#ifndef MAP_H
#define MAP_H

#include "stdafx.h"

#define TILE_FROM_XY(x,y) (int)((((y) >> 4) << MapLogX()) + ((x) >> 4))
#define TILE_XY(x,y) (((y) << MapLogX()) + (x))

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

extern byte   *_map_type_and_height;
extern byte   *_map_owner;
extern uint16 *_map2;
extern byte   *_map3_lo;
extern byte   *_map3_hi;
extern byte   *_map5;
extern byte   *_map_extra_bits;

void InitMap(uint log_x, uint log_y);

// 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(); }

// Scale a number relative to the map size
uint ScaleByMapSize(uint); // Scale relative to the number of tiles
uint ScaleByMapSize1D(uint); // Scale relative to the circumference of the map

typedef uint32 TileIndex;
enum {
	INVALID_TILE = (uint32) -1
};

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

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


typedef int32 TileIndexDiff;

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

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


#ifndef _DEBUG
	#define TILE_ADD(x,y) ((x) + (y))
#else
	extern TileIndex TileAdd(TileIndex tile, TileIndexDiff add,
		const char *exp, const char *file, int line);
	#define TILE_ADD(x, y) (TileAdd((x), (y), #x " + " #y, __FILE__, __LINE__))
#endif

#define TILE_ADDXY(tile, x, y) TILE_ADD(tile, TILE_XY(x, y))

uint TileAddWrap(TileIndex tile, int addx, int addy);

static inline TileIndexDiffC TileIndexDiffCByDir(uint dir) {
	extern const TileIndexDiffC _tileoffs_by_dir[4];
	return _tileoffs_by_dir[dir];
}

/* Returns tile + the diff given in diff. If the result tile would end up
 * outside of the map, INVALID_TILE is returned instead.
 */
static inline TileIndex AddTileIndexDiffCWrap(TileIndex tile, TileIndexDiffC diff) {
	int x = TileX(tile) + diff.x;
	int y = TileY(tile) + diff.y;
	if (x < 0 || y < 0 || x > (int)MapMaxX() || y > (int)MapMaxY())
		return INVALID_TILE;
	else
		return TILE_XY(x, y);
}

// Functions to calculate distances
uint DistanceManhattan(TileIndex, TileIndex); // also known as L1-Norm
uint DistanceSquare(TileIndex, TileIndex); // euclidian- or L2-Norm squared
uint DistanceMax(TileIndex, TileIndex); // also known as L-Infinity-Norm
uint DistanceMaxPlusManhattan(TileIndex, TileIndex); // Max + Manhattan
uint DistanceFromEdge(TileIndex); // shortest distance from any edge of the map


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