; i != 0; i--) {
 366                 PlaceTreesRandomly();
 367         }
 368 }
 369
 370 /**
 371  * Plant a tree.
 372  * @param tile end tile of area-drag
 373  * @param flags type of operation
 374  * @param p1 tree type, TREE_INVALID means random.
 375  * @param p2 start tile of area-drag of tree plantation
 376  * @param text unused
 377  * @return the cost of this operation or an error
 378  */
 379 CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 380 {
 381         StringID msg = INVALID_STRING_ID;
 382         CommandCost cost(EXPENSES_OTHER);
 383         const byte tree_to_plant = GB(p1, 0, 8); // We cannot use Extract as min and max are climate specific.
 384
 385         if (p2 >= MapSize()) return CMD_ERROR;
 386         /* Check the tree type within the current climate */
 387         if (tree_to_plant != TREE_INVALID && !IsInsideBS(tree_to_plant, _tree_base_by_landscape[_settings_game.game_creation.landscape], _tree_count_by_landscape[_settings_game.game_creation.landscape])) return CMD_ERROR;
 388
 389         Company *c = (_game_mode != GM_EDITOR) ? Company::GetIfValid(_current_company) : nullptr;
 390         int limit = (c == nullptr ? INT32_MAX : GB(c->tree_limit, 16, 16));
 391
 392         TileArea ta(tile, p2);
 393         TILE_AREA_LOOP(tile, ta) {
 394                 switch (GetTileType(tile)) {
 395                         case MP_TREES:
 396                                 /* no more space for trees? */
 397                                 if (GetTreeCount(tile) == 4) {
 398                                         msg = STR_ERROR_TREE_ALREADY_HERE;
 399                                         continue;
 400                                 }
 401
 402                                 /* Test tree limit. */
 403                                 if (--limit < 1) {
 404                                         msg = STR_ERROR_TREE_PLANT_LIMIT_REACHED;
 405                                         break;
 406                                 }
 407
 408                                 if (flags & DC_EXEC) {
 409                                         AddTreeCount(tile, 1);
 410                                         MarkTileDirtyByTile(tile);
 411                                         if (c != nullptr) c->tree_limit -= 1 << 16;
 412                                 }
 413                                 /* 2x as expensive to add more trees to an existing tile */
 414                                 cost.AddCost(_price[PR_BUILD_TREES] * 2);
 415                                 break;
 416
 417                         case MP_WATER:
 418                                 if (!IsCoast(tile) || IsSlopeWithOneCornerRaised(GetTileSlope(tile))) {
 419                                         msg = STR_ERROR_CAN_T_BUILD_ON_WATER;
 420                                         continue;
 421                                 }
 422                                 FALLTHROUGH;
 423
 424                         case MP_CLEAR: {
 425                                 if (IsBridgeAbove(tile)) {
 426                                         msg = STR_ERROR_SITE_UNSUITABLE;
 427                                         continue;
 428                                 }
 429
 430                                 TreeType treetype = (TreeType)tree_to_plant;
 431                                 /* Be a bit picky about which trees go where. */
 432                                 if (_settings_game.game_creation.landscape == LT_TROPIC && treetype != TREE_INVALID && (
 433                                                 /* No cacti outside the desert */
 434                                                 (treetype == TREE_CACTUS && GetTropicZone(tile) != TROPICZONE_DESERT) ||
 435                                                 /* No rain forest trees outside the rain forest, except in the editor mode where it makes those tiles rain forest tile */
