| 1 | ;;; pong.el --- classical implementation of pong |
| 2 | |
| 3 | ;; Copyright (C) 1999-2013 Free Software Foundation, Inc. |
| 4 | |
| 5 | ;; Author: Benjamin Drieu <bdrieu@april.org> |
| 6 | ;; Keywords: games |
| 7 | |
| 8 | ;; This file is part of GNU Emacs. |
| 9 | |
| 10 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
| 11 | ;; it under the terms of the GNU General Public License as published by |
| 12 | ;; the Free Software Foundation, either version 3 of the License, or |
| 13 | ;; (at your option) any later version. |
| 14 | |
| 15 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 16 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | ;; GNU General Public License for more details. |
| 19 | |
| 20 | ;; You should have received a copy of the GNU General Public License |
| 21 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
| 22 | |
| 23 | ;;; Commentary: |
| 24 | |
| 25 | ;; This is an implementation of the classical game pong. |
| 26 | |
| 27 | ;;; Code: |
| 28 | |
| 29 | (eval-when-compile (require 'cl-lib)) |
| 30 | |
| 31 | (require 'gamegrid) |
| 32 | |
| 33 | ;;; Customization |
| 34 | |
| 35 | (defgroup pong nil |
| 36 | "Emacs-Lisp implementation of the classical game pong." |
| 37 | :tag "Pong" |
| 38 | :group 'games) |
| 39 | |
| 40 | (defcustom pong-buffer-name "*Pong*" |
| 41 | "Name of the buffer used to play." |
| 42 | :group 'pong |
| 43 | :type '(string)) |
| 44 | |
| 45 | (defcustom pong-width 50 |
| 46 | "Width of the playfield." |
| 47 | :group 'pong |
| 48 | :type '(integer)) |
| 49 | |
| 50 | (defcustom pong-height (min 30 (- (frame-height) 6)) |
| 51 | "Height of the playfield." |
| 52 | :group 'pong |
| 53 | :type '(integer)) |
| 54 | |
| 55 | (defcustom pong-bat-width 3 |
| 56 | "Width of the bats for pong." |
| 57 | :group 'pong |
| 58 | :type '(integer)) |
| 59 | |
| 60 | (defcustom pong-blank-color "black" |
| 61 | "Color used for background." |
| 62 | :group 'pong |
| 63 | :type 'color) |
| 64 | |
| 65 | (defcustom pong-bat-color "yellow" |
| 66 | "Color used for bats." |
| 67 | :group 'pong |
| 68 | :type 'color) |
| 69 | |
| 70 | (defcustom pong-ball-color "red" |
| 71 | "Color used for the ball." |
| 72 | :group 'pong |
| 73 | :type 'color) |
| 74 | |
| 75 | (defcustom pong-border-color "white" |
| 76 | "Color used for pong borders." |
| 77 | :group 'pong |
| 78 | :type 'color) |
| 79 | |
| 80 | (defcustom pong-left-key "4" |
| 81 | "Alternate key to press for bat 1 to go up (primary one is [left])." |
| 82 | :group 'pong |
| 83 | :type '(restricted-sexp :match-alternatives (stringp vectorp))) |
| 84 | |
| 85 | (defcustom pong-right-key "6" |
| 86 | "Alternate key to press for bat 1 to go down (primary one is [right])." |
| 87 | :group 'pong |
| 88 | :type '(restricted-sexp :match-alternatives (stringp vectorp))) |
| 89 | |
| 90 | (defcustom pong-up-key "8" |
| 91 | "Alternate key to press for bat 2 to go up (primary one is [up])." |
| 92 | :group 'pong |
| 93 | :type '(restricted-sexp :match-alternatives (stringp vectorp))) |
| 94 | |
