src/terraform_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 terraform_cmd.cpp Commands related to terraforming. */
   9
  10 #include "stdafx.h"
  11 #include "command_func.h"
  12 #include "tunnel_map.h"
  13 #include "bridge_map.h"
  14 #include "viewport_func.h"
  15 #include "genworld.h"
  16 #include "object_base.h"
  17 #include "company_base.h"
  18 #include "company_func.h"
  19 #include "core/backup_type.hpp"
  20 #include "terraform_cmd.h"
  21 #include "landscape_cmd.h"
  22
  23 #include "table/strings.h"
  24
  25 #include "safeguards.h"
  26
  27 /** Set of tiles. */
  28 typedef std::set<TileIndex> TileIndexSet;
  29 /** Mapping of tiles to their height. */
  30 typedef std::map<TileIndex, int> TileIndexToHeightMap;
  31
  32 /** State of the terraforming. */
  33 struct TerraformerState {
  34         TileIndexSet dirty_tiles;                ///< The tiles that need to be redrawn.
  35         TileIndexToHeightMap tile_to_new_height; ///< The tiles for which the height has changed.
  36 };
  37
  38 /**
  39  * Gets the TileHeight (height of north corner) of a tile as of current terraforming progress.
  40  *
  41  * @param ts TerraformerState.
  42  * @param tile Tile.
  43  * @return TileHeight.
  44  */
  45 static int TerraformGetHeightOfTile(const TerraformerState *ts, TileIndex tile)
  46 {
  47         TileIndexToHeightMap::const_iterator it = ts->tile_to_new_height.find(tile);
  48         return it != ts->tile_to_new_height.end() ? it->second : TileHeight(tile);
  49 }
  50
  51 /**
  52  * Stores the TileHeight (height of north corner) of a tile in a TerraformerState.
  53  *
  54  * @param ts TerraformerState.
  55  * @param tile Tile.
  56  * @param height New TileHeight.
  57  */
  58 static void TerraformSetHeightOfTile(TerraformerState *ts, TileIndex tile, int height)
  59 {
  60         ts->tile_to_new_height[tile] = height;
  61 }
  62
  63 /**
  64  * Adds a tile to the "tile_table" in a TerraformerState.
  65  *
  66  * @param ts TerraformerState.
  67  * @param tile Tile.
  68  * @ingroup dirty
  69  */
  70 static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
  71 {
  72         ts->dirty_tiles.insert(tile);
  73 }
  74
  75 /**
  76  * Adds all tiles that incident with the north corner of a specific tile to the "tile_table" in a TerraformerState.
  77  *
  78  * @param ts TerraformerState.
  79  * @param tile Tile.
  80  * @ingroup dirty
  81  */
  82 static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
  83 {
  84         /* Make sure all tiles passed to TerraformAddDirtyTile are within [0, Map::Size()] */
  85         if (TileY(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY( 0, -1));
  86         if (TileY(tile) >= 1 && TileX(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY(-1, -1));
  87         if (TileX(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY(-1,  0));
  88         TerraformAddDirtyTile(ts, tile);
  89 }
  90
  91 /**
  92  * Terraform the north corner of a tile to a specific height.
  93  *
  94  * @param ts TerraformerState.
  95  * @param tile Tile.
  96  * @param height Aimed height.
  97  * @return Error code or cost.
  98  */
  99 static std::tuple<CommandCost, TileIndex> TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height)
 100 {
 101         assert(tile < Map::Size());
 102
 103         /* Check range of destination height */
 104         if (height < 0) return { CommandCost(STR_ERROR_ALREADY_AT_SEA_LEVEL), INVALID_TILE };
 105         if (height > _settings_game.construction.map_height_limit) return { CommandCost(STR_ERROR_TOO_HIGH), INVALID_TILE };
 106
 107         /*
 108          * Check if the terraforming has any effect.
 109          * This can only be true, if multiple corners of the start-tile are terraformed (i.e. the terraforming is done by towns/industries etc.).
 110          * In this case the terraforming should fail. (Don't know why.)
