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                 TileIndex orig_tile = tile;
 140                 static const TileIndexDiffC _terraform_tilepos[] = {
 141                         { 1,  0}, // move to tile in SE
 142                         {-2,  0}, // undo last move, and move to tile in NW
 143                         { 1,  1}, // undo last move, and move to tile in SW
 144                         { 0, -2}  // undo last move, and move to tile in NE
 145                 };
 146
 147                 for (const auto &ttm : _terraform_tilepos) {
 148                         tile += ToTileIndexDiff(ttm);
 149
 150                         if (tile >= Map::Size()) continue;
 151                         /* Make sure we don't wrap around the map */
 152                         if (Delta(TileX(orig_tile), TileX(tile)) == Map::SizeX() - 1) continue;
 153                         if (Delta(TileY(orig_tile), TileY(tile)) == Map::SizeY() - 1) continue;
 154
 155                         /* Get TileHeight of neighboured tile as of current terraform progress */
 156                         int r = TerraformGetHeightOfTile(ts, tile);
 157                         int height_diff = height - r;
 158
 159                         /* Is the height difference to the neighboured corner greater than 1? */
 160                         if (abs(height_diff) > 1) {
 161                                 /* Terraform the neighboured corner. The resulting height difference should be 1. */
 162                                 height_diff += (height_diff < 0 ? 1 : -1);
 163                                 auto [cost, err_tile] = TerraformTileHeight(ts, tile, r + height_diff);
 164                                 if (cost.Failed()) return { cost, err_tile };
 165                                 total_cost.AddCost(cost);
 166                         }
 167                 }
 168         }
 169
 170         return { total_cost, INVALID_TILE };
 171 }
 172
 173 /**
 174  * Terraform land
 175  * @param flags for this command type
 176  * @param tile tile to terraform
 177  * @param slope corners to terraform (SLOPE_xxx)
 178  * @param dir_up direction; eg up (true) or down (false)
 179  * @return the cost of this operation or an error
 180  */
 181 std::tuple<CommandCost, Money, TileIndex> CmdTerraformLand(DoCommandFlag flags, TileIndex tile, Slope slope, bool dir_up)
 182 {
 183         CommandCost total_cost(EXPENSES_CONSTRUCTION);
 184         int direction = (dir_up ? 1 : -1);
 185         TerraformerState ts;
 186
 187         /* Compute the costs and the terraforming result in a model of the landscape */
 188         if ((slope & SLOPE_W) != 0 && tile + TileDiffXY(1, 0) < Map::Size()) {
 189                 TileIndex t = tile + TileDiffXY(1, 0);
 190                 auto [cost, err_tile] = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 191                 if (cost.Failed()) return { cost, 0, err_tile };
 192                 total_cost.AddCost(cost);
 193         }
 194
 195         if ((slope & SLOPE_S) != 0 && tile + TileDiffXY(1, 1) < Map::Size()) {
 196                 TileIndex t = tile + TileDiffXY(1, 1);
 197                 auto [cost, err_tile] = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 198                 if (cost.Failed()) return { cost, 0, err_tile };
 199                 total_cost.AddCost(cost);
 200         }
 201
 202         if ((slope & SLOPE_E) != 0 && tile + TileDiffXY(0, 1) < Map::Size()) {
 203                 TileIndex t = tile + TileDiffXY(0, 1);
 204                 auto [cost, err_tile] = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 205                 if (cost.Failed()) return { cost, 0, err_tile };
 206                 total_cost.AddCost(cost);
 207         }
 208
 209         if ((slope & SLOPE_N) != 0) {
 210                 TileIndex t = tile + TileDiffXY(0, 0);
 211                 auto [cost, err_tile] = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 212                 if (cost.Failed()) return { cost, 0, err_tile };
 213                 total_cost.AddCost(cost);
 214         }
 215
 216         /* Check if the terraforming is valid wrt. tunnels, bridges and objects on the surface
 217          * Pass == 0: Collect tileareas which are caused to be auto-cleared.
