Method validateUpDown

src/Battlescape/Pathfinding.cpp:805–832

* Checks, for the up/down button, if the movement is valid. Either there is a grav lift or the unit can fly and there are no obstructions. * @param bu Pointer to unit. * @param startPosition Unit starting position. * @param direction Up or Down * @return bool Whether it's valid. */

 * @return bool Whether it's valid.
 */
bool Pathfinding::validateUpDown(BattleUnit *bu, Position startPosition, const int direction)
{
	Position endPosition;
	directionToVector(direction, &endPosition);
	endPosition += startPosition;
	Tile *startTile = _save->getTile(startPosition);
	Tile *belowStart = _save->getTile(startPosition + Position(0,0,-1));
	Tile *destinationTile = _save->getTile(endPosition);
	if (startTile->getMapData(MapData::O_FLOOR) && destinationTile && destinationTile->getMapData(MapData::O_FLOOR) &&
		(startTile->getMapData(MapData::O_FLOOR)->isGravLift() && destinationTile->getMapData(MapData::O_FLOOR)->isGravLift()))
	{
		return true;
	}
	else
	{
		if (bu->getArmor()->getMovementType() == MT_FLY)
		{
			if ((direction == DIR_UP && destinationTile && !destinationTile->getMapData(MapData::O_FLOOR)) // flying up only possible when there is no roof
				|| (direction == DIR_DOWN && destinationTile && startTile->hasNoFloor(belowStart)) // falling down only possible when there is no floor
				)
			{
				return true;
			}
		}
	}

	return false;
}

/**
 * Marks tiles for the path preview.