src/terraform_cmd.cpp

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * 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.
   6  * 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.
   7  * 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/>.
   8  */
   9
  10 /** @file terraform_cmd.cpp Commands related to terraforming. */
  11
  12 #include "stdafx.h"
  13 #include "command_func.h"
  14 #include "tunnel_map.h"
  15 #include "bridge_map.h"
  16 #include "viewport_func.h"
  17 #include "genworld.h"
  18 #include "object_base.h"
  19 #include "company_base.h"
  20 #include "company_func.h"
  21
  22 #include "table/strings.h"
  23
  24 /*
  25  * In one terraforming command all four corners of a initial tile can be raised/lowered (though this is not available to the player).
  26  * The maximal amount of height modifications is achieved when raising a complete flat land from sea level to MAX_TILE_HEIGHT or vice versa.
  27  * This affects all corners with a manhatten distance smaller than MAX_TILE_HEIGHT to one of the initial 4 corners.
  28  * Their maximal amount is computed to 4 * \sum_{i=1}^{h_max} i  =  2 * h_max * (h_max + 1).
  29  */
  30 static const int TERRAFORMER_MODHEIGHT_SIZE = 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 1);
  31
  32 /*
  33  * The maximal amount of affected tiles (i.e. the tiles that incident with one of the corners above, is computed similar to
  34  * 1 + 4 * \sum_{i=1}^{h_max} (i+1)  =  1 + 2 * h_max + (h_max + 3).
  35  */
  36 static const int TERRAFORMER_TILE_TABLE_SIZE = 1 + 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 3);
  37
  38 struct TerraformerHeightMod {
  39         TileIndex tile;   ///< Referenced tile.
  40         byte height;      ///< New TileHeight (height of north corner) of the tile.
  41 };
  42
  43 struct TerraformerState {
  44         int modheight_count;  ///< amount of entries in "modheight".
  45         int tile_table_count; ///< amount of entries in "tile_table".
  46
  47         /**
  48          * Dirty tiles, i.e.\ at least one corner changed.
  49          *
  50          * This array contains the tiles which are or will be marked as dirty.
  51          *
  52          * @ingroup dirty
  53          */
  54         TileIndex tile_table[TERRAFORMER_TILE_TABLE_SIZE];
  55         TerraformerHeightMod modheight[TERRAFORMER_MODHEIGHT_SIZE];  ///< Height modifications.
  56 };
  57
  58 TileIndex _terraform_err_tile; ///< first tile we couldn't terraform
  59
  60 /**
  61  * Gets the TileHeight (height of north corner) of a tile as of current terraforming progress.
  62  *
  63  * @param ts TerraformerState.
  64  * @param tile Tile.
  65  * @return TileHeight.
  66  */
  67 static int TerraformGetHeightOfTile(const TerraformerState *ts, TileIndex tile)
  68 {
  69         const TerraformerHeightMod *mod = ts->modheight;
  70
  71         for (int count = ts->modheight_count; count != 0; count--, mod++) {
  72                 if (mod->tile == tile) return mod->height;
  73         }
  74
  75         /* TileHeight unchanged so far, read value from map. */
  76         return TileHeight(tile);
  77 }
  78
  79 /**
  80  * Stores the TileHeight (height of north corner) of a tile in a TerraformerState.
  81  *
  82  * @param ts TerraformerState.
  83  * @param tile Tile.
  84  * @param height New TileHeight.
  85  */
  86 static void TerraformSetHeightOfTile(TerraformerState *ts, TileIndex tile, int height)
  87 {
  88         /* Find tile in the "modheight" table.
  89          * Note: In a normal user-terraform command the tile will not be found in the "modheight" table.
  90          *       But during house- or industry-construction multiple corners can be terraformed at once. */
  91         TerraformerHeightMod *mod = ts->modheight;
  92         int count = ts->modheight_count;
  93
  94         while ((count > 0) && (mod->tile != tile)) {
  95                 mod++;
  96                 count--;
  97         }
  98
  99         /* New entry? */
 100         if (count == 0) {
 101                 assert(ts->modheight_count < TERRAFORMER_MODHEIGHT_SIZE);
 102                 ts->modheight_count++;
 103         }
 104
 105         /* Finally store the new value */
 106         mod->tile = tile;
 107         mod->height = (byte)height;
 108 }
 109
 110 /**
 111  * Adds a tile to the "tile_table" in a TerraformerState.