| 95 | (defcustom pong-down-key "2" |
| 96 | "Alternate key to press for bat 2 to go down (primary one is [down])." |
| 97 | :group 'pong |
| 98 | :type '(restricted-sexp :match-alternatives (stringp vectorp))) |
| 99 | |
| 100 | (defcustom pong-quit-key "q" |
| 101 | "Key to press to quit pong." |
| 102 | :group 'pong |
| 103 | :type '(restricted-sexp :match-alternatives (stringp vectorp))) |
| 104 | |
| 105 | (defcustom pong-pause-key "p" |
| 106 | "Key to press to pause pong." |
| 107 | :group 'pong |
| 108 | :type '(restricted-sexp :match-alternatives (stringp vectorp))) |
| 109 | |
| 110 | (defcustom pong-resume-key "p" |
| 111 | "Key to press to resume pong." |
| 112 | :group 'pong |
| 113 | :type '(restricted-sexp :match-alternatives (stringp vectorp))) |
| 114 | |
| 115 | (defcustom pong-timer-delay 0.1 |
| 116 | "Time to wait between every cycle." |
| 117 | :group 'pong |
| 118 | :type 'number) |
| 119 | |
| 120 | |
| 121 | ;;; This is black magic. Define colors used |
| 122 | |
| 123 | (defvar pong-blank-options |
| 124 | '(((glyph colorize) |
| 125 | (t ?\040)) |
| 126 | ((color-x color-x) |
| 127 | (mono-x grid-x) |
| 128 | (color-tty color-tty)) |
| 129 | (((glyph color-x) [0 0 0]) |
| 130 | (color-tty pong-blank-color)))) |
| 131 | |
| 132 | (defvar pong-bat-options |
| 133 | '(((glyph colorize) |
| 134 | (emacs-tty ?O) |
| 135 | (t ?\040)) |
| 136 | ((color-x color-x) |
| 137 | (mono-x mono-x) |
| 138 | (color-tty color-tty) |
| 139 | (mono-tty mono-tty)) |
| 140 | (((glyph color-x) [1 1 0]) |
| 141 | (color-tty pong-bat-color)))) |
| 142 | |
| 143 | (defvar pong-ball-options |
| 144 | '(((glyph colorize) |
| 145 | (t ?\*)) |
| 146 | ((color-x color-x) |
| 147 | (mono-x grid-x) |
| 148 | (color-tty color-tty)) |
| 149 | (((glyph color-x) [1 0 0]) |
| 150 | (color-tty pong-ball-color)))) |
| 151 | |
| 152 | (defvar pong-border-options |
| 153 | '(((glyph colorize) |
| 154 | (t ?\+)) |
| 155 | ((color-x color-x) |
| 156 | (mono-x grid-x) |
| 157 | (color-tty color-tty)) |
| 158 | (((glyph color-x) [0.5 0.5 0.5]) |
| 159 | (color-tty pong-border-color)))) |
| 160 | |
| 161 | (defconst pong-blank 0) |
| 162 | (defconst pong-bat 1) |
| 163 | (defconst pong-ball 2) |
| 164 | (defconst pong-border 3) |
| 165 | |
| 166 | |
| 167 | ;;; Determine initial positions for bats and ball |
| 168 | |
| 169 | (defvar pong-xx nil |
| 170 | "Horizontal speed of the ball.") |
| 171 | |
| 172 | (defvar pong-yy nil |
| 173 | "Vertical speed of the ball.") |
| 174 | |
| 175 | (defvar pong-x nil |
| 176 | "Horizontal position of the ball.") |
| 177 | |
| 178 | (defvar pong-y nil |
| 179 | "Vertical position of the ball.") |
| 180 | |
| 181 | (defvar pong-bat-player1 nil |
| 182 | "Vertical position of bat 1.") |
| 183 | |
| 184 | (defvar pong-bat-player2 nil |
| 185 | "Vertical position of bat 2.") |
| 186 | |
| 187 | (defvar pong-score-player1 nil) |
| 188 | (defvar pong-score-player2 nil) |
| 189 | |
| 190 | ;;; Initialize maps |
| 191 | |
| 192 | (defvar pong-mode-map |
| 193 | (let ((map (make-sparse-keymap 'pong-mode-map))) |
