CVec[][] CreateTilesByDistance()
{
var ts = new List<CVec>[MaximumTileSearchRange + 1];
for (var i = 0; i < MaximumTileSearchRange + 1; i++)
ts[i] = new List<CVec>();
for (var j = -MaximumTileSearchRange; j <= MaximumTileSearchRange; j++)
for (var i = -MaximumTileSearchRange; i <= MaximumTileSearchRange; i++)
if (MaximumTileSearchRange * MaximumTileSearchRange >= i * i + j * j)
ts[Exts.ISqrt(i * i + j * j, Exts.ISqrtRoundMode.Ceiling)].Add(new CVec(i, j));
// Sort each integer-distance group by the actual distance
foreach (var list in ts)
{
list.Sort((a, b) =>
{
var result = a.LengthSquared.CompareTo(b.LengthSquared);
if (result != 0)
return result;
// If the lengths are equal, use other means to sort them.
// Try the hash code first because it gives more
// random-appearing results than X or Y that would always
// prefer the leftmost/topmost position.
result = a.GetHashCode().CompareTo(b.GetHashCode());
if (result != 0)
return result;
result = a.X.CompareTo(b.X);
if (result != 0)
return result;
return a.Y.CompareTo(b.Y);
});
}
return ts.Select(list => list.ToArray()).ToArray();
}