 436                                                 (IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS) && GetTropicZone(tile) != TROPICZONE_RAINFOREST && _game_mode != GM_EDITOR) ||
 437                                                 /* And no subtropical trees in the desert/rain forest */
 438                                                 (IsInsideMM(treetype, TREE_SUB_TROPICAL, TREE_TOYLAND) && GetTropicZone(tile) != TROPICZONE_NORMAL))) {
 439                                         msg = STR_ERROR_TREE_WRONG_TERRAIN_FOR_TREE_TYPE;
 440                                         continue;
 441                                 }
 442
 443                                 /* Test tree limit. */
 444                                 if (--limit < 1) {
 445                                         msg = STR_ERROR_TREE_PLANT_LIMIT_REACHED;
 446                                         break;
 447                                 }
 448
 449                                 if (IsTileType(tile, MP_CLEAR)) {
 450                                         /* Remove fields or rocks. Note that the ground will get barrened */
 451                                         switch (GetRawClearGround(tile)) {
 452                                                 case CLEAR_FIELDS:
 453                                                 case CLEAR_ROCKS: {
 454                                                         CommandCost ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 455                                                         if (ret.Failed()) return ret;
 456                                                         cost.AddCost(ret);
 457                                                         break;
 458                                                 }
 459
 460                                                 default: break;
 461                                         }
 462                                 }
 463
 464                                 if (_game_mode != GM_EDITOR && Company::IsValidID(_current_company)) {
 465                                         Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
 466                                         if (t != nullptr) ChangeTownRating(t, RATING_TREE_UP_STEP, RATING_TREE_MAXIMUM, flags);
 467                                 }
 468
 469                                 if (flags & DC_EXEC) {
 470                                         if (treetype == TREE_INVALID) {
 471                                                 treetype = GetRandomTreeType(tile, GB(Random(), 24, 8));
 472                                                 if (treetype == TREE_INVALID) treetype = TREE_CACTUS;
 473                                         }
 474
 475                                         /* Plant full grown trees in scenario editor */
 476                                         PlantTreesOnTile(tile, treetype, 0, _game_mode == GM_EDITOR ? 3 : 0);
 477                                         MarkTileDirtyByTile(tile);
 478                                         if (c != nullptr) c->tree_limit -= 1 << 16;
 479
 480                                         /* When planting rainforest-trees, set tropiczone to rainforest in editor. */
 481                                         if (_game_mode == GM_EDITOR && IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS)) {
 482                                                 SetTropicZone(tile, TROPICZONE_RAINFOREST);
 483                                         }
 484                                 }
 485                                 cost.AddCost(_price[PR_BUILD_TREES]);
 486                                 break;
 487                         }
 488
 489                         default:
 490                                 msg = STR_ERROR_SITE_UNSUITABLE;
 491                                 break;
 492                 }
 493