 111          */
 112         if (height == TerraformGetHeightOfTile(ts, tile)) return { CMD_ERROR, INVALID_TILE };
 113
 114         /* Check "too close to edge of map". Only possible when freeform-edges is off. */
 115         uint x = TileX(tile);
 116         uint y = TileY(tile);
 117         if (!_settings_game.construction.freeform_edges && ((x <= 1) || (y <= 1) || (x >= Map::MaxX() - 1) || (y >= Map::MaxY() - 1))) {
 118                 /*
 119                  * Determine a sensible error tile
 120                  */
 121                 if (x == 1) x = 0;
 122                 if (y == 1) y = 0;
 123                 return { CommandCost(STR_ERROR_TOO_CLOSE_TO_EDGE_OF_MAP), TileXY(x, y) };
 124         }
 125
 126         /* Mark incident tiles that are involved in the terraforming. */
 127         TerraformAddDirtyTileAround(ts, tile);
 128
 129         /* Store the height modification */
 130         TerraformSetHeightOfTile(ts, tile, height);
 131
 132         CommandCost total_cost(EXPENSES_CONSTRUCTION);
 133
 134         /* Increment cost */
 135         total_cost.AddCost(_price[PR_TERRAFORM]);
 136
 137         /* Recurse to neighboured corners if height difference is larger than 1 */
 138         {
 139                 const TileIndexDiffC *ttm;
 140
 141                 TileIndex orig_tile = tile;
 142                 static const TileIndexDiffC _terraform_tilepos[] = {
 143                         { 1,  0}, // move to tile in SE
 144                         {-2,  0}, // undo last move, and move to tile in NW
 145                         { 1,  1}, // undo last move, and move to tile in SW
 146                         { 0, -2}  // undo last move, and move to tile in NE
 147                 };
 148
 149                 for (ttm = _terraform_tilepos; ttm != endof(_terraform_tilepos); ttm++) {
 150                         tile += ToTileIndexDiff(*ttm);
 151
 152                         if (tile >= Map::Size()) continue;
 153                         /* Make sure we don't wrap around the map */
 154                         if (Delta(TileX(orig_tile), TileX(tile)) == Map::SizeX() - 1) continue;
 155                         if (Delta(TileY(orig_tile), TileY(tile)) == Map::SizeY() - 1) continue;
 156
 157                         /* Get TileHeight of neighboured tile as of current terraform progress */
 158                         int r = TerraformGetHeightOfTile(ts, tile);
 159                         int height_diff = height - r;
 160
 161                         /* Is the height difference to the neighboured corner greater than 1? */
 162                         if (abs(height_diff) > 1) {
 163                                 /* Terraform the neighboured corner. The resulting height difference should be 1. */
 164                                 height_diff += (height_diff < 0 ? 1 : -1);
 165                                 auto [cost, err_tile] = TerraformTileHeight(ts, tile, r + height_diff);
 166                                 if (cost.Failed()) return { cost, err_tile };
 167                                 total_cost.AddCost(cost);
 168                         }
 169                 }
 170         }
 171
 172         return { total_cost, INVALID_TILE };
 173 }
 174
 175 /**
 176  * Terraform land
 177  * @param flags for this command type
 178  * @param tile tile to terraform
 179  * @param slope corners to terraform (SLOPE_xxx)
 180  * @param dir_up direction; eg up (true) or down (false)
 181  * @return the cost of this operation or an error
 182  */
 183 std::tuple<CommandCost, Money, TileIndex> CmdTerraformLand(DoCommandFlag flags, TileIndex tile, Slope slope, bool dir_up)
 184 {
 185         CommandCost total_cost(EXPENSES_CONSTRUCTION);
 186         int direction = (dir_up ? 1 : -1);
 187         TerraformerState ts;
 188
 189         /* Compute the costs and the terraforming result in a model of the landscape */
 190         if ((slope & SLOPE_W) != 0 && tile + TileDiffXY(1, 0) < Map::Size()) {
 191                 TileIndex t = tile + TileDiffXY(1, 0);
 192                 auto [cost, err_tile] = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 193                 if (cost.Failed()) return { cost, 0, err_tile };
 194                 total_cost.AddCost(cost);
 195         }
 196
 197         if ((slope & SLOPE_S) != 0 && tile + TileDiffXY(1, 1) < Map::Size()) {
 198                 TileIndex t = tile + TileDiffXY(1, 1);
 199                 auto [cost, err_tile] = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 200                 if (cost.Failed()) return { cost, 0, err_tile };
 201                 total_cost.AddCost(cost);
 202         }
 203
 204         if ((slope & SLOPE_E) != 0 && tile + TileDiffXY(0, 1) < Map::Size()) {
 205                 TileIndex t = tile + TileDiffXY(0, 1);
 206                 auto [cost, err_tile] = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 207                 if (cost.Failed()) return { cost, 0, err_tile };
 208                 total_cost.AddCost(cost);
 209         }
 210
 211         if ((slope & SLOPE_N) != 0) {
 212                 TileIndex t = tile + TileDiffXY(0, 0);
 213                 auto [cost, err_tile] = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 214                 if (cost.Failed()) return { cost, 0, err_tile };
 215                 total_cost.AddCost(cost);
 216         }
 217
 218         /* Check if the terraforming is valid wrt. tunnels, bridges and objects on the surface
 219          * Pass == 0: Collect tileareas which are caused to be auto-cleared.
