public void Reset()
{
this.Score = 0;
Cells = new Cell[this.ColumnCount][];
for (int i = 0; i < this.ColumnCount; ++i)
{
Cells[i] = new Cell[this.RowCount];
}
for (int y = 0; y < this.RowCount; ++y)
{
for (int x = 0; x < this.ColumnCount; ++x)
{
Cells[x][y] = new Cell(x, y);
}
}
}
private void MergeCells(Cell SourceCell, Cell DestinationCell)
{
// Assumes that an appropriate merge CAN definitely be done.
if (!(SourceCell.X == DestinationCell.X ^ SourceCell.Y == DestinationCell.Y))
{
throw new InvalidOperationException("Cells to be merged must share either a row or column but not both");
}
if (DestinationCell.IsEmpty())
{
// This is the last available empty cell so take it!
DestinationCell.Value = SourceCell.Value;
DestinationCell.PreviousPosition = SourceCell.PreviousPosition ?? new Coordinate(SourceCell.X, SourceCell.Y);
SourceCell.Value = 0;
SourceCell.PreviousPosition = null;
}
else
{
if (DestinationCell.WasMerged)
{
throw new InvalidOperationException("Destination cell has already been merged");
}
else if (SourceCell.Value != DestinationCell.Value)
{
throw new InvalidOperationException("Source and destination cells must have the same value");
}
// The next available cell has the same value and hasn't yet
// been merged, so lets merge them!
DestinationCell.Value *= 2;
DestinationCell.WasMerged = true;
DestinationCell.PreviousPosition = SourceCell.PreviousPosition ?? new Coordinate(SourceCell.X, SourceCell.Y);
SourceCell.Value = 0;
SourceCell.PreviousPosition = null;
// Update the score
Score += DestinationCell.Value;
}
}
