terraform_cmd.cpp

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00001 /* $Id: terraform_cmd.cpp 21500 2010-12-13 15:15:02Z 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 "functions.h"
00018 #include "economy_func.h"
00019 #include "genworld.h"
00020 #include "object_base.h"
00021 
00022 #include "table/strings.h"
00023 
00024 /*
00025  * In one terraforming command all four corners of a initial tile can be raised/lowered (though this is not available to the player).
00026  * The maximal amount of height modifications is archieved when raising a complete flat land from sea level to MAX_TILE_HEIGHT or vice versa.
00027  * This affects all corners with a manhatten distance smaller than MAX_TILE_HEIGHT to one of the initial 4 corners.
00028  * Their maximal amount is computed to 4 * \sum_{i=1}^{h_max} i  =  2 * h_max * (h_max + 1).
00029  */
00030 static const int TERRAFORMER_MODHEIGHT_SIZE = 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 1);
00031 
00032 /*
00033  * The maximal amount of affected tiles (i.e. the tiles that incident with one of the corners above, is computed similiar to
00034  * 1 + 4 * \sum_{i=1}^{h_max} (i+1)  =  1 + 2 * h_max + (h_max + 3).
00035  */
00036 static const int TERRAFORMER_TILE_TABLE_SIZE = 1 + 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 3);
00037 
00038 struct TerraformerHeightMod {
00039   TileIndex tile;   
00040   byte height;      
00041 };
00042 
00043 struct TerraformerState {
00044   int modheight_count;  
00045   int tile_table_count; 
00046 
00054   TileIndex tile_table[TERRAFORMER_TILE_TABLE_SIZE];
00055   TerraformerHeightMod modheight[TERRAFORMER_MODHEIGHT_SIZE];  
00056 };
00057 
00058 TileIndex _terraform_err_tile; 
00059 
00067 static int TerraformGetHeightOfTile(const TerraformerState *ts, TileIndex tile)
00068 {
00069   const TerraformerHeightMod *mod = ts->modheight;
00070 
00071   for (int count = ts->modheight_count; count != 0; count--, mod++) {
00072     if (mod->tile == tile) return mod->height;
00073   }
00074 
00075   /* TileHeight unchanged so far, read value from map. */
00076   return TileHeight(tile);
00077 }
00078 
00086 static void TerraformSetHeightOfTile(TerraformerState *ts, TileIndex tile, int height)
00087 {
00088   /* Find tile in the "modheight" table.
00089    * Note: In a normal user-terraform command the tile will not be found in the "modheight" table.
00090    *       But during house- or industry-construction multiple corners can be terraformed at once. */
00091   TerraformerHeightMod *mod = ts->modheight;
00092   int count = ts->modheight_count;
00093 
00094   while ((count > 0) && (mod->tile != tile)) {
00095     mod++;
00096     count--;
00097   }
00098 
00099   /* New entry? */
00100   if (count == 0) {
00101     assert(ts->modheight_count < TERRAFORMER_MODHEIGHT_SIZE);
00102     ts->modheight_count++;
00103   }
00104 
00105   /* Finally store the new value */
00106   mod->tile = tile;
00107   mod->height = (byte)height;
00108 }
00109 
00117 static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
00118 {
00119   int count = ts->tile_table_count;
00120 
00121   for (TileIndex *t = ts->tile_table; count != 0; count--, t++) {
00122     if (*t == tile) return;
00123   }
00124 
00125   assert(ts->tile_table_count < TERRAFORMER_TILE_TABLE_SIZE);
00126 
00127   ts->tile_table[ts->tile_table_count++] = tile;
00128 }
00129 
00137 static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
00138 {
00139   /* Make sure all tiles passed to TerraformAddDirtyTile are within [0, MapSize()] */
00140   if (TileY(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY( 0, -1));
00141   if (TileY(tile) >= 1 && TileX(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY(-1, -1));
00142   if (TileX(tile) >= 1) TerraformAddDirtyTile(ts, tile + TileDiffXY(-1,  0));
00143   TerraformAddDirtyTile(ts, tile);
00144 }
00145 
00154 static CommandCost TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height)
00155 {
00156   assert(tile < MapSize());
00157 
00158   /* Check range of destination height */
00159   if (height < 0) return_cmd_error(STR_ERROR_ALREADY_AT_SEA_LEVEL);
00160   if (height > (int)MAX_TILE_HEIGHT) return_cmd_error(STR_ERROR_TOO_HIGH);
00161 
00162   /*
00163    * Check if the terraforming has any effect.
