def move(self, frompos, topos, promotion=QUEEN):
assert(frompos != topos)
piece = self.grid.get(frompos)
if piece is None:
# could have been killed in between
raise InvalidMove("no piece at frompos")
piece.promotion = promotion
victim = self.grid.get(topos)
pstart = frompos.y == mgen.PAWN_START[piece.color]
if not mgen.allowed_move(piece.piece,
topos - frompos, mgen.FORWARDDIR[piece.color],
victim is not None,
pstart):
raise InvalidMove("illegal direction for %s" % FENCODE[piece.piece])
if self.in_between(frompos, topos, piece):
raise InvalidMove("position in between occupied")
if victim is not None:
if victim.color == piece.color:
raise InvalidMove("occupied by own color")
else:
piece.attack(topos)
else:
if piece.delay == 0:
self.relocate(frompos, topos)
def attack_on_pos(self, gridpos, attacker_color):
"""returns the first possible attack at gridpos"""
for kdir in mgen.RELMOVES_KNIGHT:
frompos = gridpos + kdir
cand = self.grid.get(frompos)
if cand is not None and cand.piece == KNIGHT and cand.color == attacker_color:
return frompos
for dir in mgen.MAINDIRS:
frompos = gridpos + dir
while mgen.on_board(frompos) and not frompos in self.grid:
frompos += dir
if mgen.on_board(frompos):
attacker = self.grid[frompos]
if attacker.color == attacker_color and mgen.allowed_move(attacker.piece,
gridpos - frompos,
mgen.FORWARDDIR[attacker.color],
True, False):
return frompos
return None