Merge from origin/emacs-25

[gnu-emacs] / lisp / play / snake.el

diff --git a/lisp/play/snake.el b/lisp/play/snake.el
index 418c898e825c0fdedce11100455c1afef7688e6d..371c7133c743b2233dbf0069b24841be6b37ad55 100644 (file)
--- a/lisp/play/snake.el
+++ b/lisp/play/snake.el
@@ -1,6 +1,6 @@
 ;;; snake.el --- implementation of Snake for Emacs
 
-;; Copyright (C) 1997, 2001-2011 Free Software Foundation, Inc.
+;; Copyright (C) 1997, 2001-2016 Free Software Foundation, Inc.
 
 ;; Author: Glynn Clements <glynn@sensei.co.uk>
 ;; Created: 1997-09-10
@@ -25,8 +25,7 @@
 
 ;;; Code:
 
-(eval-when-compile
-  (require 'cl))
+(eval-when-compile (require 'cl-lib))
 
 (require 'gamegrid)
 
@@ -145,7 +144,6 @@
 (defvar snake-velocity-x 1)
 (defvar snake-velocity-y 0)
 (defvar snake-positions nil)
-(defvar snake-cycle 0)
 (defvar snake-score 0)
 (defvar snake-paused nil)
 (defvar snake-moved-p nil)
@@ -165,7 +163,6 @@ and then start moving it leftwards.")
 (make-variable-buffer-local 'snake-velocity-x)
 (make-variable-buffer-local 'snake-velocity-y)
 (make-variable-buffer-local 'snake-positions)
-(make-variable-buffer-local 'snake-cycle)
 (make-variable-buffer-local 'snake-score)
 (make-variable-buffer-local 'snake-paused)
 (make-variable-buffer-local 'snake-moved-p)
@@ -195,7 +192,7 @@ and then start moving it leftwards.")
 
 (defun snake-display-options ()
   (let ((options (make-vector 256 nil)))
-    (loop for c from 0 to 255 do
+    (dotimes (c 256)
       (aset options c
            (cond ((= c snake-blank)
                   snake-blank-options)
@@ -214,7 +211,7 @@ and then start moving it leftwards.")
 (defun snake-update-score ()
   (let* ((string (format "Score:  %05d" snake-score))
         (len (length string)))
-    (loop for x from 0 to (1- len) do
+    (dotimes (x len)
       (gamegrid-set-cell (+ snake-score-x x)
                         snake-score-y
                         (aref string x)))))
@@ -224,12 +221,12 @@ and then start moving it leftwards.")
                        snake-buffer-height
                        snake-space)
   (let ((buffer-read-only nil))
-    (loop for y from 0 to (1- snake-height) do
-         (loop for x from 0 to (1- snake-width) do
-               (gamegrid-set-cell x y snake-border)))
-    (loop for y from 1 to (- snake-height 2) do
-         (loop for x from 1 to (- snake-width 2) do
-               (gamegrid-set-cell x y snake-blank)))))
+    (dotimes (y snake-height)
+      (dotimes (x snake-width)
+        (gamegrid-set-cell x y snake-border)))
+    (cl-loop for y from 1 to (- snake-height 2) do
+             (cl-loop for x from 1 to (- snake-width 2) do
+                      (gamegrid-set-cell x y snake-blank)))))
 
 (defun snake-reset-game ()
   (gamegrid-kill-timer)
@@ -238,7 +235,6 @@ and then start moving it leftwards.")
        snake-velocity-x        snake-initial-velocity-x
        snake-velocity-y        snake-initial-velocity-y
        snake-positions         nil
-       snake-cycle             1
        snake-score             0
        snake-paused            nil
        snake-moved-p           nil
@@ -248,10 +244,18 @@ and then start moving it leftwards.")
     (dotimes (i snake-length)
       (gamegrid-set-cell x y snake-snake)
       (setq snake-positions (cons (vector x y) snake-positions))
-      (incf x snake-velocity-x)
-      (incf y snake-velocity-y)))
+      (cl-incf x snake-velocity-x)
+      (cl-incf y snake-velocity-y)))
   (snake-update-score))
 
+(defun snake-set-dot ()
+  (let ((x (random snake-width))
+       (y (random snake-height)))
+    (while (not (= (gamegrid-get-cell x y) snake-blank))
+      (setq x (random snake-width))
+      (setq y (random snake-height)))
+    (gamegrid-set-cell x y snake-dot)))
+
 (defun snake-update-game (snake-buffer)
   "Called on each clock tick.
 Advances the snake one square, testing for collision.
@@ -267,25 +271,22 @@ Argument SNAKE-BUFFER is the name of the buffer."
              (= c snake-snake))
          (snake-end-game)
        (cond ((= c snake-dot)
-              (incf snake-length)
-              (incf snake-score)
-              (snake-update-score))
+              (cl-incf snake-length)
+              (cl-incf snake-score)
+              (snake-update-score)
+              (snake-set-dot))
              (t
               (let* ((last-cons (nthcdr (- snake-length 2)
                                         snake-positions))
                      (tail-pos (cadr last-cons))
                      (x0 (aref tail-pos 0))
                      (y0 (aref tail-pos 1)))
-                (gamegrid-set-cell x0 y0
-                                   (if (= (% snake-cycle 5) 0)
-                                       snake-dot
-                                     snake-blank))
-                (incf snake-cycle)
+                (gamegrid-set-cell x0 y0 snake-blank)
                 (setcdr last-cons nil))))
        (gamegrid-set-cell x y snake-snake)
        (setq snake-positions
              (cons (vector x y) snake-positions))
-         (setq snake-moved-p nil)))))
+       (setq snake-moved-p nil)))))
 
 (defun snake-update-velocity ()
   (unless snake-moved-p
@@ -340,6 +341,7 @@ Argument SNAKE-BUFFER is the name of the buffer."
   "Start a new game of Snake."
   (interactive)
   (snake-reset-game)
+  (snake-set-dot)
   (use-local-map snake-mode-map)
   (gamegrid-start-timer snake-tick-period 'snake-update-game))
 
@@ -354,21 +356,13 @@ Argument SNAKE-BUFFER is the name of the buffer."
 
 (put 'snake-mode 'mode-class 'special)
 
-(defun snake-mode ()
-  "A mode for playing Snake.
-
-Snake mode keybindings:
-   \\{snake-mode-map}
-"
-  (kill-all-local-variables)
+(define-derived-mode snake-mode special-mode "Snake"
+  "A mode for playing Snake."
 
   (add-hook 'kill-buffer-hook 'gamegrid-kill-timer nil t)
 
   (use-local-map snake-null-map)
 
-  (setq major-mode 'snake-mode)
-  (setq mode-name "Snake")
-
   (unless (featurep 'emacs)
     (setq mode-popup-menu
          '("Snake Commands"
@@ -383,9 +377,7 @@ Snake mode keybindings:
   (setq gamegrid-use-glyphs snake-use-glyphs-flag)
   (setq gamegrid-use-color snake-use-color-flag)
 
-  (gamegrid-init (snake-display-options))
-
-  (run-mode-hooks 'snake-mode-hook))
+  (gamegrid-init (snake-display-options)))
 
 ;;;###autoload
 (defun snake ()