c#: Clean way to fit a collection into a multidimensional array?
- by Rosarch
I have an ICollection<MapNode>. Each MapNode has a Position attribute, which is a Point. I want to sort these points first by Y value, then by X value, and put them in a multidimensional array (MapNode[,]).
The collection would look something like this:
(30, 20)
(20, 20)
(20, 30)
(30, 10)
(30, 30)
(20, 10)
And the final product:
(20, 10) (20, 20) (20, 30)
(30, 10) (30, 20) (30, 30)
Here is the code I have come up with to do it. Is this hideously unreadable? I feel like it's more hacky than it needs to be.
private Map createWorldPathNodes()
{
ICollection<MapNode> points = new HashSet<MapNode>();
Rectangle worldBounds = WorldQueryUtils.WorldBounds();
for (float x = worldBounds.Left; x < worldBounds.Right; x += PATH_NODE_CHUNK_SIZE)
{
for (float y = worldBounds.Y; y > worldBounds.Height; y -= PATH_NODE_CHUNK_SIZE)
{
// default is that everywhere is navigable;
// a different function is responsible for determining the real value
points.Add(new MapNode(true, new Point((int)x, (int)y)));
}
}
int distinctXValues = points.Select(node => node.Position.X).Distinct().Count();
int distinctYValues = points.Select(node => node.Position.Y).Distinct().Count();
IList<MapNode[]> mapNodeRowsToAdd = new List<MapNode[]>();
while (points.Count > 0) // every iteration will take a row out of points
{
// get all the nodes with the greatest Y value currently in the collection
int currentMaxY = points.Select(node => node.Position.Y).Max();
ICollection<MapNode> ythRow = points.Where(node => node.Position.Y == currentMaxY).ToList();
// remove these nodes from the pool we're picking from
points = points.Where(node => ! ythRow.Contains(node)).ToList(); // ToList() is just so it is still a collection
// put the nodes with max y value in the array, sorting by X value
mapNodeRowsToAdd.Add(ythRow.OrderByDescending(node => node.Position.X).ToArray());
}
MapNode[,] mapNodes = new MapNode[distinctXValues, distinctYValues];
int xValuesAdded = 0;
int yValuesAdded = 0;
foreach (MapNode[] mapNodeRow in mapNodeRowsToAdd)
{
xValuesAdded = 0;
foreach (MapNode node in mapNodeRow)
{
// [y, x] may seem backwards, but mapNodes[y] == the yth row
mapNodes[yValuesAdded, xValuesAdded] = node;
xValuesAdded++;
}
yValuesAdded++;
}
return pathNodes;
}
The above function seems to work pretty well, but it hasn't been subjected to bulletproof testing yet.