 494                 /* Tree limit used up? No need to check more. */
 495                 if (limit < 0) break;
 496         }
 497
 498         if (cost.GetCost() == 0) {
 499                 return_cmd_error(msg);
 500         } else {
 501                 return cost;
 502         }
 503 }
 504
 505 struct TreeListEnt : PalSpriteID {
 506         byte x, y;
 507 };
 508
 509 static void DrawTile_Trees(TileInfo *ti)
 510 {
 511         switch (GetTreeGround(ti->tile)) {
 512                 case TREE_GROUND_SHORE: DrawShoreTile(ti->tileh); break;
 513                 case TREE_GROUND_GRASS: DrawClearLandTile(ti, GetTreeDensity(ti->tile)); break;
 514                 case TREE_GROUND_ROUGH: DrawHillyLandTile(ti); break;
 515                 default: DrawGroundSprite(_clear_land_sprites_snow_desert[GetTreeDensity(ti->tile)] + SlopeToSpriteOffset(ti->tileh), PAL_NONE); break;
 516         }
 517
 518         /* Do not draw trees when the invisible trees setting is set */
 519         if (IsInvisibilitySet(TO_TREES)) return;
 520
 521         uint tmp = CountBits(ti->tile + ti->x + ti->y);
 522         uint index = GB(tmp, 0, 2) + (GetTreeType(ti->tile) << 2);
 523
 524         /* different tree styles above one of the grounds */
 525         if ((GetTreeGround(ti->tile) == TREE_GROUND_SNOW_DESERT || GetTreeGround(ti->tile) == TREE_GROUND_ROUGH_SNOW) &&
 526                         GetTreeDensity(ti->tile) >= 2 &&
 527                         IsInsideMM(index, TREE_SUB_ARCTIC << 2, TREE_RAINFOREST << 2)) {
 528                 index += 164 - (TREE_SUB_ARCTIC << 2);
 529         }
 530
 531         assert(index < lengthof(_tree_layout_sprite));
 532
 533         const PalSpriteID *s = _tree_layout_sprite[index];
 534         const TreePos *d = _tree_layout_xy[GB(tmp, 2, 2)];
 535
 536         /* combine trees into one sprite object */
 537         StartSpriteCombine();
 538
 539         TreeListEnt te[4];
 540
 541         /* put the trees to draw in a list */
 542         uint trees = GetTreeCount(ti->tile);
 543
 544         for (uint i = 0; i < trees; i++) {
 545                 SpriteID sprite = s[0].sprite + (i == trees - 1 ? GetTreeGrowth(ti->tile) : 3);
 546                 PaletteID pal = s[0].pal;
 547
 548                 te[i].sprite = sprite;
 549                 te[i].pal    = pal;
 550                 te[i].x = d->x;
 551                 te[i].y = d->y;
 552                 s++;
 553                 d++;
 554         }
 555
 556         /* draw them in a sorted way */
 557         int z = ti->z + GetSlopeMaxPixelZ(ti->tileh) / 2;
 558
 559         for (; trees > 0; trees--) {
 560                 uint min = te[0].x + te[0].y;
 561                 uint mi = 0;
 562
 563                 for (uint i = 1; i < trees; i++) {
 564                         if ((uint)(te[i].x + te[i].y) < min) {
 565                                 min = te[i].x + te[i].y;
 566                                 mi = i;
 567                         }
 568                 }
 569
 570                 AddSortableSpriteToDraw(te[mi].sprite, te[mi].pal, ti->x + te[mi].x, ti->y + te[mi].y, 16 - te[mi].x, 16 - te[mi].y, 0x30, z, IsTransparencySet(TO_TREES), -te[mi].x, -te[mi].y);
 571
 572                 /* replace the removed one with the last one */
 573                 te[mi] = te[trees - 1];
 574         }
 575
 576         EndSpriteCombine();
 577 }
 578
 579
 580 static int GetSlopePixelZ_Trees(TileIndex tile, uint x, uint y)
 581 {
 582         int z;
 583         Slope tileh = GetTilePixelSlope(tile, &z);
 584
 585         return z + GetPartialPixelZ(x & 0xF, y & 0xF, tileh);
 586 }
 587
 588 static Foundation GetFoundation_Trees(TileIndex tile, Slope tileh)
 589 {
 590         return FOUNDATION_NONE;
 591 }
 592
 593 static CommandCost ClearTile_Trees(TileIndex tile, DoCommandFlag flags)
 594 {
 595         uint num;
 596
 597         if (Company::IsValidID(_current_company)) {
