terraform_cmd.cpp

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00001 /* $Id: terraform_cmd.cpp 19665 2010-04-17 22:27:49Z rubidium $ */
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 "openttd.h"
00014 #include "command_func.h"
00015 #include "tunnel_map.h"
00016 #include "bridge_map.h"
00017 #include "variables.h"
00018 #include "functions.h"
00019 #include "economy_func.h"
00020 
00021 #include "table/strings.h"
00022 
00023 /*
00024  * In one terraforming command all four corners of a initial tile can be raised/lowered (though this is not available to the player).
00025  * The maximal amount of height modifications is archieved when raising a complete flat land from sea level to MAX_TILE_HEIGHT or vice versa.
00026  * This affects all corners with a manhatten distance smaller than MAX_TILE_HEIGHT to one of the initial 4 corners.
00027  * Their maximal amount is computed to 4 * \sum_{i=1}^{h_max} i  =  2 * h_max * (h_max + 1).
00028  */
00029 static const int TERRAFORMER_MODHEIGHT_SIZE = 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 1);
00030 
00031 /*
00032  * The maximal amount of affected tiles (i.e. the tiles that incident with one of the corners above, is computed similiar to
00033  * 1 + 4 * \sum_{i=1}^{h_max} (i+1)  =  1 + 2 * h_max + (h_max + 3).
00034  */
00035 static const int TERRAFORMER_TILE_TABLE_SIZE = 1 + 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 3);
00036 
00037 struct TerraformerHeightMod {
00038   TileIndex tile;   
00039   byte height;      
00040 };
00041 
00042 struct TerraformerState {
00043   int modheight_count;  
00044   int tile_table_count; 
00045 
00053   TileIndex tile_table[TERRAFORMER_TILE_TABLE_SIZE];
00054   TerraformerHeightMod modheight[TERRAFORMER_MODHEIGHT_SIZE];  
00055 };
00056 
00057 TileIndex _terraform_err_tile; 
00058 
00066 static int TerraformGetHeightOfTile(const TerraformerState *ts, TileIndex tile)
00067 {
00068   const TerraformerHeightMod *mod = ts->modheight;
00069 
00070   for (int count = ts->modheight_count; count != 0; count--, mod++) {
00071     if (mod->tile == tile) return mod->height;
00072   }
00073 
00074   /* TileHeight unchanged so far, read value from map. */
00075   return TileHeight(tile);
00076 }
00077 
00085 static void TerraformSetHeightOfTile(TerraformerState *ts, TileIndex tile, int height)
00086 {
00087   /* Find tile in the "modheight" table.
00088    * Note: In a normal user-terraform command the tile will not be found in the "modheight" table.
00089    *       But during house- or industry-construction multiple corners can be terraformed at once. */
00090   TerraformerHeightMod *mod = ts->modheight;
00091   int count = ts->modheight_count;
00092 
00093   while ((count > 0) && (mod->tile != tile)) {
00094     mod++;
00095     count--;
00096   }
00097 
00098   /* New entry? */
00099   if (count == 0) {
00100     assert(ts->modheight_count < TERRAFORMER_MODHEIGHT_SIZE);
00101     ts->modheight_count++;
00102   }
00103 
00104   /* Finally store the new value */
00105   mod->tile = tile;
00106   mod->height = (byte)height;
00107 }
00108 
00116 static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
00117 {
00118   int count = ts->tile_table_count;
00119 
00120   for (TileIndex *t = ts->tile_table; count != 0; count--, t++) {
00121     if (*t == tile) return;
00122   }
00123 
00124   assert(ts->tile_table_count < TERRAFORMER_TILE_TABLE_SIZE);
00125 
00126   ts->tile_table[ts->tile_table_count++] = tile;
00127 }
00128 
00136 static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
00137 {
00138   /* Make sure all tiles passed to TerraformAddDirtyTile are within [0, MapSize()] */
00139   if (TileY(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY( 0, -1));
00140   if (TileY(tile) >= 1 && TileX(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY(-1, -1));
00141   if (TileX(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY(-1,  0));
00142   TerraformAddDirtyTile(ts, tile);
00143 }
00144 
00153 static CommandCost TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height)
00154 {
00155   assert(tile < MapSize());
00156 
00157   /* Check range of destination height */
00158   if (height < 0) return_cmd_error(STR_ERROR_ALREADY_AT_SEA_LEVEL);
00159   if (height > MAX_TILE_HEIGHT) return_cmd_error(STR_ERROR_TOO_HIGH);
00160 
00161   /*
00162    * Check if the terraforming has any effect.
00163    * This can only be true, if multiple corners of the start-tile are terraformed (i.e. the terraforming is done by towns/industries etc.).
00164    * In this case the terraforming should fail. (Don't know why.)