 112  *
 113  * @param ts TerraformerState.
 114  * @param tile Tile.
 115  * @ingroup dirty
 116  */
 117 static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
 118 {
 119         int count = ts->tile_table_count;
 120
 121         for (TileIndex *t = ts->tile_table; count != 0; count--, t++) {
 122                 if (*t == tile) return;
 123         }
 124
 125         assert(ts->tile_table_count < TERRAFORMER_TILE_TABLE_SIZE);
 126
 127         ts->tile_table[ts->tile_table_count++] = tile;
 128 }
 129
 130 /**
 131  * Adds all tiles that incident with the north corner of a specific tile to the "tile_table" in a TerraformerState.
 132  *
 133  * @param ts TerraformerState.
 134  * @param tile Tile.
 135  * @ingroup dirty
 136  */
 137 static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
 138 {
 139         /* Make sure all tiles passed to TerraformAddDirtyTile are within [0, MapSize()] */
 140         if (TileY(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY( 0, -1));
 141         if (TileY(tile) >= 1 && TileX(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY(-1, -1));
 142         if (TileX(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY(-1,  0));
 143         TerraformAddDirtyTile(ts, tile);
 144 }
 145
 146 /**
 147  * Terraform the north corner of a tile to a specific height.
 148  *
 149  * @param ts TerraformerState.
 150  * @param tile Tile.
 151  * @param height Aimed height.
 152  * @return Error code or cost.
 153  */
 154 static CommandCost TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height)
 155 {
 156         assert(tile < MapSize());
 157
 158         /* Check range of destination height */
 159         if (height < 0) return_cmd_error(STR_ERROR_ALREADY_AT_SEA_LEVEL);
 160         if (height > (int)MAX_TILE_HEIGHT) return_cmd_error(STR_ERROR_TOO_HIGH);
 161
 162         /*
 163          * Check if the terraforming has any effect.
 164          * This can only be true, if multiple corners of the start-tile are terraformed (i.e. the terraforming is done by towns/industries etc.).
 165          * In this case the terraforming should fail. (Don't know why.)
 166          */
 167         if (height == TerraformGetHeightOfTile(ts, tile)) return CMD_ERROR;
 168
 169         /* Check "too close to edge of map". Only possible when freeform-edges is off. */
 170         uint x = TileX(tile);
 171         uint y = TileY(tile);
 172         if (!_settings_game.construction.freeform_edges && ((x <= 1) || (y <= 1) || (x >= MapMaxX() - 1) || (y >= MapMaxY() - 1))) {
 173                 /*
 174                  * Determine a sensible error tile
 175                  */
 176                 if (x == 1) x = 0;
 177                 if (y == 1) y = 0;
 178                 _terraform_err_tile = TileXY(x, y);
 179                 return_cmd_error(STR_ERROR_TOO_CLOSE_TO_EDGE_OF_MAP);
 180         }
 181
 182         /* Mark incident tiles that are involved in the terraforming. */
 183         TerraformAddDirtyTileAround(ts, tile);
 184
 185         /* Store the height modification */
 186         TerraformSetHeightOfTile(ts, tile, height);
 187
 188         CommandCost total_cost(EXPENSES_CONSTRUCTION);
 189
 190         /* Increment cost */
 191         total_cost.AddCost(_price[PR_TERRAFORM]);
 192
 193         /* Recurse to neighboured corners if height difference is larger than 1 */
 194         {
 195                 const TileIndexDiffC *ttm;
 196
 197                 TileIndex orig_tile = tile;
 198                 static const TileIndexDiffC _terraform_tilepos[] = {
 199                         { 1,  0}, // move to tile in SE
 200                         {-2,  0}, // undo last move, and move to tile in NW
 201                         { 1,  1}, // undo last move, and move to tile in SW