 598                 Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
 599                 if (t != nullptr) ChangeTownRating(t, RATING_TREE_DOWN_STEP, RATING_TREE_MINIMUM, flags);
 600         }
 601
 602         num = GetTreeCount(tile);
 603         if (IsInsideMM(GetTreeType(tile), TREE_RAINFOREST, TREE_CACTUS)) num *= 4;
 604
 605         if (flags & DC_EXEC) DoClearSquare(tile);
 606
 607         return CommandCost(EXPENSES_CONSTRUCTION, num * _price[PR_CLEAR_TREES]);
 608 }
 609
 610 static void GetTileDesc_Trees(TileIndex tile, TileDesc *td)
 611 {
 612         TreeType tt = GetTreeType(tile);
 613
 614         if (IsInsideMM(tt, TREE_RAINFOREST, TREE_CACTUS)) {
 615                 td->str = STR_LAI_TREE_NAME_RAINFOREST;
 616         } else {
 617                 td->str = tt == TREE_CACTUS ? STR_LAI_TREE_NAME_CACTUS_PLANTS : STR_LAI_TREE_NAME_TREES;
 618         }
 619
 620         td->owner[0] = GetTileOwner(tile);
 621 }
 622
 623 static void TileLoopTreesDesert(TileIndex tile)
 624 {
 625         switch (GetTropicZone(tile)) {
 626                 case TROPICZONE_DESERT:
 627                         if (GetTreeGround(tile) != TREE_GROUND_SNOW_DESERT) {
 628                                 SetTreeGroundDensity(tile, TREE_GROUND_SNOW_DESERT, 3);
 629                                 MarkTileDirtyByTile(tile);
 630                         }
 631                         break;
 632
 633                 case TROPICZONE_RAINFOREST: {
 634                         static const SoundFx forest_sounds[] = {
 635                                 SND_42_LOON_BIRD,
 636                                 SND_43_LION,
 637                                 SND_44_MONKEYS,
 638                                 SND_48_DISTANT_BIRD
 639                         };
 640                         uint32 r = Random();
 641
 642                         if (Chance16I(1, 200, r) && _settings_client.sound.ambient) SndPlayTileFx(forest_sounds[GB(r, 16, 2)], tile);
 643                         break;
 644                 }
 645
 646                 default: break;
 647         }
 648 }
 649
 650 static void TileLoopTreesAlps(TileIndex tile)
 651 {
 652         int k = GetTileZ(tile) - GetSnowLine() + 1;
 653
 654         if (k < 0) {
 655                 switch (GetTreeGround(tile)) {
 656                         case TREE_GROUND_SNOW_DESERT: SetTreeGroundDensity(tile, TREE_GROUND_GRASS, 3); break;
 657                         case TREE_GROUND_ROUGH_SNOW:  SetTreeGroundDensity(tile, TREE_GROUND_ROUGH, 3); break;
 658                         default: return;
 659                 }
 660         } else {
 661                 uint density = std::min<uint>(k, 3);
 662
 663                 if (GetTreeGround(tile) != TREE_GROUND_SNOW_DESERT && GetTreeGround(tile) != TREE_GROUND_ROUGH_SNOW) {
 664                         TreeGround tg = GetTreeGround(tile) == TREE_GROUND_ROUGH ? TREE_GROUND_ROUGH_SNOW : TREE_GROUND_SNOW_DESERT;
 665                         SetTreeGroundDensity(tile, tg, density);
 666                 } else if (GetTreeDensity(tile) != density) {
 667                         SetTreeGroundDensity(tile, GetTreeGround(tile), density);
 668                 } else {
 669                         if (GetTreeDensity(tile) == 3) {
 670                                 uint32 r = Random();
 671                                 if (Chance16I(1, 200, r) && _settings_client.sound.ambient) {
 672                                         SndPlayTileFx((r & 0x80000000) ? SND_39_HEAVY_WIND : SND_34_WIND, tile);
 673                                 }
 674                         }
 675                         return;
 676                 }
 677         }
 678         MarkTileDirtyByTile(tile);
 679 }
 680
 681 static bool CanPlantExtraTrees(TileIndex tile)
 682 {
 683         return ((_settings_game.game_creation.landscape == LT_TROPIC && GetTropicZone(tile) == TROPICZONE_RAINFOREST) ?
