tree_cmd.cpp

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00001 /* $Id$ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * 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.
00006  * 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.
00007  * 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/>.
00008  */
00009 
00012 #include "stdafx.h"
00013 #include "clear_map.h"
00014 #include "landscape.h"
00015 #include "tree_map.h"
00016 #include "viewport_func.h"
00017 #include "command_func.h"
00018 #include "town.h"
00019 #include "genworld.h"
00020 #include "clear_func.h"
00021 #include "company_func.h"
00022 #include "sound_func.h"
00023 #include "water.h"
00024 #include "company_base.h"
00025 #include "core/random_func.hpp"
00026 #include "newgrf_generic.h"
00027 
00028 #include "table/strings.h"
00029 #include "table/tree_land.h"
00030 #include "table/clear_land.h"
00031 
00037 enum TreePlacer {
00038   TP_NONE,     
00039   TP_ORIGINAL, 
00040   TP_IMPROVED, 
00041 };
00042 
00044 enum ExtraTreePlacement {
00045   ETP_NONE,       
00046   ETP_RAINFOREST, 
00047   ETP_ALL,        
00048 };
00049 
00051 byte _trees_tick_ctr;
00052 
00053 static const uint16 DEFAULT_TREE_STEPS = 1000;             
00054 static const uint16 DEFAULT_RAINFOREST_TREE_STEPS = 15000; 
00055 static const uint16 EDITOR_TREE_DIV = 5;                   
00056 
00065 static bool CanPlantTreesOnTile(TileIndex tile, bool allow_desert)
00066 {
00067   switch (GetTileType(tile)) {
00068     case MP_WATER:
00069       return !IsBridgeAbove(tile) && IsCoast(tile) && !IsSlopeWithOneCornerRaised(GetTileSlope(tile));
00070 
00071     case MP_CLEAR:
00072       return !IsBridgeAbove(tile) && !IsClearGround(tile, CLEAR_FIELDS) && GetRawClearGround(tile) != CLEAR_ROCKS &&
00073              (allow_desert || !IsClearGround(tile, CLEAR_DESERT));
00074 
00075     default: return false;
00076   }
00077 }
00078 
00090 static void PlantTreesOnTile(TileIndex tile, TreeType treetype, uint count, uint growth)
00091 {
00092   assert(treetype != TREE_INVALID);
00093   assert(CanPlantTreesOnTile(tile, true));
00094 
00095   TreeGround ground;
00096   uint density = 3;
00097 
00098   switch (GetTileType(tile)) {
00099     case MP_WATER:
00100       ground = TREE_GROUND_SHORE;
00101       break;
00102 
00103     case MP_CLEAR:
00104       switch (GetClearGround(tile)) {
00105         case CLEAR_GRASS:  ground = TREE_GROUND_GRASS;       break;
00106         case CLEAR_ROUGH:  ground = TREE_GROUND_ROUGH;       break;
00107         case CLEAR_SNOW:   ground = GetRawClearGround(tile) == CLEAR_ROUGH ? TREE_GROUND_ROUGH_SNOW : TREE_GROUND_SNOW_DESERT; break;
00108         default:           ground = TREE_GROUND_SNOW_DESERT; break;
00109       }
00110       if (GetClearGround(tile) != CLEAR_ROUGH) density = GetClearDensity(tile);
00111       break;
00112 
00113     default: NOT_REACHED();
00114   }
00115 
00116   MakeTree(tile, treetype, count, growth, ground, density);
00117 }
00118 
00130 static TreeType GetRandomTreeType(TileIndex tile, uint seed)
00131 {
00132   switch (_settings_game.game_creation.landscape) {
00133     case LT_TEMPERATE:
00134       return (TreeType)(seed * TREE_COUNT_TEMPERATE / 256 + TREE_TEMPERATE);
00135 
00136     case LT_ARCTIC:
00137       return (TreeType)(seed * TREE_COUNT_SUB_ARCTIC / 256 + TREE_SUB_ARCTIC);
