terraform_cmd.cpp

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00001 /* $Id: terraform_cmd.cpp 11828 2008-01-13 01:21:35Z rubidium $ */
00002 
00005 #include "stdafx.h"
00006 #include "openttd.h"
00007 #include "strings_type.h"
00008 #include "command_func.h"
00009 #include "tile_map.h"
00010 #include "tunnel_map.h"
00011 #include "bridge_map.h"
00012 #include "variables.h"
00013 #include "functions.h"
00014 #include "economy_func.h"
00015 
00016 #include "table/strings.h"
00017 
00018 /*
00019  * In one terraforming command all four corners of a initial tile can be raised/lowered (though this is not available to the player).
00020  * The maximal amount of height modifications is archieved when raising a complete flat land from sea level to MAX_TILE_HEIGHT or vice versa.
00021  * This affects all corners with a manhatten distance smaller than MAX_TILE_HEIGHT to one of the initial 4 corners.
00022  * Their maximal amount is computed to 4 * \sum_{i=1}^{h_max} i  =  2 * h_max * (h_max + 1).
00023  */
00024 static const int TERRAFORMER_MODHEIGHT_SIZE = 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 1);
00025 
00026 /*
00027  * The maximal amount of affected tiles (i.e. the tiles that incident with one of the corners above, is computed similiar to
00028  * 1 + 4 * \sum_{i=1}^{h_max} (i+1)  =  1 + 2 * h_max + (h_max + 3).
00029  */
00030 static const int TERRAFORMER_TILE_TABLE_SIZE = 1 + 2 * MAX_TILE_HEIGHT * (MAX_TILE_HEIGHT + 3);
00031 
00032 struct TerraformerHeightMod {
00033   TileIndex tile;   
00034   byte height;      
00035 };
00036 
00037 struct TerraformerState {
00038   int modheight_count;                                         
00039   int tile_table_count;                                        
00040 
00048   TileIndex tile_table[TERRAFORMER_TILE_TABLE_SIZE];
00049   TerraformerHeightMod modheight[TERRAFORMER_MODHEIGHT_SIZE];  
00050 };
00051 
00052 TileIndex _terraform_err_tile;
00053 
00061 static int TerraformGetHeightOfTile(TerraformerState *ts, TileIndex tile)
00062 {
00063   TerraformerHeightMod *mod = ts->modheight;
00064   int count;
00065 
00066   for (count = ts->modheight_count; count != 0; count--, mod++) {
00067     if (mod->tile == tile) return mod->height;
00068   }
00069 
00070   /* TileHeight unchanged so far, read value from map. */
00071   return TileHeight(tile);
00072 }
00073 
00081 static void TerraformSetHeightOfTile(TerraformerState *ts, TileIndex tile, int height)
00082 {
00083   /* Find tile in the "modheight" table.
00084    * Note: In a normal user-terraform command the tile will not be found in the "modheight" table.
00085    *       But during house- or industry-construction multiple corners can be terraformed at once. */
00086   TerraformerHeightMod *mod = ts->modheight;
00087   int count = ts->modheight_count;
00088   while ((count > 0) && (mod->tile != tile)) {
00089     mod++;
00090     count--;
00091   }
00092 
00093   /* New entry? */
00094   if (count == 0) {
00095     assert(ts->modheight_count < TERRAFORMER_MODHEIGHT_SIZE);
00096     ts->modheight_count++;
00097   }
00098 
00099   /* Finally store the new value */
00100   mod->tile = tile;
00101   mod->height = (byte)height;
00102 }
00103 
00111 static void TerraformAddDirtyTile(TerraformerState *ts, TileIndex tile)
00112 {
00113   int count;
00114   TileIndex *t;
00115 
00116   count = ts->tile_table_count;
00117 
00118   for (t = ts->tile_table; count != 0; count--, t++) {
00119     if (*t == tile) return;
00120   }
00121 
00122   assert(ts->tile_table_count < TERRAFORMER_TILE_TABLE_SIZE);
00123 
00124   ts->tile_table[ts->tile_table_count++] = tile;
00125 }
00126 
00134 static void TerraformAddDirtyTileAround(TerraformerState *ts, TileIndex tile)
00135 {
00136   TerraformAddDirtyTile(ts, tile + TileDiffXY( 0, -1));
00137   TerraformAddDirtyTile(ts, tile + TileDiffXY(-1, -1));
00138   TerraformAddDirtyTile(ts, tile + TileDiffXY(-1,  0));
00139   TerraformAddDirtyTile(ts, tile);
00140 }
00141 
00150 static CommandCost TerraformTileHeight(TerraformerState *ts, TileIndex tile, int height)
00151 {
00152   CommandCost total_cost(EXPENSES_CONSTRUCTION);
00153 
00154   assert(tile < MapSize());
00155 
00156   /* Check range of destination height */
00157   if (height < 0) return_cmd_error(STR_1003_ALREADY_AT_SEA_LEVEL);
00158   if (height > MAX_TILE_HEIGHT) return_cmd_error(STR_1004_TOO_HIGH);
00159 
00160   /*
00161    * Check if the terraforming has any effect.