| 194 | (define-key map [left] 'pong-move-left) |
| 195 | (define-key map [right] 'pong-move-right) |
| 196 | (define-key map [up] 'pong-move-up) |
| 197 | (define-key map [down] 'pong-move-down) |
| 198 | (define-key map pong-left-key 'pong-move-left) |
| 199 | (define-key map pong-right-key 'pong-move-right) |
| 200 | (define-key map pong-up-key 'pong-move-up) |
| 201 | (define-key map pong-down-key 'pong-move-down) |
| 202 | (define-key map pong-quit-key 'pong-quit) |
| 203 | (define-key map pong-pause-key 'pong-pause) |
| 204 | map) |
| 205 | "Modemap for pong-mode.") |
| 206 | |
| 207 | (defvar pong-null-map |
| 208 | (make-sparse-keymap 'pong-null-map) "Null map for pong-mode.") |
| 209 | |
| 210 | |
| 211 | |
| 212 | ;;; Fun stuff -- The code |
| 213 | |
| 214 | (defun pong-display-options () |
| 215 | "Computes display options (required by gamegrid for colors)." |
| 216 | (let ((options (make-vector 256 nil))) |
| 217 | (dotimes (c 256) |
| 218 | (aset options c |
| 219 | (cond ((= c pong-blank) |
| 220 | pong-blank-options) |
| 221 | ((= c pong-bat) |
| 222 | pong-bat-options) |
| 223 | ((= c pong-ball) |
| 224 | pong-ball-options) |
| 225 | ((= c pong-border) |
| 226 | pong-border-options) |
| 227 | (t |
| 228 | '(nil nil nil))))) |
| 229 | options)) |
| 230 | |
| 231 | |
| 232 | |
| 233 | (defun pong-init-buffer () |
| 234 | "Initialize pong buffer and draw stuff thanks to gamegrid library." |
| 235 | (interactive) |
| 236 | (get-buffer-create pong-buffer-name) |
| 237 | (switch-to-buffer pong-buffer-name) |
| 238 | (use-local-map pong-mode-map) |
| 239 | |
| 240 | (setq gamegrid-use-glyphs t) |
| 241 | (setq gamegrid-use-color t) |
| 242 | (gamegrid-init (pong-display-options)) |
| 243 | |
| 244 | (gamegrid-init-buffer pong-width |
| 245 | (+ 2 pong-height) |
| 246 | ?\s) |
| 247 | |
| 248 | (let ((buffer-read-only nil)) |
| 249 | (dotimes (y pong-height) |
| 250 | (dotimes (x pong-width) |
| 251 | (gamegrid-set-cell x y pong-border))) |
| 252 | (cl-loop for y from 1 to (- pong-height 2) do |
| 253 | (cl-loop for x from 1 to (- pong-width 2) do |
| 254 | (gamegrid-set-cell x y pong-blank)))) |
| 255 | |
| 256 | (cl-loop for y from pong-bat-player1 |
| 257 | to (1- (+ pong-bat-player1 pong-bat-width)) |
| 258 | do (gamegrid-set-cell 2 y pong-bat)) |
| 259 | (cl-loop for y from pong-bat-player2 |
| 260 | to (1- (+ pong-bat-player2 pong-bat-width)) |
| 261 | do (gamegrid-set-cell (- pong-width 3) y pong-bat))) |
| 262 | |
| 263 | |
| 264 | (defun pong-move-left () |
| 265 | "Move bat 2 up. |
| 266 | This is called left for historical reasons, since in some pong |
| 267 | implementations you move with left/right paddle." |
| 268 | (interactive) |
| 269 | (if (> pong-bat-player1 1) |
| 270 | (and |
| 271 | (setq pong-bat-player1 (1- pong-bat-player1)) |
| 272 | (pong-update-bat 2 pong-bat-player1)))) |
| 273 | |
| 274 | |
| 275 | |
| 276 | (defun pong-move-right () |
| 277 | "Move bat 2 up." |
| 278 | (interactive) |
| 279 | (if (< (+ pong-bat-player1 pong-bat-width) (1- pong-height)) |