00138 
00139     case LT_TROPIC:
00140       switch (GetTropicZone(tile)) {
00141         case TROPICZONE_NORMAL:  return (TreeType)(seed * TREE_COUNT_SUB_TROPICAL / 256 + TREE_SUB_TROPICAL);
00142         case TROPICZONE_DESERT:  return (TreeType)((seed > 12) ? TREE_INVALID : TREE_CACTUS);
00143         default:                 return (TreeType)(seed * TREE_COUNT_RAINFOREST / 256 + TREE_RAINFOREST);
00144       }
00145 
00146     default:
00147       return (TreeType)(seed * TREE_COUNT_TOYLAND / 256 + TREE_TOYLAND);
00148   }
00149 }
00150 
00160 static void PlaceTree(TileIndex tile, uint32 r)
00161 {
00162   TreeType tree = GetRandomTreeType(tile, GB(r, 24, 8));
00163 
00164   if (tree != TREE_INVALID) {
00165     PlantTreesOnTile(tile, tree, GB(r, 22, 2), min(GB(r, 16, 3), 6));
00166 
00167     /* Rerandomize ground, if neither snow nor shore */
00168     TreeGround ground = GetTreeGround(tile);
00169     if (ground != TREE_GROUND_SNOW_DESERT && ground != TREE_GROUND_ROUGH_SNOW && ground != TREE_GROUND_SHORE) {
00170       SetTreeGroundDensity(tile, (TreeGround)GB(r, 28, 1), 3);
00171     }
00172 
00173     /* Set the counter to a random start value */
00174     SetTreeCounter(tile, (TreeGround)GB(r, 24, 4));
00175   }
00176 }
00177 
00184 static void PlaceTreeGroups(uint num_groups)
00185 {
00186   do {
00187     TileIndex center_tile = RandomTile();
00188 
00189     for (uint i = 0; i < DEFAULT_TREE_STEPS; i++) {
00190       uint32 r = Random();
00191       int x = GB(r, 0, 5) - 16;
00192       int y = GB(r, 8, 5) - 16;
00193       uint dist = abs(x) + abs(y);
00194       TileIndex cur_tile = TileAddWrap(center_tile, x, y);
00195 
00196       IncreaseGeneratingWorldProgress(GWP_TREE);
00197 
00198       if (cur_tile != INVALID_TILE && dist <= 13 && CanPlantTreesOnTile(cur_tile, true)) {
00199         PlaceTree(cur_tile, r);
00200       }
00201     }
00202 
00203   } while (--num_groups);
00204 }
00205 
00215 static void PlaceTreeAtSameHeight(TileIndex tile, int height)
00216 {
00217   for (uint i = 0; i < DEFAULT_TREE_STEPS; i++) {
00218     uint32 r = Random();
00219     int x = GB(r, 0, 5) - 16;
00220     int y = GB(r, 8, 5) - 16;
00221     TileIndex cur_tile = TileAddWrap(tile, x, y);
00222     if (cur_tile == INVALID_TILE) continue;
00223 
00224     /* Keep in range of the existing tree */
00225     if (abs(x) + abs(y) > 16) continue;
00226 
00227     /* Clear tile, no farm-tiles or rocks */
00228     if (!CanPlantTreesOnTile(cur_tile, true)) continue;
00229 
00230     /* Not too much height difference */
00231     if (Delta(GetTileZ(cur_tile), height) > 2) continue;
00232 
00233     /* Place one tree and quit */
00234     PlaceTree(cur_tile, r);
00235     break;
00236   }
00237 }
00238 
00244 void PlaceTreesRandomly()
00245 {
00246   int i, j, ht;
00247 
00248   i = ScaleByMapSize(DEFAULT_TREE_STEPS);
00249   if (_game_mode == GM_EDITOR) i /= EDITOR_TREE_DIV;
00250   do {
00251     uint32 r = Random();
00252     TileIndex tile = RandomTileSeed(r);
00253 
00254     IncreaseGeneratingWorldProgress(GWP_TREE);
00255 
00256     if (CanPlantTreesOnTile(tile, true)) {
00257       PlaceTree(tile, r);
00258       if (_settings_game.game_creation.tree_placer != TP_IMPROVED) continue;
00259 
00260       /* Place a number of trees based on the tile height.