 218          * Pass == 1: Collect the actual cost. */
 219         for (int pass = 0; pass < 2; pass++) {
 220                 for (const auto &t : ts.dirty_tiles) {
 221                         assert(t < Map::Size());
 222                         /* MP_VOID tiles can be terraformed but as tunnels and bridges
 223                          * cannot go under / over these tiles they don't need checking. */
 224                         if (IsTileType(t, MP_VOID)) continue;
 225
 226                         /* Find new heights of tile corners */
 227                         int z_N = TerraformGetHeightOfTile(&ts, t + TileDiffXY(0, 0));
 228                         int z_W = TerraformGetHeightOfTile(&ts, t + TileDiffXY(1, 0));
 229                         int z_S = TerraformGetHeightOfTile(&ts, t + TileDiffXY(1, 1));
 230                         int z_E = TerraformGetHeightOfTile(&ts, t + TileDiffXY(0, 1));
 231
 232                         /* Find min and max height of tile */
 233                         int z_min = std::min({z_N, z_W, z_S, z_E});
 234                         int z_max = std::max({z_N, z_W, z_S, z_E});
 235
 236                         /* Compute tile slope */
 237                         Slope tileh = (z_max > z_min + 1 ? SLOPE_STEEP : SLOPE_FLAT);
 238                         if (z_W > z_min) tileh |= SLOPE_W;
 239                         if (z_S > z_min) tileh |= SLOPE_S;
 240                         if (z_E > z_min) tileh |= SLOPE_E;
 241                         if (z_N > z_min) tileh |= SLOPE_N;
 242
 243                         if (pass == 0) {
 244                                 /* Check if bridge would take damage */
 245                                 if (IsBridgeAbove(t)) {
 246                                         int bridge_height = GetBridgeHeight(GetSouthernBridgeEnd(t));
 247
 248                                         /* Check if bridge would take damage. */
 249                                         if (direction == 1 && bridge_height <= z_max) {
 250                                                 return { CommandCost(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST), 0, t }; // highlight the tile under the bridge
 251                                         }
 252
 253                                         /* Is the bridge above not too high afterwards? */
 254                                         if (direction == -1 && bridge_height > (z_min + _settings_game.construction.max_bridge_height)) {
 255                                                 return { CommandCost(STR_ERROR_BRIDGE_TOO_HIGH_AFTER_LOWER_LAND), 0, t };
 256                                         }
 257                                 }
 258                                 /* Check if tunnel would take damage */
 259                                 if (direction == -1 && IsTunnelInWay(t, z_min)) {
 260                                         return { CommandCost(STR_ERROR_EXCAVATION_WOULD_DAMAGE), 0, t }; // highlight the tile above the tunnel
 261                                 }
 262                         }
 263
 264                         /* Is the tile already cleared? */
 265                         const ClearedObjectArea *coa = FindClearedObject(t);
 266                         bool indirectly_cleared = coa != nullptr && coa->first_tile != t;
 267
 268                         /* Check tiletype-specific things, and add extra-cost */
 269                         Backup<bool> old_generating_world(_generating_world);
 270                         if (_game_mode == GM_EDITOR) old_generating_world.Change(true); // used to create green terraformed land
 271                         DoCommandFlag tile_flags = flags | DC_AUTO | DC_FORCE_CLEAR_TILE;
 272                         if (pass == 0) {
 273                                 tile_flags &= ~DC_EXEC;
 274                                 tile_flags |= DC_NO_MODIFY_TOWN_RATING;
 275                         }
 276                         CommandCost cost;
 277                         if (indirectly_cleared) {
 278                                 cost = Command<CMD_LANDSCAPE_CLEAR>::Do(tile_flags, t);
 279                         } else {
 280                                 cost = _tile_type_procs[GetTileType(t)]->terraform_tile_proc(t, tile_flags, z_min, tileh);
 281                         }
 282                         old_generating_world.Restore();
 283                         if (cost.Failed()) {
 284                                 return { cost, 0, t };
 285                         }
 286                         if (pass == 1) total_cost.AddCost(cost);
 287                 }
 288         }
 289
 290         Company *c = Company::GetIfValid(_current_company);
 291         if (c != nullptr && GB(c->terraform_limit, 16, 16) < ts.tile_to_new_height.size()) {
 292                 return { CommandCost(STR_ERROR_TERRAFORM_LIMIT_REACHED), 0, INVALID_TILE };
 293         }
 294
 295         if (flags & DC_EXEC) {
 296                 /* Mark affected areas dirty. */
 297                 for (const auto &t : ts.dirty_tiles) {
 298                         MarkTileDirtyByTile(t);
 299                         TileIndexToHeightMap::const_iterator new_height = ts.tile_to_new_height.find(t);
 300                         if (new_height == ts.tile_to_new_height.end()) continue;
 301                         MarkTileDirtyByTile(t, 0, new_height->second);
 302                 }
 303
 304                 /* change the height */
 305                 for (const auto &it : ts.tile_to_new_height) {
 306                         TileIndex t = it.first;
 307                         int height = it.second;
 308
 309                         SetTileHeight(t, (uint)height);
 310                 }
 311
 312                 if (c != nullptr) c->terraform_limit -= (uint32_t)ts.tile_to_new_height.size() << 16;
 313         }
 314         return { total_cost, 0, total_cost.Succeeded() ? tile : INVALID_TILE };
 315 }
 316
 317
 318 /**
 319  * Levels a selected (rectangle) area of land
 320  * @param flags for this command type
 321  * @param tile end tile of area-drag
 322  * @param start_tile start tile of area drag
 323  * @param diagonal Whether to use the Orthogonal (false) or Diagonal (true) iterator.
