shellshock

   1 #!/usr/bin/env bash
   2
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License version 2, June 1991.
   5 #
   6 # This program is distributed in the hope that it will be useful,
   7 # but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 # GNU General Public License for more details.
  10 #
  11 # You should have received a copy of the GNU General Public License
  12 # along with this program. If not, see <https://www.gnu.org/licenses/gpl-2.0.html>,
  13 # or in pdf format at <http://www.dhampir.no/stuff/private/gpl-2.0.pdf>
  14
  15 # Copyright 2012 - Øyvind 'bolt' Hvidsten   <bolt@dhampir.no>
  16
  17 # Applied patches:
  18 #
  19 # v1.07, 2012.03.26 - Steve McMurphy
  20 # v1.11, 2014.09.30 - Øyvind A. Holm
  21 #
  22
  23 # Description:
  24 #
  25 # ShellShock is a top-down space shooter written for Bash 3 / Bash 4
  26 # Tested on Linux (Debian, RedHat and CentOS)
  27 #
  28 # Please note: A game in Bash is very demanding on resources.
  29 #              This script requires a modern computer to run at a decent speed.
  30 #              This script uses a tab width of 4, which is automatically applied
  31 #              if you're using vim with modelines enabled (see bottom line).
  32 #
  33 # For updates, please see <http://www.dhampir.no/stuff/bash/shellshock.bash>.
  34 #
  35 # Comments welcome, improvements/patches twice as welcome.
  36 #
  37
  38 # Releases / Changelog:
  39 #
  40 # v1.00, 2012.03.18 - Initial v1.0 release
  41 #                   * All intended functionality implemented
  42 #
  43 # v1.01, 2012.03.19 - Bash 3
  44 #                   * Tweaks to run on Bash 3
  45 #
  46 # v1.05, 2012.03.25 - Several changes based on feedback
  47 #                   * Added score display
  48 #                   * Added increasing difficulty
  49 #
  50 # v1.06, 2012.03.26 - More feedback
  51 #                   * Ship aft collision improved
  52 #                   * Added pause option
  53 #                   * Added simple high score storage
  54 #                   * Runs on Bash 3 again
  55 #
  56 # v1.07, 2012.03.26 - OSX
  57 #                   * Added rudimentary support for Mac OS X
  58 #
  59 # v1.08, 2012.03.26 - Cleanup
  60 #                   * Improved some comments and made clearer error messages
  61 #
  62 # v1.09, 2012.03.27 - Ubuntu
  63 #                   * Various fixes for Ubuntu
  64 #
  65 # v1.10, 2012.03.29 - Pause
  66 #                   * Improved the pause function to avoid problems with timers
  67 #
  68 # v1.11, 2014.09.30 - Better cleanup
  69 #                   * Using "stty sane" to clean up terminal settings on exit
  70 #
  71
  72 # get uname
  73 uname=$(uname -s)
  74
  75 # queue temp files for deletion on script exit
  76 function rm_queue { _rm_queue[${#_rm_queue[*]}]="$1"; }
  77 function rm_process { local file; for file in "${_rm_queue[@]}"; do rm "$file"; done; }
  78
  79 # check if tput actually outputs something useful for this terminal
  80 if [[ -z "$(tput sgr0)" ]] || [[ -z "$(tput bold)" ]]; then
  81         echo 'Error: tput is not working as expected with your current terminal settings!' >&2
  82         echo 'Try setting your $TERM to something more standard?' >&2
  83         exit 1
  84 fi
  85
  86 # read a single character
  87 function readc { IFS= read -r -n1 -s "$@" c; }
  88
  89 # variable variables :)
  90 gamepid=""
  91 saved_term=false
  92
  93 # list of files to be removed on cleanup
  94 _rm_queue=()
  95
  96 # cleanup
  97 function cleanup
  98 {
  99         [[ -z "$gamepid" ]] || { kill -TERM "$gamepid"; wait "$gamepid"; } 2>/dev/null
 100         rm_process                                      # remove temp files
 101         tput sgr0                                       # reset color
 102         clear                                           # clear the screen
 103         tput cnorm                                      # show the cursor
 104         stty echo                                       # show input
 105         stty sane                                       # reset terminal
 106         ! $saved_term || tput rmcup     # restore the terminal view
 107         case "$uname" in
 108                 Darwin)
 109                         reset
 110                 ;;
 111         esac
 112 }
 113 trap cleanup EXIT
 114
 115 # make comm file
 116 # TODO: better solution for inter-thread communication. must work on bash3
 117 case "$uname" in
 118         Darwin)
 119                 comm=$(mktemp /tmp/shellshock.XXXXXX)
 120         ;;
 121         *)
 122                 comm=$(mktemp)
 123         ;;
 124 esac
 125 if [[ -n "$comm" ]]; then
 126         rm_queue "$comm"
 127 else
 128         echo "Error: Communications file creation failed!" >&2
 129         exit 1
 130 fi
 131
 132 # init
 133 tput smcup && saved_term=true   # save the current terminal view
 134 tput civis                                              # hide the cursor
 135
 136 # game subshell
 137 (
 138         reset 2>/dev/null
 139         input=false
 140         trap 'input=true' USR1
 141         trap 'exit 0' TERM INT HUP
 142
 143         # test parent shell
 144         function testparent
 145         {
 146                 kill -0 $$ 2>/dev/null || exit 1
 147         }
 148
 149         # how to print stuff
 150         function xyecho
 151         {
 152                 local x=$1 y=$2
 153                 shift 2
 154
 155                 # running this in a loop with 2>/dev/null to avoid "interrupted system call" messages
 156                 while { ! builtin echo -n "${posarray[$((y*cols+x))]}$@"; } 2>/dev/null; do testparent; done
 157         }
 158         function safeecho
 159         {
 160                 # running this in a loop with 2>/dev/null to avoid "interrupted system call" messages
 161                 while { ! builtin echo -n "${posarray[$((y*cols+x))]}$@"; } 2>/dev/null; do testparent; done
 162         }
 163         function xyprintf
 164         {
 165                 local x=$1 y=$2
 166                 shift 2
 167
 168                 # running this in a loop with 2>/dev/null to avoid "interrupted system call" messages
 169                 while { ! builtin printf "${posarray[$((y*cols+x))]}$@"; } 2>/dev/null; do testparent; done
 170         }
 171         function safeprintf
 172         {
 173                 # running this in a loop with 2>/dev/null to avoid "interrupted system call" messages
 174                 while { ! builtin printf "${posarray[$((y*cols+x))]}$@"; } 2>/dev/null; do testparent; done
 175         }
 176
 177         # called when the player fires his/her weapons
 178         function fire # no parameters
 179         {
 180                 (( ff_ammo_current > 0 )) || return
 181
 182                 if ${ff_alive[ff_next]}; then
 183                         xyprintf $((origo_x+ff_x[ff_next])) $((origo_y+ff_y[ff_next])) " "
 184                 fi
 185
 186                 if ((++ff_total%2 == 0)); then
 187                         ff_x[ff_next]=$((dynel_cx[0]-3))
 188                         ff_y[ff_next]=$((dynel_cy[0]-8))
 189                 else
 190                         ff_x[ff_next]=$((dynel_cx[0]+3))
 191                         ff_y[ff_next]=$((dynel_cy[0]-8))
 192                 fi
 193
 194                 if ! outofbounds "$((origo_x+ff_x[ff_next]))" "$((origo_y+ff_y[ff_next]))"; then
 195                         ff_ydiv[ff_next]=1
 196                         ff_symbol[ff_next]="|"
 197                         ff_damage[ff_next]=1
 198                         ff_alive[ff_next]=true
 199                         (( ++ff_count ))
 200                         ff_new[ff_next]=true
 201                         (( --ff_ammo_current ))
 202                         ff_next=$(( ++ff_next < ff_count_max ? ff_next : 0 ))
 203                 fi
 204
 205                 if ((ff_total%3 == 0)); then
 206                         if ${ff_alive[ff_next]}; then
 207                                 xyprintf $((origo_x+ff_x[ff_next])) $((origo_y+ff_y[ff_next])) " "
 208                         fi
 209
 210                         if ((ff_total%2 == 0)); then
 211                                 ff_x[ff_next]=$((dynel_cx[0]+5))
 212                                 ff_y[ff_next]=$((dynel_cy[0]-7))
 213                         else
 214                                 ff_x[ff_next]=$((dynel_cx[0]-5))
 215                                 ff_y[ff_next]=$((dynel_cy[0]-7))
 216                         fi
 217
 218                         if ! outofbounds "$((origo_x+ff_x[ff_next]))" "$((origo_y+ff_y[ff_next]))"; then
 219                                 ff_ydiv[ff_next]=2
 220                                 ff_symbol[ff_next]="¤"
 221                                 ff_damage[ff_next]=4
 222                                 ff_alive[ff_next]=true
 223                                 (( ++ff_count ))
 224                                 ff_new[ff_next]=true
 225                                 ff_next=$(( ++ff_next < ff_count_max ? ff_next : 0 ))
 226                         fi
 227                 fi
 228         }
 229
 230 #######################################################
 231 ## BEGIN ASCII ART SECTION - NO TABS, NO INDENTATION ##
 232 #######################################################
 233 # title
 234 ascii_title_w=78
 235 ascii_title_h=6
 236 ascii_title=$(
 237 cat - <<"EOF"
 238   _________.__           .__  .__    _________.__                   __   ._.