 202                         { 0, -2}  // undo last move, and move to tile in NE
 203                 };
 204
 205                 for (ttm = _terraform_tilepos; ttm != endof(_terraform_tilepos); ttm++) {
 206                         tile += ToTileIndexDiff(*ttm);
 207
 208                         if (tile >= MapSize()) continue;
 209                         /* Make sure we don't wrap around the map */
 210                         if (Delta(TileX(orig_tile), TileX(tile)) == MapSizeX() - 1) continue;
 211                         if (Delta(TileY(orig_tile), TileY(tile)) == MapSizeY() - 1) continue;
 212
 213                         /* Get TileHeight of neighboured tile as of current terraform progress */
 214                         int r = TerraformGetHeightOfTile(ts, tile);
 215                         int height_diff = height - r;
 216
 217                         /* Is the height difference to the neighboured corner greater than 1? */
 218                         if (abs(height_diff) > 1) {
 219                                 /* Terraform the neighboured corner. The resulting height difference should be 1. */
 220                                 height_diff += (height_diff < 0 ? 1 : -1);
 221                                 CommandCost cost = TerraformTileHeight(ts, tile, r + height_diff);
 222                                 if (cost.Failed()) return cost;
 223                                 total_cost.AddCost(cost);
 224                         }
 225                 }
 226         }
 227
 228         return total_cost;
 229 }
 230
 231 /**
 232  * Terraform land
 233  * @param tile tile to terraform
 234  * @param flags for this command type
 235  * @param p1 corners to terraform (SLOPE_xxx)
 236  * @param p2 direction; eg up (non-zero) or down (zero)
 237  * @param text unused
 238  * @return the cost of this operation or an error
 239  */
 240 CommandCost CmdTerraformLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 241 {
 242         _terraform_err_tile = INVALID_TILE;
 243
 244         CommandCost total_cost(EXPENSES_CONSTRUCTION);
 245         int direction = (p2 != 0 ? 1 : -1);
 246         TerraformerState ts;
 247
 248         ts.modheight_count = ts.tile_table_count = 0;
 249
 250         /* Compute the costs and the terraforming result in a model of the landscape */
 251         if ((p1 & SLOPE_W) != 0 && tile + TileDiffXY(1, 0) < MapSize()) {
 252                 TileIndex t = tile + TileDiffXY(1, 0);
 253                 CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 254                 if (cost.Failed()) return cost;
 255                 total_cost.AddCost(cost);
 256         }
 257
 258         if ((p1 & SLOPE_S) != 0 && tile + TileDiffXY(1, 1) < MapSize()) {
 259                 TileIndex t = tile + TileDiffXY(1, 1);
 260                 CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 261                 if (cost.Failed()) return cost;
 262                 total_cost.AddCost(cost);
 263         }
 264
 265         if ((p1 & SLOPE_E) != 0 && tile + TileDiffXY(0, 1) < MapSize()) {
 266                 TileIndex t = tile + TileDiffXY(0, 1);
 267                 CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 268                 if (cost.Failed()) return cost;
 269                 total_cost.AddCost(cost);
 270         }
 271
 272         if ((p1 & SLOPE_N) != 0) {
 273                 TileIndex t = tile + TileDiffXY(0, 0);
 274                 CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
 275                 if (cost.Failed()) return cost;
 276                 total_cost.AddCost(cost);
 277         }
 278
 279         /* Check if the terraforming is valid wrt. tunnels, bridges and objects on the surface
 280          * Pass == 0: Collect tileareas which are caused to be auto-cleared.
