public void Add(int ix, MagicMoveTable.Info info)
{
Debug.Assert(ix >= 0 && ix < 64);
if (!MagicFinder.CheckMagic(info.Mask, info.Magic))
{
// we don't need to warn that magic was invalid if they didn't provide a magic
if (info.Magic != 0)
{
_magicFailed = true;
}
info.Magic = _magicFinder.FindMagic(info.Mask);
}
_infos.Add(ix, info);
}
private static void AddMovesFromSquare(MagicMoveTableBuilder builder, int srcFile, int srcRank, Color color)
{
ulong mask = 0;
List <ulong> occupancies = new List <ulong>();
List <ulong> moves = new List <ulong>();
int direction = color.GetPawnDirection();
var dstRank = srcRank + (direction * 2);
var inbetweenRank = srcRank + direction;
if (IsStartingRank(srcRank, color))
{
mask |= Position.ValueFromFileRank(srcFile, inbetweenRank);
mask |= Position.ValueFromFileRank(srcFile, dstRank);
}
int maskBits = Bits.PopCount(mask);
int maskPermutations = 1 << maskBits;
for (int permutation = 0; permutation < maskPermutations; permutation++)
{
ulong occupancy = Bits.ParallelBitDeposit((ulong)permutation, mask);
ulong singularMoves = 0;
// if there are any pieces in the 2 squares we're checking, then
if (IsStartingRank(srcRank, color) && occupancy == 0)
{
singularMoves |= Position.ValueFromFileRank(srcFile, dstRank);
}
occupancies.Add(occupancy);
moves.Add(singularMoves);
}
var ix = Position.IxFromFileRank(srcFile, srcRank);
var info = new MagicMoveTable.Info
{
Magic = Magics[(int)color].GetOrDefault(ix),
Mask = mask,
MaskedOccupancyKeys = occupancies.ToArray(),
MovesValues = moves.ToArray(),
};
builder.Add(ix, info);
}
private static void AddMovesFromSquare(MagicMoveTableBuilder builder, int srcFile, int srcRank)
{
ulong mask = 0;
List <ulong> occupancies = new List <ulong>();
List <ulong> moves = new List <ulong>();
// populate mask
// Note: mask rays don't extend to the edge of the map; this is because if a ray reaches all the way to the edge of the board, that square's occupancy doesn't affect move generation.
// up/left
for (int i = 1;; i++)
{
int dstFile = srcFile - i;
int dstRank = srcRank + i;
if (!InsideOuterRing(dstFile, dstRank))
{
break;
}
mask |= Position.ValueFromFileRank(dstFile, dstRank);
}
// up/right
for (int i = 1; ; i++)
{
int dstFile = srcFile + i;
int dstRank = srcRank + i;
if (!InsideOuterRing(dstFile, dstRank))
{
break;
}
mask |= Position.ValueFromFileRank(dstFile, dstRank);
}
// down/left
for (int i = 1; ; i++)
{
int dstFile = srcFile - i;
int dstRank = srcRank - i;
if (!InsideOuterRing(dstFile, dstRank))
{
break;
}
mask |= Position.ValueFromFileRank(dstFile, dstRank);
}
// down/right
for (int i = 1; ; i++)
{
int dstFile = srcFile + i;
int dstRank = srcRank - i;
if (!InsideOuterRing(dstFile, dstRank))
{
break;
}
mask |= Position.ValueFromFileRank(dstFile, dstRank);
}
int maskBits = Bits.PopCount(mask);
int maskPermutations = 1 << maskBits;
for (int permutation = 0; permutation < maskPermutations; permutation++)
{
ulong occupancy = Bits.ParallelBitDeposit((ulong)permutation, mask);
ulong singularMoves = 0;
// Note: rays do now reach all the way to the edge of the board; we do want to generate moves that would reach the end of the board.
// up/left
for (int i = 1; ; i++)
{
int dstFile = srcFile - i;
int dstRank = srcRank + i;
if (!Position.FileRankOnBoard(dstFile, dstRank))
{
break;
}
ulong move = Position.ValueFromFileRank(dstFile, dstRank);
singularMoves |= move;
if ((occupancy & move) > 0)
{
break;
}
}
// up/right
for (int i = 1; ; i++)
{
int dstFile = srcFile + i;
int dstRank = srcRank + i;
if (!Position.FileRankOnBoard(dstFile, dstRank))
{
break;
}
ulong move = Position.ValueFromFileRank(dstFile, dstRank);
singularMoves |= move;
if ((occupancy & move) > 0)
{
break;
}
}
// down/left
for (int i = 1; ; i++)
{
int dstFile = srcFile - i;
int dstRank = srcRank - i;
if (!Position.FileRankOnBoard(dstFile, dstRank))
{
break;
}
ulong move = Position.ValueFromFileRank(dstFile, dstRank);
singularMoves |= move;
if ((occupancy & move) > 0)
{
break;
}
}
// down/right
for (int i = 1; ; i++)
{
int dstFile = srcFile + i;
int dstRank = srcRank - i;
if (!Position.FileRankOnBoard(dstFile, dstRank))
{
break;
}
ulong move = Position.ValueFromFileRank(dstFile, dstRank);
singularMoves |= move;
if ((occupancy & move) > 0)
{
break;
}
}
occupancies.Add(occupancy);
moves.Add(singularMoves);
}
var ix = Position.IxFromFileRank(srcFile, srcRank);
var info = new MagicMoveTable.Info
{
Magic = Magics.GetOrDefault(ix),
Mask = mask,
MaskedOccupancyKeys = occupancies.ToArray(),
MovesValues = moves.ToArray(),
};
builder.Add(ix, info);
}