 239  /   _____/|  |__   ____ |  | |  |  /   _____/|  |__   ____   ____ |  | _| |
 240  \_____  \ |  |  \_/ __ \|  | |  |  \_____  \ |  |  \ /  _ \_/ ___\|  |/ / |
 241  /        \|   Y  \  ___/|  |_|  |__/        \|   Y  (  <_> )  \___|    < \|
 242 /_______  /|___|  /\___  >____/____/_______  /|___|  /\____/ \___  >__|_ \__
 243         \/      \/     \/                  \/      \/            \/     \/\/
 244 EOF
 245 )
 246 # keybindings
 247 ascii_keybindings_w=74 #21 - fake width to print off-center
 248 ascii_keybindings_h=5
 249 ascii_keybindings=$(
 250 cat - <<"EOF"
 251 Keybindings:
 252     arrow keys - move
 253     SPACE      - fire
 254     z          - toggle autofire
 255     p          - pause
 256     q          - quit
 257 EOF
 258 )
 259 # dead meat - written in quotes because all the parenthesis confuse vim's syntax highlighting
 260 #           - this also means the first line has to be offset, so the ascii looks ugly in code
 261 ascii_dead_w=36
 262 ascii_dead_h=8
 263 ascii_dead=\
 264 ' ______   _______  _______  ______
 265 (  __  \ (  ____ \(  ___  )(  __  \
 266 | (  \  )| (    \/| (   ) || (  \  )
 267 | |   ) || (__    | (___) || |   ) |
 268 | |   | ||  __)   |  ___  || |   | |
 269 | |   ) || (      | (   ) || |   ) |
 270 | (__/  )| (____/\| )   ( || (__/  )
 271 (______/ (_______/|/     \|(______/'
 272 # press q
 273 ascii_press_q_w=42
 274 ascii_press_q_h=1
 275 ascii_press_q=$(
 276 cat - <<"EOF"
 277 -= Press q to quit to the title screen! =-
 278 EOF
 279 )
 280 # press fire
 281 ascii_press_fire_w=27
 282 ascii_press_fire_h=1
 283 ascii_press_fire=$(
 284 cat - <<"EOF"
 285 -= Press SPACE to start! =-
 286 EOF
 287 )
 288 # pause
 289 ascii_pause_w=11
 290 ascii_pause_h=1
 291 ascii_pause=$(
 292 cat - <<"EOF"
 293 -= PAUSE =-
 294 EOF
 295 )
 296 # pause frame
 297 ascii_pauseframe_w=25
 298 ascii_pauseframe_h=5
 299 ascii_pauseframe=$(
 300 cat - <<"EOF"
 301 *************************
 302 *                       *
 303 *                       *
 304 *                       *
 305 *************************
 306 EOF
 307 )
 308
 309 # player's spaceship
 310 ascii_playerdynel_w=21
 311 ascii_playerdynel_h=9
 312 ascii_playership=$(
 313 cat - <<"EOF"
 314 08]
 315 06]         /^\
 316 03]       |/.!.\|
 317 01]    _|/_/]=[\_\|_
 318 00]  _/     | |     \_
 319 00] |_____. | | ._____|
 320 00]     \_________/
 321 04]      |@|   |@|
 322 05]
 323 EOF
 324 )
 325 # rock 1
 326 ascii_rock0_w=9
 327 ascii_rock0_h=7
 328 ascii_rock0=$(
 329 cat - <<"EOF"
 330 02]
 331 01]   __
 332 01]  /  \_
 333 00] |     \
 334 01]  \   _|
 335 01]   \_/
 336 02]
 337 EOF
 338 )
 339 ascii_rock1_w=14
 340 ascii_rock1_h=8
 341 ascii_rock1=$(
 342 cat - <<"EOF"
 343 06]
 344 01]       __
 345 00]  ____/  \_
 346 00] /         \
 347 00] \          |
 348 00]  \     ___/
 349 01]   \___/
 350 02]
 351 EOF
 352 )
 353 ascii_rock2_w=8
 354 ascii_rock2_h=8
 355 ascii_rock2=$(
 356 cat - <<"EOF"
 357 02]
 358 01]   __
 359 00]  /  \
 360 00] |   |
 361 00] |    \
 362 00] |   _/
 363 00] \__/
 364 00]
 365 EOF
 366 )
 367 ascii_rock3_w=9
 368 ascii_rock3_h=7
 369 ascii_rock3=$(
 370 cat - <<"EOF"
 371 01]
 372 00]  _____
 373 00] /     \
 374 00] |     |
 375 00] \   _/
 376 00]  \_/
 377 01]
 378 EOF
 379 )
 380 ascii_rock4_w=13
 381 ascii_rock4_h=8
 382 ascii_rock4=$(
 383 cat - <<"EOF"
 384 01]
 385 00]  ___
 386 00] /   \_____
 387 00] |        _|
 388 00] \       /
 389 00]  \_    /
 390 01]    \__/
 391 03]
 392 EOF
 393 )
 394 #######################################################
 395 ## END ASCII ART SECTION                             ##
 396 #######################################################
 397
 398         # pretty colours
 399         color_background=$(tput setab 0)
 400         color_reset="$(tput sgr0)${color_background}"
 401         color_black="${color_reset}$(tput setaf 0)"
 402         color_red="${color_reset}$(tput setaf 1)"
 403         color_green="${color_reset}$(tput setaf 2)"
 404         color_orange="${color_reset}$(tput setaf 3)"
 405         color_blue="${color_reset}$(tput setaf 4)"
 406         color_magenta="${color_reset}$(tput setaf 5)"
 407         color_cyan="${color_reset}$(tput setaf 6)"
 408         color_light_gray="${color_reset}$(tput setaf 7)"
 409         color_dark_gray="${color_reset}$(tput bold)$(tput setaf 0)"
 410         color_light_red="${color_reset}$(tput bold)$(tput setaf 1)"
 411         color_light_green="${color_reset}$(tput bold)$(tput setaf 2)"
 412         color_yellow="${color_reset}$(tput bold)$(tput setaf 3)"
 413         color_light_blue="${color_reset}$(tput bold)$(tput setaf 4)"
 414         color_light_magenta="${color_reset}$(tput bold)$(tput setaf 5)"
 415         color_light_cyan="${color_reset}$(tput bold)$(tput setaf 6)"
 416         color_white="${color_reset}$(tput bold)$(tput setaf 7)"
 417
 418         # specific colors for stuff
 419         color_debug=$color_orange                                       # debug prints (FPS, seconds, rocks count, etc)
 420         color_ship=$color_white                                         # player's ship
 421         color_fire=$color_light_magenta                         # player's missiles
 422         color_engine_1=$color_light_red                         # player's engines (blinking)
 423         color_engine_2=$color_red                                       # player's engines (blinking)
 424         color_border=$color_red                                         # border
 425         color_score_result=$color_yellow                        # score result (death screen)
 426         color_origo=$color_green                                        # origo         (bottom center)
 427         color_rock_healthy=$color_light_cyan            # healthy rocks
 428         color_rock_damaged=$color_cyan                          # damaged rocks
 429         color_death_1=$color_light_red                          # death animation stage 1
 430         color_death_2=$color_red                                        # death animation stage 2
 431         color_death_3=$color_dark_gray                          # death animation stage 3
 432         color_death_4=$color_black                                      # death animation stage 4 (erase)
 433         color_title=$color_yellow                                       # ShellShock!