00261        *  This gives a cool effect of multiple trees close together.
00262        *  It is almost real life ;) */
00263       ht = GetTileZ(tile);
00264       /* The higher we get, the more trees we plant */
00265       j = GetTileZ(tile) * 2;
00266       /* Above snowline more trees! */
00267       if (_settings_game.game_creation.landscape == LT_ARCTIC && ht > GetSnowLine()) j *= 3;
00268       while (j--) {
00269         PlaceTreeAtSameHeight(tile, ht);
00270       }
00271     }
00272   } while (--i);
00273 
00274   /* place extra trees at rainforest area */
00275   if (_settings_game.game_creation.landscape == LT_TROPIC) {
00276     i = ScaleByMapSize(DEFAULT_RAINFOREST_TREE_STEPS);
00277     if (_game_mode == GM_EDITOR) i /= EDITOR_TREE_DIV;
00278 
00279     do {
00280       uint32 r = Random();
00281       TileIndex tile = RandomTileSeed(r);
00282 
00283       IncreaseGeneratingWorldProgress(GWP_TREE);
00284 
00285       if (GetTropicZone(tile) == TROPICZONE_RAINFOREST && CanPlantTreesOnTile(tile, false)) {
00286         PlaceTree(tile, r);
00287       }
00288     } while (--i);
00289   }
00290 }
00291 
00298 void GenerateTrees()
00299 {
00300   uint i, total;
00301 
00302   if (_settings_game.game_creation.tree_placer == TP_NONE) return;
00303 
00304   switch (_settings_game.game_creation.tree_placer) {
00305     case TP_ORIGINAL: i = _settings_game.game_creation.landscape == LT_ARCTIC ? 15 : 6; break;
00306     case TP_IMPROVED: i = _settings_game.game_creation.landscape == LT_ARCTIC ?  4 : 2; break;
00307     default: NOT_REACHED();
00308   }
00309 
00310   total = ScaleByMapSize(DEFAULT_TREE_STEPS);
00311   if (_settings_game.game_creation.landscape == LT_TROPIC) total += ScaleByMapSize(DEFAULT_RAINFOREST_TREE_STEPS);
00312   total *= i;
00313   uint num_groups = (_settings_game.game_creation.landscape != LT_TOYLAND) ? ScaleByMapSize(GB(Random(), 0, 5) + 25) : 0;
00314   total += num_groups * DEFAULT_TREE_STEPS;
00315   SetGeneratingWorldProgress(GWP_TREE, total);
00316 
00317   if (num_groups != 0) PlaceTreeGroups(num_groups);
00318 
00319   for (; i != 0; i--) {
00320     PlaceTreesRandomly();
00321   }
00322 }
00323 
00333 CommandCost CmdPlantTree(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00334 {
00335   StringID msg = INVALID_STRING_ID;
00336   CommandCost cost(EXPENSES_OTHER);
00337   const byte tree_to_plant = GB(p1, 0, 8); // We cannot use Extract as min and max are climate specific.
