map_func.h

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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 #ifndef MAP_FUNC_H
00013 #define MAP_FUNC_H
00014 
00015 #include "core/math_func.hpp"
00016 #include "tile_type.h"
00017 #include "map_type.h"
00018 #include "direction_func.h"
00019 
00020 extern uint _map_tile_mask;
00021 
00028 #define TILE_MASK(x) ((x) & _map_tile_mask)
00029 
00036 extern Tile *_m;
00037 
00044 extern TileExtended *_me;
00045 
00046 void AllocateMap(uint size_x, uint size_y);
00047 
00053 static inline uint MapLogX()
00054 {
00055   extern uint _map_log_x;
00056   return _map_log_x;
00057 }
00058 
00064 static inline uint MapLogY()
00065 {
00066   extern uint _map_log_y;
00067   return _map_log_y;
00068 }
00069 
00074 static inline uint MapSizeX()
00075 {
00076   extern uint _map_size_x;
00077   return _map_size_x;
00078 }
00079 
00084 static inline uint MapSizeY()
00085 {
00086   extern uint _map_size_y;
00087   return _map_size_y;
00088 }
00089 
00094 static inline uint MapSize()
00095 {
00096   extern uint _map_size;
00097   return _map_size;
00098 }
00099 
00104 static inline uint MapMaxX()
00105 {
00106   return MapSizeX() - 1;
00107 }
00108 
00113 static inline uint MapMaxY()
00114 {
00115   return MapSizeY() - 1;
00116 }
00117 
00124 static inline uint ScaleByMapSize(uint n)
00125 {
00126   /* Subtract 12 from shift in order to prevent integer overflow
00127    * for large values of n. It's safe since the min mapsize is 64x64. */
00128   return CeilDiv(n << (MapLogX() + MapLogY() - 12), 1 << 4);
00129 }
00130 
00131 
00138 static inline uint ScaleByMapSize1D(uint n)
00139 {
00140   /* Normal circumference for the X+Y is 256+256 = 1<<9
00141    * Note, not actually taking the full circumference into account,
00142    * just half of it. */
00143   return CeilDiv((n << MapLogX()) + (n << MapLogY()), 1 << 9);
00144 }
00145 
00156 typedef int32 TileIndexDiff;
00157 
00165 static inline TileIndex TileXY(uint x, uint y)
00166 {
00167   return (y << MapLogX()) + x;
00168 }
00169 
00181 static inline TileIndexDiff TileDiffXY(int x, int y)
00182 {
00183   /* Multiplication gives much better optimization on MSVC than shifting.
00184    * 0 << shift isn't optimized to 0 properly.
00185    * Typically x and y are constants, and then this doesn't result
00186    * in any actual multiplication in the assembly code.. */
00187   return (y * MapSizeX()) + x;
00188 }
00189 
00196 static inline TileIndex TileVirtXY(uint x, uint y)
00197 {
00198   return (y >> 4 << MapLogX()) + (x >> 4);
00199 }
00200 
00201 
00207 static inline uint TileX(TileIndex tile)
00208 {
00209   return tile & MapMaxX();
00210 }
00211 
00217 static inline uint TileY(TileIndex tile)
00218 {
00219   return tile >> MapLogX();
00220 }
00221 
00232 static inline TileIndexDiff ToTileIndexDiff(TileIndexDiffC tidc)
00233 {
00234   return (tidc.y << MapLogX()) + tidc.x;
00235 }
00236 
00237 
00238 #ifndef _DEBUG
00239 
00246   #define TILE_ADD(x, y) ((x) + (y))
00247 #else
00248   extern TileIndex TileAdd(TileIndex tile, TileIndexDiff add,
00249     const char *exp, const char *file, int line);
00250   #define TILE_ADD(x, y) (TileAdd((x), (y), #x " + " #y, __FILE__, __LINE__))
00251 #endif
00252 
00260 #define TILE_ADDXY(tile, x, y) TILE_ADD(tile, TileDiffXY(x, y))
00261 
00262 TileIndex TileAddWrap(TileIndex tile, int addx, int addy);
