map.cpp

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00001 /* $Id$ */
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 "debug.h"
00014 #include "core/alloc_func.hpp"
00015 #include "core/random_func.hpp"
00016 #include "tile_map.h"
00017 #include "genworld.h"
00018 #include "water_map.h"
00019 
00020 uint8 _head_to_head;
00021 
00022 #if defined(_MSC_VER)
00023 /* Why the hell is that not in all MSVC headers?? */
00024 extern "C" _CRTIMP void __cdecl _assert(void *, void *, unsigned);
00025 #endif
00026 
00027 uint _map_log_x;     
00028 uint _map_log_y;     
00029 uint _map_size_x;    
00030 uint _map_size_y;    
00031 uint _map_size;      
00032 uint _map_tile_mask; 
00033 
00034 Tile *_m = NULL;          
00035 TileExtended *_me = NULL; 
00036 
00037 TileIndex RandomTileInArea(uint area)
00038 {
00039   uint r = Random();
00040   uint x = GB(r, 0, MapLogX());
00041   uint y = GB(r, MapLogX(), MapLogY() - FIND_FIRST_BIT(_settings_game.game_creation.head_to_head_areas)) + (area - 1) * MapSizeY() / _settings_game.game_creation.head_to_head_areas;
00042   assert(GetAreaByTile(TileXY(x, y)) == area);
00043   return TileXY(x, y);
00044 }
00045 
00051 void AllocateMap(uint size_x, uint size_y)
00052 {
00053   /* Make sure that the map size is within the limits and that
00054    * size of both axes is a power of 2. */
00055   if (!IsInsideMM(size_x, MIN_MAP_SIZE, MAX_MAP_SIZE + 1) ||
00056       !IsInsideMM(size_y, MIN_MAP_SIZE, MAX_MAP_SIZE + 1) ||
00057       (size_x & (size_x - 1)) != 0 ||
00058       (size_y & (size_y - 1)) != 0) {
00059     error("Invalid map size");
00060   }
00061 
00062   DEBUG(map, 1, "Allocating map of size %dx%d", size_x, size_y);
00063 
00064   _map_log_x = FindFirstBit(size_x);
00065   _map_log_y = FindFirstBit(size_y);
00066   _map_size_x = size_x;
00067   _map_size_y = size_y;
00068   _map_size = size_x * size_y;
00069   _map_tile_mask = _map_size - 1;
00070 
00071   free(_m);
00072   free(_me);
00073 
00074   _m = CallocT<Tile>(_map_size);
00075   _me = CallocT<TileExtended>(_map_size);
00076 }
00077 
00078 
00079 #ifdef _DEBUG
00080 TileIndex TileAdd(TileIndex tile, TileIndexDiff add,
00081   const char *exp, const char *file, int line)
00082 {
00083   int dx;
00084   int dy;
00085   uint x;
00086   uint y;
00087 
00088   dx = add & MapMaxX();
00089   if (dx >= (int)MapSizeX() / 2) dx -= MapSizeX();
00090   dy = (add - dx) / (int)MapSizeX();
00091 
00092   x = TileX(tile) + dx;
00093   y = TileY(tile) + dy;
00094 
00095   if (x >= MapSizeX() || y >= MapSizeY()) {
00096     char buf[512];
00097 
00098     snprintf(buf, lengthof(buf), "TILE_ADD(%s) when adding 0x%.4X and 0x%.4X failed",
00099       exp, tile, add);
00100 #if !defined(_MSC_VER) || defined(WINCE)
00101     fprintf(stderr, "%s:%d %s\n", file, line, buf);
00102 #else
00103     _assert(buf, (char*)file, line);
00104 #endif
00105   }
00106 
00107   assert(TileXY(x, y) == TILE_MASK(tile + add));
00108 
00109   return TileXY(x, y);
00110 }
00111 #endif
00112 
00126 TileIndex TileAddWrap(TileIndex tile, int addx, int addy)
00127 {
00128   uint x = TileX(tile) + addx;
00129   uint y = TileY(tile) + addy;
00130 
00131   /* Disallow void tiles at the north border. */
00132   if ((x == 0 || y == 0) && _settings_game.construction.freeform_edges) return INVALID_TILE;
00133 
00134   /* Are we about to wrap? */