00338 
00339   if (p2 >= MapSize()) return CMD_ERROR;
00340   /* Check the tree type within the current climate */
00341   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;
00342 
00343   TileArea ta(tile, p2);
00344   TILE_AREA_LOOP(tile, ta) {
00345     switch (GetTileType(tile)) {
00346       case MP_TREES:
00347         /* no more space for trees? */
00348         if (_game_mode != GM_EDITOR && GetTreeCount(tile) == 4) {
00349           msg = STR_ERROR_TREE_ALREADY_HERE;
00350           continue;
00351         }
00352 
00353         if (flags & DC_EXEC) {
00354           AddTreeCount(tile, 1);
00355           MarkTileDirtyByTile(tile);
00356         }
00357         /* 2x as expensive to add more trees to an existing tile */
00358         cost.AddCost(_price[PR_BUILD_TREES] * 2);
00359         break;
00360 
00361       case MP_WATER:
00362         if (!IsCoast(tile) || IsSlopeWithOneCornerRaised(GetTileSlope(tile))) {
00363           msg = STR_ERROR_CAN_T_BUILD_ON_WATER;
00364           continue;
00365         }
00366         /* FALL THROUGH */
00367       case MP_CLEAR: {
00368         if (IsBridgeAbove(tile)) {
00369           msg = STR_ERROR_SITE_UNSUITABLE;
00370           continue;
00371         }
00372 
00373         TreeType treetype = (TreeType)tree_to_plant;
00374         /* Be a bit picky about which trees go where. */
00375         if (_settings_game.game_creation.landscape == LT_TROPIC && treetype != TREE_INVALID && (
00376             /* No cacti outside the desert */
00377             (treetype == TREE_CACTUS && GetTropicZone(tile) != TROPICZONE_DESERT) ||
00378             /* No rain forest trees outside the rain forest, except in the editor mode where it makes those tiles rain forest tile */
00379             (IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS) && GetTropicZone(tile) != TROPICZONE_RAINFOREST && _game_mode != GM_EDITOR) ||
00380             /* And no subtropical trees in the desert/rain forest */
00381             (IsInsideMM(treetype, TREE_SUB_TROPICAL, TREE_TOYLAND) && GetTropicZone(tile) != TROPICZONE_NORMAL))) {
00382           msg = STR_ERROR_TREE_WRONG_TERRAIN_FOR_TREE_TYPE;
00383           continue;
00384         }
00385 
00386         if (IsTileType(tile, MP_CLEAR)) {
00387           /* Remove fields or rocks. Note that the ground will get barrened */
00388           switch (GetRawClearGround(tile)) {
00389             case CLEAR_FIELDS:
00390             case CLEAR_ROCKS: {
00391               CommandCost ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00392               if (ret.Failed()) return ret;
00393               cost.AddCost(ret);
00394               break;
00395             }
00396 
00397             default: break;
00398           }
00399         }
00400 
00401         if (_game_mode != GM_EDITOR && Company::IsValidID(_current_company)) {
00402           Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
00403           if (t != NULL) ChangeTownRating(t, RATING_TREE_UP_STEP, RATING_TREE_MAXIMUM, flags);
00404         }
00405 
00406         if (flags & DC_EXEC) {
00407           if (treetype == TREE_INVALID) {
00408             treetype = GetRandomTreeType(tile, GB(Random(), 24, 8));
00409             if (treetype == TREE_INVALID) treetype = TREE_CACTUS;
00410           }
00411 
00412           /* Plant full grown trees in scenario editor */
00413           PlantTreesOnTile(tile, treetype, 0, _game_mode == GM_EDITOR ? 3 : 0);
