/* $Id$ */ /** @file map.cpp */ #include "stdafx.h" #include "openttd.h" #include "debug.h" #include "functions.h" #include "macros.h" #include "map.h" #include "direction.h" #include "helpers.hpp" #if defined(_MSC_VER) && _MSC_VER >= 1400 /* VStudio 2005 is stupid! */ /* Why the hell is that not in all MSVC headers?? */ extern "C" _CRTIMP void __cdecl _assert(void *, void *, unsigned); #endif uint _map_log_x; ///< 2^_map_log_x == _map_size_x uint _map_size_x; ///< Size of the map along the X uint _map_size_y; ///< Size of the map along the Y uint _map_size; ///< The number of tiles on the map uint _map_tile_mask; ///< _map_size - 1 (to mask the mapsize) Tile *_m = NULL; ///< Tiles of the map TileExtended *_me = NULL; ///< Extended Tiles of the map /** * (Re)allocates a map with the given dimension * @param size_x the width of the map along the NE/SW edge * @param size_y the 'height' of the map along the SE/NW edge */ void AllocateMap(uint size_x, uint size_y) { /* Make sure that the map size is within the limits and that * the x axis size is a power of 2. */ if (size_x < 64 || size_x > 2048 || size_y < 64 || size_y > 2048 || (size_x & (size_x - 1)) != 0 || (size_y & (size_y - 1)) != 0) error("Invalid map size"); DEBUG(map, 1, "Allocating map of size %dx%d", size_x, size_y); _map_log_x = FindFirstBit(size_x); _map_size_x = size_x; _map_size_y = size_y; _map_size = size_x * size_y; _map_tile_mask = _map_size - 1; free(_m); free(_me); _m = CallocT<Tile>(_map_size); _me = CallocT<TileExtended>(_map_size); /* XXX @todo handle memory shortage more gracefully * Maybe some attemps could be made to try with smaller maps down to 64x64 * Maybe check for available memory before doing the calls, after all, we know how big * the map is */ if ((_m == NULL) || (_me == NULL)) error("Failed to allocate memory for the map"); } #ifdef _DEBUG TileIndex TileAdd(TileIndex tile, TileIndexDiff add, const char *exp, const char *file, int line) { int dx; int dy; uint x; uint y; dx = add & MapMaxX(); if (dx >= (int)MapSizeX() / 2) dx -= MapSizeX(); dy = (add - dx) / (int)MapSizeX(); x = TileX(tile) + dx; y = TileY(tile) + dy; if (x >= MapSizeX() || y >= MapSizeY()) { char buf[512]; snprintf(buf, lengthof(buf), "TILE_ADD(%s) when adding 0x%.4X and 0x%.4X failed", exp, tile, add); #if !defined(_MSC_VER) fprintf(stderr, "%s:%d %s\n", file, line, buf); #else _assert(buf, (char*)file, line); #endif } assert(TileXY(x, y) == TILE_MASK(tile + add)); return TileXY(x, y); } #endif /** * Scales the given value by the map size, where the given value is * for a 256 by 256 map * @param n the value to scale * @return the scaled size */ uint ScaleByMapSize(uint n) { /* First shift by 12 to prevent integer overflow for large values of n. * >>12 is safe since the min mapsize is 64x64 * Add (1<<4)-1 to round upwards. */ return (n * (MapSize() >> 12) + (1 << 4) - 1) >> 4; } /** * Scales the given value by the maps circumference, where the given * value is for a 256 by 256 map * @param n the value to scale * @return the scaled size */ uint ScaleByMapSize1D(uint n) { /* Normal circumference for the X+Y is 256+256 = 1<<9 * Note, not actually taking the full circumference into account, * just half of it. * (1<<9) - 1 is there to scale upwards. */ return (n * (MapSizeX() + MapSizeY()) + (1 << 9) - 1) >> 9; } /** * This function checks if we add addx/addy to tile, if we * do wrap around the edges. For example, tile = (10,2) and * addx = +3 and addy = -4. This function will now return * INVALID_TILE, because the y is wrapped. This is needed in * for example, farmland. When the tile is not wrapped, * the result will be tile + TileDiffXY(addx, addy) * @param tile the 'starting' point of the adding * @param addx the amount of tiles in the X direction to add * @param addy the amount of tiles in the Y direction to add * @return translated tile, or INVALID_TILE when it would've wrapped. */ uint TileAddWrap(TileIndex tile, int addx, int addy) { uint x = TileX(tile) + addx; uint y = TileY(tile) + addy; /* Are we about to wrap? */ if (x < MapMaxX() && y < MapMaxY()) return tile + TileDiffXY(addx, addy); return INVALID_TILE; } /** 'Lookup table' for tile offsets given a DiagDirection */ extern const TileIndexDiffC _tileoffs_by_diagdir[] = { {-1, 0}, ///< DIAGDIR_NE { 0, 1}, ///< DIAGDIR_SE { 1, 0}, ///< DIAGDIR_SW { 