summaryrefslogtreecommitdiff
path: root/src/map.c
blob: df16343c7d36c75f7498809e46cd1db86de4898f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
/* $Id$ */

#include "stdafx.h"
#include "openttd.h"
#include "debug.h"
#include "functions.h"
#include "macros.h"
#include "map.h"
#include "direction.h"

#if defined(_MSC_VER) && _MSC_VER >= 1400 /* VStudio 2005 is stupid! */
/* Why the hell is that not in all MSVC headers?? */
_CRTIMP void __cdecl _assert(void *, void *, unsigned);
#endif

uint _map_log_x;
uint _map_size_x;
uint _map_size_y;
uint _map_tile_mask;
uint _map_size;

Tile* _m = NULL;


void AllocateMap(uint size_x, uint size_y)
{
	// Make sure that the map size is within the limits and that
	// the x axis size is a power of 2.
	if (size_x < 64 || size_x > 2048 ||
			size_y < 64 || size_y > 2048 ||
			(size_x&(size_x-1)) != 0 ||
			(size_y&(size_y-1)) != 0)
		error("Invalid map size");

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

	_map_log_x = FindFirstBit(size_x);
	_map_size_x = size_x;
	_map_size_y = size_y;
	_map_size = size_x * size_y;
	_map_tile_mask = _map_size - 1;

	free(_m);
	_m = calloc(_map_size, sizeof(*_m));

	// XXX TODO handle memory shortage more gracefully
	if (_m == NULL) error("Failed to allocate memory for the map");
}


#ifdef _DEBUG
TileIndex TileAdd(TileIndex tile, TileIndexDiff add,
	const char *exp, const char *file, int line)
{
	int dx;
	int dy;
	uint x;
	uint y;

	dx = add & MapMaxX();
	if (dx >= (int)MapSizeX() / 2) dx -= MapSizeX();
	dy = (add - dx) / (int)MapSizeX();

	x = TileX(tile) + dx;
	y = TileY(tile) + dy;

	if (x >= MapSizeX() || y >= MapSizeY()) {
		char buf[512];

		snprintf(buf, lengthof(buf), "TILE_ADD(%s) when adding 0x%.4X and 0x%.4X failed",
			exp, tile, add);
#if !defined(_MSC_VER)
		fprintf(stderr, "%s:%d %s\n", file, line, buf);
#else
		_assert(buf, (char*)file, line);
#endif
	}

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

	return TileXY(x,y);
}
#endif


uint ScaleByMapSize(uint n)
{
	// First shift by 12 to prevent integer overflow for large values of n.
	// >>12 is safe since the min mapsize is 64x64
	// Add (1<<4)-1 to round upwards.
	return (n * (MapSize() >> 12) + (1<<4) - 1) >> 4;
}


// Scale relative to the circumference of the map
uint ScaleByMapSize1D(uint n)
{
	// Normal circumference for the X+Y is 256+256 = 1<<9
	// Note, not actually taking the full circumference into account,
	// just half of it.
	// (1<<9) - 1 is there to scale upwards.
	return (n * (MapSizeX() + MapSizeY()) + (1<<9) - 1) >> 9;
}


// This function checks if we add addx/addy to tile, if we
//  do wrap around the edges. For example, tile = (10,2) and
//  addx = +3 and addy = -4. This function will now return
//  INVALID_TILE, because the y is wrapped. This is needed in
//  for example, farmland. When the tile is not wrapped,
//  the result will be tile + TileDiffXY(addx, addy)
uint TileAddWrap(TileIndex tile, int addx, int addy)
{
	uint x = TileX(tile) + addx;
	uint y = TileY(tile) + addy;