| 280 | (and |
| 281 | (setq pong-bat-player1 (1+ pong-bat-player1)) |
| 282 | (pong-update-bat 2 pong-bat-player1)))) |
| 283 | |
| 284 | |
| 285 | |
| 286 | (defun pong-move-up () |
| 287 | "Move bat 2 up." |
| 288 | (interactive) |
| 289 | (if (> pong-bat-player2 1) |
| 290 | (and |
| 291 | (setq pong-bat-player2 (1- pong-bat-player2)) |
| 292 | (pong-update-bat (- pong-width 3) pong-bat-player2)))) |
| 293 | |
| 294 | |
| 295 | |
| 296 | (defun pong-move-down () |
| 297 | "Move bat 2 down." |
| 298 | (interactive) |
| 299 | (if (< (+ pong-bat-player2 pong-bat-width) (1- pong-height)) |
| 300 | (and |
| 301 | (setq pong-bat-player2 (1+ pong-bat-player2)) |
| 302 | (pong-update-bat (- pong-width 3) pong-bat-player2)))) |
| 303 | |
| 304 | |
| 305 | |
| 306 | (defun pong-update-bat (x y) |
| 307 | "Move a bat (suppress a cell and draw another one on the other side)." |
| 308 | |
| 309 | (cond |
| 310 | ((string-equal (buffer-name (current-buffer)) pong-buffer-name) |
| 311 | (gamegrid-set-cell x y pong-bat) |
| 312 | (gamegrid-set-cell x (1- (+ y pong-bat-width)) pong-bat) |
| 313 | (if (> y 1) |
| 314 | (gamegrid-set-cell x (1- y) pong-blank)) |
| 315 | (if (< (+ y pong-bat-width) (1- pong-height)) |
| 316 | (gamegrid-set-cell x (+ y pong-bat-width) pong-blank))))) |
| 317 | |
| 318 | |
| 319 | |
| 320 | (defun pong-init () |
| 321 | "Initialize a game." |
| 322 | |
| 323 | (define-key pong-mode-map pong-pause-key 'pong-pause) |
| 324 | |
| 325 | (add-hook 'kill-buffer-hook 'pong-quit nil t) |
| 326 | |
| 327 | ;; Initialization of some variables |
| 328 | (setq pong-bat-player1 (1+ (/ (- pong-height pong-bat-width) 2))) |
| 329 | (setq pong-bat-player2 pong-bat-player1) |
| 330 | (setq pong-xx -1) |
| 331 | (setq pong-yy 0) |
| 332 | (setq pong-x (/ pong-width 2)) |
| 333 | (setq pong-y (/ pong-height 2)) |
| 334 | |
| 335 | (pong-init-buffer) |
| 336 | (gamegrid-kill-timer) |
| 337 | (gamegrid-start-timer pong-timer-delay 'pong-update-game) |
| 338 | (pong-update-score)) |
| 339 | |
| 340 | |
| 341 | |
| 342 | (defun pong-update-game (pong-buffer) |
| 343 | "\"Main\" function for pong. |
| 344 | It is called every pong-cycle-delay seconds and |
| 345 | updates ball and bats positions. It is responsible of collision |
| 346 | detection and checks if a player scores." |
| 347 | (if (not (eq (current-buffer) pong-buffer)) |
| 348 | (pong-pause) |
| 349 | |
| 350 | (let ((old-x pong-x) |
| 351 | (old-y pong-y)) |
| 352 | |
| 353 | (setq pong-x (+ pong-x pong-xx)) |
| 354 | (setq pong-y (+ pong-y pong-yy)) |
| 355 | |
| 356 | (if (and (> old-y 0) |
| 357 | (< old-y (- pong-height 1))) |
| 358 | (gamegrid-set-cell old-x old-y pong-blank)) |
| 359 | |
| 360 | (if (and (> pong-y 0) |
| 361 | (< pong-y (- pong-height 1))) |
| 362 | (gamegrid-set-cell pong-x pong-y pong-ball)) |
| 363 | |
| 364 | (cond |
| 365 | ((or (= pong-x 3) (= pong-x 2)) |
| 366 | (if (and (>= pong-y pong-bat-player1) |
| 367 | (< pong-y (+ pong-bat-player1 pong-bat-width))) |
| 368 | (and |
| 369 | (setq pong-yy (+ pong-yy |
