1 /* $Id$ */

     2 

     3 #include "stdafx.h"

     4 #include "openttd.h"

     5 #include "tile.h"

     6 #include "tunnel_map.h"

     7 

     8 TileIndex GetOtherTunnelEnd(TileIndex tile)

     9 {

    10 	DiagDirection dir = GetTunnelDirection(tile);

    11 	TileIndexDiff delta = TileOffsByDiagDir(dir);

    12 	uint z = GetTileZ(tile);

    13 

    14 	dir = ReverseDiagDir(dir);

    15 	do {

    16 		tile += delta;

    17 	} while (

    18 		!IsTunnelTile(tile) ||

    19 		GetTunnelDirection(tile) != dir ||

    20 		GetTileZ(tile) != z

    21 	);

    22 

    23 	return tile;

    24 }

    25 

    26 

    27 static bool IsTunnelInWayDir(TileIndex tile, uint z, DiagDirection dir)

    28 {

    29 	TileIndexDiff delta = TileOffsByDiagDir(dir);

    30 	uint height;

    31 

    32 	do {

    33 		tile -= delta;

    34 		height = GetTileZ(tile);

    35 	} while (z < height);

    36 

    37 	return

    38 		z == height &&

    39 		IsTunnelTile(tile) &&

    40 		GetTunnelDirection(tile) == dir;

    41 }

    42 

    43 bool IsTunnelInWay(TileIndex tile, uint z)

    44 {

    45 	return

    46 		IsTunnelInWayDir(tile, z, DIAGDIR_NE) ||

    47 		IsTunnelInWayDir(tile, z, DIAGDIR_SE) ||

    48 		IsTunnelInWayDir(tile, z, DIAGDIR_SW) ||

    49 		IsTunnelInWayDir(tile, z, DIAGDIR_NW);

    50 }