check.c

   1 // check.c
   2 // 26 Aug 2007
   3
   4 Int64 inCheckFromKnight(Position * pos, int side){
   5     int kingSquare = lowestBit(pos->pieces[12 ^ side]);
   6     Int64 knightAttacks = knightFields[kingSquare];
   7     return knightAttacks & pos->pieces[5 ^ side];
   8 }
   9
  10 Int64 inCheckFromSlider(Position * pos, int side){
  11     int kingSquare = lowestBit(pos->pieces[12 ^ side]);
  12     Position children[32];
  13     Position * endChildren;
  14
  15     Int64 occupancy[4];
  16     int i;
  17     for (i = 0; i < 4; i++)
  18         occupancy[i] = pos->white[i] | pos->black[i];
  19
  20     Int64 rdests = rookDestinations(pos, kingSquare, occupancy);
  21     if (rdests & pos->pieces[9 ^ side])
  22         return 1;
  23
  24     return 0;
  25 }
  26
  27 Int64 inCheckFromPawn(Position * pos, int side){
  28     return 0;
  29 }
  30
  31 Int64 areKingsAdjacent(Position * pos){
  32     Int64 wkingSquare = lowestBit(pos->pieces[12]);
  33     return kingFields[wkingSquare] & pos->pieces[13];
  34 }
  35
  36 int inCheck(Position * pos, int side){
  37     return (inCheckFromKnight(pos, side) || inCheckFromSlider(pos, side)
  38         || inCheckFromPawn(pos, side) || areKingsAdjacent(pos)) != 0ULL;
  39 }
  40