| 370 | (cond |
| 371 | ((= pong-y pong-bat-player1) -1) |
| 372 | ((= pong-y (1+ pong-bat-player1)) 0) |
| 373 | (t 1)))) |
| 374 | (setq pong-xx (- pong-xx))))) |
| 375 | |
| 376 | ((or (= pong-x (- pong-width 4)) (= pong-x (- pong-width 3))) |
| 377 | (if (and (>= pong-y pong-bat-player2) |
| 378 | (< pong-y (+ pong-bat-player2 pong-bat-width))) |
| 379 | (and |
| 380 | (setq pong-yy (+ pong-yy |
| 381 | (cond |
| 382 | ((= pong-y pong-bat-player2) -1) |
| 383 | ((= pong-y (1+ pong-bat-player2)) 0) |
| 384 | (t 1)))) |
| 385 | (setq pong-xx (- pong-xx))))) |
| 386 | |
| 387 | ((<= pong-y 1) |
| 388 | (setq pong-yy (- pong-yy))) |
| 389 | |
| 390 | ((>= pong-y (- pong-height 2)) |
| 391 | (setq pong-yy (- pong-yy))) |
| 392 | |
| 393 | ((< pong-x 1) |
| 394 | (setq pong-score-player2 (1+ pong-score-player2)) |
| 395 | (pong-init)) |
| 396 | |
| 397 | ((>= pong-x (- pong-width 1)) |
| 398 | (setq pong-score-player1 (1+ pong-score-player1)) |
| 399 | (pong-init)))))) |
| 400 | |
| 401 | |
| 402 | |
| 403 | (defun pong-update-score () |
| 404 | "Update score and print it on bottom of the game grid." |
| 405 | (let* ((string (format "Score: %d / %d" |
| 406 | pong-score-player1 pong-score-player2)) |
| 407 | (len (length string))) |
| 408 | (dotimes (x len) |
| 409 | (if (string-equal (buffer-name (current-buffer)) pong-buffer-name) |
| 410 | (gamegrid-set-cell x pong-height (aref string x)))))) |
| 411 | |
| 412 | |
| 413 | |
| 414 | (defun pong-pause () |
| 415 | "Pause the game." |
| 416 | (interactive) |
| 417 | (gamegrid-kill-timer) |
| 418 | ;; Oooohhh ugly. I don't know why, gamegrid-kill-timer don't do the |
| 419 | ;; jobs it is made for. So I have to do it "by hand". Anyway, next |
| 420 | ;; line is harmless. |
| 421 | (cancel-function-timers 'pong-update-game) |
| 422 | (define-key pong-mode-map pong-resume-key 'pong-resume)) |
| 423 | |
| 424 | |
| 425 | |
| 426 | (defun pong-resume () |
| 427 | "Resume a paused game." |
| 428 | (interactive) |
| 429 | (define-key pong-mode-map pong-pause-key 'pong-pause) |
| 430 | (gamegrid-start-timer pong-timer-delay 'pong-update-game)) |
| 431 | |
| 432 | |
| 433 | |
| 434 | (defun pong-quit () |
| 435 | "Quit the game and kill the pong buffer." |
| 436 | (interactive) |
| 437 | (gamegrid-kill-timer) |
| 438 | ;; Be sure not to draw things in another buffer and wait for some |
| 439 | ;; time. |
| 440 | (run-with-timer pong-timer-delay nil 'kill-buffer pong-buffer-name)) |
| 441 | |
| 442 | |
| 443 | |
| 444 | ;;;###autoload |
| 445 | (defun pong () |
| 446 | "Play pong and waste time. |
| 447 | This is an implementation of the classical game pong. |
| 448 | Move left and right bats and try to bounce the ball to your opponent. |
| 449 | |
| 450 | pong-mode keybindings:\\<pong-mode-map> |
| 451 | |
| 452 | \\{pong-mode-map}" |
| 453 | (interactive) |
| 454 | (setq pong-score-player1 0) |
| 455 | (setq pong-score-player2 0) |
| 456 | (pong-init)) |
| 457 | |
| 458 | |
| 459 | |
| 460 | (provide 'pong) |
| 461 | |
| 462 | ;;; pong.el ends here |