public t Get(int x, int y)
{
/* Fetches an object from the Cartesian Map at (x, y), or returns null if none exist. */
QuadrantCoordinates quadcoords = ConvertToQuadrants(x, y);
List <List <t> > grid = GetQuadrant(quadcoords.quadrant);
if (grid.Count <= quadcoords.x || grid[quadcoords.x].Count <= quadcoords.y)
{
return(default(t));
}
return(grid[quadcoords.x][quadcoords.y]);
}
public void Insert(int x, int y, t obj)
{
/* Inserts an object into the Cartesian Map at (x, y).
*
* If caching is enabled, also records that item in a List.
* If an item is overwritten or deleted, also overwrites or deletes that item from a list.
*/
QuadrantCoordinates quadcoords = ConvertToQuadrants(x, y);
List <List <t> > grid = GetQuadrant(quadcoords.quadrant);
while (grid.Count <= quadcoords.x)
{
grid.Add(new List <t>());
}
while (grid[quadcoords.x].Count <= quadcoords.y)
{
grid[quadcoords.x].Add(default(t));
}
if (_use_caching)
{
/* Caches entries to the list '_all_items'. */
t old_item = grid[quadcoords.x][quadcoords.y];
// Inserting a new entry.
if (!obj.Equals(default(t)) && (old_item == null || old_item.Equals(default(t))))
{
CartesianItem cartesian_item = new CartesianItem();
cartesian_item.x = x;
cartesian_item.y = y;
cartesian_item.item = obj;
_all_items.Add(cartesian_item);
}
// Replacing an old entry.
else if (!obj.Equals(default(t)) && (old_item != null && !old_item.Equals(default(t))))
{
CartesianItem old_cartesian_item = new CartesianItem()
{
x = x,
y = y,
item = old_item
};
int i = _all_items.FindIndex(entry => entry.Equals(old_cartesian_item));
CartesianItem new_cartesian_item = new CartesianItem()
{
x = x,
y = y,
item = obj
};
_all_items[i] = new_cartesian_item;
}
// Deleting an old entry.
else if (obj.Equals(default(t)) && (old_item != null && !old_item.Equals(default(t))))
{
CartesianItem old_cartesian_item = new CartesianItem()
{
x = x,
y = y,
item = old_item
};
_all_items.Remove(old_cartesian_item);
}
// Ignore deleting a non-existant entry.
}
grid[quadcoords.x][quadcoords.y] = obj;
}