00162    * This can only be true, if multiple corners of the start-tile are terraformed (i.e. the terraforming is done by towns/industries etc.).
00163    * In this case the terraforming should fail. (Don't know why.)
00164    */
00165   if (height == TerraformGetHeightOfTile(ts, tile)) return CMD_ERROR;
00166 
00167   /* Check "too close to edge of map" */
00168   uint x = TileX(tile);
00169   uint y = TileY(tile);
00170   if ((x <= 1) || (y <= 1) || (x >= MapMaxX() - 1) || (y >= MapMaxY() - 1)) {
00171     /*
00172      * Determine a sensible error tile
00173      * Note: If x and y are both zero this will disable the error tile. (Tile 0 cannot be highlighted :( )
00174      */
00175     if ((x == 1) && (y != 0)) x = 0;
00176     if ((y == 1) && (x != 0)) y = 0;
00177     _terraform_err_tile = TileXY(x, y);
00178     return_cmd_error(STR_0002_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   /* Increment cost */
00188   total_cost.AddCost(_price.terraform);
00189 
00190   /* Recurse to neighboured corners if height difference is larger than 1 */
00191   {
00192     const TileIndexDiffC *ttm;
00193 
00194     static const TileIndexDiffC _terraform_tilepos[] = {
00195       { 1,  0}, // move to tile in SE
00196       {-2,  0}, // undo last move, and move to tile in NW
00197       { 1,  1}, // undo last move, and move to tile in SW
00198       { 0, -2}  // undo last move, and move to tile in NE
00199     };
00200 
00201     for (ttm = _terraform_tilepos; ttm != endof(_terraform_tilepos); ttm++) {
00202       tile += ToTileIndexDiff(*ttm);
00203 
00204       /* Get TileHeight of neighboured tile as of current terraform progress */
00205       int r = TerraformGetHeightOfTile(ts, tile);
00206       int height_diff = height - r;
00207 
00208       /* Is the height difference to the neighboured corner greater than 1? */
00209       if (abs(height_diff) > 1) {
00210         /* Terraform the neighboured corner. The resulting height difference should be 1. */
00211         height_diff += (height_diff < 0 ? 1 : -1);
00212         CommandCost cost = TerraformTileHeight(ts, tile, r + height_diff);
00213         if (CmdFailed(cost)) return cost;
00214         total_cost.AddCost(cost);
00215       }
00216     }
00217   }
00218 
00219   return total_cost;
00220 }
00221 
00229 CommandCost CmdTerraformLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00230 {
00231   TerraformerState ts;
00232   CommandCost total_cost(EXPENSES_CONSTRUCTION);
00233   int direction = (p2 != 0 ? 1 : -1);
00234 
00235   _terraform_err_tile = 0;
00236 
00237   ts.modheight_count = ts.tile_table_count = 0;
00238 
00239   /* Make an extra check for map-bounds cause we add tiles to the originating tile */
00240   if (tile + TileDiffXY(1, 1) >= MapSize()) return CMD_ERROR;
00241 
00242   /* Compute the costs and the terraforming result in a model of the landscape */
00243   if ((p1 & SLOPE_W) != 0) {
00244     TileIndex t = tile + TileDiffXY(1, 0);
00245     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00246     if (CmdFailed(cost)) return cost;
00247     total_cost.AddCost(cost);
00248   }
00249 
00250   if ((p1 & SLOPE_S) != 0) {
00251     TileIndex t = tile + TileDiffXY(1, 1);
00252     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00253     if (CmdFailed(cost)) return cost;
00254     total_cost.AddCost(cost);
00255   }
00256 
00257   if ((p1 & SLOPE_E) != 0) {
00258     TileIndex t = tile + TileDiffXY(0, 1);
00259     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00260     if (CmdFailed(cost)) return cost;
00261     total_cost.AddCost(cost);
00262   }
00263 
00264   if ((p1 & SLOPE_N) != 0) {
00265     TileIndex t = tile + TileDiffXY(0, 0);
00266     CommandCost cost = TerraformTileHeight(&ts, t, TileHeight(t) + direction);
00267     if (CmdFailed(cost)) return cost;
00268     total_cost.AddCost(cost);
00269   }
00270 
00271   /* Check if the terraforming is valid wrt. tunnels, bridges and objects on the surface */
00272   {
00273     int count;
00274     TileIndex *ti = ts.tile_table;
00275 
00276     for (count = ts.tile_table_count; count != 0; count--, ti++) {
00277       TileIndex tile = *ti;
00278 
00279       /* Find new heights of tile corners */
00280       uint z_N = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 0));
00281       uint z_W = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 0));
