Snak3

Create by juanka1uno game SNAK3
#!/bin/bash
IFS=''
declare -i height=30 width=60
# row and column number of head
declare -i head_r head_c tail_r tail_c
declare -i alive
declare -i length
declare body
declare -i direction delta_dir
declare -i score=0
border_color="\E[30;43m"
snake_color="\E[32;42m"
food_color="\E[34;44m"
text_color="\E[31;43m"
no_color="\E[0m"
# signals
SIG_UP=35
SIG_RIGHT=36
SIG_DOWN=37
SIG_LEFT=38
SIG_QUIT=39
SIG_DEAD=40
# direction arrays: 0=up, 1=right, 2=down, 3=left
move_r=([0]=-1 [1]=0 [2]=1 [3]=0)
move_c=([0]=0 [1]=1 [2]=0 [3]=-1)
init_game() {
clear
echo -ne "\033[?25l"
stty -echo
for ((i=0; i<height; i++)); do
for ((j=0; j<width; j++)); do
eval "arr$i[$j]=' '"
done
done
}
move_and_draw() {
echo -ne "\E[${1};${2}H$3"
}
# print everything in the buffer
draw_board() {
move_and_draw 1 1 "$border_color+$no_color"
for ((i=2; i<=width+1; i++)); do
move_and_draw 1 $i "$border_color-$no_color"
done
move_and_draw 1 $((width + 2)) "$border_color+$no_color"
echo
for ((i=0; i<height; i++)); do
move_and_draw $((i+2)) 1 "$border_color|$no_color"
eval echo -en "\"\${arr$i[*]}\""
echo -e "$border_color|$no_color"
done
move_and_draw $((height+2)) 1 "$border_color+$no_color"
for ((i=2; i<=width+1; i++)); do
move_and_draw $((height+2)) $i "$border_color-$no_color"
done
move_and_draw $((height+2)) $((width + 2)) "$border_color+$no_color"
echo
}
# set the snake's initial state
init_snake() {
alive=0
length=10
direction=0
delta_dir=-1
head_r=$((height/2-2))
head_c=$((width/2))
body=''
for ((i=0; i<length-1; i++)); do
body="1$body"
done
local p=$((${move_r[1]} * (length-1)))
local q=$((${move_c[1]} * (length-1)))
tail_r=$((head_r+p))
tail_c=$((head_c+q))
eval "arr$head_r[$head_c]=\"${snake_color}o$no_color\""
prev_r=$head_r
prev_c=$head_c
b=$body
while [ -n "$b" ]; do
# change in each direction
local p=${move_r[$(echo $b | grep -o '^[0-3]')]}
local q=${move_c[$(echo $b | grep -o '^[0-3]')]}
new_r=$((prev_r+p))
new_c=$((prev_c+q))
eval "arr$new_r[$new_c]=\"${snake_color}o$no_color\""
prev_r=$new_r
prev_c=$new_c
b=${b#[0-3]}
done
}
is_dead() {
if [ "$1" -lt 0 ] || [ "$1" -ge "$height" ] || \
[ "$2" -lt 0 ] || [ "$2" -ge "$width" ]; then
return 0
fi
eval "local pos=\${arr$1[$2]}"
if [ "$pos" == "${snake_color}o$no_color" ]; then
return 0
fi
return 1
}
give_food() {
local food_r=$((RANDOM % height))
local food_c=$((RANDOM % width))
eval "local pos=\${arr$food_r[$food_c]}"
while [ "$pos" != ' ' ]; do
food_r=$((RANDOM % height))
food_c=$((RANDOM % width))
eval "pos=\${arr$food_r[$food_c]}"
done
eval "arr$food_r[$food_c]=\"$food_color@$no_color\""
}
move_snake() {
local newhead_r=$((head_r + move_r[direction]))
local newhead_c=$((head_c + move_c[direction]))
eval "local pos=\${arr$newhead_r[$newhead_c]}"
if $(is_dead $newhead_r $newhead_c); then
alive=1
return
fi
if [ "$pos" == "$food_color@$no_color" ]; then
length+=1
eval "arr$newhead_r[$newhead_c]=\"${snake_color}o$no_color\""
body="$(((direction+2)%4))$body"
head_r=$newhead_r
head_c=$newhead_c
score+=1
give_food;
return
fi
head_r=$newhead_r
head_c=$newhead_c
local d=$(echo $body | grep -o '[0-3]$')
body="$(((direction+2)%4))${body%[0-3]}"
eval "arr$tail_r[$tail_c]=' '"
eval "arr$head_r[$head_c]=\"${snake_color}o$no_color\""
# new tail
local p=${move_r[(d+2)%4]}
local q=${move_c[(d+2)%4]}
tail_r=$((tail_r+p))
tail_c=$((tail_c+q))
}
change_dir() {
if [ $(((direction+2)%4)) -ne $1 ]; then
direction=$1
fi
delta_dir=-1
}
getchar() {
trap "" SIGINT SIGQUIT
trap "return;" $SIG_DEAD
while true; do
read -s -n 1 key
case "$key" in
[qQ]) kill -$SIG_QUIT $game_pid
return
;;
[kK]) kill -$SIG_UP $game_pid
;;
[lL]) kill -$SIG_RIGHT $game_pid
;;
[jJ]) kill -$SIG_DOWN $game_pid
;;
[hH]) kill -$SIG_LEFT $game_pid
;;
esac
done
}
game_loop() {
trap "delta_dir=0;" $SIG_UP
trap "delta_dir=1;" $SIG_RIGHT
trap "delta_dir=2;" $SIG_DOWN
trap "delta_dir=3;" $SIG_LEFT
trap "exit 1;" $SIG_QUIT
while [ "$alive" -eq 0 ]; do
echo -e "\n${text_color} Your score: $score $no_color"
if [ "$delta_dir" -ne -1 ]; then
change_dir $delta_dir
fi
move_snake
draw_board
sleep 0.03
done
echo -e "${text_color}Oh, No! You 0xdead$no_color"
# signals the input loop that the snake is dead
kill -$SIG_DEAD $$
}
clear_game() {
stty echo
echo -e "\033[?25h"
}
init_game
init_snake
give_food
draw_board
game_loop &
game_pid=$!
getchar
clear_game
exit 0