00165    */
00166   if (height == TerraformGetHeightOfTile(ts, tile)) return CMD_ERROR;
00167 
00168   /* Check "too close to edge of map". Only possible when freeform-edges is off. */
00169   uint x = TileX(tile);
00170   uint y = TileY(tile);
00171   if (!_settings_game.construction.freeform_edges && ((x <= 1) || (y <= 1) || (x >= MapMaxX() - 1) || (y >= MapMaxY() - 1))) {
00172     /*
00173      * Determine a sensible error tile
00174      */
00175     if (x == 1) x = 0;
00176     if (y == 1) y = 0;
00177     _terraform_err_tile = TileXY(x, y);
00178     return_cmd_error(STR_ERROR_TOO_CLOSE_TO_EDGE_OF_MAP);
00179   }
00180 
00181   /* Mark incident tiles, that are involved in the terraforming */
00182   TerraformAddDirtyTileAround(ts, tile);
00183 
00184   /* Store the height modification */
00185   TerraformSetHeightOfTile(ts, tile, height);
00186 
00187   CommandCost total_cost(EXPENSES_CONSTRUCTION);
00188 
00189   /* Increment cost */
00190   total_cost.AddCost(_price[PR_TERRAFORM]);
00191 
00192   /* Recurse to neighboured corners if height difference is larger than 1 */
00193   {
00194     const TileIndexDiffC *ttm;
00195 
00196     TileIndex orig_tile = tile;
00197     static const TileIndexDiffC _terraform_tilepos[] = {
00198       { 1,  0}, // move to tile in SE
00199       {-2,  0}, // undo last move, and move to tile in NW
00200       { 1,  1}, // undo last move, and move to tile in SW
00201       { 0, -2}  // undo last move, and move to tile in NE
00202     };
00203 
00204     for (ttm = _terraform_tilepos; ttm != endof(_terraform_tilepos); ttm++) {
00205       tile += ToTileIndexDiff(*ttm);
00206 
00207       if (tile >= MapSize()) continue;
00208       /* Make sure we don't wrap around the map */
00209       if (Delta(TileX(orig_tile), TileX(tile)) == MapSizeX() - 1) continue;
00210       if (Delta(TileY(orig_tile), TileY(tile)) == MapSizeY() - 1) continue;
00211 
00212       /* Get TileHeight of neighboured tile as of current terraform progress */
00213       int r = TerraformGetHeightOfTile(ts, tile);
00214       int height_diff = height - r;
00215 
00216       /* Is the height difference to the neighboured corner greater than 1? */
00217       if (abs(height_diff) > 1) {
00218         /* Terraform the neighboured corner. The resulting height difference should be 1. */
00219         height_diff += (height_diff < 0 ? 1 : -1);
00220         CommandCost cost = TerraformTileHeight(ts, tile, r + height_diff);
00221         if (cost.Failed()) return cost;
00222         total_cost.AddCost(cost);
00223       }
00224     }
00225   }
00226 
00227   return total_cost;
00228 }
00229 
00238 CommandCost CmdTerraformLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00239 {
00240   _terraform_err_tile = INVALID_TILE;
00241 
00242   CommandCost total_cost(EXPENSES_CONSTRUCTION);
00243   int direction = (p2 != 0 ? 1 : -1);
00244   TerraformerState ts;
00245 
00246   ts.modheight_count = ts.tile_table_count = 0;
00247 
00248   /* Compute the costs and the terraforming result in a model of the landscape */
00249   if ((p1 & SLOPE_W) != 0 && tile + TileDiffXY(1, 0) < MapSize()) {
00250     TileIndex t = tile + TileDiffXY(1, 0);
00251     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00252     if (cost.Failed()) return cost;
00253     total_cost.AddCost(cost);
00254   }
00255 
00256   if ((p1 & SLOPE_S) != 0 && tile + TileDiffXY(1, 1) < MapSize()) {
00257     TileIndex t = tile + TileDiffXY(1, 1);
00258     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00259     if (cost.Failed()) return cost;
00260     total_cost.AddCost(cost);
00261   }
00262 
00263   if ((p1 & SLOPE_E) != 0 && tile + TileDiffXY(0, 1) < MapSize()) {
00264     TileIndex t = tile + TileDiffXY(0, 1);
00265     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00266     if (cost.Failed()) return cost;
00267     total_cost.AddCost(cost);
00268   }
00269 
00270   if ((p1 & SLOPE_N) != 0) {
00271     TileIndex t = tile + TileDiffXY(0, 0);
00272     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00273     if (cost.Failed()) return cost;
00274     total_cost.AddCost(cost);
00275   }
00276 
00277   /* Check if the terraforming is valid wrt. tunnels, bridges and objects on the surface */
00278   {
00279     TileIndex *ti = ts.tile_table;
00280 
00281     for (int count = ts.tile_table_count; count != 0; count--, ti++) {
00282       TileIndex tile = *ti;
00283 
00284       assert(tile < MapSize());
00285       /* MP_VOID tiles can be terraformed but as tunnels and bridges
