public Board()
{
// Allocate board space
_Board = new Cell[_NumRows][];
for (int row = 0; row < _NumRows; row++)
_Board[row] = new Cell[_NumColumns];
// Initialize board space
for (int row = 0; row < _NumRows; row++)
for (int col = 0; col < _NumColumns; col++)
_Board[row][col] = new Cell(_Empty, row, col);
_Random = new Random();
_WorkArray = new int[Math.Max(_NumRows, _NumColumns)];
}
// Shift assumes that the cells are in the reverse order of the current MoveDirection
private bool Shift(Cell[] line)
{
bool movedOrMerged = false;
int w = 0; // An iterator for the workArray
ClearWorkArray();
// Puts cell values from line in the appropriate index in workArray
for (int i = 0; i < line.Length; i++)
{
if (!line[i].Empty)
{
if (_WorkArray[w] == _Empty)
{
_WorkArray[w] = line[i].Value;
}
else if (_WorkArray[w] == line[i].Value)
{
_WorkArray[w] *= 2;
line[w++].Merged = true;
}
else
{
_WorkArray[++w] = line[i].Value;
}
}
}
// Determine if any cells merged or moved while copying the work array
for (int i = 0; i < line.Length; i++)
{
if (line[i].Value != _WorkArray[i])
movedOrMerged = true;
line[i].Value = _WorkArray[i];
}
return movedOrMerged;
}
// CanShift assumes that the cells are in order of the current MoveDirection
private bool CanShift(Cell[] line)
{
// Check for an empty cell a non-empty cell can move into.
bool foundNumber = false;
for (int i = 0; i < line.Length; i++)
{
if (foundNumber && line[i].Empty)
return true;
if (!line[i].Empty)
foundNumber = true;
}
// Check for non-empty adjacent cells with same value
for (int i = 0; i < line.Length - 1; i++)
if (!line[i].Empty)
if (line[i].Value == line[i + 1].Value)
return true;
return false;
}