00164    * This can only be true, if multiple corners of the start-tile are terraformed (i.e. the terraforming is done by towns/industries etc.).
00165    * In this case the terraforming should fail. (Don't know why.)
00166    */
00167   if (height == TerraformGetHeightOfTile(ts, tile)) return CMD_ERROR;
00168 
00169   /* Check "too close to edge of map". Only possible when freeform-edges is off. */
00170   uint x = TileX(tile);
00171   uint y = TileY(tile);
00172   if (!_settings_game.construction.freeform_edges && ((x <= 1) || (y <= 1) || (x >= MapMaxX() - 1) || (y >= MapMaxY() - 1))) {
00173     /*
00174      * Determine a sensible error tile
00175      */
00176     if (x == 1) x = 0;
00177     if (y == 1) y = 0;
00178     _terraform_err_tile = TileXY(x, y);
00179     return_cmd_error(STR_ERROR_TOO_CLOSE_TO_EDGE_OF_MAP);
00180   }
00181 
00182   /* Mark incident tiles that are involved in the terraforming. */
00183   TerraformAddDirtyTileAround(ts, tile);
00184 
00185   /* Store the height modification */
00186   TerraformSetHeightOfTile(ts, tile, height);
00187 
00188   CommandCost total_cost(EXPENSES_CONSTRUCTION);
00189 
00190   /* Increment cost */
00191   total_cost.AddCost(_price[PR_TERRAFORM]);
00192 
00193   /* Recurse to neighboured corners if height difference is larger than 1 */
00194   {
00195     const TileIndexDiffC *ttm;
00196 
00197     TileIndex orig_tile = tile;
00198     static const TileIndexDiffC _terraform_tilepos[] = {
00199       { 1,  0}, // move to tile in SE
00200       {-2,  0}, // undo last move, and move to tile in NW
00201       { 1,  1}, // undo last move, and move to tile in SW
00202       { 0, -2}  // undo last move, and move to tile in NE
00203     };
00204 
00205     for (ttm = _terraform_tilepos; ttm != endof(_terraform_tilepos); ttm++) {
00206       tile += ToTileIndexDiff(*ttm);
00207 
00208       if (tile >= MapSize()) continue;
00209       /* Make sure we don't wrap around the map */
00210       if (Delta(TileX(orig_tile), TileX(tile)) == MapSizeX() - 1) continue;
00211       if (Delta(TileY(orig_tile), TileY(tile)) == MapSizeY() - 1) continue;
00212 
00213       /* Get TileHeight of neighboured tile as of current terraform progress */
00214       int r = TerraformGetHeightOfTile(ts, tile);
00215       int height_diff = height - r;
00216 
00217       /* Is the height difference to the neighboured corner greater than 1? */
00218       if (abs(height_diff) > 1) {
00219         /* Terraform the neighboured corner. The resulting height difference should be 1. */
00220         height_diff += (height_diff < 0 ? 1 : -1);
00221         CommandCost cost = TerraformTileHeight(ts, tile, r + height_diff);
00222         if (cost.Failed()) return cost;
00223         total_cost.AddCost(cost);
00224       }
00225     }
00226   }
00227 
00228   return total_cost;
00229 }
00230 
00240 CommandCost CmdTerraformLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00241 {
00242   _terraform_err_tile = INVALID_TILE;
00243 
00244   CommandCost total_cost(EXPENSES_CONSTRUCTION);
00245   int direction = (p2 != 0 ? 1 : -1);
00246   TerraformerState ts;
00247 
00248   ts.modheight_count = ts.tile_table_count = 0;
00249 
00250   /* Compute the costs and the terraforming result in a model of the landscape */
00251   if ((p1 & SLOPE_W) != 0 && tile + TileDiffXY(1, 0) < MapSize()) {
00252     TileIndex t = tile + TileDiffXY(1, 0);
00253     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00254     if (cost.Failed()) return cost;
00255     total_cost.AddCost(cost);
