1 /* $Id$ */

     2 

     3 /** @file newgrf_commons.h This file simplyfies and embeds a common mechanism of

     4  * loading/saving and mapping of grf entities.

     5  */

     6 

     7 #ifndef NEWGRF_COMMONS_H

     8 #define NEWGRF_COMMONS_H

     9 

    10 /**

    11  * Maps an entity id stored on the map to a GRF file.

    12  * Entities are objects used ingame (houses, industries, industry tiles) for

    13  * which we need to correlate the ids from the grf files with the ones in the

    14  * the savegames themselves.

    15  * An array of EntityIDMapping structs is saved with the savegame so

    16  * that those GRFs can be loaded in a different order, or removed safely. The

    17  * index in the array is the entity's ID stored on the map.

    18  *

    19  * The substitute ID is the ID of an original entity that should be used instead

    20  * if the GRF containing the new entity is not available.

    21  */

    22 struct EntityIDMapping {

    23 	uint32 grfid;          ///< The GRF ID of the file the entity belongs to

    24 	uint8  entity_id;      ///< The entity ID within the GRF file

    25 	uint8  substitute_id;  ///< The (original) entity ID to use if this GRF is not available

    26 };

    27 

    28 class OverrideManagerBase

    29 {

    30 protected:

    31 	uint16 *entity_overrides;

    32 

    33 	uint16 max_offset;       ///< what is the length of the original entity's array of specs

    34 	uint16 max_new_entities; ///< what is the amount of entities, old and new summed

    35 

    36 	uint16 invalid_ID;       ///< ID used to dected invalid entities;

    37 

    38 	virtual uint16 AddEntityID(byte grf_local_id, uint32 grfid, byte substitute_id);

    39 public:

    40 	EntityIDMapping *mapping_ID; ///< mapping of ids from grf files.  Public out of convenience

    41 

    42 	OverrideManagerBase(uint16 offset, uint16 maximum, uint16 invalid);

    43 	virtual ~OverrideManagerBase();

    44 

    45 	void ResetOverride();

    46 	void ResetMapping();

    47 

    48 	void Add(uint8 local_id, uint entity_type);

    49 

    50 	uint16 GetSubstituteID(byte entity_id);

    51 	uint16 GetID(uint8 grf_local_id, uint32 grfid);

    52 

    53 	inline uint16 GetMaxMapping() { return max_new_entities; };

    54 	inline uint16 GetMaxOffset() { return max_offset; };

    55 };

    56 

    57 

    58 struct HouseSpec;

    59 class HouseOverrideManager : public OverrideManagerBase

    60 {

    61 public:

    62 	HouseOverrideManager(uint16 offset, uint16 maximum, uint16 invalid) : OverrideManagerBase(offset, maximum, invalid) {};

    63 	void SetEntitySpec(const HouseSpec *hs);

    64 };

    65 

    66 

    67 extern HouseOverrideManager _house_mngr;

    68 

    69 #endif /* NEWGRF_COMMONS_H */