00263 
00270 static inline TileIndexDiffC TileIndexDiffCByDiagDir(DiagDirection dir)
00271 {
00272   extern const TileIndexDiffC _tileoffs_by_diagdir[DIAGDIR_END];
00273 
00274   assert(IsValidDiagDirection(dir));
00275   return _tileoffs_by_diagdir[dir];
00276 }
00277 
00284 static inline TileIndexDiffC TileIndexDiffCByDir(Direction dir)
00285 {
00286   extern const TileIndexDiffC _tileoffs_by_dir[DIR_END];
00287 
00288   assert(IsValidDirection(dir));
00289   return _tileoffs_by_dir[dir];
00290 }
00291 
00302 static inline TileIndex AddTileIndexDiffCWrap(TileIndex tile, TileIndexDiffC diff)
00303 {
00304   int x = TileX(tile) + diff.x;
00305   int y = TileY(tile) + diff.y;
00306   /* Negative value will become big positive value after cast */
00307   if ((uint)x >= MapSizeX() || (uint)y >= MapSizeY()) return INVALID_TILE;
00308   return TileXY(x, y);
00309 }
00310 
00318 static inline TileIndexDiffC TileIndexToTileIndexDiffC(TileIndex tile_a, TileIndex tile_b)
00319 {
00320   TileIndexDiffC difference;
00321 
00322   difference.x = TileX(tile_a) - TileX(tile_b);
00323   difference.y = TileY(tile_a) - TileY(tile_b);
00324 
00325   return difference;
00326 }
00327 
00328 /* Functions to calculate distances */
00329 uint DistanceManhattan(TileIndex, TileIndex); 
00330 uint DistanceSquare(TileIndex, TileIndex); 
00331 uint DistanceMax(TileIndex, TileIndex); 
00332 uint DistanceMaxPlusManhattan(TileIndex, TileIndex); 
00333 uint DistanceFromEdge(TileIndex); 
00334 uint DistanceFromEdgeDir(TileIndex, DiagDirection); 
00335 
00343 static inline TileIndexDiff TileOffsByDiagDir(DiagDirection dir)
00344 {
00345   extern const TileIndexDiffC _tileoffs_by_diagdir[DIAGDIR_END];
00346 
00347   assert(IsValidDiagDirection(dir));
00348   return ToTileIndexDiff(_tileoffs_by_diagdir[dir]);
00349 }
00350 
00357 static inline TileIndexDiff TileOffsByDir(Direction dir)
00358 {
00359   extern const TileIndexDiffC _tileoffs_by_dir[DIR_END];
00360 
00361   assert(IsValidDirection(dir));
00362   return ToTileIndexDiff(_tileoffs_by_dir[dir]);
00363 }
00364 
00372 static inline TileIndex TileAddByDiagDir(TileIndex tile, DiagDirection dir)
00373 {
00374   return TILE_ADD(tile, TileOffsByDiagDir(dir));
00375 }
00376 
00384 static inline DiagDirection DiagdirBetweenTiles(TileIndex tile_from, TileIndex tile_to)
00385 {
00386   int dx = (int)TileX(tile_to) - (int)TileX(tile_from);
00387   int dy = (int)TileY(tile_to) - (int)TileY(tile_from);
00388   if (dx == 0) {
00389     if (dy == 0) return INVALID_DIAGDIR;
00390     return (dy < 0 ? DIAGDIR_NW : DIAGDIR_SE);
00391   } else {
00392     if (dy != 0) return INVALID_DIAGDIR;
00393     return (dx < 0 ? DIAGDIR_NE : DIAGDIR_SW);
00394   }
00395 }
00396 
00404 typedef bool TestTileOnSearchProc(TileIndex tile, void *user_data);
00405 
00406 bool CircularTileSearch(TileIndex *tile, uint size, TestTileOnSearchProc proc, void *user_data);
00407 bool CircularTileSearch(TileIndex *tile, uint radius, uint w, uint h, TestTileOnSearchProc proc, void *user_data);
00408 
00414 static inline TileIndex RandomTileSeed(uint32 r)
00415 {
00416   return TILE_MASK(r);
00417 }
00418 
00425 #define RandomTile() RandomTileSeed(Random())
00426 
00427 uint GetClosestWaterDistance(TileIndex tile, bool water);
00428 
00429 #endif /* MAP_FUNC_H */

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