day11/robot.sh

   1 #!/bin/bash
   2
   3 set -u
   4
   5 __robot_direction=u
   6 __robot_lowest_x=0
   7 __robot_lowest_y=0
   8 __robot_highest_x=0
   9 __robot_highest_y=0
  10 __robot_cur_x=0
  11 __robot_cur_y=0
  12 __robot_start_on_white=0
  13 declare -A __robot_grid
  14 declare -A __robot_painted
  15
  16 reset_robot() {
  17     __robot_direction=u
  18     __robot_lowest_x=0
  19     __robot_lowest_y=0
  20     __robot_highest_x=0
  21     __robot_highest_y=0
  22     __robot_cur_x=0
  23     __robot_cur_y=0
  24     __robot_start_on_white=0
  25     unset __robot_grid
  26     unset __robot_painted
  27     declare -g -A __robot_grid
  28     declare -g -A __robot_painted
  29 }
  30
  31 get_robot_paint_colour() {
  32     get_paint_colour $__robot_cur_x $__robot_cur_y
  33 }
  34
  35 get_paint_colour() {
  36     x=$1
  37     y=$2
  38
  39     if [ ${__robot_grid[$x,$y]+a} ]; then
  40         echo ${__robot_grid[$x,$y]}
  41     else
  42         if [ $x -eq 0 ] && [ $y -eq 0 ] && [ $__robot_start_on_white -eq 1 ]; then
  43             echo 1
  44         else
  45             echo 0
  46         fi
  47     fi
  48 }
  49
  50 set_robot_start_on_white() {
  51     start=${1:-1}
  52
  53     __robot_start_on_white=$start
  54 }
  55
  56 set_robot_paint_colour() {
  57     paint_colour=$1
  58
  59     __robot_grid[$__robot_cur_x,$__robot_cur_y]=$paint_colour
  60     if ! [ ${__robot_painted[$__robot_cur_x,$__robot_cur_y]+a} ]; then
  61         __robot_painted[$__robot_cur_x,$__robot_cur_y]=1
  62     fi
  63 }
  64
  65 get_robot_paint_count() {
  66     echo ${#__robot_painted[@]}
  67 }
  68
  69 do_robot_move() {
  70     direction=$1
  71
  72     case $direction in
  73         0)
  74             case $__robot_direction in
  75                 u)
  76                     __robot_direction=l
  77                     __robot_cur_x=$((__robot_cur_x - 1))
  78                     ;;
  79                 l)
  80                     __robot_direction=d
  81                     __robot_cur_y=$((__robot_cur_y - 1))
  82                     ;;
  83                 d)
  84                     __robot_direction=r
  85                     __robot_cur_x=$((__robot_cur_x + 1))
  86                     ;;
  87                 r)
  88                     __robot_direction=u
  89                     __robot_cur_y=$((__robot_cur_y + 1))
  90                     ;;
  91             esac
  92             ;;
  93         1)
  94             case $__robot_direction in
  95                 u)
  96                     __robot_direction=r
  97                     __robot_cur_x=$((__robot_cur_x + 1))
  98                     ;;
  99                 r)
 100                     __robot_direction=d
 101                     __robot_cur_y=$((__robot_cur_y - 1))
 102                     ;;
 103                 d)
 104                     __robot_direction=l
 105                     __robot_cur_x=$((__robot_cur_x - 1))
 106                     ;;
 107                 l)
 108                     __robot_direction=u
 109                     __robot_cur_y=$((__robot_cur_y + 1))
 110                     ;;
 111             esac
 112             ;;
 113     esac
 114
 115     # adjust min/max
 116     if [ $__robot_cur_x -lt $__robot_lowest_x ]; then
 117         __robot_lowest_x=$__robot_cur_x
 118     fi
 119
 120     if [ $__robot_cur_x -gt $__robot_highest_x ]; then
 121         __robot_highest_x=$__robot_cur_x
 122     fi
 123
 124     if [ $__robot_cur_y -lt $__robot_lowest_y ]; then
 125         __robot_lowest_y=$__robot_cur_y
 126     fi
 127
 128     if [ $__robot_cur_y -gt $__robot_highest_y ]; then
 129         __robot_highest_y=$__robot_cur_y
 130     fi
 131 }
 132
 133 do_robot_paint_and_move() {
 134     paint_colour=$1
 135     direction=$2
 136     set_robot_paint_colour $paint_colour
 137     do_robot_move $direction
 138 }
 139
 140 draw_panel() {
 141     colours=("." "#")
 142
 143     # we draw upside down, in effect, starting from the bottom and going to
 144     # the top, so when outputting, we should switch that round
 145     for (( y=$__robot_highest_y; y>=$__robot_lowest_y; y-- )); do
 146         for (( x=$__robot_lowest_x; x<=$__robot_highest_x; x++ )); do
 147             echo -n ${colours[$(get_paint_colour $x $y)]}
 148         done
 149         echo
 150     done
 151 }