00414           MarkTileDirtyByTile(tile);
00415 
00416           /* When planting rainforest-trees, set tropiczone to rainforest in editor. */
00417           if (_game_mode == GM_EDITOR && IsInsideMM(treetype, TREE_RAINFOREST, TREE_CACTUS)) {
00418             SetTropicZone(tile, TROPICZONE_RAINFOREST);
00419           }
00420         }
00421         cost.AddCost(_price[PR_BUILD_TREES]);
00422         break;
00423       }
00424 
00425       default:
00426         msg = STR_ERROR_SITE_UNSUITABLE;
00427         break;
00428     }
00429   }
00430 
00431   if (cost.GetCost() == 0) {
00432     return_cmd_error(msg);
00433   } else {
00434     return cost;
00435   }
00436 }
00437 
00438 struct TreeListEnt : PalSpriteID {
00439   byte x, y;
00440 };
00441 
00442 static void DrawTile_Trees(TileInfo *ti)
00443 {
00444   switch (GetTreeGround(ti->tile)) {
00445     case TREE_GROUND_SHORE: DrawShoreTile(ti->tileh); break;
00446     case TREE_GROUND_GRASS: DrawClearLandTile(ti, GetTreeDensity(ti->tile)); break;
00447     case TREE_GROUND_ROUGH: DrawHillyLandTile(ti); break;
00448     default: DrawGroundSprite(_clear_land_sprites_snow_desert[GetTreeDensity(ti->tile)] + SlopeToSpriteOffset(ti->tileh), PAL_NONE); break;
00449   }
00450 
00451   /* Do not draw trees when the invisible trees setting is set */
00452   if (IsInvisibilitySet(TO_TREES)) return;
00453 
00454   uint tmp = CountBits(ti->tile + ti->x + ti->y);
00455   uint index = GB(tmp, 0, 2) + (GetTreeType(ti->tile) << 2);
00456 
00457   /* different tree styles above one of the grounds */
00458   if ((GetTreeGround(ti->tile) == TREE_GROUND_SNOW_DESERT || GetTreeGround(ti->tile) == TREE_GROUND_ROUGH_SNOW) &&
00459       GetTreeDensity(ti->tile) >= 2 &&
00460       IsInsideMM(index, TREE_SUB_ARCTIC << 2, TREE_RAINFOREST << 2)) {
00461     index += 164 - (TREE_SUB_ARCTIC << 2);
00462   }
00463 
00464   assert(index < lengthof(_tree_layout_sprite));
00465 
00466   const PalSpriteID *s = _tree_layout_sprite[index];
00467   const TreePos *d = _tree_layout_xy[GB(tmp, 2, 2)];
00468 
00469   /* combine trees into one sprite object */
00470   StartSpriteCombine();
00471 
00472   TreeListEnt te[4];
00473 
00474   /* put the trees to draw in a list */
00475   uint trees = GetTreeCount(ti->tile);
00476 
00477   for (uint i = 0; i < trees; i++) {
00478     SpriteID sprite = s[0].sprite + (i == trees - 1 ? GetTreeGrowth(ti->tile) : 3);
00479     PaletteID pal = s[0].pal;
00480 
00481     te[i].sprite = sprite;
00482     te[i].pal    = pal;
00483     te[i].x = d->x;
00484     te[i].y = d->y;
00485     s++;
00486     d++;
00487   }
00488 
00489   /* draw them in a sorted way */
00490   int z = ti->z + GetSlopeMaxPixelZ(ti->tileh) / 2;
00491 
00492   for (; trees > 0; trees--) {
00493     uint min = te[0].x + te[0].y;
00494     uint mi = 0;
00495 
00496     for (uint i = 1; i < trees; i++) {
00497       if ((uint)(te[i].x + te[i].y) < min) {
00498         min = te[i].x + te[i].y;
00499         mi = i;
00500       }
00501     }
00502 
00503     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);
00504 
00505     /* replace the removed one with the last one */
00506     te[mi] = te[trees - 1];
00507   }
00508 
00509   EndSpriteCombine();
00510 }
00511 
00512 
00513 static int GetSlopePixelZ_Trees(TileIndex tile, uint x, uint y)
00514 {
00515   int z;
00516   Slope tileh = GetTilePixelSlope(tile, &z);
