private Func <int, int, int> CreateValueGetter(_2048MoveDirection move)
{
return(this.getters[(int)move]);
}
private Action <int, int, int> CreateValueSetter(_2048MoveDirection move)
{
return(this.setters[(int)move]);
}
public bool TryMove(_2048MoveDirection move, bool autoAddTile = true)
{
if (this.emptyTilesCount.HasValue)
{
throw new InvalidOperationException("Tile wasn't added after previous move!");
}
bool moved = false;
var get = this.CreateValueGetter(move);
var set = this.CreateValueSetter(move);
for (int row = 0; row < size; ++row)
{
int destination = -1;
int destinationValue;
int source = 0;
int sourceValue = -1;
bool sourceMoved = source < size;
do
{
destinationValue = get(row, ++destination);
// move source to non-empty tile.
while ((sourceMoved = ++source < size) &&
(sourceValue = get(row, source)) == 0
)
{
;
}
if (sourceMoved)
{
bool repeat;
do
{
repeat = false;
// move tile into empty space
if (destinationValue == 0)
{
destinationValue = sourceValue;
set(row, destination, destinationValue);
sourceValue = 0;
set(row, source, sourceValue);
moved = true;
/*
* even moved tile can be subsequently
* merged so we need to move the source
* enumerator to the next tile and
* repeat with the same destination
* to try to merge them.
*/
while ((sourceMoved = ++source < size) &&
(sourceValue = get(row, source)) == 0
)
{
;
}
repeat = true;
}
// merge tiles with the same value
else if (destinationValue == sourceValue)
{
this._score += destinationValue *= 2;
set(row, destination, destinationValue);
sourceValue = 0;
set(row, source, sourceValue);
moved = true;
}
/*
* if there is a gap between source and
* destination we can try to move destination
* closer to source and repeat.
*/
else if (destination < source - 1)
{
destinationValue = get(row, ++destination);
repeat = true;
}
} while (repeat && sourceMoved);
}
} while (sourceMoved);
}
if (moved)
{
this.__matrix = null;
this.SetEmptyTiles();
return(!autoAddTile || this.TryAutoAddTile());
}
else
{
return(false);
}
}