static IEnumerable <CellMap <T> > GridCells <T>(this GridSpec <T> spec)
where T : struct
{
var bit = 0;
var seg = 0;
var segbits = spec.CellSize;
for (int row = 0, rowbit = 0; row < spec.RowCount; row++)
{
for (var col = 0; col < spec.ColCount; col++, bit++, rowbit++, segbits--)
{
if (segbits == 0)
{
seg++;
segbits = spec.CellSize;
}
var offset = (byte)(spec.CellSize - segbits).Bits;
var pos = CellIndex <T> .Define((ushort)seg, offset);
yield return(new CellMap <T>(pos.Segment, pos.Offset, pos.LinearIndex, row, col));
}
seg++;
segbits = spec.CellSize;
}
}
public Bit this[Index r]
{
[MethodImpl(Inline)]
get
{
var pos = CellIndex <ulong> .FromIndex((uint)r.Value);
return(part <ulong>(pos.Segment).TestBit(pos.Offset));
}
}
/// <summary>
/// Calculates a canonical bijection from a contiguous sequence of bits onto a contiguous sequence of segments
/// </summary>
/// <param name="bitcount">The total number of bits to distribute over one or more segments</param>
public static CellIndex <T>[] BitMap <T>(BitSize bitcount)
where T : struct
{
var dst = new CellIndex <T> [bitcount];
var capacity = bitsize <T>();
ushort seg = 0;
byte offset = 0;
for (var i = 0; i < bitcount; i++)
{
if (i != 0)
{
if ((i % capacity) == 0)
{
seg++;
offset = 0;
}
}
dst[i] = (seg, offset++);
}
return(dst);
}