00517 
00518   return z + GetPartialPixelZ(x & 0xF, y & 0xF, tileh);
00519 }
00520 
00521 static Foundation GetFoundation_Trees(TileIndex tile, Slope tileh)
00522 {
00523   return FOUNDATION_NONE;
00524 }
00525 
00526 static CommandCost ClearTile_Trees(TileIndex tile, DoCommandFlag flags)
00527 {
00528   uint num;
00529 
00530   if (Company::IsValidID(_current_company)) {
00531     Town *t = ClosestTownFromTile(tile, _settings_game.economy.dist_local_authority);
00532     if (t != NULL) ChangeTownRating(t, RATING_TREE_DOWN_STEP, RATING_TREE_MINIMUM, flags);
00533   }
00534 
00535   num = GetTreeCount(tile);
00536   if (IsInsideMM(GetTreeType(tile), TREE_RAINFOREST, TREE_CACTUS)) num *= 4;
00537 
00538   if (flags & DC_EXEC) DoClearSquare(tile);
00539 
00540   return CommandCost(EXPENSES_CONSTRUCTION, num * _price[PR_CLEAR_TREES]);
00541 }
00542 
00543 static void GetTileDesc_Trees(TileIndex tile, TileDesc *td)
00544 {
00545   TreeType tt = GetTreeType(tile);
00546 
00547   if (IsInsideMM(tt, TREE_RAINFOREST, TREE_CACTUS)) {
00548     td->str = STR_LAI_TREE_NAME_RAINFOREST;
00549   } else {
00550     td->str = tt == TREE_CACTUS ? STR_LAI_TREE_NAME_CACTUS_PLANTS : STR_LAI_TREE_NAME_TREES;
00551   }
00552 
00553   td->owner[0] = GetTileOwner(tile);
00554 }
00555 
00556 static void TileLoopTreesDesert(TileIndex tile)
00557 {
00558   switch (GetTropicZone(tile)) {
00559     case TROPICZONE_DESERT:
00560       if (GetTreeGround(tile) != TREE_GROUND_SNOW_DESERT) {
00561         SetTreeGroundDensity(tile, TREE_GROUND_SNOW_DESERT, 3);
00562         MarkTileDirtyByTile(tile);
00563       }
00564       break;
00565 
00566     case TROPICZONE_RAINFOREST: {
00567       static const SoundFx forest_sounds[] = {
00568         SND_42_LOON_BIRD,
00569         SND_43_LION,
00570         SND_44_MONKEYS,
00571         SND_48_DISTANT_BIRD
00572       };
00573       uint32 r = Random();
00574 
00575       if (Chance16I(1, 200, r)) SndPlayTileFx(forest_sounds[GB(r, 16, 2)], tile);
00576       break;
00577     }
00578 
00579     default: break;
00580   }
00581 }
00582 
00583 static void TileLoopTreesAlps(TileIndex tile)
00584 {
00585   int k = GetTileZ(tile) - GetSnowLine() + 1;
00586 
00587   if (k < 0) {
00588     switch (GetTreeGround(tile)) {
00589       case TREE_GROUND_SNOW_DESERT: SetTreeGroundDensity(tile, TREE_GROUND_GRASS, 3); break;
00590       case TREE_GROUND_ROUGH_SNOW:  SetTreeGroundDensity(tile, TREE_GROUND_ROUGH, 3); break;
00591       default: return;
00592     }
00593   } else {
00594     uint density = min<uint>(k, 3);
00595 
00596     if (GetTreeGround(tile) != TREE_GROUND_SNOW_DESERT && GetTreeGround(tile) != TREE_GROUND_ROUGH_SNOW) {
00597       TreeGround tg = GetTreeGround(tile) == TREE_GROUND_ROUGH ? TREE_GROUND_ROUGH_SNOW : TREE_GROUND_SNOW_DESERT;
00598       SetTreeGroundDensity(tile, tg, density);
00599     } else if (GetTreeDensity(tile) != density) {
00600       SetTreeGroundDensity(tile, GetTreeGround(tile), density);
00601     } else {
00602       if (GetTreeDensity(tile) == 3) {
00603         uint32 r = Random();
00604         if (Chance16I(1, 200, r)) {
00605           SndPlayTileFx((r & 0x80000000) ? SND_39_HEAVY_WIND : SND_34_WIND, tile);
00606         }
00607       }
00608       return;
00609     }
00610   }
00611   MarkTileDirtyByTile(tile);
00612 }
00613 
00614 static void TileLoop_Trees(TileIndex tile)
00615 {