 281          * Pass == 1: Collect the actual cost. */
 282         for (int pass = 0; pass < 2; pass++) {
 283                 TileIndex *ti = ts.tile_table;
 284
 285                 for (int count = ts.tile_table_count; count != 0; count--, ti++) {
 286                         TileIndex tile = *ti;
 287
 288                         assert(tile < MapSize());
 289                         /* MP_VOID tiles can be terraformed but as tunnels and bridges
 290                          * cannot go under / over these tiles they don't need checking. */
 291                         if (IsTileType(tile, MP_VOID)) continue;
 292
 293                         /* Find new heights of tile corners */
 294                         int z_N = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
 295                         int z_W = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
 296                         int z_S = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
 297                         int z_E = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));
 298
 299                         /* Find min and max height of tile */
 300                         int z_min = min(min(z_N, z_W), min(z_S, z_E));
 301                         int z_max = max(max(z_N, z_W), max(z_S, z_E));
 302
 303                         /* Compute tile slope */
 304                         Slope tileh = (z_max > z_min + 1 ? SLOPE_STEEP : SLOPE_FLAT);
 305                         if (z_W > z_min) tileh |= SLOPE_W;
 306                         if (z_S > z_min) tileh |= SLOPE_S;
 307                         if (z_E > z_min) tileh |= SLOPE_E;
 308                         if (z_N > z_min) tileh |= SLOPE_N;
 309
 310                         if (pass == 0) {
 311                                 /* Check if bridge would take damage */
 312                                 if (direction == 1 && MayHaveBridgeAbove(tile) && IsBridgeAbove(tile) &&
 313                                                 GetBridgeHeight(GetSouthernBridgeEnd(tile)) <= z_max) {
 314                                         _terraform_err_tile = tile; // highlight the tile under the bridge
 315                                         return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
 316                                 }
 317                                 /* Check if tunnel would take damage */
 318                                 if (direction == -1 && IsTunnelInWay(tile, z_min)) {
 319                                         _terraform_err_tile = tile; // highlight the tile above the tunnel
 320                                         return_cmd_error(STR_ERROR_EXCAVATION_WOULD_DAMAGE);
 321                                 }
 322                         }
 323
 324                         /* Is the tile already cleared? */
 325                         const ClearedObjectArea *coa = FindClearedObject(tile);
 326                         bool indirectly_cleared = coa != NULL && coa->first_tile != tile;
 327
 328                         /* Check tiletype-specific things, and add extra-cost */
 329                         const bool curr_gen = _generating_world;
 330                         if (_game_mode == GM_EDITOR) _generating_world = true; // used to create green terraformed land
 331                         DoCommandFlag tile_flags = flags | DC_AUTO | DC_FORCE_CLEAR_TILE;
 332                         if (pass == 0) {
 333                                 tile_flags &= ~DC_EXEC;
 334                                 tile_flags |= DC_NO_MODIFY_TOWN_RATING;
 335                         }
 336                         CommandCost cost;
 337                         if (indirectly_cleared) {
 338                                 cost = DoCommand(tile, 0, 0, tile_flags, CMD_LANDSCAPE_CLEAR);
 339                         } else {
 340                                 cost = _tile_type_procs[GetTileType(tile)]->terraform_tile_proc(tile, tile_flags, z_min, tileh);
 341                         }
 342                         _generating_world = curr_gen;
 343                         if (cost.Failed()) {
 344                                 _terraform_err_tile = tile;
 345                                 return cost;
 346                         }
 347                         if (pass == 1) total_cost.AddCost(cost);
 348                 }
 349         }
 350
 351         Company *c = Company::GetIfValid(_current_company);
 352         if (c != NULL && (int)GB(c->terraform_limit, 16, 16) < ts.modheight_count) {
 353                 return_cmd_error(STR_ERROR_TERRAFORM_LIMIT_REACHED);
 354         }
 355
 356         if (flags & DC_EXEC) {
 357                 /* change the height */
 358                 {
 359                         int count;
 360                         TerraformerHeightMod *mod;
 361
 362                         mod = ts.modheight;
 363                         for (count = ts.modheight_count; count != 0; count--, mod++) {
 364                                 TileIndex til = mod->tile;
 365
 366                                 SetTileHeight(til, mod->height);
 367                         }
 368                 }
 369
 370                 /* finally mark the dirty tiles dirty */
 371                 {
 372                         int count;
 373                         TileIndex *ti = ts.tile_table;
 374                         for (count = ts.tile_table_count; count != 0; count--, ti++) {
 375                                 MarkTileDirtyByTile(*ti);
 376                         }
 377                 }
 378
 379                 if (c != NULL) c->terraform_limit -= ts.modheight_count << 16;
 380         }
 381         return total_cost;
 382 }
 383
 384
 385 /**
 386  * Levels a selected (rectangle) area of land
 387  * @param tile end tile of area-drag
 388  * @param flags for this command type
 389  * @param p1 start tile of area drag
 390  * @param p2 various bitstuffed data.
