/* --------------------------------------------------------------------------------- *\
* Description:
* Paint a single isle using DFS to find all relevant pixels
*
* Parameters:
* int n_src_x:
* int n_src_y:
* int n_pixel_ind:
* int n_color:
* CBoard _board:
\* --------------------------------------------------------------------------------- */
private static void paint_isle(int n_src_x, int n_src_y, int n_pixel_ind, int n_color, CBoard _board)
{
Stack <CPathNode> _path = new Stack <CPathNode>();
paint_n_push(n_src_x, n_src_y, n_pixel_ind, n_color, _board, _path);
while (0 != _path.Count)
{
bool b_is_painted = false;
CPathNode _path_node = _path.Peek();
int n_center_x = _path_node.x;
int n_center_y = _path_node.y;
for (int i = _path_node.next_neighbour_ind; i < ma_neighbours.Length; i++)
{
int n_neighbour_x = n_center_x + ma_neighbours[_path_node.next_neighbour_ind].Item1;
int n_neighbour_y = n_center_y + ma_neighbours[_path_node.next_neighbour_ind].Item2;
_path_node.next_neighbour_ind++;
if (0 > n_neighbour_x || _board.width <= n_neighbour_x)
{
continue;
}
if (0 > n_neighbour_y || _board.height <= n_neighbour_y)
{
continue;
}
int n_neighbour_ind = _board.pixel_ind(n_neighbour_x, n_neighbour_y);
if (_board.is_black_pixel(n_neighbour_ind))
{
paint_n_push(n_neighbour_x, n_neighbour_y, n_neighbour_ind, n_color, _board, _path);
b_is_painted = true;
break;
}
}
if (b_is_painted)
{
continue;
}
_path.Pop();
}
} // paint_isle()
/* --------------------------------------------------------------------------------- *\
* Description:
* Paint and count all islands
*
* Parameters:
* CBoard _board:
* CColorGenerator _color_generator:
*
* Returns int:
\* --------------------------------------------------------------------------------- */
public static int paint(CBoard _board, CColorGenerator _color_generator)
{
int n_isle_count = 0;
for (int y = 0; y < _board.height; y++)
{
for (int x = 0; x < _board.width; x++)
{
int n_pixel_ind = _board.pixel_ind(x, y);
if (!_board.is_black_pixel(n_pixel_ind))
{
continue;
}
n_isle_count++;
paint_isle(x, y, n_pixel_ind, _color_generator.generate_color(), _board);
}
}
return(n_isle_count);
}