 434         color_pause_1=$color_light_red                          # pause text (blinking)
 435         color_pause_2=$color_red                                        # pause text (blinking)
 436         color_pauseframe=$color_red                                     # frame around pause text
 437         color_youaredead=$color_light_red                       # YOU ARE DEAD
 438         color_keybindings=$color_green                          # keybindings...
 439         color_pressfire_1=$color_blue                           # press space to start (blinking)
 440         color_pressfire_2=$color_light_blue                     # press space to start (blinking)
 441         color_pressq_1=$color_dark_gray                         # press q for title screen (blinking)
 442         color_pressq_2=$color_light_gray                        # press q for title screen (blinking)
 443
 444         # score display (top right) (drawn on white background)
 445         color_score="${color_black}$(tput setab 7)"
 446         # ammo display (drawn with spaces on background color in the top left)
 447         color_ammo_1="${color_black}$(tput setab 5)"
 448         color_ammo_2="${color_black}$(tput setab 7)"
 449
 450         # home
 451         home=$(tput home)
 452
 453         # has the size changed?
 454         function sizechanged
 455         {
 456                 if (( cols != $(tput cols) )) || (( rows != $(tput lines) )); then
 457                         cols=$(tput cols)
 458                         rows=$(tput lines)
 459                         origo_x=$((cols/2))
 460                         origo_y=$((rows-1))
 461
 462                         return 0
 463                 fi
 464                 return 1
 465         }
 466
 467         # clear
 468         redraw=false
 469         function wipe
 470         {
 471                 # "tput clear" doesn't fill with background color in bash3, screen, etc.
 472                 # must write a shitload of spaces instead
 473                 safeprintf "${color_reset}${home}%$((cols*rows))s" ""
 474
 475                 # everything needs redrawing after this
 476                 redraw=true
 477         }
 478
 479         # get the current time in microseconds
 480         case "$uname" in
 481                 Darwin)
 482                         # this is slow. very slow.
 483                         function microtime {
 484                                 local time=$(python <<<"import time; print \"%.6f\" % time.time();")
 485                                 echo -n ${time/./}
 486                         }
 487                 ;;
 488                 *)
 489                         function microtime {
 490                                 local time=$(date +%s%N)
 491                                 echo -n ${time:0:((${#time}-3))}
 492                         }
 493                 ;;
 494         esac
 495
 496         # build tput position array
 497         # moving using this 10x faster than running tput
 498         _pos_cols=0
 499         _pos_rows=0
 500         function buildposarray
 501         {
 502                 if ((cols == _pos_cols)) && ((rows == _pos_rows)); then
 503                         return 1
 504                 fi
 505
 506                 wipe
 507                 _pos_cols=$cols
 508                 _pos_rows=$rows
 509                 posarray=()
 510
 511                 local q=false
 512                 local e=$(echo -e "\e")
 513                 if [[ "$(tput cup 0 0)" = "${e}[1;1H" ]]; then
 514                         # standard terminal movement commands - quick generation
 515                         q=true
 516                 fi
 517
 518                 local string="Building position array for ${cols}x${rows}... "
 519                 local pos=$(tput cup 0 ${#string})
 520
 521                 local x y
 522                 safeecho "${color_debug}${home}${string}"
 523                 for ((x=0; x < cols; x++)); do
 524                         if sizechanged; then
 525                                 buildposarray
 526                                 return $?
 527                         fi
 528                         echo -n "${pos}$((x*100/cols))%"
 529                         for ((y=0; y < rows; y++)); do
 530                                 if $q; then
 531                                         posarray[$((y*cols+x))]="${e}[$((y+1));$((x+1))H"
 532                                 else
 533                                         posarray[$((y*cols+x))]=$(tput cup "$y" "$x")
 534                                 fi
 535                         done
 536                 done
 537
 538                 return 0
 539         }
 540
 541         # print something at a spot
 542         function catc { cat "$@"; }     # draw centered (x coordinate specifies width, not x pos)
 543         function catd { cat "$@"; } # draw a dynel (supports black outline)
 544         function cat
 545         {
 546                 local x=$1 y=$2 i=0 cy dynel=false first=true offset=0
 547
 548                 case "${FUNCNAME[1]}" in
 549                         catd) dynel=true ;;
 550                         catc)
 551                                 x=$(( (cols - x) / 2)) # center
 552                                 (( x > 0 )) || x=1
 553                         ;;
 554                 esac
 555
 556                 while IFS= read -r line; do
 557                         cy=$(( y + i++ ))
 558                         if $dynel; then
 559                                 offset="$(( 10#${line:0:2} ))"
 560                                 line=${line:3+offset}
 561                                 cx=$(( x + offset ))
 562                         else
 563                                 cx=$x
 564                         fi
 565                         (( cx < cols-1 )) || continue                                   # don't write on or outside the right border
 566                         (( cy > 0 )) || continue                                                # don't write on or above the top border
 567                         (( cy < rows-1 )) || break                                              # don't write on or below the bottom border
 568                         (( cx >= 1 )) || { line=${line:1-cx}; cx=1; }   # cut to fit inside left border
 569                         line=${line:0:cols-1-cx}                                                # cut to fit inside right border
 570
 571                         xyecho $cx $cy "$line"
 572                 done
 573         }
 574
 575         # border drawing
 576         function border
 577         {
 578                 safeecho $color_border
 579
 580                 # no printf -v on bash3 :(
 581                 local line
 582                 while { ! line=$(builtin printf "%${cols}s" ""); } 2>/dev/null; do :; done
 583                 line=${line// /#}
 584
 585                 xyecho 0 0 "$line"
 586
 587                 local y
 588                 for (( y=1; y<rows-1; y++ )); do
 589                         xyecho 0 $y "#"
 590                         xyecho $((cols-1)) $y "#"
 591                 done
 592
 593                 xyecho 0 $((rows-1)) "$line"
 594         }
 595
 596         # is something outside the screen?
