src/tunnel_map.cpp
author peter1138
Tue, 22 Jan 2008 07:27:06 +0000
changeset 8374 7a1b6c89cb89
parent 8108 b42a0e5c67ef
child 9111 48ce04029fe4
permissions -rw-r--r--
(svn r11940) -Codechange: Store short filename once per open file instead of once per sprite cache entry. Not all file types need this, but most of the time no sprite cache entry needed it either.
/* $Id$ */

/** @file tunnel_map.cpp */

#include "stdafx.h"
#include "openttd.h"
#include "tunnel_map.h"
#include "tunnelbridge_map.h"


/**
 * Gets the other end of the tunnel. Where a vehicle would reappear when it
 * enters at the given tile.
 * @param tile the tile to search from.
 * @return the tile of the other end of the tunnel.
 */
TileIndex GetOtherTunnelEnd(TileIndex tile)
{
	DiagDirection dir = GetTunnelBridgeDirection(tile);
	TileIndexDiff delta = TileOffsByDiagDir(dir);
	uint z = GetTileZ(tile);

	dir = ReverseDiagDir(dir);
	do {
		tile += delta;
	} while (
		!IsTunnelTile(tile) ||
		GetTunnelBridgeDirection(tile) != dir ||
		GetTileZ(tile) != z
	);

	return tile;
}


/**
 * Is there a tunnel in the way in the given direction?
 * @param tile the tile to search from.
 * @param z    the 'z' to search on.
 * @param dir  the direction to start searching to.
 * @return true if and only if there is a tunnel.
 */
bool IsTunnelInWayDir(TileIndex tile, uint z, DiagDirection dir)
{
	TileIndexDiff delta = TileOffsByDiagDir(dir);
	uint height;

	do {
		tile -= delta;
		height = GetTileZ(tile);
	} while (z < height);

	return
		z == height &&
		IsTunnelTile(tile) &&
		GetTunnelBridgeDirection(tile) == dir;
}

/**
 * Is there a tunnel in the way in any direction?
 * @param tile the tile to search from.
 * @param z the 'z' to search on.
 * @return true if and only if there is a tunnel.
 */
bool IsTunnelInWay(TileIndex tile, uint z)
{
	return
		IsTunnelInWayDir(tile, z, (TileX(tile) > (MapMaxX() / 2)) ? DIAGDIR_NE : DIAGDIR_SW) ||
		IsTunnelInWayDir(tile, z, (TileY(tile) > (MapMaxY() / 2)) ? DIAGDIR_NW : DIAGDIR_SE);
}