static CVec[][] InitTilesByDistance(int max)
{
var ts = new List <CVec> [max + 1];
for (var i = 0; i < max + 1; i++)
{
ts [i] = new List <CVec>();
}
for (var j = -max; j <= max; j++)
{
for (var i = -max; i <= max; i++)
{
if (max * max >= 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 hashcode 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());
}