map_func.h

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00001 /* $Id: map_func.h 21490 2010-12-12 20:58:33Z 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 #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 
00049 void AllocateMap(uint size_x, uint size_y);
00050 
00056 static inline uint MapLogX()
00057 {
00058   extern uint _map_log_x;
00059   return _map_log_x;
00060 }
00061 
00067 static inline uint MapLogY()
00068 {
00069   extern uint _map_log_y;
00070   return _map_log_y;
00071 }
00072 
00077 static inline uint MapSizeX()
00078 {
00079   extern uint _map_size_x;
00080   return _map_size_x;
00081 }
00082 
00087 static inline uint MapSizeY()
00088 {
00089   extern uint _map_size_y;
00090   return _map_size_y;
00091 }
00092 
00097 static inline uint MapSize()
00098 {
00099   extern uint _map_size;
00100   return _map_size;
00101 }
00102 
00107 static inline uint MapMaxX()
00108 {
00109   return MapSizeX() - 1;
00110 }
00111 
00116 static inline uint MapMaxY()
00117 {
00118   return MapSizeY() - 1;
00119 }
00120 
00127 static inline uint ScaleByMapSize(uint n)
00128 {
00129   /* Subtract 12 from shift in order to prevent integer overflow
00130    * for large values of n. It's safe since the min mapsize is 64x64. */
00131   return CeilDiv(n << (MapLogX() + MapLogY() - 12), 1 << 4);
00132 }
00133 
00134 
00141 static inline uint ScaleByMapSize1D(uint n)
00142 {
00143   /* Normal circumference for the X+Y is 256+256 = 1<<9
00144    * Note, not actually taking the full circumference into account,
00145    * just half of it. */
00146   return CeilDiv((n << MapLogX()) + (n << MapLogY()), 1 << 9);
00147 }
00148 
00159 typedef int32 TileIndexDiff;
00160 
00168 static inline TileIndex TileXY(uint x, uint y)
00169 {
00170   return (y << MapLogX()) + x;
00171 }
00172 
00184 static inline TileIndexDiff TileDiffXY(int x, int y)
00185 {
00186   /* Multiplication gives much better optimization on MSVC than shifting.
00187    * 0 << shift isn't optimized to 0 properly.
00188    * Typically x and y are constants, and then this doesn't result
00189    * in any actual multiplication in the assembly code.. */
00190   return (y * MapSizeX()) + x;
00191 }
00192 
00193 static inline TileIndex TileVirtXY(uint x, uint y)
00194 {
00195   return (y >> 4 << MapLogX()) + (x >> 4);
00196 }
00197 
00198 
00204 static inline uint TileX(TileIndex tile)
00205 {
00206   return tile & MapMaxX();
00207 }
00208 
00214 static inline uint TileY(TileIndex tile)
00215 {
00216   return tile >> MapLogX();
00217 }
00218 
00229 static inline TileIndexDiff ToTileIndexDiff(TileIndexDiffC tidc)
00230 {
00231   return (tidc.y << MapLogX()) + tidc.x;
00232 }
00233 
00234 
00235 #ifndef _DEBUG
00236 
00243   #define TILE_ADD(x, y) ((x) + (y))
00244 #else
00245   extern TileIndex TileAdd(TileIndex tile, TileIndexDiff add,
00246     const char *exp, const char *file, int line);
00247   #define TILE_ADD(x, y) (TileAdd((x), (y), #x " + " #y, __FILE__, __LINE__))
00248 #endif
00249 
00257 #define TILE_ADDXY(tile, x, y) TILE_ADD(tile, TileDiffXY(x, y))
00258 
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 
00409 bool CircularTileSearch(TileIndex *tile, uint size, TestTileOnSearchProc proc, void *user_data);
00410 
00414 bool CircularTileSearch(TileIndex *tile, uint radius, uint w, uint h, TestTileOnSearchProc proc, void *user_data);
00415 
00421 static inline TileIndex RandomTileSeed(uint32 r)
00422 {
00423   return TILE_MASK(r);
00424 }
00425 
00432 #define RandomTile() RandomTileSeed(Random())
00433 
00437 uint GetClosestWaterDistance(TileIndex tile, bool water);
00438 
00439 #endif /* MAP_FUNC_H */

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