00135   if (x >= MapMaxX() || y >= MapMaxY()) return INVALID_TILE;
00136 
00137   return TileXY(x, y);
00138 }
00139 
00140 TileIndex TileAddAreaWrap(TileIndex tile, int addx, int addy)
00141 {
00142   if (_generating_world) return TileAddWrap(tile, addx, addy);
00143 
00144   int x = TileX(tile) + addx;
00145   int y = TileY(tile) + addy;
00146 
00147   uint8 backup_h2h = _head_to_head;
00148   _head_to_head = GetAreaByTile(tile);
00149   if (x < (int)AreaMinX() || y < (int)AreaMinY() || x >= (int)AreaMaxX() || y >= (int)AreaMaxY()) {
00150     tile = INVALID_TILE;
00151   } else {
00152     tile = TileXY(x, y);
00153   }
00154   _head_to_head = backup_h2h;
00155 
00156   return tile;
00157 }
00158 
00160 extern const TileIndexDiffC _tileoffs_by_diagdir[] = {
00161   {-1,  0}, 
00162   { 0,  1}, 
00163   { 1,  0}, 
00164   { 0, -1}  
00165 };
00166 
00168 extern const TileIndexDiffC _tileoffs_by_dir[] = {
00169   {-1, -1}, 
00170   {-1,  0}, 
00171   {-1,  1}, 
00172   { 0,  1}, 
00173   { 1,  1}, 
00174   { 1,  0}, 
00175   { 1, -1}, 
00176   { 0, -1}  
00177 };
00178 
00188 uint DistanceManhattan(TileIndex t0, TileIndex t1)
00189 {
00190   const uint dx = Delta(TileX(t0), TileX(t1));
00191   const uint dy = Delta(TileY(t0), TileY(t1));
00192   return dx + dy;
00193 }
00194 
00195 
00205 uint DistanceSquare(TileIndex t0, TileIndex t1)
00206 {
00207   const int dx = TileX(t0) - TileX(t1);
00208   const int dy = TileY(t0) - TileY(t1);
00209   return dx * dx + dy * dy;
00210 }
00211 
00212 
00220 uint DistanceMax(TileIndex t0, TileIndex t1)
00221 {
00222   const uint dx = Delta(TileX(t0), TileX(t1));
00223   const uint dy = Delta(TileY(t0), TileY(t1));
00224   return max(dx, dy);
00225 }
00226 
00227 
00236 uint DistanceMaxPlusManhattan(TileIndex t0, TileIndex t1)
00237 {
00238   const uint dx = Delta(TileX(t0), TileX(t1));
00239   const uint dy = Delta(TileY(t0), TileY(t1));
00240   return dx > dy ? 2 * dx + dy : 2 * dy + dx;
00241 }
00242 
00248 uint DistanceFromEdge(TileIndex tile)
00249 {
00250   uint8 h2h_backup = _head_to_head;
00251   _head_to_head = GetAreaByTile(tile);
00252   const uint xl = TileX(tile) - AreaMinX();
00253   const uint yl = TileY(tile) - AreaMinY();
00254   const uint xh = AreaMaxX() - 1 - xl;
00255   const uint yh = AreaMaxY() - 1 - yl;
00256   const uint minl = min(xl, yl);
00257   const uint minh = min(xh, yh);
00258   _head_to_head = h2h_backup;
00259   return min(minl, minh);
00260 }
00261 
00268 uint DistanceFromEdgeDir(TileIndex tile, DiagDirection dir)
00269 {
00270   switch (dir) {
00271     case DIAGDIR_NE: return             TileX(tile) - (_settings_game.construction.freeform_edges ? 1 : 0);
00272     case DIAGDIR_NW: return             TileY(tile) - (_settings_game.construction.freeform_edges ? 1 : 0);
00273     case DIAGDIR_SW: return MapMaxX() - TileX(tile) - 1;
00274     case DIAGDIR_SE: return MapMaxY() - TileY(tile) - 1;
00275     default: NOT_REACHED();
00276   }
00277 }
00278 
00292 bool CircularTileSearch(TileIndex *tile, uint size, TestTileOnSearchProc proc, void *user_data)
00293 {
00294   assert(proc != NULL);
00295   assert(size > 0);
00296 
00297   if (size % 2 == 1) {
00298     /* If the length of the side is uneven, the center has to be checked
00299      * separately, as the pattern of uneven sides requires to go around the center */
00300     if (proc(*tile, user_data)) return true;
00301 
