diff options
Diffstat (limited to 'depot.h')
| -rw-r--r-- | depot.h | 25 |
1 files changed, 25 insertions, 0 deletions
@@ -1,6 +1,9 @@ #ifndef DEPOT_H #define DEPOT_H +/** @file depot.h Header files for depots (not hangars) + * @see depot.c */ + #include "pool.h" #include "tile.h" @@ -112,6 +115,28 @@ static inline DiagDirection GetDepotDirection(TileIndex tile, TransportType type } } +/** + Find out if the slope of the tile is suitable to build a depot of given direction + @param direction The direction in which the depot's exit points. Starts with 0 as NE and goes Clockwise + @param tileh The slope of the tile in question + @return true if the construction is possible + + + This is checked by the ugly 0x4C >> direction magic, which does the following: + 0x4C is 0100 1100 and tileh has only bits 0..3 set (steep tiles are ruled out) + So: for direction (only the significant bits are shown)<p> + 00 (exit towards NE) we need either bit 2 or 3 set in tileh: 0x4C >> 0 = 1100<p> + 01 (exit towards SE) we need either bit 1 or 2 set in tileh: 0x4C >> 1 = 0110<p> + 02 (exit towards SW) we need either bit 0 or 1 set in tileh: 0x4C >> 2 = 0011<p> + 03 (exit towards NW) we need either bit 0 or 4 set in tileh: 0x4C >> 3 = 1001<p> + So ((0x4C >> p2) & tileh) determines whether the depot can be built on the current tileh +*/ +static inline bool CanBuildDepotByTileh(uint32 direction, uint tileh) +{ + return (0x4C >> direction) & tileh; +} + + Depot *GetDepotByTile(TileIndex tile); void InitializeDepot(void); Depot *AllocateDepot(void); |