From 1dbd2223ad1584a7f41503966e509d4abf4ec9c2 Mon Sep 17 00:00:00 2001 From: rubidium Date: Tue, 10 Aug 2010 23:31:43 +0000 Subject: (svn r20443) -Codechange: more TileHash to a more generic location --- src/tile_map.h | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'src/tile_map.h') diff --git a/src/tile_map.h b/src/tile_map.h index 393b89e01..202ad04e9 100644 --- a/src/tile_map.h +++ b/src/tile_map.h @@ -206,4 +206,35 @@ Slope GetTileSlope(TileIndex tile, uint *h); uint GetTileZ(TileIndex tile); uint GetTileMaxZ(TileIndex tile); -#endif /* TILE_TYPE_H */ + +/** + * Calculate a hash value from a tile position + * + * @param x The X coordinate + * @param y The Y coordinate + * @return The hash of the tile + */ +static inline uint TileHash(uint x, uint y) +{ + uint hash = x >> 4; + hash ^= x >> 6; + hash ^= y >> 4; + hash -= y >> 6; + return hash; +} + +/** + * Get the last two bits of the TileHash + * from a tile position. + * + * @see TileHash() + * @param x The X coordinate + * @param y The Y coordinate + * @return The last two bits from hash of the tile + */ +static inline uint TileHash2Bit(uint x, uint y) +{ + return GB(TileHash(x, y), 0, 2); +} + +#endif /* TILE_MAP_H */ -- cgit v1.2.3-54-g00ecf