00302     /* If tile test is not successful, get one tile up,
00303      * ready for a test in first circle around center tile */
00304     *tile = TILE_ADD(*tile, TileOffsByDir(DIR_N));
00305     return CircularTileSearch(tile, size / 2, 1, 1, proc, user_data);
00306   } else {
00307     return CircularTileSearch(tile, size / 2, 0, 0, proc, user_data);
00308   }
00309 }
00310 
00330 bool CircularTileSearch(TileIndex *tile, uint radius, uint w, uint h, TestTileOnSearchProc proc, void *user_data)
00331 {
00332   assert(proc != NULL);
00333   assert(radius > 0);
00334 
00335   uint x = TileX(*tile) + w + 1;
00336   uint y = TileY(*tile);
00337 
00338   const uint extent[DIAGDIR_END] = { w, h, w, h };
00339 
00340   for (uint n = 0; n < radius; n++) {
00341     for (DiagDirection dir = DIAGDIR_BEGIN; dir < DIAGDIR_END; dir++) {
00342       /* Is the tile within the map? */
00343       for (uint j = extent[dir] + n * 2 + 1; j != 0; j--) {
00344         if (x < MapSizeX() && y < MapSizeY()) {
00345           TileIndex t = TileXY(x, y);
00346           /* Is the callback successful? */
00347           if (proc(t, user_data)) {
00348             /* Stop the search */
00349             *tile = t;
00350             return true;
00351           }
00352         }
00353 
00354         /* Step to the next 'neighbour' in the circular line */
00355         x += _tileoffs_by_diagdir[dir].x;
00356         y += _tileoffs_by_diagdir[dir].y;
00357       }
00358     }
00359     /* Jump to next circle to test */
00360     x += _tileoffs_by_dir[DIR_W].x;
00361     y += _tileoffs_by_dir[DIR_W].y;
00362   }
00363 
00364   *tile = INVALID_TILE;
00365   return false;
00366 }
00367 
00374 uint GetClosestWaterDistance(TileIndex tile, bool water)
00375 {
00376   if (HasTileWaterGround(tile) == water) return 0;
00377 
00378   uint max_dist = water ? 0x7F : 0x200;
00379 
00380   int x = TileX(tile);
00381   int y = TileY(tile);
00382 
00383   uint max_x = MapMaxX();
00384   uint max_y = MapMaxY();
00385   uint min_xy = _settings_game.construction.freeform_edges ? 1 : 0;
00386 
00387   /* go in a 'spiral' with increasing manhattan distance in each iteration */
00388   for (uint dist = 1; dist < max_dist; dist++) {
00389     /* next 'diameter' */
00390     y--;
00391 
00392     /* going counter-clockwise around this square */
00393     for (DiagDirection dir = DIAGDIR_BEGIN; dir < DIAGDIR_END; dir++) {
00394       static const int8 ddx[DIAGDIR_END] = { -1,  1,  1, -1};
00395       static const int8 ddy[DIAGDIR_END] = {  1,  1, -1, -1};
00396 
00397       int dx = ddx[dir];
00398       int dy = ddy[dir];
00399 
00400       /* each side of this square has length 'dist' */
00401       for (uint a = 0; a < dist; a++) {
00402         /* MP_VOID tiles are not checked (interval is [min; max) for IsInsideMM())*/
00403         if (IsInsideMM(x, min_xy, max_x) && IsInsideMM(y, min_xy, max_y)) {
00404           TileIndex t = TileXY(x, y);
00405           if (HasTileWaterGround(t) == water) return dist;
00406         }
00407         x += dx;
00408         y += dy;
00409       }
00410     }
00411   }
00412 
00413   if (!water) {
00414     /* no land found - is this a water-only map? */
00415     for (TileIndex t = 0; t < MapSize(); t++) {
00416       if (!IsTileType(t, MP_VOID) && !IsTileType(t, MP_WATER)) return 0x1FF;
00417     }
00418   }
00419 
00420   return max_dist;
00421 }