00286        * cannot go under / over these tiles they don't need checking. */
00287       if (IsTileType(tile, MP_VOID)) continue;
00288 
00289       /* Find new heights of tile corners */
00290       uint z_N = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
00291       uint z_W = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
00292       uint z_S = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
00293       uint z_E = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));
00294 
00295       /* Find min and max height of tile */
00296       uint z_min = min(min(z_N, z_W), min(z_S, z_E));
00297       uint z_max = max(max(z_N, z_W), max(z_S, z_E));
00298 
00299       /* Compute tile slope */
00300       Slope tileh = (z_max > z_min + 1 ? SLOPE_STEEP : SLOPE_FLAT);
00301       if (z_W > z_min) tileh |= SLOPE_W;
00302       if (z_S > z_min) tileh |= SLOPE_S;
00303       if (z_E > z_min) tileh |= SLOPE_E;
00304       if (z_N > z_min) tileh |= SLOPE_N;
00305 
00306       /* Check if bridge would take damage */
00307       if (direction == 1 && MayHaveBridgeAbove(tile) && IsBridgeAbove(tile) &&
00308           GetBridgeHeight(GetSouthernBridgeEnd(tile)) <= z_max * TILE_HEIGHT) {
00309         _terraform_err_tile = tile; // highlight the tile under the bridge
00310         return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00311       }
00312       /* Check if tunnel would take damage */
00313       if (direction == -1 && IsTunnelInWay(tile, z_min * TILE_HEIGHT)) {
00314         _terraform_err_tile = tile; // highlight the tile above the tunnel
00315         return_cmd_error(STR_ERROR_EXCAVATION_WOULD_DAMAGE);
00316       }
00317       /* Check tiletype-specific things, and add extra-cost */
00318       const bool curr_gen = _generating_world;
00319       if (_game_mode == GM_EDITOR) _generating_world = true; // used to create green terraformed land
00320       CommandCost cost = _tile_type_procs[GetTileType(tile)]->terraform_tile_proc(tile, flags | DC_AUTO, z_min * TILE_HEIGHT, tileh);
00321       _generating_world = curr_gen;
00322       if (cost.Failed()) {
00323         _terraform_err_tile = tile;
00324         return cost;
00325       }
00326       total_cost.AddCost(cost);
00327     }
00328   }
00329 
00330   if (flags & DC_EXEC) {
00331     /* change the height */
00332     {
00333       int count;
00334       TerraformerHeightMod *mod;
00335 
00336       mod = ts.modheight;
00337       for (count = ts.modheight_count; count != 0; count--, mod++) {
00338         TileIndex til = mod->tile;
00339 
00340         SetTileHeight(til, mod->height);
00341       }
00342     }
00343 
00344     /* finally mark the dirty tiles dirty */
00345     {
00346       int count;
00347       TileIndex *ti = ts.tile_table;
00348       for (count = ts.tile_table_count; count != 0; count--, ti++) {
00349         MarkTileDirtyByTile(*ti);
00350       }
00351     }
00352   }
00353   return total_cost;
00354 }
00355 
00356 
00365 CommandCost CmdLevelLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00366 {
00367   if (p1 >= MapSize()) return CMD_ERROR;
00368 
00369   _terraform_err_tile = INVALID_TILE;
00370 
00371   /* remember level height */
00372   uint oldh = TileHeight(p1);
00373 
00374   /* compute new height */
00375   uint h = oldh + (int8)p2;
00376 
00377   /* Check range of destination height */
00378   if (h > MAX_TILE_HEIGHT) return_cmd_error((oldh == 0) ? STR_ERROR_ALREADY_AT_SEA_LEVEL : STR_ERROR_TOO_HIGH);
00379   if (p2 == 0) _error_message = STR_ERROR_ALREADY_LEVELLED;
00380 
00381   Money money = GetAvailableMoneyForCommand();
00382   CommandCost cost(EXPENSES_CONSTRUCTION);
00383 
00384   TileArea ta(tile, p1);
00385   TILE_AREA_LOOP(tile, ta) {
00386     uint curh = TileHeight(tile);
00387     while (curh != h) {
00388       CommandCost ret = DoCommand(tile, SLOPE_N, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND);
00389       if (ret.Failed()) break;
00390 
00391       if (flags & DC_EXEC) {
00392         money -= ret.GetCost();
00393         if (money < 0) {
00394           _additional_cash_required = ret.GetCost();
00395           return cost;
00396         }
00397         DoCommand(tile, SLOPE_N, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
00398       }
00399 
00400       cost.AddCost(ret);
00401       curh += (curh > h) ? -1 : 1;
00402     }
00403   }
00404 
00405   return (cost.GetCost() == 0) ? CMD_ERROR : cost;
00406 }

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