#ifndef MAP_H
#define MAP_H

#define TILE_X_BITS 8
#define TILE_Y_BITS 8

#define TILE_MASK(x) (int)((x) & ((1 << (MapLogX() + MapLogY())) - 1))

extern byte   _map_type_and_height[];
extern byte   _map5[];
extern byte   _map3_lo[];
extern byte   _map3_hi[];
extern byte   _map_owner[];
extern uint16 _map2[];
extern byte   _map_extra_bits[];

// binary logarithm of the map size, try to avoid using this one
static inline uint MapLogX(void)  { extern uint _map_log_x; return _map_log_x; }
static inline uint MapLogY(void)  { extern uint _map_log_y; return _map_log_y; }
/* The size of the map */
static inline uint MapSizeX(void) { return 1 << MapLogX(); }
static inline uint MapSizeY(void) { return 1 << MapLogY(); }
/* The maximum coordinates */
static inline uint MapMaxX(void) { return MapSizeX() - 1; }
static inline uint MapMaxY(void) { return MapSizeY() - 1; }
/* The number of tiles in the map */
static inline uint MapSize(void) { return MapSizeX() * MapSizeY(); }


typedef uint16 TileIndex;

static inline uint TileX(TileIndex tile)
{
	return tile & MapMaxX();
}

static inline uint TileY(TileIndex tile)
{
	return tile >> MapLogX();
}


typedef int16 TileIndexDiff;

typedef struct TileIndexDiffC {
	int16 x;
	int16 y;
} TileIndexDiffC;

static inline TileIndexDiff ToTileIndexDiff(TileIndexDiffC tidc)
{
	return (tidc.y << MapLogX()) + tidc.x;
}

static inline TileIndexDiff TileOffsByDir(uint dir)
{
	extern const TileIndexDiffC _tileoffs_by_dir[4];

	assert(dir < lengthof(_tileoffs_by_dir));
	return ToTileIndexDiff(_tileoffs_by_dir[dir]);
}

#endif