00282       uint z_S = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(1, 1));
00283       uint z_E = TerraformGetHeightOfTile(&ts, tile + TileDiffXY(0, 1));
00284 
00285       /* Find min and max height of tile */
00286       uint z_min = min(min(z_N, z_W), min(z_S, z_E));
00287       uint z_max = max(max(z_N, z_W), max(z_S, z_E));
00288 
00289       /* Compute tile slope */
00290       uint tileh = (z_max > z_min + 1 ? SLOPE_STEEP : SLOPE_FLAT);
00291       if (z_W > z_min) tileh += SLOPE_W;
00292       if (z_S > z_min) tileh += SLOPE_S;
00293       if (z_E > z_min) tileh += SLOPE_E;
00294       if (z_N > z_min) tileh += SLOPE_N;
00295 
00296       /* Check if bridge would take damage */
00297       if (direction == 1 && MayHaveBridgeAbove(tile) && IsBridgeAbove(tile) &&
00298           GetBridgeHeight(GetSouthernBridgeEnd(tile)) <= z_max * TILE_HEIGHT) {
00299         _terraform_err_tile = tile; // highlight the tile under the bridge
00300         return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
00301       }
00302       /* Check if tunnel would take damage */
00303       if (direction == -1 && IsTunnelInWay(tile, z_min * TILE_HEIGHT)) {
00304         _terraform_err_tile = tile; // highlight the tile above the tunnel
00305         return_cmd_error(STR_1002_EXCAVATION_WOULD_DAMAGE);
00306       }
00307       /* Check tiletype-specific things, and add extra-cost */
00308       CommandCost cost = _tile_type_procs[GetTileType(tile)]->terraform_tile_proc(tile, flags | DC_AUTO, z_min * TILE_HEIGHT, (Slope) tileh);
00309       if (CmdFailed(cost)) {
00310         _terraform_err_tile = tile;
00311         return cost;
00312       }
00313       total_cost.AddCost(cost);
00314     }
00315   }
00316 
00317   if (flags & DC_EXEC) {
00318     /* change the height */
00319     {
00320       int count;
00321       TerraformerHeightMod *mod;
00322 
00323       mod = ts.modheight;
00324       for (count = ts.modheight_count; count != 0; count--, mod++) {
00325         TileIndex til = mod->tile;
00326 
00327         SetTileHeight(til, mod->height);
00328       }
00329     }
00330 
00331     /* finally mark the dirty tiles dirty */
00332     {
00333       int count;
00334       TileIndex *ti = ts.tile_table;
00335       for (count = ts.tile_table_count; count != 0; count--, ti++) {
00336         MarkTileDirtyByTile(*ti);
00337       }
00338     }
00339   }
00340   return total_cost;
00341 }
00342 
00343 
00351 CommandCost CmdLevelLand(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
00352 {
00353   int size_x, size_y;
00354   int ex;
00355   int ey;
00356   int sx, sy;
00357   uint h, oldh, curh;
00358   CommandCost money;
00359   CommandCost ret;
00360   CommandCost cost(EXPENSES_CONSTRUCTION);
00361 
00362   if (p1 >= MapSize()) return CMD_ERROR;
00363 
00364   /* remember level height */
00365   oldh = TileHeight(p1);
00366 
00367   /* compute new height */
00368   h = oldh + p2;
00369 
00370   /* Check range of destination height */
00371   if (h > MAX_TILE_HEIGHT) return_cmd_error((oldh == 0) ? STR_1003_ALREADY_AT_SEA_LEVEL : STR_1004_TOO_HIGH);
00372 
00373   /* make sure sx,sy are smaller than ex,ey */
00374   ex = TileX(tile);
00375   ey = TileY(tile);
00376   sx = TileX(p1);
00377   sy = TileY(p1);
00378   if (ex < sx) Swap(ex, sx);
00379   if (ey < sy) Swap(ey, sy);
00380   tile = TileXY(sx, sy);
00381 
00382   size_x = ex - sx + 1;
00383   size_y = ey - sy + 1;
00384 
00385   money.AddCost(GetAvailableMoneyForCommand());
00386 
00387   BEGIN_TILE_LOOP(tile2, size_x, size_y, tile) {
00388     curh = TileHeight(tile2);
00389     while (curh != h) {
00390       ret = DoCommand(tile2, SLOPE_N, (curh > h) ? 0 : 1, flags & ~DC_EXEC, CMD_TERRAFORM_LAND);
00391       if (CmdFailed(ret)) break;
00392 
00393       if (flags & DC_EXEC) {
00394         money.AddCost(-ret.GetCost());
00395         if (money.GetCost() < 0) {
00396           _additional_cash_required = ret.GetCost();
00397           return cost;
00398         }
00399         DoCommand(tile2, SLOPE_N, (curh > h) ? 0 : 1, flags, CMD_TERRAFORM_LAND);
00400       }
00401 
00402       cost.AddCost(ret);
00403       curh += (curh > h) ? -1 : 1;
00404     }
00405   } END_TILE_LOOP(tile2, size_x, size_y, tile)
00406 
00407   return (cost.GetCost() == 0) ? CMD_ERROR : cost;
00408 }

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