 597         function outofbounds # $1 - x coordinate, $2 - y coordinate
 598         {
 599                 local x=$1 y=$2
 600                 if
 601                         (( x < 1 )) || (( x >= cols-1 )) ||
 602                         (( y < 1 )) || (( y >= rows-1 ))
 603                 then
 604                         return 0
 605                 fi
 606                 return 1
 607         }
 608
 609         # pushes a dynel until it's within the right and left borders
 610         function restrict_xaxis # $1 - dynel_* index
 611         {
 612                 local i=$1
 613                 dynel_x[i]=${dynel_cx[i]}
 614                 while ! canmoveright $i;        do (( dynel_cx[i]-- )); done;
 615                 while ! canmoveleft $i;         do (( dynel_cx[i]++ )); done;
 616                 (( dynel_cx[i] < dynel_x[i] )) && (( dynel_cx[i]++ ))
 617                 (( dynel_cx[i] > dynel_x[i] )) && (( dynel_cx[i]-- ))
 618                 dynel_x[i]=${dynel_cx[i]}
 619         }
 620
 621         # pushes a dynel until it's within the top and bottom borders
 622         function restrict_yaxis # $1 - dynel_* index
 623         {
 624                 local i=$1
 625                 dynel_y[i]=${dynel_cy[i]}
 626                 while ! canmoveup $i;           do (( dynel_cy[i]++ )); done;
 627                 while ! canmovedown $i;         do (( dynel_cy[i]-- )); done;
 628                 (( dynel_cy[i] < dynel_y[i] )) && (( dynel_cy[i]++ ))
 629                 (( dynel_cy[i] > dynel_y[i] )) && (( dynel_cy[i]-- ))
 630                 dynel_y[i]=${dynel_cy[i]}
 631         }
 632
 633         # collides dynels based on simple squares (width, height)
 634         function squarecollide # $1 - dynel_* index
 635         {
 636                 local i=$1
 637                 for j in "${!dynel_alive[@]}"; do
 638                         ${dynel_alive[j]} || continue   # don't check dead dynels
 639                         (( j != i )) || continue                # don't check yourself
 640                         (( j >= rock_pos )) || continue # don't check the playership
 641                         local distance_x=$((dynel_cx[i] > dynel_cx[j] ? dynel_cx[i]-dynel_cx[j] : dynel_cx[j]-dynel_cx[i]))
 642                         local distance_y=$((dynel_cy[j] - dynel_cy[i]))
 643                         if
 644                                 (( distance_x < (dynel_w[i]+dynel_w[j])/2 )) &&
 645                                 {
 646                                         if (( distance_y < 0 )); then
 647                                                 # j (compare dynel) is above i
 648                                                 (( -distance_y < dynel_h[j] ))
 649                                         else
 650                                                 # j (compare dynel) is below i
 651                                                 (( distance_y < dynel_h[j] ))
 652                                         fi
 653                                 }
 654                         then
 655                                 # collision!
 656                                 return 0
 657                         fi
 658                 done
 659
 660                 # no collision
 661                 return 1
 662         }
 663
 664         # collides the player's ship
 665         # basically the same as square collision, but with some tweaks to make it feel better
 666         function shipcollide # no parameters
 667         {
 668                 local i=0
 669                 for j in "${!dynel_alive[@]}"; do
 670                         ${dynel_alive[j]} || continue   # don't check dead dynels
 671                         (( j != i )) || continue                # don't check yourself
 672                         local distance_x=$((dynel_cx[i] > dynel_cx[j] ? dynel_cx[i]-dynel_cx[j] : dynel_cx[j]-dynel_cx[i]))
 673                         local distance_y=$((dynel_cy[j] - dynel_cy[i]))
 674                         if
 675                                 (( distance_x + 2 < (dynel_w[i]+dynel_w[j])/2 )) && # make the ship a little narrower
 676                                 {
 677                                         if (( distance_y < 0 )); then
 678                                                 # j (compare dynel) is above i
 679                                                 (( -distance_y < dynel_h[j] )) &&
 680                                                 (( (distance_y + dynel_h[i]) > distance_x - 4 )) # make a somewhat cone-shaped ship
 681                                         else
 682                                                 # j (compare dynel) is below i
 683                                                 (( distance_y + 2 < dynel_h[j] )) && # make the ship a little shorter
 684                                                 {
 685                                                         ((dynel_h[j] - distance_y - 2 > 2)) ||                          # 2 lines into ship from bottom
 686                                                         ((4 + (dynel_h[j] - distance_y - 2) > distance_x))      # engine hit
 687                                                 }
 688                                         fi
 689                                 }
 690                         then
 691                                 # collision!
 692                                 return 0
 693                         fi
 694                 done
 695
 696                 # no collision
 697                 return 1
 698         }
 699
 700         # runs hit tests on friendly fire and damages any rocks encountered
 701         function ffhit # $1 - ff_* index
 702         {
 703                 local x=${ff_x[$1]} y=${ff_y[$1]} i j
 704                 for i in "${!dynel_alive[@]}"; do
 705                         (( i >= rock_pos )) || continue # only check rocks
 706                         ${dynel_alive[i]} || continue   # don't check dead dynels
 707                         if
 708                                 ((y > dynel_y[i]-2)) ||                                                                                         # haven't reached rock yet - miss
 709                                 ((y < dynel_y[i]-dynel_h[i])) ||                                                                        # behind the rock - miss
 710                                 (( (x > dynel_x[i] ? x-dynel_x[i] : dynel_x[i]-x) > dynel_w[i]/2 ))     # simple square collision
 711                         then
 712                                 continue
 713                         else
 714                                 ((dynel_hp[i] -= ff_damage[$1]))
 715                                 if ((dynel_hp[i] > 0)) && ((dynel_hp[i] < rock_hp/2)); then
 716                                         dynel_color[i]=$color_rock_damaged
 717                                         dynel_redraw[i]=true
 718                                 fi
 719                                 (( score_current += score_rockshot * ff_damage[$1] ))
 720                                 # it's a hit!
