public IAsciiField GetFieldInDirection(PathDirection pathDirection, IAsciiField lastValidField)
{
IAsciiField field = null;
switch (pathDirection)
{
case PathDirection.East:
field = GetField(lastValidField.Row, lastValidField.Column + 1);
break;
case PathDirection.North:
field = GetField(lastValidField.Row - 1, lastValidField.Column);
break;
case PathDirection.South:
field = GetField(lastValidField.Row + 1, lastValidField.Column);
break;
case PathDirection.West:
field = GetField(lastValidField.Row, lastValidField.Column - 1);
break;
default:
break;
}
return(field);
}
private static bool IsDirectionPreserved(IAsciiMap map, IAsciiField field, PathDirection direction)
{
var nextField = map.GetFieldInDirection(direction, field);
return(nextField != null &&
IsPassableCharacter(nextField.Character));
}
private static bool IsDirectionValid(IAsciiMap map, IAsciiField field, PathDirection direction)
{
var nextField = map.GetFieldInDirection(direction, field);
return(nextField != null &&
!nextField.AlreadyVisited &&
IsPassableCharacter(nextField.Character));
}
public void AddPathCharacter(IAsciiField field)
{
PathCharacters.Add(field.Character);
if (!field.AlreadyVisited &&
field.Character >= (int)MapCharacter.FirstTextCharacter &&
field.Character <= (int)MapCharacter.LastTextCharacter)
{
PathLetters.Add(field.Character);
}
field.AlreadyVisited = true;
}
public static void FindPath(IAsciiMap map, IAsciiField currentField, PathDirection currentDirection)
{
map.AddPathCharacter(currentField);
var directionToMoveNext = ScanArea(map, currentField, currentDirection);
IAsciiField nextField = map.GetFieldInDirection(directionToMoveNext, currentField);
if (IsAsciiEndCharacter(nextField.Character))
{
map.AddPathCharacter(nextField);
}
else
{
FindPath(map, nextField, directionToMoveNext);
}
}
public static PathDirection ScanArea(IAsciiMap map, IAsciiField currentField, PathDirection currentPathDirection)
{
if (currentPathDirection != PathDirection.Unknown &&
IsDirectionPreserved(map, currentField, currentPathDirection))
{
return(currentPathDirection);
}
foreach (PathDirection direction in Enum.GetValues(typeof(PathDirection)))
{
if (IsDirectionValid(map, currentField, direction))
{
return(direction);
}
}
return(PathDirection.Unknown);
}