 391  *  bit      0: Whether to use the Orthogonal (0) or Diagonal (1) iterator.
 392  *  bits 1 - 2: Mode of leveling \c LevelMode.
 393  * @param text unused
 394  * @return the cost of this operation or an error
 395  */
 396 CommandCost CmdLevelLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
 397 {
 398         if (p1 >= MapSize()) return CMD_ERROR;
 399
 400         _terraform_err_tile = INVALID_TILE;
 401
 402         /* remember level height */
 403         uint oldh = TileHeight(p1);
 404
 405         /* compute new height */
 406         uint h = oldh;
 407         LevelMode lm = (LevelMode)GB(p2, 1, 2);
 408         switch (lm) {
 409                 case LM_LEVEL: break;
 410                 case LM_RAISE: h++; break;
 411                 case LM_LOWER: h--; break;
 412                 default: return CMD_ERROR;
 413         }
 414
 415         /* Check range of destination height */
 416         if (h > MAX_TILE_HEIGHT) return_cmd_error((oldh == 0) ? STR_ERROR_ALREADY_AT_SEA_LEVEL : STR_ERROR_TOO_HIGH);
 417
 418         Money money = GetAvailableMoneyForCommand();
 419         CommandCost cost(EXPENSES_CONSTRUCTION);
 420         CommandCost last_error(lm == LM_LEVEL ? STR_ERROR_ALREADY_LEVELLED : INVALID_STRING_ID);
 421         bool had_success = false;
 422
 423         const Company *c = Company::GetIfValid(_current_company);
 424         int limit = (c == NULL ? INT32_MAX : GB(c->terraform_limit, 16, 16));
 425         if (limit == 0) return_cmd_error(STR_ERROR_TERRAFORM_LIMIT_REACHED);
 426
 427         TileArea ta(tile, p1);
 428         TileIterator *iter = HasBit(p2, 0) ? (TileIterator *)new DiagonalTileIterator(tile, p1) : new OrthogonalTileIterator(ta);
 429         for (; *iter != INVALID_TILE; ++(*iter)) {
 430                 TileIndex t = *iter;
 431                 uint curh = TileHeight(t);
 432                 while (curh != h) {
 433                         CommandCost ret = DoCommand(t, SLOPE_N, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND);
 434                         if (ret.Failed()) {
 435                                 last_error = ret;
 436
 437                                 /* Did we reach the limit? */
 438                                 if (ret.GetErrorMessage() == STR_ERROR_TERRAFORM_LIMIT_REACHED) limit = 0;
 439                                 break;
 440                         }
 441
 442                         if (flags & DC_EXEC) {
 443                                 money -= ret.GetCost();
 444                                 if (money < 0) {
 445                                         _additional_cash_required = ret.GetCost();
 446                                         delete iter;
 447                                         return cost;
 448                                 }
 449                                 DoCommand(t, SLOPE_N, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
 450                         } else {
 451                                 /* When we're at the terraform limit we better bail (unneeded) testing as well.
 452                                  * This will probably cause the terraforming cost to be underestimated, but only
 453                                  * when it's near the terraforming limit. Even then, the estimation is
 454                                  * completely off due to it basically counting terraforming double, so it being
 455                                  * cut off earlier might even give a better estimate in some cases. */
 456                                 if (--limit <= 0) {
 457                                         had_success = true;
 458                                         break;
 459                                 }
 460                         }
 461
 462                         cost.AddCost(ret);
 463                         curh += (curh > h) ? -1 : 1;
 464                         had_success = true;
 465                 }
 466
 467                 if (limit <= 0) break;
 468         }
 469
 470         delete iter;
 471         return had_success ? cost : last_error;
 472 }