 721                                 return 0
 722                         fi
 723                 done
 724
 725                 # missed
 726                 return 1
 727         }
 728
 729         # changes the color of a dynel several times until it's finally drawn with black to disappear
 730         function deathanimation # $1 - dynel_* index
 731         {
 732                 local i=$1
 733                 # it helps to read this backwards :)
 734                 case "${dynel_color[i]}" in
 735                         "$color_death_4") return 1 ;;
 736                         "$color_death_3") dynel_color[i]=$color_death_4 ;;
 737                         "$color_death_2") dynel_color[i]=$color_death_3 ;;
 738                         "$color_death_1") dynel_color[i]=$color_death_2 ;;
 739                         *) dynel_color[i]=$color_death_1 ;;
 740                 esac
 741                 return 0
 742         }
 743
 744         # limit the amount of rocks
 745         function limitrocks
 746         {
 747                 rock_count_max=$(((rows*cols) / 720))
 748         }
 749
 750         # update the amount of score you get for stuff
 751         function updatescore
 752         {
 753                 score_rockshot=10                                                       # score per damage point that hits a rock
 754                 score_deadrock=$((500000 / (rows*cols)))        # score per dead rock (off screen or shot to pieces)
 755                 case "$state_current" in
 756                         ingame) ;;
 757                         title)
 758                                 score_current=0                                         # current score
 759                                 score_last=-1                                           # last drawn sore
 760                                 score_second=0                                          # score per second passed
 761                         ;;
 762                 esac
 763         }
 764
 765         # movable? # $1 - dynel_* index
 766         function canmoveup    { (( origo_y+dynel_cy[$1]-dynel_h[$1] > 0 )); }
 767         function canmovedown  { (( origo_y+dynel_cy[$1] < rows )); }
 768         function canmoveright { (( origo_x+dynel_cx[$1]+(dynel_w[$1]/2)+1 < cols )); }
 769         function canmoveleft  { (( origo_x+dynel_cx[$1]-(dynel_w[$1]/2) > 0 )); }
 770
 771         # tput position array
 772         posarray=()                                                             # position array for faster cursor movement
 773         sizechanged                                                             # run console size check (will always have changed)
 774
 775         # pause and unpause
 776         function registerpausetimer
 777         {
 778                 pausetimers[${#pausetimers[*]}]="$1"
 779         }
 780         function pause
 781         {
 782                 if ! $pause; then
 783                         local timer value
 784                         for timer in "${pausetimers[@]}"; do
 785                                 value=${!timer}
 786                                 if (( value != 0 )); then
 787                                         (( value -= time_now ))
 788                                 else
 789                                         value="zero"
 790                                 fi
 791                                 IFS= read -r $timer <<< "$value"
 792                         done
 793                         pause=true
 794                 fi
 795         }
 796         function unpause
 797         {
 798                 if $pause; then
 799                         local timer value
 800                         for timer in "${pausetimers[@]}"; do
 801                                 value=${!timer}
 802                                 if [[ value != "zero" ]]; then
 803                                         (( value += time_now ))
 804                                 else
 805                                         value=0
 806                                 fi
 807                                 IFS= read -r $timer <<< "$value"
 808                         done
 809                         pause=false
 810                 fi
 811         }
 812
 813         # ammo line - no printf -v on bash3 :(
 814         ff_ammo_max=30                                                  # maximum ammunition
 815         while { ! ff_line=$(builtin printf "%${ff_ammo_max}s" ""); } 2>/dev/null; do :; done
 816
 817         # init
 818         time_start=$(microtime)                                 # time the game was started
 819         time_last=$time_start                                   # time of last game loop
 820         time_now=$time_start                                    # current time
 821         timer_resize=0                                                  # resize check timer
 822         timerd_resize=1000000                                   # resize check timer delta
 823         state_current="title"                                   # current game state
 824         state_last=""                                                   # game state last loop
 825         movespeed_x=7                                                   # how fast the player ship moves horizontally
 826         movespeed_y=3                                                   # how fast the player ship moves vertically
 827         blink_pressfire=""                                              # blink status for the "press fire" text on title screen
 828         blink_pressq=""                                                 # blink status for the "press q" text on death screen
 829         blink_engines=""                                                # blink status for the ship's engines
 830         blink_pause=""                                                  # blink status for the pause message
 831         messageheight=4                                                 # how far away from the top we print the title and such
 832         cpusavesleep=0.2                                                # time to sleep if saving cpu (dead, paused, menu)
 833         redraw=true                                                             # should we redraw everything? (size probably changed)
 834
 835         # reset the game
 836         function resetgame
 837         {
 838                 # dynels
 839                 dynel_img=( "ascii_playership" )        # drawing
 840                 dynel_x=( 0 )                                           # current screen position (last drawn)
 841                 dynel_y=( 1 )                                           # current screen position (last drawn)
 842                 dynel_cx=( ${dynel_x[0]} )                      # actual position
 843                 dynel_cy=( ${dynel_y[0]} )                      # actual position
 844                 dynel_ydiv=( 0 )                                        # automatic movement (for non-player dynels)
 845                 dynel_w=( $ascii_playerdynel_w )        # width
 846                 dynel_h=( $ascii_playerdynel_h )        # height
 847                 dynel_hp=( 1 )                                          # health
 848                 dynel_color=( $color_ship )                     # color
 849                 dynel_redraw=( true )                           # needs redrawing or not
 850                 dynel_alive=( true )                            # dynel exists
 851
 852                 # rocks
 853                 rock_pos=${#dynel_alive[*]}                     # rock position in dynel array
 854                 rock_count=0                                            # current number of live rocks
 855                 rock_hp=12                                                      # rock health
 856                 rock_total=0                                            # total number of rocks spawned
 857                 rock_add=0                                                      # additional rocks for difficulty
 858                 limitrocks                                                      # set the max rock count
 859
 860                 # friendly fire
 861                 ff_x=()                                                         # screen position
 862                 ff_y=()                                                         # screen position
 863                 ff_ydiv=()                                                      # speed divisor
 864                 ff_new=()                                                       # when new, don't move, only draw
 865                 ff_symbol=()                                            # symbol to draw
 866                 ff_damage=()                                            # how much damage this shot does
 867                 ff_count=0                                                      # current number of live shots
 868                 ff_count_max=64                                         # max shot count at any given time
 869                 ff_total=0                                                      # total number of shots fired
 870                 ff_next=0                                                       # next shot
 871                 ff_alive=()                                                     # shot exists
 872                 ff_ammo_current=$((ff_ammo_max/2))      # current ammo
 873                 ff_ammo_last=0                                          # last drawn ammo
 874                 counter_fire=0                                          # number of shots fired
 875                 for (( i=0; i<ff_count_max; i++ )); do ff_alive[i]=false; done
 876
 877                 # timers and stuff
 878                 pausetimers=()
 879                 timer_ammo=$time_now                            # timer for ammo generation
 880                 timerd_ammo=450000                                      # timer delta for above
 881                 registerpausetimer "timer_ammo"
 882                 timer_autofire=$time_now                        # timer for the autofire function
 883                 timerd_autofire=200000                          # timer delta for above
 884                 registerpausetimer "timer_autofire"
 885                 timer_manualfire=$time_now                      # timer for manual fire
 886                 timerd_manualfire=100000                        # timer delta for above
 887                 registerpausetimer "timer_manualfire"
 888                 timer_fire=$time_now                            # timer for update/drawing of fire
 889                 timerd_fire=50000                                       # timer delta for above
 890                 registerpausetimer "timer_fire"
 891                 timer_rocks=$time_now                           # timer for update/drawing of rocks
 892                 timerd_rocks=""                                         # timer delta for above
 893                 registerpausetimer "timer_rocks"
 894                 timer_playerdeath=0                                     # used for drawing the player ship death animation
 895                 timerd_playerdeath=500000                       # timer delta for above
 896                 registerpausetimer "timer_playerdeath"
 897                 seconds_last=0                                          # runtime in seconds (last printed)
 898
 899                 # blinking - allows blinking text and stuff to blink in sync
 900                 blink_fast=false
 901                 timer_blink_fast=$time_start
 902                 blink_medium=false
 903                 timer_blink_medium=$time_start
 904                 blink_slow=false
 905                 timer_blink_slow=$time_start
 906
 907                 # misc
 908                 autofire=false                                          # is autofire enabled?
