int Level::clearRows()
{
    bool isComplete;
    int rows = 0;
    for (int i = 0; i < height; i++)
    {
        for (int j = 0; j < width; j++)
        {
            if (board[j][i] == RGB(0,0,0))
            {
                isComplete = false;
                break;
            }
            // The row is full
            if (j == width - 1)
                isComplete = true;
        }
        // If the row is full, clear it (fill with black)
        if (isComplete)
        {
            for (int j = 0; j < width; j++)
                board[j][i] = RGB(0,0,0);

            // Move rows down
            for (int k = i; k < height - 1; k++)
            {
                for (int m = 0; m < width; m++)
                    board[m][k] = board[m][k+1];
            }
            i = -1;
            rows++;
        }
    }
    return rows;
}