	// Are we about to wrap?
	if (x < MapMaxX() && y < MapMaxY())
		return tile + TileDiffXY(addx, addy);

	return INVALID_TILE;
}

const TileIndexDiffC _tileoffs_by_diagdir[] = {
	{-1,  0}, // DIAGDIR_NE
	{ 0,  1}, // DIAGDIR_SE
	{ 1,  0}, // DIAGDIR_SW
	{ 0, -1}  // DIAGDIR_NW
};

const TileIndexDiffC _tileoffs_by_dir[] = {
	{-1, -1}, // DIR_N
	{-1,  0}, // DIR_NE
	{-1,  1}, // DIR_E
	{ 0,  1}, // DIR_SE
	{ 1,  1}, // DIR_S
	{ 1,  0}, // DIR_SW
	{ 1, -1}, // DIR_W
	{ 0, -1}  // DIR_NW
};

uint DistanceManhattan(TileIndex t0, TileIndex t1)
{
	const uint dx = abs(TileX(t0) - TileX(t1));
	const uint dy = abs(TileY(t0) - TileY(t1));
	return dx + dy;
}


uint DistanceSquare(TileIndex t0, TileIndex t1)
{
	const int dx = TileX(t0) - TileX(t1);
	const int dy = TileY(t0) - TileY(t1);
	return dx * dx + dy * dy;
}


uint DistanceMax(TileIndex t0, TileIndex t1)
{
	const uint dx = abs(TileX(t0) - TileX(t1));
	const uint dy = abs(TileY(t0) - TileY(t1));
	return dx > dy ? dx : dy;
}


uint DistanceMaxPlusManhattan(TileIndex t0, TileIndex t1)
{
	const uint dx = abs(TileX(t0) - TileX(t1));
	const uint dy = abs(TileY(t0) - TileY(t1));
	return dx > dy ? 2 * dx + dy : 2 * dy + dx;
}

uint DistanceFromEdge(TileIndex tile)
{
	const uint xl = TileX(tile);
	const uint yl = TileY(tile);
	const uint xh = MapSizeX() - 1 - xl;
	const uint yh = MapSizeY() - 1 - yl;
	const uint minl = xl < yl ? xl : yl;
	const uint minh = xh < yh ? xh : yh;
	return minl < minh ? minl : minh;
}

/**
 * Function performing a search around a center tile and going outward, thus in circle.
 * Although it really is a square search...
 * Every tile will be tested by means of the callback function proc,
 * which will determine if yes or no the given tile meets criteria of search.
 * @param tile to start the search from
 * @param size: number of tiles per side of the desired search area
 * @param proc: callback testing function pointer.
 * @param data to be passed to the callback function. Depends on the implementation
 * @result of the search
 * @pre proc != NULL
 * @pre size > 0
 */
bool CircularTileSearch(TileIndex tile, uint size, TestTileOnSearchProc proc, uint32 data)
{
	uint n, x, y;
	DiagDirection dir;

	assert(proc != NULL);
	assert(size > 0);

	x = TileX(tile);
	y = TileY(tile);

	if (size % 2 == 1) {
		/* If the length of the side is uneven, the center has to be checked
		 * separately, as the pattern of uneven sides requires to go around the center */
		n = 2;
		if (proc(TileXY(x, y), data)) return true;

		/* If tile test is not successfull, get one tile down and left,
		 * ready for a test in first circle around center tile */
		x += _tileoffs_by_dir[DIR_W].x;
		y += _tileoffs_by_dir[DIR_W].y;
	} else {
		n = 1;
		/* To use _tileoffs_by_diagdir's order, we must relocate to
		 * another tile, as we now first go 'up', 'right', 'down', 'left'
		 * instead of 'right', 'down', 'left', 'up', which the calling
		 * function assume. */
		x++;
	}

	for (; n < size; n += 2) {
		for (dir = DIAGDIR_NE; dir < DIAGDIR_END; dir++) {
			uint j;
			for (j = n; j != 0; j--) {
				if (x <= MapMaxX() && y <= MapMaxY() && ///< Is the tile within the map?
						proc(TileXY(x, y), data)) {     ///< Is the callback successfulll?
					return true;                        ///< then stop the search
				}

				/* Step to the next 'neighbour' in the circular line */
				x += _tileoffs_by_diagdir[dir].x;
				y += _tileoffs_by_diagdir[dir].y;
			}
		}
		/* Jump to next circle to test */
		x += _tileoffs_by_dir[DIR_W].x;
		y += _tileoffs_by_dir[DIR_W].y;
	}
	return false;
}