0, -1} ///< DIAGDIR_NW }; /** 'Lookup table' for tile offsets given a Direction */ extern const TileIndexDiffC _tileoffs_by_dir[] = { {-1, -1}, ///< DIR_N {-1, 0}, ///< DIR_NE {-1, 1}, ///< DIR_E { 0, 1}, ///< DIR_SE { 1, 1}, ///< DIR_S { 1, 0}, ///< DIR_SW { 1, -1}, ///< DIR_W { 0, -1} ///< DIR_NW }; /** * Gets the Manhattan distance between the two given tiles. * The Manhattan distance is the sum of the delta of both the * X and Y component. * Also known as L1-Norm * @param t0 the start tile * @param t1 the end tile * @return the distance */ uint DistanceManhattan(TileIndex t0, TileIndex t1) { const uint dx = delta(TileX(t0), TileX(t1)); const uint dy = delta(TileY(t0), TileY(t1)); return dx + dy; } /** * Gets the 'Square' distance between the two given tiles. * The 'Square' distance is the square of the shortest (straight line) * distance between the two tiles. * Also known as euclidian- or L2-Norm squared. * @param t0 the start tile * @param t1 the end tile * @return the distance */ uint DistanceSquare(TileIndex t0, TileIndex t1) { const int dx = TileX(t0) - TileX(t1); const int dy = TileY(t0) - TileY(t1); return dx * dx + dy * dy; } /** * Gets the biggest distance component (x or y) between the two given tiles. * Also known as L-Infinity-Norm. * @param t0 the start tile * @param t1 the end tile * @return the distance */ uint DistanceMax(TileIndex t0, TileIndex t1) { const uint dx = delta(TileX(t0), TileX(t1)); const uint dy = delta(TileY(t0), TileY(t1)); return dx > dy ? dx : dy; } /** * Gets the biggest distance component (x or y) between the two given tiles * plus the Manhattan distance, i.e. two times the biggest distance component * and once the smallest component. * @param t0 the start tile * @param t1 the end tile * @return the distance */ uint DistanceMaxPlusManhattan(TileIndex t0, TileIndex t1) { const uint dx = delta(TileX(t0), TileX(t1)); const uint dy = delta(TileY(t0), TileY(t1)); return dx > dy ? 2 * dx + dy : 2 * dy + dx; } /** * Param the minimum distance to an edge * @param tile the tile to get the distance from * @return the distance from the edge in tiles */ uint DistanceFromEdge(TileIndex tile) { const uint xl = TileX(tile); const uint yl = TileY(tile); const uint xh = MapSizeX() - 1 - xl; const uint yh = MapSizeY() - 1 - yl; const uint minl = xl < yl ? xl : yl; const uint minh = xh < yh ? xh : yh; return minl < minh ? minl : minh; } /** * Function performing a search around a center tile and going outward, thus in circle. * Although it really is a square search... * Every tile will be tested by means of the callback function proc, * which will determine if yes or no the given tile meets criteria of search. * @param tile to start the search from * @param size: number of tiles per side of the desired search area * @param proc: callback testing function pointer. * @param data to be passed to the callback function. Depends on the implementation * @return result of the search * @pre proc != NULL * @pre size > 0 */ bool CircularTileSearch(TileIndex tile, uint size, TestTileOnSearchProc proc, uint32 data) { uint n, x, y; DiagDirection dir; assert(proc != NULL); assert(size > 0); x = TileX(tile); y = TileY(tile); if (size % 2 == 1) { /* If the length of the side is uneven, the center has to be checked * separately, as the pattern of uneven sides requires to go around the center */ n = 2; if (proc(TileXY(x, y), data)) return true; /* If tile test is not successful, get one tile down and left, * ready for a test in first circle around center tile */ x += _tileoffs_by_dir[DIR_W].x; y += _tileoffs_by_dir[DIR_W].y; } else { n = 1; /* To use _tileoffs_by_diagdir's order, we must relocate to * another tile, as we now first go 'up', 'right', 'down', 'left' * instead of 'right', 'down', 'left', 'up', which the calling * function assume. */ x++; } for (; n < size; n += 2) { for (dir = DIAGDIR_NE; dir < DIAGDIR_END; dir++) { uint j; for (j = n; j != 0; j--) { if (x <= MapMaxX() && y <= MapMaxY() && ///< Is the tile within the map? proc(TileXY(x, y), data)) { ///< Is the callback successful? return true; ///< then stop the search } /* Step to the next 'neighbour' in the circular line */ x += _tileoffs_by_diagdir[dir].x; y += _tileoffs_by_diagdir[dir].y; } } /* Jump to next circle to test */ x += _tileoffs_by_dir[DIR_W].x; y += _tileoffs_by_dir[DIR_W].y; } return false; }