 909                 runshipcollision=false                          # run ship collision this frame?
 910                 pause=false                                                     # is the game paused?
 911                 pause_last=false                                        # was the game paused last frame?
 912         }
 913         resetgame
 914
 915         # game loop
 916         while true; do
 917                 time_now=$(microtime)
 918                 seconds=$(((time_now-time_start)/1000000))
 919                 framecounter=${framecounter:-0}
 920                 fps=${fps:-$framecounter}
 921                 (( framecounter++ ))
 922
 923                 # blinking
 924                 if (( timer_blink_fast + 200000 < time_now )); then
 925                         timer_blink_fast=$time_now
 926                         $blink_fast && blink_fast=false || blink_fast=true
 927                 fi
 928                 if (( timer_blink_medium + 600000 < time_now )); then
 929                         timer_blink_medium=$time_now
 930                         $blink_medium && blink_medium=false || blink_medium=true
 931                 fi
 932                 if (( timer_blink_slow + 999999 < time_now )); then
 933                         timer_blink_slow=$time_now
 934                         $blink_slow && blink_slow=false || blink_slow=true
 935                 fi
 936
 937                 # resize if needed
 938                 if
 939                         [[ "$state_current" != "$state_last" ]] ||
 940                         [[ "$pause" != "$pause_last" ]] ||
 941                         {
 942                                 (( timer_resize + timerd_resize < time_now )) &&
 943                                 {
 944                                         timer_resize=$time_now
 945                                         # this check is frakkin' expensive - do it only once per second
 946                                         sizechanged
 947                                 }
 948                         }
 949                 then
 950                         state_last=$state_current
 951                         pause_last=$pause
 952
 953                         # clean up and resize
 954                         wipe                    # wipe the screen
 955                         buildposarray   # build new position array to move about
 956                         limitrocks              # update the number of rocks we should have
 957                         updatescore             # update how much score you get
 958
 959                         # push dynels inwards
 960                         for i in "${!dynel_alive[@]}"; do
 961                                 ${dynel_alive[i]} || continue
 962                                 restrict_xaxis $i
 963                                 if ((i == 0)); then
 964                                         restrict_yaxis $i
 965                                 fi
 966                         done
 967                 fi
 968                 if $redraw; then
 969                         border
 970                         safeecho $color_origo
 971                         xyecho $origo_x $origo_y "#"
 972                 fi
 973
 974                 # fps & counter
 975                 safeecho $color_debug
 976                 if (( seconds > seconds_last )); then
 977                         fps=$framecounter
 978                         framecounter=0
 979                         case "$state_current" in
 980                                 ingame|dead)
 981                                         xyprintf $((cols-2-9)) 2 "Dynl: %3d" "${#dynel_alive[*]}"
 982                                         xyprintf $((cols-2-9)) 3 "Rock: %3d" "$rock_count"
 983                                         xyprintf $((cols-2-9)) 4 "Shot: %3d" "$ff_count"
 984                                         xyprintf $((cols-2-6)) 5 "%6d" "$timerd_rocks"
 985 #                                       xyecho $((cols-2-${#seconds})) 6 "$seconds"
 986                                 ;;
 987                         esac
 988                 fi
 989                 xyprintf $((cols-10)) 1 "FPS: %3d" "$fps"
 990
 991                 # read input
 992                 if $input; then
 993                         readc <"$comm"
 994
 995                         case "$state_current" in
 996                                 ingame)
 997                                         case "$c" in
 998                                                 A|B|C|D)
 999                                                         if ! $pause && ((dynel_hp[0] > 0)); then
1000                                                                 case "$c" in
1001                                                                                 A) # up
1002                                                                                         for (( i=0; i<movespeed_y; i++ )); do
1003                                                                                                 canmoveup               0 && dynel_redraw[0]=true && runshipcollision=true || break && (( dynel_cy[0]-- ))
1004                                                                                         done
1005                                                                                 ;;
1006                                                                                 B) # down
1007                                                                                         for (( i=0; i<movespeed_y; i++ )); do
1008                                                                                                 canmovedown             0 && dynel_redraw[0]=true && runshipcollision=true || break && (( dynel_cy[0]++ ))
1009                                                                                         done
1010                                                                                 ;;
1011                                                                                 C) # right
1012                                                                                         for (( i=0; i<movespeed_x; i++ )); do
1013                                                                                                 canmoveright    0 && dynel_redraw[0]=true && runshipcollision=true || break && (( dynel_cx[0]++ ))
1014                                                                                         done
1015                                                                                 ;;
1016                                                                                 D) # left
1017                                                                                         for (( i=0; i<movespeed_x; i++ )); do
1018                                                                                                 canmoveleft             0 && dynel_redraw[0]=true && runshipcollision=true || break && (( dynel_cx[0]-- ))
1019                                                                                         done
1020                                                                                 ;;
1021                                                                 esac
1022                                                         fi
1023                                                 ;;
1024                                                 ' ')
1025                                                         if ! $pause && ((dynel_hp[0] > 0)) && ! $autofire && (( timer_manualfire + timerd_manualfire < time_now )); then
1026                                                                 timer_manualfire=$time_now
1027                                                                 fire
1028                                                         fi
1029                                                 ;;
1030                                                 'p')
1031                                                         if ! $pause; then
1032                                                                 pause
1033                                                         else
1034                                                                 unpause
1035                                                         fi
1036                                                 ;;
1037                                                 'z')
1038                                                         if ! $pause; then
1039                                                                 if ((dynel_hp[0] > 0)); then
1040                                                                         $autofire && autofire=false || autofire=true
1041                                                                 fi
1042                                                         fi
1043                                                 ;;
1044                                                 'q')
1045                                                         if ! $pause; then
1046                                                                 state_current="title"
1047                                                         else
1048                                                                 unpause
1049                                                         fi
1050                                                 ;;
1051                                         esac
1052                                 ;;
1053                                 title)
1054                                         case "$c" in
1055                                                 ' ')
1056                                                         resetgame
1057                                                         updatescore
1058                                                         timerd_rocks=100000
1059                                                         autofire=false
1060                                                         state_current="ingame"
1061                                                 ;;
1062                                                 'q') kill -TERM $$; exit 0; ;;
1063                                         esac
1064                                 ;;
1065                                 dead)
1066                                         case "$c" in
1067                                                 'q') resetgame; state_current="title" ;;
1068                                         esac
1069                                 ;;
1070                         esac
1071
1072                         input=false
1073                 fi
1074
1075                 # move and draw
1076                 case "$state_current" in
1077                         title)
1078                                 if $redraw; then
1079                                         safeecho $color_title
1080                                         catc $ascii_title_w $messageheight <<<"${ascii_title}"
1081                                 fi
1082                                 if $redraw; then
1083                                         safeecho $color_keybindings
1084                                         catc $ascii_keybindings_w $((messageheight + ascii_title_h + 3)) <<<"${ascii_keybindings}"
1085                                 fi
1086                                 if $redraw || [[ "$blink_pressfire" != "$blink_medium" ]]; then
1087                                         blink_pressfire=$blink_medium
1088                                         $blink_medium && safeecho $color_pressfire_1 || safeecho $color_pressfire_2
1089                                         catc $ascii_press_fire_w $((messageheight + ascii_title_h + 1)) <<<"$ascii_press_fire"
1090                                 fi
1091
1092                                 # sleep to save cpu
1093                                 sleep $cpusavesleep
1094                         ;;
1095                         dead)
1096                                 if $redraw; then
1097                                         safeecho $color_youaredead
1098                                         catc 7 $messageheight <<<"YOU ARE"
1099                                         catc $ascii_dead_w $((messageheight + 1)) <<<"${ascii_dead}"
1100                                 fi
1101                                 if $redraw; then
1102                                         safeecho $color_score_result
1103                                         catc $((19+${#score_current})) $((messageheight + ascii_dead_h + 2)) <<<"You scored $score_current points!"
