public static UInt64 GetKingAttacks(UInt64 king)
{
UInt64 attacks = BitOps.OneStepEast(king) | BitOps.OneStepWest(king);
king |= attacks;
attacks |= BitOps.OneStepNorth(king) | BitOps.OneStepSouth(king);
return(attacks);
}
private static UInt64 GetPawnsAbleToSinglePush(bool isPlayer, UInt64 pawns, UInt64 empty)
{
if (isPlayer)
{
return(BitOps.OneStepSouth(empty) & pawns);
}
else
{
return(BitOps.OneStepNorth(empty) & pawns);
}
}
private static UInt64 GetSinglePushTargets(bool isPlayer, UInt64 pawns, UInt64 empty)
{
if (isPlayer)
{
return(BitOps.OneStepNorth(pawns) & empty);
}
else
{
return(BitOps.OneStepSouth(pawns) & empty);
}
}
private static UInt64 GetPawnsAbleToDoublePush(bool isPlayer, UInt64 pawns, UInt64 empty)
{
if (isPlayer)
{
UInt64 emptyRank3 = BitOps.OneStepSouth(empty & Constants.Ranks.Four) & empty;
return(GetPawnsAbleToSinglePush(isPlayer, pawns, emptyRank3));
}
else
{
UInt64 emptyRank6 = BitOps.OneStepNorth(empty & Constants.Ranks.Six) & empty;
return(GetPawnsAbleToSinglePush(isPlayer, pawns, emptyRank6));
}
}
private static UInt64 GetDoublePushTargets(bool isPlayer, UInt64 pawns, UInt64 empty)
{
UInt64 singlePush = GetSinglePushTargets(isPlayer, pawns, empty);
if (isPlayer)
{
return(BitOps.OneStepNorth(singlePush) & empty & Constants.Ranks.Four);
}
else
{
return(BitOps.OneStepSouth(singlePush) & empty & Constants.Ranks.Five);
}
}
public static void initRayAttacks()
{
UInt64 rayAttack;
for (byte i = 0; i < 64; i++)
{
UInt64 square = 1UL << i;
//nort
rayAttack = BitOps.OneStepNorth(square);
rayAttack |= BitOps.OneStepNorth(rayAttack);
rayAttack |= BitOps.OneStepNorth(rayAttack);
rayAttack |= BitOps.OneStepNorth(rayAttack);
rayAttack |= BitOps.OneStepNorth(rayAttack);
rayAttack |= BitOps.OneStepNorth(rayAttack);
rayAttack |= BitOps.OneStepNorth(rayAttack);
rayAttacks[0, i] = rayAttack;
//sout
rayAttack = BitOps.OneStepSouth(square);
rayAttack |= BitOps.OneStepSouth(rayAttack);
rayAttack |= BitOps.OneStepSouth(rayAttack);
rayAttack |= BitOps.OneStepSouth(rayAttack);
rayAttack |= BitOps.OneStepSouth(rayAttack);
rayAttack |= BitOps.OneStepSouth(rayAttack);
rayAttack |= BitOps.OneStepSouth(rayAttack);
rayAttacks[1, i] = rayAttack;
//east
rayAttack = BitOps.OneStepEast(square);
rayAttack |= BitOps.OneStepEast(rayAttack);
rayAttack |= BitOps.OneStepEast(rayAttack);
rayAttack |= BitOps.OneStepEast(rayAttack);
rayAttack |= BitOps.OneStepEast(rayAttack);
rayAttack |= BitOps.OneStepEast(rayAttack);
rayAttack |= BitOps.OneStepEast(rayAttack);
rayAttacks[2, i] = rayAttack;
//west
rayAttack = BitOps.OneStepWest(square);
rayAttack |= BitOps.OneStepWest(rayAttack);
rayAttack |= BitOps.OneStepWest(rayAttack);
rayAttack |= BitOps.OneStepWest(rayAttack);
rayAttack |= BitOps.OneStepWest(rayAttack);
rayAttack |= BitOps.OneStepWest(rayAttack);
rayAttack |= BitOps.OneStepWest(rayAttack);
rayAttacks[3, i] = rayAttack;
//noEa
rayAttack = BitOps.OneStepNorthEast(square);
rayAttack |= BitOps.OneStepNorthEast(rayAttack);
rayAttack |= BitOps.OneStepNorthEast(rayAttack);
rayAttack |= BitOps.OneStepNorthEast(rayAttack);
rayAttack |= BitOps.OneStepNorthEast(rayAttack);
rayAttack |= BitOps.OneStepNorthEast(rayAttack);
rayAttack |= BitOps.OneStepNorthEast(rayAttack);
rayAttacks[4, i] = rayAttack;
//soWe
rayAttack = BitOps.OneStepSouthWest(square);
rayAttack |= BitOps.OneStepSouthWest(rayAttack);
rayAttack |= BitOps.OneStepSouthWest(rayAttack);
rayAttack |= BitOps.OneStepSouthWest(rayAttack);
rayAttack |= BitOps.OneStepSouthWest(rayAttack);
rayAttack |= BitOps.OneStepSouthWest(rayAttack);
rayAttack |= BitOps.OneStepSouthWest(rayAttack);
rayAttacks[5, i] = rayAttack;
//noWe
rayAttack = BitOps.OneStepNorthWest(square);
rayAttack |= BitOps.OneStepNorthWest(rayAttack);
rayAttack |= BitOps.OneStepNorthWest(rayAttack);
rayAttack |= BitOps.OneStepNorthWest(rayAttack);
rayAttack |= BitOps.OneStepNorthWest(rayAttack);
rayAttack |= BitOps.OneStepNorthWest(rayAttack);
rayAttack |= BitOps.OneStepNorthWest(rayAttack);
rayAttacks[6, i] = rayAttack;
//soEa
rayAttack = BitOps.OneStepSouthEast(square);
rayAttack |= BitOps.OneStepSouthEast(rayAttack);
rayAttack |= BitOps.OneStepSouthEast(rayAttack);
rayAttack |= BitOps.OneStepSouthEast(rayAttack);
rayAttack |= BitOps.OneStepSouthEast(rayAttack);
rayAttack |= BitOps.OneStepSouthEast(rayAttack);
rayAttack |= BitOps.OneStepSouthEast(rayAttack);
rayAttacks[7, i] = rayAttack;
}
}
