1

#include "stdafx.h"

     2

#include "openttd.h"

     3

#include "debug.h"

     4

#include "functions.h"

     5

#include "map.h"

     6

     7

uint _map_log_x;

     8

uint _map_size_x;

     9

uint _map_size_y;

    10

uint _map_tile_mask;

    11

uint _map_size;

    12

    13

Tile* _m = NULL;

    14

    15

    16

void AllocateMap(uint size_x, uint size_y)

    17

{

    18

	// Make sure that the map size is within the limits and that

    19

	// the x axis size is a power of 2.

    20

	if (size_x < 64 || size_x > 2048 ||

    21

			size_y < 64 || size_y > 2048 ||

    22

			(size_x&(size_x-1)) != 0 ||

    23

			(size_y&(size_y-1)) != 0)

    24

		error("Invalid map size");

    25

    26

	DEBUG(map, 1)("Allocating map of size %dx%d", size_x, size_y);

    27

    28

	_map_log_x = FindFirstBit(size_x);

    29

	_map_size_x = size_x;

    30

	_map_size_y = size_y;

    31

	_map_size = size_x * size_y;

    32

	_map_tile_mask = _map_size - 1;

    33

    34

	// free/malloc uses less memory than realloc.

    35

	free(_m);

    36

	_m = malloc(_map_size * sizeof(*_m));

    37

    38

	// XXX TODO handle memory shortage more gracefully

    39

	if (_m == NULL) error("Failed to allocate memory for the map");

    40

}

    41

    42

    43

#ifdef _DEBUG

    44

TileIndex TileAdd(TileIndex tile, TileIndexDiff add,

    45

	const char *exp, const char *file, int line)

    46

{

    47

	int dx;

    48

	int dy;

    49

	uint x;

    50

	uint y;

    51

    52

	dx = add & MapMaxX();

    53

	if (dx >= (int)MapSizeX() / 2) dx -= MapSizeX();

    54

	dy = (add - dx) / (int)MapSizeX();

    55

    56

	x = TileX(tile) + dx;

    57

	y = TileY(tile) + dy;

    58

    59

	if (x >= MapSizeX() || y >= MapSizeY()) {

    60

		char buf[512];

    61

    62

		sprintf(buf, "TILE_ADD(%s) when adding 0x%.4X and 0x%.4X failed",

    63

			exp, tile, add);

    64

#if !defined(_MSC_VER)

    65

		fprintf(stderr, "%s:%d %s\n", file, line, buf);

    66

#else

    67

		_assert(buf, (char*)file, line);

    68

#endif

    69

	}

    70

    71

	assert(TileXY(x,y) == TILE_MASK(tile + add));

    72

    73

	return TileXY(x,y);

    74

}

    75

#endif

    76

    77

    78

uint ScaleByMapSize(uint n)

    79

{

    80

	// First shift by 12 to prevent integer overflow for large values of n.

    81

	// >>12 is safe since the min mapsize is 64x64

    82

	// Add (1<<4)-1 to round upwards.

    83

	return (n * (MapSize() >> 12) + (1<<4) - 1) >> 4;

    84

}

    85

    86

    87

// Scale relative to the circumference of the map

    88

uint ScaleByMapSize1D(uint n)

    89

{

    90

	// Normal circumference for the X+Y is 256+256 = 1<<9

    91

	// Note, not actually taking the full circumference into account,

    92

	// just half of it.

    93

	// (1<<9) - 1 is there to scale upwards.

    94

	return (n * (MapSizeX() + MapSizeY()) + (1<<9) - 1) >> 9;

    95

}

    96

    97

    98

// This function checks if we add addx/addy to tile, if we

    99

//  do wrap around the edges. For example, tile = (10,2) and

   100

//  addx = +3 and addy = -4. This function will now return

   101

//  INVALID_TILE, because the y is wrapped. This is needed in

   102

//  for example, farmland. When the tile is not wrapped,

   103

//  the result will be tile + TileDiffXY(addx, addy)

   104

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

   105

{

   106

	uint x, y;

   107

	x = TileX(tile) + addx;

   108

	y = TileY(tile) + addy;

   109

   110

	// Are we about to wrap?

   111

	if (x < MapMaxX() && y < MapMaxY())

   112

		return tile + TileDiffXY(addx, addy);

   113

   114

	return INVALID_TILE;

   115

}

   116

   117

const TileIndexDiffC _tileoffs_by_dir[] = {

   118

	{-1,  0},

   119

	{ 0,  1},

   120

	{ 1,  0},

   121

	{ 0, -1}

   122

};

   123

   124

uint DistanceManhattan(TileIndex t0, TileIndex t1)

   125

{

   126

	const uint dx = abs(TileX(t0) - TileX(t1));

   127

	const uint dy = abs(TileY(t0) - TileY(t1));

   128

	return dx + dy;

   129

}

   130

   131

   132

uint DistanceSquare(TileIndex t0, TileIndex t1)

   133

{

   134

	const int dx = TileX(t0) - TileX(t1);

   135

	const int dy = TileY(t0) - TileY(t1);

   136

	return dx * dx + dy * dy;

   137

}

   138

   139

   140

uint DistanceMax(TileIndex t0, TileIndex t1)

   141

{

   142

	const uint dx = abs(TileX(t0) - TileX(t1));

   143

	const uint dy = abs(TileY(t0) - TileY(t1));

   144

	return dx > dy ? dx : dy;

   145

}

   146

   147

   148

uint DistanceMaxPlusManhattan(TileIndex t0, TileIndex t1)

   149

{

   150

	const uint dx = abs(TileX(t0) - TileX(t1));

   151

	const uint dy = abs(TileY(t0) - TileY(t1));

   152

	return dx > dy ? 2 * dx + dy : 2 * dy + dx;

   153

}

   154

   155

uint DistanceTrack(TileIndex t0, TileIndex t1)

   156

{

   157

	const uint dx = abs(TileX(t0) - TileX(t1));

   158

	const uint dy = abs(TileY(t0) - TileY(t1));

   159

   160

	const uint straightTracks = 2 * min(dx, dy); /* The number of straight (not full length) tracks */

   161

	/* OPTIMISATION:

   162

	 * Original: diagTracks = max(dx, dy) - min(dx,dy);

   163

	 * Proof:

   164

	 * (dx-dy) - straightTracks  == (min + max) - straightTracks = min + // max - 2 * min = max - min */

   165

	const uint diagTracks = dx + dy - straightTracks; /* The number of diagonal (full tile length) tracks. */

   166

   167

	return diagTracks + straightTracks * STRAIGHT_TRACK_LENGTH;

   168

}

   169

   170

uint DistanceFromEdge(TileIndex tile)

   171

{

   172

	const uint xl = TileX(tile);

   173

	const uint yl = TileY(tile);

   174

	const uint xh = MapSizeX() - 1 - xl;

   175

	const uint yh = MapSizeY() - 1 - yl;

   176

	const uint minl = xl < yl ? xl : yl;

   177

	const uint minh = xh < yh ? xh : yh;

   178

	return minl < minh ? minl : minh;

   179

}

   180