1104                                 fi
1105                                 if $redraw; then
1106                                         # reading and writing this high score is sensitive to signal interruption and is somewhat error prone
1107                                         highscore=$(command cat "${HOME}/.shellshock" 2>/dev/null)
1108                                         if ((score_current > highscore)); then
1109                                                 echo -n "$score_current" >"${HOME}/.shellshock"
1110                                         fi
1111                                         safeecho $color_score_result
1112                                         if ((score_current >= highscore)); then
1113                                                 catc 15 $((messageheight + ascii_dead_h + 3)) <<<"NEW HIGH SCORE!"
1114                                         else
1115                                                 catc $((12+${#highscore})) $((messageheight + ascii_dead_h + 3)) <<<"High Score: $highscore"
1116                                         fi
1117                                 fi
1118                                 if $redraw || [[ "$blink_pressq" != "$blink_slow" ]]; then
1119                                         blink_pressq=$blink_slow
1120                                         $blink_slow && safeecho $color_pressq_1 || safeecho $color_pressq_2
1121                                         catc $ascii_press_q_w $((messageheight + ascii_dead_h + 5)) <<<"$ascii_press_q"
1122                                 fi
1123
1124                                 # sleep to save cpu
1125                                 sleep $cpusavesleep
1126                         ;;
1127                         ingame)
1128                                 if ! $pause; then
1129                                         # need to run ship collision?
1130                                         runshipcollision=false
1131
1132                                         # speed up and add score every second
1133                                         if (( seconds > seconds_last )); then
1134                                                 timerd_rocks=$(( timerd_rocks > 250 ? timerd_rocks - 250 : 0))
1135                                                 (( score_current += ++score_second ))
1136                                                 rock_add=$((rock_count_max * score_current / 200000))
1137                                         fi
1138                                 fi
1139
1140                                 # move and impact friendly fire
1141                                 if
1142                                         $redraw ||
1143                                         {
1144                                                 ! $pause &&
1145                                                 (( timer_fire + timerd_fire < time_now ))
1146                                         }
1147                                 then
1148                                         if ! $pause; then
1149                                                 timer_fire=$time_now
1150                                                 (( counter_fire++ ))
1151                                         fi
1152                                         safeecho $color_fire
1153                                         for (( i=0; i<ff_count_max; i++ )); do
1154                                                 if ${ff_alive[i]}; then
1155                                                         if
1156                                                                 $redraw &&
1157                                                                 outofbounds "$((origo_x+ff_x[i]))" "$((origo_y+ff_y[i]))"
1158                                                         then
1159                                                                 ff_alive[i]=false
1160                                                                 (( --ff_count ))
1161                                                         elif ${ff_new[i]}; then
1162                                                                 ff_new[i]=false
1163                                                                 if ffhit $i; then
1164                                                                         ff_alive[i]=false
1165                                                                         (( --ff_count ))
1166                                                                 else
1167                                                                         xyecho $((origo_x+ff_x[i])) $((origo_y+ff_y[i])) "${ff_symbol[i]}"
1168                                                                 fi
1169                                                         else
1170                                                                 if $redraw; then
1171                                                                         xyecho $((origo_x+ff_x[i])) $((origo_y+ff_y[i])) "${ff_symbol[i]}"
1172                                                                 fi
1173                                                                 if ! $pause && (( counter_fire % ff_ydiv[i] == 0 )); then
1174                                                                         xyecho $((origo_x+ff_x[i])) $((origo_y+ff_y[i])) " "
1175                                                                         if (( origo_y + --ff_y[i] == 0 )); then
1176                                                                                 ff_alive[i]=false
1177                                                                                 (( --ff_count ))
1178                                                                         else
1179                                                                                 if ffhit $i; then
1180                                                                                         ff_alive[i]=false
1181                                                                                         (( --ff_count ))
1182                                                                                 else
1183                                                                                         xyecho $((origo_x+ff_x[i])) $((origo_y+ff_y[i])) "${ff_symbol[i]}"
1184                                                                                 fi
1185                                                                         fi
1186                                                                 fi
1187                                                         fi
1188                                                 fi
1189                                         done
1190                                 fi
1191
1192                                 if ! $pause; then
1193                                         # autofire
1194                                         if $autofire && (( timer_autofire + timerd_autofire < time_now )); then
1195                                                 timer_autofire=$time_now
1196                                                 timer_manualfire=$time_now
1197                                                 fire
1198                                         fi
1199
1200                                         # move rocks?
1201                                         if ((dynel_hp[0] > 0)) && ((timer_rocks + timerd_rocks < time_now)); then
1202                                                 timer_rocks=$time_now
1203                                                 (( ++rock_total ))
1204                                         fi
1205
1206                                         # deal with rocks
1207                                         if ((dynel_hp[0] > 0)); then
1208                                                 first_dead=""
1209                                                 for i in "${!dynel_alive[@]}"; do
1210                                                         (( i >= rock_pos )) || continue
1211                                                         ${dynel_alive[i]} || { first_dead=${first_dead:-$i}; continue; }
1212                                                         if
1213                                                                 # outside bottom of screen by entire height
1214                                                                 (( dynel_y[i] - dynel_h[i] > 0 ))
1215                                                         then
1216                                                                 dynel_alive[i]=false
1217                                                                 (( --rock_count ))
1218                                                                 first_dead=${first_dead:-$i}
1219                                                                 (( score_current += score_deadrock ))
1220                                                         elif
1221                                                                 # should be moved now
1222                                                                 (( timer_rocks == time_now )) &&
1223                                                                 (( rock_total % dynel_ydiv[i] == 0 ))
1224                                                         then
1225                                                                 if ((dynel_hp[i] <= 0)); then
1226                                                                         if ! deathanimation $i; then
1227                                                                                 dynel_alive[i]=false
1228                                                                                 (( --rock_count ))
1229                                                                                 first_dead=${first_dead:-$i}
1230                                                                                 (( score_current += score_deadrock ))
1231                                                                         fi
1232                                                                 fi
1233                                                                 (( dynel_cy[i]++ ))
1234                                                                 dynel_redraw[i]=true
1235                                                                 runshipcollision=true
1236                                                         fi
1237                                                 done
1238
1239                                                 if ((rock_count < rock_count_max + rock_add)); then