 684                 (_settings_game.construction.extra_tree_placement == ETP_SPREAD_ALL || _settings_game.construction.extra_tree_placement == ETP_SPREAD_RAINFOREST) :
 685                 _settings_game.construction.extra_tree_placement == ETP_SPREAD_ALL);
 686 }
 687
 688 static void TileLoop_Trees(TileIndex tile)
 689 {
 690         if (GetTreeGround(tile) == TREE_GROUND_SHORE) {
 691                 TileLoop_Water(tile);
 692         } else {
 693                 switch (_settings_game.game_creation.landscape) {
 694                         case LT_TROPIC: TileLoopTreesDesert(tile); break;
 695                         case LT_ARCTIC: TileLoopTreesAlps(tile);   break;
 696                 }
 697         }
 698
 699         AmbientSoundEffect(tile);
 700
 701         uint treeCounter = GetTreeCounter(tile);
 702
 703         /* Handle growth of grass (under trees/on MP_TREES tiles) at every 8th processings, like it's done for grass on MP_CLEAR tiles. */
 704         if ((treeCounter & 7) == 7 && GetTreeGround(tile) == TREE_GROUND_GRASS) {
 705                 uint density = GetTreeDensity(tile);
 706                 if (density < 3) {
 707                         SetTreeGroundDensity(tile, TREE_GROUND_GRASS, density + 1);
 708                         MarkTileDirtyByTile(tile);
 709                 }
 710         }
 711
 712         if (_settings_game.construction.extra_tree_placement == ETP_NO_GROWTH_NO_SPREAD) return;
 713
 714         if (GetTreeCounter(tile) < 15) {
 715                 AddTreeCounter(tile, 1);
 716                 return;
 717         }
 718         SetTreeCounter(tile, 0);
 719
 720         switch (GetTreeGrowth(tile)) {
 721                 case 3: // regular sized tree
 722                         if (_settings_game.game_creation.landscape == LT_TROPIC &&
 723                                         GetTreeType(tile) != TREE_CACTUS &&
 724                                         GetTropicZone(tile) == TROPICZONE_DESERT) {
 725                                 AddTreeGrowth(tile, 1);
 726                         } else {
 727                                 switch (GB(Random(), 0, 3)) {
 728                                         case 0: // start destructing
 729                                                 AddTreeGrowth(tile, 1);
 730                                                 break;
 731
 732                                         case 1: // add a tree
 733                                                 if (GetTreeCount(tile) < 4 && CanPlantExtraTrees(tile)) {
 734                                                         AddTreeCount(tile, 1);
 735                                                         SetTreeGrowth(tile, 0);
 736                                                         break;
 737                                                 }
 738                                                 FALLTHROUGH;
 739
 740                                         case 2: { // add a neighbouring tree
 741                                                 if (!CanPlantExtraTrees(tile)) break;
 742
 743                                                 TreeType treetype = GetTreeType(tile);
 744
 745                                                 tile += TileOffsByDir((Direction)(Random() & 7));
 746
 747                                                 /* Cacti don't spread */
 748                                                 if (!CanPlantTreesOnTile(tile, false)) return;
 749
 750                                                 /* Don't plant trees, if ground was freshly cleared */
 751                                                 if (IsTileType(tile, MP_CLEAR) && GetClearGround(tile) == CLEAR_GRASS && GetClearDensity(tile) != 3) return;
 752
 753                                                 PlantTreesOnTile(tile, treetype, 0, 0);
 754
 755                                                 break;
 756                                         }
 757
 758                                         default:
 759                                                 return;
 760                                 }
 761                         }
 762                         break;
 763
 764                 case 6: // final stage of tree destruction
 765                         if (!CanPlantExtraTrees(tile)) {
 766                                 /* if trees can't spread just plant a new one to prevent deforestation */
 767                                 SetTreeGrowth(tile, 0);
 768                         } else if (GetTreeCount(tile) > 1) {
 769                                 /* more than one tree, delete it */
 770                                 AddTreeCount(tile, -1);
 771                                 SetTreeGrowth(tile, 3);
 772                         } else {