00616   if (GetTreeGround(tile) == TREE_GROUND_SHORE) {
00617     TileLoop_Water(tile);
00618   } else {
00619     switch (_settings_game.game_creation.landscape) {
00620       case LT_TROPIC: TileLoopTreesDesert(tile); break;
00621       case LT_ARCTIC: TileLoopTreesAlps(tile);   break;
00622     }
00623   }
00624 
00625   AmbientSoundEffect(tile);
00626 
00627   uint treeCounter = GetTreeCounter(tile);
00628 
00629   /* Handle growth of grass (under trees/on MP_TREES tiles) at every 8th processings, like it's done for grass on MP_CLEAR tiles. */
00630   if ((treeCounter & 7) == 7 && GetTreeGround(tile) == TREE_GROUND_GRASS) {
00631     uint density = GetTreeDensity(tile);
00632     if (density < 3) {
00633       SetTreeGroundDensity(tile, TREE_GROUND_GRASS, density + 1);
00634       MarkTileDirtyByTile(tile);
00635     }
00636   }
00637   if (GetTreeCounter(tile) < 15) {
00638     AddTreeCounter(tile, 1);
00639     return;
00640   }
00641   SetTreeCounter(tile, 0);
00642 
00643   switch (GetTreeGrowth(tile)) {
00644     case 3: // regular sized tree
00645       if (_settings_game.game_creation.landscape == LT_TROPIC &&
00646           GetTreeType(tile) != TREE_CACTUS &&
00647           GetTropicZone(tile) == TROPICZONE_DESERT) {
00648         AddTreeGrowth(tile, 1);
00649       } else {
00650         switch (GB(Random(), 0, 3)) {
00651           case 0: // start destructing
00652             AddTreeGrowth(tile, 1);
00653             break;
00654 
00655           case 1: // add a tree
00656             if (GetTreeCount(tile) < 4) {
00657               AddTreeCount(tile, 1);
00658               SetTreeGrowth(tile, 0);
00659               break;
00660             }
00661             /* FALL THROUGH */
00662 
00663           case 2: { // add a neighbouring tree
00664             /* Don't plant extra trees if that's not allowed. */
00665             if ((_settings_game.game_creation.landscape == LT_TROPIC && GetTropicZone(tile) == TROPICZONE_RAINFOREST) ?
00666                 _settings_game.construction.extra_tree_placement == ETP_NONE :
00667                 _settings_game.construction.extra_tree_placement != ETP_ALL) {
00668               break;
00669             }
00670 
00671             TreeType treetype = GetTreeType(tile);
00672 
00673             tile += TileOffsByDir((Direction)(Random() & 7));
00674 
00675             /* Cacti don't spread */
00676             if (!CanPlantTreesOnTile(tile, false)) return;
00677 
00678             /* Don't plant trees, if ground was freshly cleared */
00679             if (IsTileType(tile, MP_CLEAR) && GetClearGround(tile) == CLEAR_GRASS && GetClearDensity(tile) != 3) return;
00680 
00681             PlantTreesOnTile(tile, treetype, 0, 0);
00682 
00683             break;
00684           }
00685 
00686           default:
00687             return;
00688         }
00689       }
00690       break;
00691 
00692     case 6: // final stage of tree destruction
00693       if (GetTreeCount(tile) > 1) {
00694         /* more than one tree, delete it */
00695         AddTreeCount(tile, -1);
00696         SetTreeGrowth(tile, 3);
00697       } else {
00698         /* just one tree, change type into MP_CLEAR */
00699         switch (GetTreeGround(tile)) {
00700           case TREE_GROUND_SHORE: MakeShore(tile); break;
00701           case TREE_GROUND_GRASS: MakeClear(tile, CLEAR_GRASS, GetTreeDensity(tile)); break;
00702           case TREE_GROUND_ROUGH: MakeClear(tile, CLEAR_ROUGH, 3); break;