1240                                                         i=${first_dead:-${#dynel_alive[*]}}
1241                                                         dynel_w[i]="ascii_rock$((i%5))_w"
1242                                                         dynel_w[i]=${!dynel_w[i]}
1243                                                         dynel_h[i]="ascii_rock$((i%5))_h"
1244                                                         dynel_h[i]=${!dynel_h[i]}
1245                                                         dynel_x[i]=$(( (RANDOM % (cols-2-dynel_w[i])) - ( (cols-2)/2 ) ))
1246                                                         dynel_y[i]=$((-origo_y))
1247                                                         dynel_cx[i]=${dynel_x[i]}
1248                                                         dynel_cy[i]=${dynel_y[i]}
1249                                                         restrict_xaxis $i
1250                                                         if ! squarecollide $i; then
1251                                                                 dynel_ydiv[i]=$((RANDOM%3+1))
1252                                                                 for j in "${!dynel_alive[@]}"; do
1253                                                                         (( j >= rock_pos )) || continue
1254                                                                         if
1255                                                                                 ${dynel_alive[j]} &&
1256                                                                                 ((dynel_ydiv[i] < dynel_ydiv[j] )) &&
1257                                                                                 (( (dynel_x[i] > dynel_x[j] ? dynel_x[i]-dynel_x[j] : dynel_x[j]-dynel_x[i]) < ((dynel_w[i]+dynel_w[j])/2) ))
1258                                                                         then
1259                                                                                 dynel_ydiv[i]=${dynel_ydiv[j]}
1260                                                                         fi
1261                                                                 done
1262                                                                 dynel_hp[i]=$rock_hp
1263                                                                 dynel_color[i]=$color_rock_healthy
1264                                                                 dynel_redraw[i]=false
1265                                                                 dynel_img[i]="ascii_rock$((i%5))"
1266                                                                 dynel_alive[i]=true
1267                                                                 (( ++rock_count ))
1268                                                         fi
1269                                                 fi
1270                                         fi
1271
1272                                         # do ship collision
1273                                         if $runshipcollision && shipcollide; then
1274                                                 (( dynel_hp[0]-- ))
1275                                         fi
1276                                         if ((dynel_hp[0] <= 0)) && ((timer_playerdeath + timerd_playerdeath < time_now)); then
1277                                                 timer_playerdeath=$time_now
1278                                                 dynel_redraw[0]=true
1279                                                 if ! deathanimation 0; then
1280                                                         state_current="dead"
1281                                                 fi
1282                                         fi
1283
1284                                         # regenerate ammo
1285                                         if (( timer_ammo + timerd_ammo + (timerd_rocks*3) < time_now )) && ((ff_ammo_current < ff_ammo_max)); then
1286                                                 timer_ammo=$time_now
1287                                                 (( ++ff_ammo_current ))
1288                                         fi
1289                                 fi # if ! $pause
1290
1291                                 # draw ammo
1292                                 if $redraw; then
1293                                         xyecho 0 0 "${color_ammo_1}${ff_line:0:$ff_ammo_current}"
1294                                         xyecho ${ff_ammo_current} 0 "${color_ammo_2}${ff_line:$ff_ammo_current:$ff_ammo_max}"
1295                                 else
1296                                         if ((ff_ammo_current < ff_ammo_last)); then
1297                                                 xyecho $ff_ammo_current 0 "${color_ammo_2}${ff_line:0:$((ff_ammo_last-ff_ammo_current))}"
1298                                         elif ((ff_ammo_current > ff_ammo_last)); then
1299                                                 xyecho $ff_ammo_last 0 "${color_ammo_1}${ff_line:0:$((ff_ammo_current-ff_ammo_last))}"
1300                                         fi
1301                                 fi
1302
1303                                 # score
1304                                 if $redraw || (( score_current != score_last )); then
1305                                         score_last=$score_current
1306                                         xyecho $((cols-${#score_current})) 0 "${color_score}${score_current}"
1307                                 fi
1308
1309                                 # blink engines of player ship
1310                                 if ! $pause && ((dynel_hp[0] > 0)) && ! ${dynel_redraw[0]} && [[ "$blink_engines" != "$blink_fast" ]]; then
1311                                         blink_engines=$blink_fast
1312                                         $blink_fast && safeecho $color_engine_1 || safeecho $color_engine_2
1313                                         xyecho $((origo_x+dynel_cx[0]+3)) $((origo_y+dynel_cy[0]-2)) "@"
1314                                         xyecho $((origo_x+dynel_cx[0]-3)) $((origo_y+dynel_cy[0]-2)) "@"
1315                                 fi
1316
1317                                 # draw/move dynels one step at a time to their current position
1318                                 lastalive=0
1319                                 for i in "${!dynel_alive[@]}"; do
1320                                         ${dynel_alive[i]} && lastalive=$i || continue
1321                                         $redraw || ${dynel_redraw[i]} || continue
1322
1323                                         dynel_redraw[i]=false
1324
1325                                         safeecho ${dynel_color[i]}
1326                                         while
1327                                                 if   (( dynel_x[i] < dynel_cx[i] )); then (( dynel_x[i]++ ))
1328                                                 elif (( dynel_x[i] > dynel_cx[i] )); then (( dynel_x[i]-- )); fi
1329                                                 if   (( dynel_y[i] < dynel_cy[i] )); then (( dynel_y[i]++ ))
1330                                                 elif (( dynel_y[i] > dynel_cy[i] )); then (( dynel_y[i]-- )); fi
1331
1332                                                 catd \
1333                                                 $(( origo_x-(dynel_w[i]/2)+dynel_x[i] )) \
1334                                                 $(( origo_y-dynel_h[i]+dynel_y[i] )) \
1335                                                 <<<"${!dynel_img[i]}"
1336
1337                                                 # fake do-while condition
1338                                                 (( dynel_x[i] != dynel_cx[i] )) ||
1339                                                 (( dynel_y[i] != dynel_cy[i] ))
1340                                         do :; done
1341                                 done
1342
1343                                 # draw pause anim
1344                                 if $pause_last; then # this uses pause_last to avoid drawing the pause blinker before the frame
1345                                         if $redraw; then
1346                                                 safeecho ${color_pauseframe}
1347                                                 catc $ascii_pauseframe_w $((messageheight + 4)) <<<"$ascii_pauseframe"
1348                                         fi
1349                                         if $redraw || [[ "$blink_pause" != "$blink_slow" ]]; then
1350                                                 blink_pause=$blink_slow
1351                                                 $blink_slow && safeecho $color_pause_1 || safeecho $color_pause_2
1352                                                 catc $ascii_pause_w $((messageheight + 6)) <<<"$ascii_pause"
1353                                         fi
1354
1355                                         # sleep to save cpu
1356                                         sleep $cpusavesleep
1357                                 fi
1358
1359                                 # purge dead dynels
1360                                 size=${#dynel_alive[*]}
1361                                 (( ++lastalive ))
1362                                 for ((i=lastalive; i<size; i++)); do
1363                                         unset dynel_alive[i]
1364                                 done
1365                         ;;
1366                 esac
1367                 redraw=false
1368                 ff_ammo_last=$ff_ammo_current
1369                 seconds_last=$seconds
1370         done
1371 ) &
1372 gamepid=$!
1373
1374 # exit normally on several signals
1375 trap 'exit 0' TERM INT HUP
1376
1377 # input loop
1378 stty -echo
1379 while true; do
1380         readc
1381         case "$c" in
1382                 $'\e')
1383                         readc
1384                         [[ "$c" = '[' ]] || continue
1385                         readc
1386                         case "$c" in
1387                                 A|B|C|D)
1388                                         builtin echo "$c" >"$comm"
1389                                         kill -USR1 "$gamepid"
1390                                 ;;
1391                         esac
1392                 ;;
1393                 ' '|p|q|z)
1394                         builtin echo "$c" >"$comm"
1395                         kill -USR1 "$gamepid"
1396                 ;;
1397         esac
1398 done
1399
1400 # vim: tabstop=4:softtabstop=4:shiftwidth=4:noexpandtab