 773                                 /* just one tree, change type into MP_CLEAR */
 774                                 switch (GetTreeGround(tile)) {
 775                                         case TREE_GROUND_SHORE: MakeShore(tile); break;
 776                                         case TREE_GROUND_GRASS: MakeClear(tile, CLEAR_GRASS, GetTreeDensity(tile)); break;
 777                                         case TREE_GROUND_ROUGH: MakeClear(tile, CLEAR_ROUGH, 3); break;
 778                                         case TREE_GROUND_ROUGH_SNOW: {
 779                                                 uint density = GetTreeDensity(tile);
 780                                                 MakeClear(tile, CLEAR_ROUGH, 3);
 781                                                 MakeSnow(tile, density);
 782                                                 break;
 783                                         }
 784                                         default: // snow or desert
 785                                                 if (_settings_game.game_creation.landscape == LT_TROPIC) {
 786                                                         MakeClear(tile, CLEAR_DESERT, GetTreeDensity(tile));
 787                                                 } else {
 788                                                         uint density = GetTreeDensity(tile);
 789                                                         MakeClear(tile, CLEAR_GRASS, 3);
 790                                                         MakeSnow(tile, density);
 791                                                 }
 792                                                 break;
 793                                 }
 794                         }
 795                         break;
 796
 797                 default:
 798                         AddTreeGrowth(tile, 1);
 799                         break;
 800         }
 801
 802         MarkTileDirtyByTile(tile);
 803 }
 804
 805 void OnTick_Trees()
 806 {
 807         /* Don't spread trees if that's not allowed */
 808         if (_settings_game.construction.extra_tree_placement == ETP_NO_SPREAD || _settings_game.construction.extra_tree_placement == ETP_NO_GROWTH_NO_SPREAD) return;
 809
 810         uint32 r;
 811         TileIndex tile;
 812         TreeType tree;
 813
 814         /* place a tree at a random rainforest spot */
 815         if (_settings_game.game_creation.landscape == LT_TROPIC &&
 816                         (r = Random(), tile = RandomTileSeed(r), GetTropicZone(tile) == TROPICZONE_RAINFOREST) &&
 817                         CanPlantTreesOnTile(tile, false) &&
 818                         (tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
 819                 PlantTreesOnTile(tile, tree, 0, 0);
 820         }
 821
 822         /* byte underflow */
 823         if (--_trees_tick_ctr != 0 || _settings_game.construction.extra_tree_placement == ETP_SPREAD_RAINFOREST) return;
 824
 825         /* place a tree at a random spot */
 826         r = Random();
 827         tile = RandomTileSeed(r);
 828         if (CanPlantTreesOnTile(tile, false) && (tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
 829                 PlantTreesOnTile(tile, tree, 0, 0);
 830         }
 831 }
 832
 833 static TrackStatus GetTileTrackStatus_Trees(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
 834 {
 835         return 0;
 836 }
 837
 838 static void ChangeTileOwner_Trees(TileIndex tile, Owner old_owner, Owner new_owner)
 839 {
 840         /* not used */
 841 }
 842
 843 void InitializeTrees()
 844 {
 845         _trees_tick_ctr = 0;
 846 }
 847
 848 static CommandCost TerraformTile_Trees(TileIndex tile, DoCommandFlag flags, int z_new, Slope tileh_new)
 849 {
 850         return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
 851 }
 852
 853
 854 extern const TileTypeProcs _tile_type_trees_procs = {
 855         DrawTile_Trees,           // draw_tile_proc
 856         GetSlopePixelZ_Trees,     // get_slope_z_proc
 857         ClearTile_Trees,          // clear_tile_proc
 858         nullptr,                     // add_accepted_cargo_proc
 859         GetTileDesc_Trees,        // get_tile_desc_proc
 860         GetTileTrackStatus_Trees, // get_tile_track_status_proc
 861         nullptr,                     // click_tile_proc
 862         nullptr,                     // animate_tile_proc
 863         TileLoop_Trees,           // tile_loop_proc
 864         ChangeTileOwner_Trees,    // change_tile_owner_proc
 865         nullptr,                     // add_produced_cargo_proc
 866         nullptr,                     // vehicle_enter_tile_proc
 867         GetFoundation_Trees,      // get_foundation_proc
 868         TerraformTile_Trees,      // terraform_tile_proc
 869 };