00256   }
00257 
00258   if ((p1 & SLOPE_S) != 0 && tile + TileDiffXY(1, 1) < MapSize()) {
00259     TileIndex t = tile + TileDiffXY(1, 1);
00260     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00261     if (cost.Failed()) return cost;
00262     total_cost.AddCost(cost);
00263   }
00264 
00265   if ((p1 & SLOPE_E) != 0 && tile + TileDiffXY(0, 1) < MapSize()) {
00266     TileIndex t = tile + TileDiffXY(0, 1);
00267     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00268     if (cost.Failed()) return cost;
00269     total_cost.AddCost(cost);
00270   }
00271 
00272   if ((p1 & SLOPE_N) != 0) {
00273     TileIndex t = tile + TileDiffXY(0, 0);
00274     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00275     if (cost.Failed()) return cost;
00276     total_cost.AddCost(cost);
00277   }
00278 
00279   /* Check if the terraforming is valid wrt. tunnels, bridges and objects on the surface
00280    * Pass == 0: Collect tileareas which are caused to be auto-cleared.
00281    * Pass == 1: Collect the actual cost. */
00282   for (int pass = 0; pass < 2; pass++) {
00283     TileIndex *ti = ts.tile_table;
00284 
00285     for (int count = ts.tile_table_count; count != 0; count--, ti++) {
00286       TileIndex tile = *ti;
00287 
00288       assert(tile < MapSize());
00289       /* MP_VOID tiles can be terraformed but as tunnels and bridges
00290        * cannot go under / over these tiles they don't need checking. */
00291       if (IsTileType(tile, MP_VOID)) continue;
00292 
00293       /* Find new heights of tile corners */
00294       uint z_N = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
00295       uint z_W = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
00296       uint z_S = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
00297       uint z_E = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));
00298 
00299       /* Find min and max height of tile */
00300       uint z_min = min(min(z_N, z_W), min(z_S, z_E));
00301       uint z_max = max(max(z_N, z_W), max(z_S, z_E));
00302 
00303       /* Compute tile slope */
00304       Slope tileh = (z_max > z_min + 1 ? SLOPE_STEEP : SLOPE_FLAT);
00305       if (z_W > z_min) tileh |= SLOPE_W;
00306       if (z_S > z_min) tileh |= SLOPE_S;
00307       if (z_E > z_min) tileh |= SLOPE_E;
00308       if (z_N > z_min) tileh |= SLOPE_N;
00309 
00310       /* Check if bridge would take damage */
00311       if (direction == 1 && MayHaveBridgeAbove(tile) && IsBridgeAbove(tile) &&
00312           GetBridgeHeight(GetSouthernBridgeEnd(tile)) <= z_max * TILE_HEIGHT) {
00313         _terraform_err_tile = tile; // highlight the tile under the bridge
00314         return_cmd_error(STR_ERROR_MUST_DEMOLISH_BRIDGE_FIRST);
00315       }
00316       /* Check if tunnel would take damage */
00317       if (direction == -1 && IsTunnelInWay(tile, z_min * TILE_HEIGHT)) {
00318         _terraform_err_tile = tile; // highlight the tile above the tunnel
00319         return_cmd_error(STR_ERROR_EXCAVATION_WOULD_DAMAGE);
00320       }
00321 
00322       /* Is the tile already cleared? */
00323       const ClearedObjectArea *coa = FindClearedObject(tile);
00324       bool indirectly_cleared = coa != NULL && coa->first_tile != tile;
00325 
00326       /* Check tiletype-specific things, and add extra-cost */
00327       const bool curr_gen = _generating_world;
00328       if (_game_mode == GM_EDITOR) _generating_world = true; // used to create green terraformed land
00329       DoCommandFlag tile_flags = flags | DC_AUTO | DC_FORCE_CLEAR_TILE;