 324  * @param LevelMode Mode of leveling \c LevelMode.
 325  * @return the cost of this operation or an error
 326  */
 327 std::tuple<CommandCost, Money, TileIndex> CmdLevelLand(DoCommandFlag flags, TileIndex tile, TileIndex start_tile, bool diagonal, LevelMode lm)
 328 {
 329         if (start_tile >= Map::Size()) return { CMD_ERROR, 0, INVALID_TILE };
 330
 331         /* remember level height */
 332         uint oldh = TileHeight(start_tile);
 333
 334         /* compute new height */
 335         uint h = oldh;
 336         switch (lm) {
 337                 case LM_LEVEL: break;
 338                 case LM_RAISE: h++; break;
 339                 case LM_LOWER: h--; break;
 340                 default: return { CMD_ERROR, 0, INVALID_TILE };
 341         }
 342
 343         /* Check range of destination height */
 344         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 };
 345
 346         Money money = GetAvailableMoneyForCommand();
 347         CommandCost cost(EXPENSES_CONSTRUCTION);
 348         CommandCost last_error(lm == LM_LEVEL ? STR_ERROR_ALREADY_LEVELLED : INVALID_STRING_ID);
 349         bool had_success = false;
 350
 351         const Company *c = Company::GetIfValid(_current_company);
 352         int limit = (c == nullptr ? INT32_MAX : GB(c->terraform_limit, 16, 16));
 353         if (limit == 0) return { CommandCost(STR_ERROR_TERRAFORM_LIMIT_REACHED), 0, INVALID_TILE };
 354
 355         TileIndex error_tile = INVALID_TILE;
 356         std::unique_ptr<TileIterator> iter = TileIterator::Create(tile, start_tile, diagonal);
 357         for (; *iter != INVALID_TILE; ++(*iter)) {
 358                 TileIndex t = *iter;
 359                 uint curh = TileHeight(t);
 360                 while (curh != h) {
 361                         CommandCost ret;
 362                         std::tie(ret, std::ignore, error_tile) = Command<CMD_TERRAFORM_LAND>::Do(flags & ~DC_EXEC, t, SLOPE_N, curh <= h);
 363                         if (ret.Failed()) {
 364                                 last_error = ret;
 365
 366                                 /* Did we reach the limit? */
 367                                 if (ret.GetErrorMessage() == STR_ERROR_TERRAFORM_LIMIT_REACHED) limit = 0;
 368                                 break;
 369                         }
 370
 371                         if (flags & DC_EXEC) {
 372                                 money -= ret.GetCost();
 373                                 if (money < 0) {
 374                                         return { cost, ret.GetCost(), error_tile };
 375                                 }
 376                                 Command<CMD_TERRAFORM_LAND>::Do(flags, t, SLOPE_N, curh <= h);
 377                         } else {
 378                                 /* When we're at the terraform limit we better bail (unneeded) testing as well.
 379                                  * This will probably cause the terraforming cost to be underestimated, but only
 380                                  * when it's near the terraforming limit. Even then, the estimation is
 381                                  * completely off due to it basically counting terraforming double, so it being
 382                                  * cut off earlier might even give a better estimate in some cases. */
 383                                 if (--limit <= 0) {
 384                                         had_success = true;
 385                                         break;
 386                                 }
 387                         }
 388
 389                         cost.AddCost(ret);
 390                         curh += (curh > h) ? -1 : 1;
 391                         had_success = true;
 392                 }
 393
 394                 if (limit <= 0) break;
 395         }
 396
 397         CommandCost cc_ret = had_success ? cost : last_error;
 398         return { cc_ret, 0, cc_ret.Succeeded() ? tile : error_tile };
 399 }