import pygame from pygame.locals import * class Goban: """Represents the go board. Handles stone placement, captures, etc""" # enum values for the board array EMPTY=0 WHITE=1 BLACK=2 # GRAY_WHITE=3 # GRAY_BLACK=4 def __init__(self, board_size=19): # Build the board intersections self.board_size = board_size num_points = board_size * board_size self.board = [Goban.EMPTY] * num_points self.def_draw_codes = self._make_default_draw_codes() self.to_move = Goban.BLACK self.black_captures = 0 self.white_captures = 0 self.last_move = None self.ko = None self.hover = None self.elapsed_time = 0 def set_hover(self, pos): rpos = self._real_pos(pos) if rpos == self.hover: return if not self._valid_move(rpos): self.clear_hover() return self.hover = rpos def clear_hover(self): self.hover = None # fixme - somewhere in this or its component functions we need to # identify ko points :) def place_stone(self, pos): rpos = self._real_pos(pos) if not self._valid_move(rpos): return self.board[rpos] = self.to_move self._capture(rpos) self.last_move = rpos self.to_move = self._other_color(self.to_move) self.clear_hover() def _capture(self, pos): """Look for stones captured on the 4 sides of pos, remove them and increment capture counter. This pos must be a *real* position value, not an x,y tuple.""" # Who are we capturing who = self._other_color(self.to_move) for p in self._neighbors(pos): if not self._on_board(p): continue if not self._has_liberties(p, who): if self.to_move == Goban.BLACK: self.black_captures += self._delete_group(p) elif self.to_move == Goban.WHITE: self.white_captures += self._delete_group(p) def _valid_move(self, pos): if not self._on_board(pos): return False # Can't play atop another stone if self.board[pos] != Goban.EMPTY: return False # Temporarily place the stone self.board[pos] = self.to_move liberties = self._has_liberties(pos, self.to_move) opponent = self._other_color(self.to_move) kills_group = False for d in self._neighbors(pos): if not self._on_board(d): continue if self._has_liberties(d, opponent) == 0: kills_group = True break # Remove temporary stone self.board[pos] = Goban.EMPTY return liberties > 0 or kills_group # Recursively find whether there are liberties for the group # at pos. Positive numbers are not necessarily accurate - # treat this as a boolean def _has_liberties(self, pos, who): if not self._on_board(pos) or self.board[pos] != who: return -1 bs = self.board_size * self.board_size checked = [False] * bs return self._has_liberties_r(pos, who, checked) def _has_liberties_r(self, pos, who, checked=None): if checked[pos]: return 0 else: checked[pos] = True square = self.board[pos] if square == Goban.EMPTY: return 1 elif square != who: return 0 else: liberties = 0 for d in self._neighbors(pos): liberties += self._has_liberties_r(d, who, checked) return liberties # We don't need to worry about crossing ourselves with the # recursion here, because we've already deleted the stone. # It would be more efficient to avoid going backwards, # but a lot more complicated (see _has_liberties) def _delete_group(self, pos): if not self._on_board(pos): return who = self.board[pos] if who == Goban.EMPTY: return 0 return self._delete_group_r(pos, who) if who == Goban.EMPTY: return 0 self.board[x][y].state = Goban.EMPTY def _delete_group_r(self, pos, who): if not self._on_board(pos): return if self.board[pos] != who: return 0 self.board[pos] = Goban.EMPTY num_deleted = 1 num_deleted += self._delete_group_r(pos + 1, who) num_deleted += self._delete_group_r(pos - 1, who) num_deleted += self._delete_group_r(pos + self.board_size, who) num_deleted += self._delete_group_r(pos - self.board_size, who) return num_deleted def draw_board(self, size, img_res): ret = pygame.Surface((size,size)) inc = size / self.board_size; for pos in range(len(self.board)): point = self.board[pos] if point == Goban.EMPTY: code = self.def_draw_codes[pos] elif point == Goban.BLACK: code = 'b' elif point == Goban.WHITE: code = 'w' if pos == self.last_move: code = code + 'T' s = img_res[code] s = pygame.transform.scale(s, (inc, inc)) ret.blit(s, ((pos % self.board_size) *inc, (pos / self.board_size) *inc)) if self.hover == pos: c = img_res['bH'] if self.to_move == Goban.WHITE: c = img_res['wH'] c = pygame.transform.scale(c, (inc, inc)) ret.blit(c, ((pos % self.board_size) *inc, (pos / self.board_size) *inc)) return ret.convert_alpha() def draw_info(self): textbox = pygame.Surface((150, 300)) textbox = textbox.convert() textbox.fill((250, 250, 250)) font = pygame.font.Font(None, 24) time = font.render('Time: {:02d}:{:02d}'.format(self.elapsed_time / 60, self.elapsed_time % 60), 1, (10, 10, 10)) heading = font.render('Captures', 1, (10, 10, 10)) black_cap = font.render('Black: {}'.format(self.black_captures), 1, (10, 10, 10)) white_cap = font.render('White: {}'.format(self.white_captures), 1, (10, 10, 10)) if self.to_move == Goban.BLACK: turn = font.render('To move: Black', 1, (10, 10, 10)) elif self.to_move == Goban.WHITE: turn = font.render('To move: White', 1, (10, 10, 10)) textbox.blit(heading, (0, 0)) textbox.blit(black_cap, (0, 28)) textbox.blit(white_cap, (0, 56)) textbox.blit(turn, (0, 100)) textbox.blit(time, (0, 150)) return textbox def _make_default_draw_codes(self): ret = [] for pos in range(len(self.board)): if pos == 0: ret.append('ul') elif pos == self.board_size - 1: ret.append('ur') elif pos == self.board_size * self.board_size - self.board_size: ret.append('dl') elif pos == self.board_size * self.board_size - 1: ret.append('dr') elif pos in [60, 66, 72, 174, 180, 186, 288, 294, 300]: ret.append('h') elif pos < self.board_size - 1: ret.append('u') elif pos % self.board_size == 0: ret.append('l') elif pos > (self.board_size * self.board_size - self.board_size - 1): ret.append('d') elif pos % self.board_size == 18: ret.append('r') else: ret.append('m') return ret def _real_pos(self, pos): x,y = pos return x * self.board_size + y def _on_board(self, pos): return pos >= 0 or pos < self.board_size * self.board_size def _other_color(self, color): if color == Goban.BLACK: return Goban.WHITE elif color == Goban.WHITE: return Goban.BLACK def _neighbors(self, pos): neighbors = [] if pos >= self.board_size: neighbors.append(pos - self.board_size) if pos <= self.board_size * self.board_size - self.board_size - 1: neighbors.append(pos + self.board_size) if pos % self.board_size != 0: neighbors.append(pos - 1) if (pos + 1) % self.board_size != 0: neighbors.append(pos + 1) return neighbors