00330       if (pass == 0) {
00331         tile_flags &= ~DC_EXEC;
00332         tile_flags |= DC_NO_MODIFY_TOWN_RATING;
00333       }
00334       CommandCost cost;
00335       if (indirectly_cleared) {
00336         cost = DoCommand(tile, 0, 0, tile_flags, CMD_LANDSCAPE_CLEAR);
00337       } else {
00338         cost = _tile_type_procs[GetTileType(tile)]->terraform_tile_proc(tile, tile_flags, z_min * TILE_HEIGHT, tileh);
00339       }
00340       _generating_world = curr_gen;
00341       if (cost.Failed()) {
00342         _terraform_err_tile = tile;
00343         return cost;
00344       }
00345       if (pass == 1) total_cost.AddCost(cost);
00346     }
00347   }
00348 
00349   if (flags & DC_EXEC) {
00350     /* change the height */
00351     {
00352       int count;
00353       TerraformerHeightMod *mod;
00354 
00355       mod = ts.modheight;
00356       for (count = ts.modheight_count; count != 0; count--, mod++) {
00357         TileIndex til = mod->tile;
00358 
00359         SetTileHeight(til, mod->height);
00360       }
00361     }
00362 
00363     /* finally mark the dirty tiles dirty */
00364     {
00365       int count;
00366       TileIndex *ti = ts.tile_table;
00367       for (count = ts.tile_table_count; count != 0; count--, ti++) {
00368         MarkTileDirtyByTile(*ti);
00369       }
00370     }
00371   }
00372   return total_cost;
00373 }
00374 
00375 
00387 CommandCost CmdLevelLand(TileIndex tile, DoCommandFlag flags, uint32 p1, uint32 p2, const char *text)
00388 {
00389   if (p1 >= MapSize()) return CMD_ERROR;
00390 
00391   _terraform_err_tile = INVALID_TILE;
00392 
00393   /* remember level height */
00394   uint oldh = TileHeight(p1);
00395 
00396   /* compute new height */
00397   uint h = oldh;
00398   LevelMode lm = (LevelMode)GB(p2, 1, 2);
00399   switch (lm) {
00400     case LM_LEVEL: break;
00401     case LM_RAISE: h++; break;
00402     case LM_LOWER: h--; break;
00403     default: return CMD_ERROR;
00404   }
00405 
00406   /* Check range of destination height */
00407   if (h > MAX_TILE_HEIGHT) return_cmd_error((oldh == 0) ? STR_ERROR_ALREADY_AT_SEA_LEVEL : STR_ERROR_TOO_HIGH);
00408 
00409   Money money = GetAvailableMoneyForCommand();
00410   CommandCost cost(EXPENSES_CONSTRUCTION);
00411   CommandCost last_error(lm == LM_LEVEL ? STR_ERROR_ALREADY_LEVELLED : INVALID_STRING_ID);
00412   bool had_success = false;
00413 
00414   TileArea ta(tile, p1);
00415   TileIterator *iter = HasBit(p2, 0) ? (TileIterator *)new DiagonalTileIterator(tile, p1) : new OrthogonalTileIterator(ta);
00416   for (; *iter != INVALID_TILE; ++(*iter)) {
00417     TileIndex t = *iter;
00418     uint curh = TileHeight(t);
00419     while (curh != h) {
00420       CommandCost ret = DoCommand(t, SLOPE_N, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND);
00421       if (ret.Failed()) {
00422         last_error = ret;
00423         break;
00424       }
00425 
00426       if (flags & DC_EXEC) {
00427         money -= ret.GetCost();
00428         if (money < 0) {
00429           _additional_cash_required = ret.GetCost();
00430           delete iter;
00431           return cost;
00432         }
00433         DoCommand(t, SLOPE_N, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
00434       }
00435 
00436       cost.AddCost(ret);
00437       curh += (curh > h) ? -1 : 1;
00438       had_success = true;
00439     }
00440   }
00441 
00442   delete iter;
00443   return had_success ? cost : last_error;
00444 }

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