 220          * Pass == 1: Collect the actual cost. */
 221         for (int pass = 0; pass < 2; pass++) {
 222                 for (const auto &t : ts.dirty_tiles) {
 223                         assert(t < Map::Size());
 224                         /* MP_VOID tiles can be terraformed but as tunnels and bridges
 225                          * cannot go under / over these tiles they don't need checking. */
 226                         if (IsTileType(t, MP_VOID)) continue;
 227
 228                         /* Find new heights of tile corners */
 229                         int z_N = TerraformGetHeightOfTile(&ts, t + TileDiffXY(0, 0));
 230                         int z_W = TerraformGetHeightOfTile(&ts, t + TileDiffXY(1, 0));
 231                         int z_S = TerraformGetHeightOfTile(&ts, t + TileDiffXY(1, 1));
 232                         int z_E = TerraformGetHeightOfTile(&ts, t + TileDiffXY(0, 1));
 233
 234                         /* Find min and max height of tile */
 235                         int z_min = std::min({z_N, z_W, z_S, z_E});
 236                         int z_max = std::max({z_N, z_W, z_S, z_E});
 237
 238                         /* Compute tile slope */
 239                         Slope tileh = (z_max > z_min + 1 ? SLOPE_STEEP : SLOPE_FLAT);
 240                         if (z_W > z_min) tileh |= SLOPE_W;
 241                         if (z_S > z_min) tileh |= SLOPE_S;
 242                         if (z_E > z_min) tileh |= SLOPE_E;
 243                         if (z_N > z_min) tileh |= SLOPE_N;
 244
 245                         if (pass == 0) {
 246                                 /* Check if bridge would take damage */
 247                                 if (IsBridgeAbove(t)) {
 248                                         int bridge_height = GetBridgeHeight(GetSouthernBridgeEnd(t));
 249
 250                                         /* Check if bridge would take damage. */
 251                                         if (direction == 1 && bridge_height <= z_max) {
 252                                                 return { CommandCost(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST), 0, t }; // highlight the tile under the bridge
 253                                         }
 254
 255                                         /* Is the bridge above not too high afterwards? */
 256                                         if (direction == -1 && bridge_height > (z_min + _settings_game.construction.max_bridge_height)) {
 257                                                 return { CommandCost(STR_ERROR_BRIDGE_TOO_HIGH_AFTER_LOWER_LAND), 0, t };
 258                                         }
 259                                 }
 260                                 /* Check if tunnel would take damage */
 261                                 if (direction == -1 && IsTunnelInWay(t, z_min)) {
 262                                         return { CommandCost(STR_ERROR_EXCAVATION_WOULD_DAMAGE), 0, t }; // highlight the tile above the tunnel
 263                                 }
 264                         }
 265
 266                         /* Is the tile already cleared? */
 267                         const ClearedObjectArea *coa = FindClearedObject(t);
 268                         bool indirectly_cleared = coa != nullptr && coa->first_tile != t;
 269
 270                         /* Check tiletype-specific things, and add extra-cost */
 271                         Backup<bool> old_generating_world(_generating_world, FILE_LINE);
 272                         if (_game_mode == GM_EDITOR) old_generating_world.Change(true); // used to create green terraformed land
 273                         DoCommandFlag tile_flags = flags | DC_AUTO | DC_FORCE_CLEAR_TILE;
 274                         if (pass == 0) {
 275                                 tile_flags &= ~DC_EXEC;
 276                                 tile_flags |= DC_NO_MODIFY_TOWN_RATING;
 277                         }
 278                         CommandCost cost;
 279                         if (indirectly_cleared) {
 280                                 cost = Command<CMD_LANDSCAPE_CLEAR>::Do(tile_flags, t);
 281                         } else {
 282                                 cost = _tile_type_procs[GetTileType(t)]->terraform_tile_proc(t, tile_flags, z_min, tileh);
 283                         }
 284                         old_generating_world.Restore();
 285                         if (cost.Failed()) {
 286                                 return { cost, 0, t };
 287                         }
 288                         if (pass == 1) total_cost.AddCost(cost);
 289                 }
 290         }
 291
 292         Company *c = Company::GetIfValid(_current_company);
 293         if (c != nullptr && GB(c->terraform_limit, 16, 16) < ts.tile_to_new_height.size()) {
 294                 return { CommandCost(STR_ERROR_TERRAFORM_LIMIT_REACHED), 0, INVALID_TILE };
 295         }
 296
 297         if (flags & DC_EXEC) {
 298                 /* Mark affected areas dirty. */
 299                 for (const auto &t : ts.dirty_tiles) {
 300                         MarkTileDirtyByTile(t);
 301                         TileIndexToHeightMap::const_iterator new_height = ts.tile_to_new_height.find(t);
 302                         if (new_height == ts.tile_to_new_height.end()) continue;
 303                         MarkTileDirtyByTile(t, 0, new_height->second);
 304                 }
 305
 306                 /* change the height */
 307                 for (const auto &it : ts.tile_to_new_height) {
 308                         TileIndex t = it.first;
 309                         int height = it.second;
 310
 311                         SetTileHeight(t, (uint)height);
 312                 }
 313
 314                 if (c != nullptr) c->terraform_limit -= (uint32_t)ts.tile_to_new_height.size() << 16;
 315         }
 316         return { total_cost, 0, total_cost.Succeeded() ? tile : INVALID_TILE };
 317 }
 318
 319
 320 /**
 321  * Levels a selected (rectangle) area of land
 322  * @param flags for this command type
 323  * @param tile end tile of area-drag
 324  * @param start_tile start tile of area drag
 325  * @param diagonal Whether to use the Orthogonal (false) or Diagonal (true) iterator.
