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#include "stdafx.h"
#include "openttd.h"
#include "debug.h"
#include "functions.h"
#include "macros.h"
#include "map.h"
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/malloc uses less memory than realloc.
free(_m);
_m = malloc(_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];
sprintf(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, y;
x = TileX(tile) + addx;
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_dir[] = {
{-1, 0},
{ 0, 1},
{ 1, 0},
{ 0, -1}
};
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 DistanceTrack(TileIndex t0, TileIndex t1)
{
const uint dx = abs(TileX(t0) - TileX(t1));
const uint dy = abs(TileY(t0) - TileY(t1));
const uint straightTracks = 2 * min(dx, dy); /* The number of straight (not full length) tracks */
/* OPTIMISATION:
* Original: diagTracks = max(dx, dy) - min(dx,dy);
* Proof:
* (dx-dy) - straightTracks == (min + max) - straightTracks = min + // max - 2 * min = max - min */
const uint diagTracks = dx + dy - straightTracks; /* The number of diagonal (full tile length) tracks. */
return diagTracks + straightTracks * STRAIGHT_TRACK_LENGTH;
}
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;
}
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