#include "stdafx.h"
#include "tile.h"
void SetMapExtraBits(TileIndex tile, byte bits)
{
assert(tile < MapSize());
_map_extra_bits[tile >> 2] &= ~(3 << ((tile & 3) * 2));
_map_extra_bits[tile >> 2] |= (bits&3) << ((tile & 3) * 2);
}
uint GetMapExtraBits(TileIndex tile)
{
assert(tile < MapSize());
return (_map_extra_bits[tile >> 2] >> (tile & 3) * 2) & 3;
}
uint GetTileSlope(TileIndex tile, uint *h)
{
uint a;
uint b;
uint c;
uint d;
uint min;
uint r;
assert(tile < MapSize());
if (TileX(tile) == MapMaxX() || TileY(tile) == MapMaxY()) {
if (h != NULL) *h = 0;
return 0;
}
min = a = TileHeight(tile);
b = TileHeight(tile + TILE_XY(1,0));
if (min >= b) min = b;
c = TileHeight(tile + TILE_XY(0,1));
if (min >= c) min = c;
d = TileHeight(tile + TILE_XY(1,1));
if (min >= d) min = d;
r = 0;
if ((a -= min) != 0) { r += (--a << 4) + 8; }
if ((c -= min) != 0) { r += (--c << 4) + 4; }
if ((d -= min) != 0) { r += (--d << 4) + 2; }
if ((b -= min) != 0) { r += (--b << 4) + 1; }
if (h != NULL)
*h = min * 8;
return r;
}
uint GetTileZ(TileIndex tile)
{
uint h;
GetTileSlope(tile, &h);
return h;
}