 326  * @param LevelMode Mode of leveling \c LevelMode.
 327  * @return the cost of this operation or an error
 328  */
 329 std::tuple<CommandCost, Money, TileIndex> CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal, LevelMode lm)
 330 {
 331         if (start_tile >= Map::Size()) return { CMD_ERROR, 0, INVALID_TILE };
 332
 333         /* remember level height */
 334         uint oldh = TileHeight(start_tile);
 335
 336         /* compute new height */
 337         uint h = oldh;
 338         switch (lm) {
 339                 case LM_LEVEL: break;
 340                 case LM_RAISE: h++; break;
 341                 case LM_LOWER: h--; break;
 342                 default: return { CMD_ERROR, 0, INVALID_TILE };
 343         }
 344
 345         /* Check range of destination height */
 346         if (h > _settings_game.construction.map_height_limit) return { CommandCost(oldh == 0 ? STR_ERROR_ALREADY_AT_SEA_LEVEL : STR_ERROR_TOO_HIGH), 0, INVALID_TILE };
 347
 348         Money money = GetAvailableMoneyForCommand();
 349         CommandCost cost(EXPENSES_CONSTRUCTION);
 350         CommandCost last_error(lm == LM_LEVEL ? STR_ERROR_ALREADY_LEVELLED : INVALID_STRING_ID);
 351         bool had_success = false;
 352
 353         const Company *c = Company::GetIfValid(_current_company);
 354         int limit = (c == nullptr ? INT32_MAX : GB(c->terraform_limit, 16, 16));
 355         if (limit == 0) return { CommandCost(STR_ERROR_TERRAFORM_LIMIT_REACHED), 0, INVALID_TILE };
 356
 357         TileIndex error_tile = INVALID_TILE;
 358         std::unique_ptr<TileIterator> iter = TileIterator::Create(tile, start_tile, diagonal);
 359         for (; *iter != INVALID_TILE; ++(*iter)) {
 360                 TileIndex t = *iter;
 361                 uint curh = TileHeight(t);
 362                 while (curh != h) {
 363                         CommandCost ret;
 364                         std::tie(ret, std::ignore, error_tile) = Command<CMD_TERRAFORM_LAND>::Do(flags & ~DC_EXEC, t, SLOPE_N, curh <= h);
 365                         if (ret.Failed()) {
 366                                 last_error = ret;
 367
 368                                 /* Did we reach the limit? */
 369                                 if (ret.GetErrorMessage() == STR_ERROR_TERRAFORM_LIMIT_REACHED) limit = 0;
 370                                 break;
 371                         }
 372
 373                         if (flags & DC_EXEC) {
 374                                 money -= ret.GetCost();
 375                                 if (money < 0) {
 376                                         return { cost, ret.GetCost(), error_tile };
 377                                 }
 378                                 Command<CMD_TERRAFORM_LAND>::Do(flags, t, SLOPE_N, curh <= h);
 379                         } else {
 380                                 /* When we're at the terraform limit we better bail (unneeded) testing as well.
 381                                  * This will probably cause the terraforming cost to be underestimated, but only
 382                                  * when it's near the terraforming limit. Even then, the estimation is
 383                                  * completely off due to it basically counting terraforming double, so it being
 384                                  * cut off earlier might even give a better estimate in some cases. */
 385                                 if (--limit <= 0) {
 386                                         had_success = true;
 387                                         break;
 388                                 }
 389                         }
 390
 391                         cost.AddCost(ret);
 392                         curh += (curh > h) ? -1 : 1;
 393                         had_success = true;
 394                 }
 395
 396                 if (limit <= 0) break;
 397         }
 398
 399         CommandCost cc_ret = had_success ? cost : last_error;
 400         return { cc_ret, 0, cc_ret.Succeeded() ? tile : error_tile };
 401 }