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Diffstat (limited to 'chess-ai.el')
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diff --git a/chess-ai.el b/chess-ai.el new file mode 100644 index 0000000..1cb083f --- /dev/null +++ b/chess-ai.el @@ -0,0 +1,120 @@ +;;; chess-ai.el --- A Chess playing module + +;; Copyright (C) 2004 Free Software Foundation, Inc. + +;; Author: Mario Lang <mlang@delysid.org> + +;; This file is free software; you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation; either version 2, or (at your option) +;; any later version. + +;; This file is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with GNU Emacs; see the file COPYING. If not, write to +;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +;; Boston, MA 02111-1307, USA. + +;;; Commentary: + +;; BUGS: Opponent moves are not displayed on the board! But they are announced +;; and shown in the mode-line, strange! + +;;; Code: + +(require 'chess-common) +(require 'chess-pos) +(require 'chess-ply) + +(defvar chess-pawn-value 100) +(defvar chess-knight-value 300) +(defvar chess-bishop-value 300) +(defvar chess-rook-value 500) +(defvar chess-queen-value 900) +(defvar chess-king-value 10000) + +(defun chess-eval-static (position) + (assert (vectorp position)) + (let ((v 0) + (status (chess-pos-status position))) + (if (eq status :checkmate) + -64000 + (if (eq status :stalemate) + v + (dotimes (i 64 (if (chess-pos-side-to-move position) v (- v))) + (let ((piece (aref position i))) + (cond + ((= piece ?P) (incf v chess-pawn-value)) + ((= piece ?p) (decf v chess-pawn-value)) + ((= piece ?K) (incf v chess-king-value)) + ((= piece ?k) (decf v chess-king-value)) + ((= piece ?Q) (incf v chess-queen-value)) + ((= piece ?q) (decf v chess-queen-value)) + ((= piece ?R) (incf v chess-rook-value)) + ((= piece ?r) (decf v chess-rook-value)) + ((= piece ?B) (incf v chess-bishop-value)) + ((= piece ?b) (decf v chess-bishop-value)) + ((= piece ?N) (incf v chess-knight-value)) + ((= piece ?n) (decf v chess-knight-value))))))))) + +(defun chess-ai-eval (position depth alpha beta &optional line) + (if (= depth 0) + (cons (chess-eval-static position) line) + (let ((plies (chess-legal-plies + position :color (chess-pos-side-to-move position))) + (ret (cons alpha line))) + (if (= (length plies) 0) + (cons (chess-eval-static position) line) + (while plies + (let* ((tmp1 (chess-ai-eval (chess-ply-next-pos (car plies)) + (1- depth) (- beta) (- alpha) + (cons (car plies) line))) + (tmp (- (car tmp1)))) + (if (> tmp alpha) (setq alpha tmp + ret (cons tmp (cdr tmp1)))) + (if (>= alpha beta) + (setq plies nil) + (setq plies (cdr plies))))) + ret)))) + +(defun chess-ai-best-move (position depth &optional func) + (let ((res (chess-ai-eval position depth -100000 100000))) + (cons (car res) + (if (functionp func) + (mapcar func (nreverse (cdr res))) + (nreverse (cdr res)))))) + +(defvar chess-ai-regexp-alist nil) + +(defun chess-ai-handler (game event &rest args) + (unless chess-engine-handling-event + (cond + ((eq event 'initialize) + (setq chess-engine-process t) + (setq chess-engine-opponent-name "Emacs AI") + t) + + ((eq event 'setup-pos) + t) + + ((eq event 'move) + (when (= 1 (chess-game-index game)) + (chess-game-set-tag game "White" chess-full-name) + (chess-game-set-tag game "Black" chess-engine-opponent-name)) + + (if (chess-game-over-p game) + (chess-game-set-data game 'active nil)) + (let ((bm (chess-ai-best-move (chess-engine-position nil) 3))) + (funcall chess-engine-response-handler 'move + (cadr bm)))) + + (t + (apply 'chess-common-handler game event args))))) + + +(provide 'chess-ai) +;;; chess-ai.el ends here |