00703           case TREE_GROUND_ROUGH_SNOW: {
00704             uint density = GetTreeDensity(tile);
00705             MakeClear(tile, CLEAR_ROUGH, 3);
00706             MakeSnow(tile, density);
00707             break;
00708           }
00709           default: // snow or desert
00710             if (_settings_game.game_creation.landscape == LT_TROPIC) {
00711               MakeClear(tile, CLEAR_DESERT, GetTreeDensity(tile));
00712             } else {
00713               uint density = GetTreeDensity(tile);
00714               MakeClear(tile, CLEAR_GRASS, 3);
00715               MakeSnow(tile, density);
00716             }
00717             break;
00718         }
00719       }
00720       break;
00721 
00722     default:
00723       AddTreeGrowth(tile, 1);
00724       break;
00725   }
00726 
00727   MarkTileDirtyByTile(tile);
00728 }
00729 
00730 void OnTick_Trees()
00731 {
00732   /* Don't place trees if that's not allowed */
00733   if (_settings_game.construction.extra_tree_placement == ETP_NONE) return;
00734 
00735   uint32 r;
00736   TileIndex tile;
00737   TreeType tree;
00738 
00739   /* place a tree at a random rainforest spot */
00740   if (_settings_game.game_creation.landscape == LT_TROPIC &&
00741       (r = Random(), tile = RandomTileSeed(r), GetTropicZone(tile) == TROPICZONE_RAINFOREST) &&
00742       CanPlantTreesOnTile(tile, false) &&
00743       (tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
00744     PlantTreesOnTile(tile, tree, 0, 0);
00745   }
00746 
00747   /* byte underflow */
00748   if (--_trees_tick_ctr != 0 || _settings_game.construction.extra_tree_placement != ETP_ALL) return;
00749 
00750   /* place a tree at a random spot */
00751   r = Random();
00752   tile = RandomTileSeed(r);
00753   if (CanPlantTreesOnTile(tile, false) && (tree = GetRandomTreeType(tile, GB(r, 24, 8))) != TREE_INVALID) {
00754     PlantTreesOnTile(tile, tree, 0, 0);
00755   }
00756 }
00757 
00758 static TrackStatus GetTileTrackStatus_Trees(TileIndex tile, TransportType mode, uint sub_mode, DiagDirection side)
00759 {
00760   return 0;
00761 }
00762 
00763 static void ChangeTileOwner_Trees(TileIndex tile, Owner old_owner, Owner new_owner)
00764 {
00765   /* not used */
00766 }
00767 
00768 void InitializeTrees()
00769 {
00770   _trees_tick_ctr = 0;
00771 }
00772 
00773 static CommandCost TerraformTile_Trees(TileIndex tile, DoCommandFlag flags, int z_new, Slope tileh_new)
00774 {
00775   return DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
00776 }
00777 
00778 
00779 extern const TileTypeProcs _tile_type_trees_procs = {
00780   DrawTile_Trees,           // draw_tile_proc
00781   GetSlopePixelZ_Trees,     // get_slope_z_proc
00782   ClearTile_Trees,          // clear_tile_proc
00783   NULL,                     // add_accepted_cargo_proc
00784   GetTileDesc_Trees,        // get_tile_desc_proc
00785   GetTileTrackStatus_Trees, // get_tile_track_status_proc
00786   NULL,                     // click_tile_proc
00787   NULL,                     // animate_tile_proc
00788   TileLoop_Trees,           // tile_loop_proc
00789   ChangeTileOwner_Trees,    // change_tile_owner_proc
00790   NULL,                     // add_produced_cargo_proc
00791   NULL,                     // vehicle_enter_tile_proc
00792   GetFoundation_Trees,      // get_foundation_proc
00793   TerraformTile_Trees,      // terraform_tile_proc
00794 };