Add pipes.sh

pipes.sh

@@ -0,0 +1,385 @@
+#!/usr/bin/env bash
+# pipes.sh: Animated pipes terminal screensaver.
+# https://github.com/pipeseroni/pipes.sh
+#
+# Copyright (c) 2015-2018 Pipeseroni/pipes.sh contributors
+# Copyright (c) 2013-2015 Yu-Jie Lin
+# Copyright (c) 2010 Matthew Simpson
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+
+VERSION=1.3.0
+
+M=32768  # Bash RANDOM maximum + 1
+p=1      # number of pipes
+f=75     # frame rate
+s=13     # probability of straight fitting
+r=2000   # characters limit
+t=0      # iteration counter for -r character limit
+w=80     # terminal size
+h=24
+
+# ab -> sets[][idx] = a*4 + b
+# 0: up, 1: right, 2: down, 3: left
+# 00 means going up   , then going up   -> ┃
+# 12 means going right, then going down -> ┓
+sets=(
+    "┃┏ ┓┛━┓  ┗┃┛┗ ┏━"
+    "│╭ ╮╯─╮  ╰│╯╰ ╭─"
+    "│┌ ┐┘─┐  └│┘└ ┌─"
+    "║╔ ╗╝═╗  ╚║╝╚ ╔═"
+    "|+ ++-+  +|++ +-"
+    "|/ \/-\  \|/\ /-"
+    ".. ....  .... .."
+    ".o oo.o  o.oo o."
+    "-\ /\|/  /-\/ \|"  # railway
+    "╿┍ ┑┚╼┒  ┕╽┙┖ ┎╾"  # knobby pipe
+)
+SETS=()  # rearranged all pipe chars into individul elements for easier access
+
+# pipes'
+x=()  # current position
+y=()
+l=()  # current directions
+      # 0: up, 1: right, 2: down, 3: left
+n=()  # new directions
+v=()  # current types
+c=()  # current escape codes
+
+# selected pipes'
+V=()  # types (indexes to sets[])
+C=()  # color indices for tput setaf
+VN=0  # number of selected types
+CN=0  # number of selected colors
+E=()  # pre-generated escape codes from BOLD, NOCOLOR, and C
+
+# switches
+RNDSTART=0  # randomize starting position and direction
+BOLD=1
+NOCOLOR=0
+KEEPCT=0    # keep pipe color and type
+
+
+# print help message in 72-char width
+print_help() {
+    local cgap
+    printf -v cgap '%*s' $((15 - ${#COLORS})) ''
+    cat <<HELP
+Usage: $(basename $0) [OPTION]...
+Animated pipes terminal screensaver.
+
+  -p [1-]               number of pipes (D=1)
+  -t [0-$((${#sets[@]} - 1))]              pipe type (D=0)
+  -t c[16 chars]        custom pipe type
+  -c [0-$COLORS]${cgap}pipe color INDEX (TERM=$TERM), can be
+                        hexadecimal with '#' prefix
+                        (D=-c 1 -c 2 ... -c 7 -c 0)
+  -f [20-100]           framerate (D=75)
+  -s [5-15]             going straight probability, 1 in (D=13)
+  -r [0-]               reset after (D=2000) characters, 0 if no reset
+  -R                    randomize starting position and direction
+  -B                    no bold effect
+  -C                    no color
+  -K                    keep pipe color and type when crossing edges
+  -h                    print this help message
+  -v                    print version number
+
+Note: -t and -c can be used more than once.
+HELP
+}
+
+
+# parse command-line options
+# It depends on a valid COLORS which is set by _CP_init_termcap_vars
+parse() {
+    # test if $1 is a natural number in decimal, an integer >= 0
+    is_N() {
+        [[ -n $1 && -z ${1//[0-9]} ]]
+    }
+
+
+    # test if $1 is a hexadecimal string
+    is_hex() {
+        [[ -n $1 && -z ${1//[0-9A-Fa-f]} ]]
+    }
+
+
+    # print error message for invalid argument to standard error, this
+    # - mimics getopts error message
+    # - use all positional parameters as error message
+    # - has a newline appended
+    # $arg and $OPTARG are the option name and argument set by getopts.
+    pearg() {
+        printf "%s: -$arg invalid argument -- $OPTARG; %s\n" "$0" "$*" >&2
+    }
+
+
+    OPTIND=1
+    while getopts "p:t:c:f:s:r:RBCKhv" arg; do
+    case $arg in
+        p)
+            if is_N "$OPTARG" && ((OPTARG > 0)); then
+                p=$OPTARG
+            else
+                pearg 'must be an integer and greater than 0'
+                return 1
+            fi
+            ;;
+        t)
+            if [[ "$OPTARG" = c???????????????? ]]; then
+                V+=(${#sets[@]})
+                sets+=("${OPTARG:1}")
+            elif is_N "$OPTARG" && ((OPTARG < ${#sets[@]})); then
+                V+=($OPTARG)
+            else
+                pearg 'must be an integer and from 0 to' \
+                      "$((${#sets[@]} - 1)); or a custom type"
+                return 1
+            fi
+            ;;
+        c)
+            if [[ $OPTARG == '#'* ]]; then
+                if ! is_hex "${OPTARG:1}"; then
+                    pearg 'unrecognized hexadecimal string'
+                    return 1
+                fi
+                if ((16$OPTARG >= COLORS)); then
+                    pearg 'hexadecimal must be from #0 to' \
+                          "#$(printf '%X' $((COLORS - 1)))"
+                    return 1
+                fi
+                C+=($((16$OPTARG)))
+            elif is_N "$OPTARG" && ((OPTARG < COLORS)); then
+                C+=($OPTARG)
+            else
+                pearg "must be an integer and from 0 to $((COLORS - 1));" \
+                      'or a hexadecimal string with # prefix'
+                return 1
+            fi
+            ;;
+        f)
+            if is_N "$OPTARG" && ((OPTARG >= 20 && OPTARG <= 100)); then
+                f=$OPTARG
+            else
+                pearg 'must be an integer and from 20 to 100'
+                return 1
+            fi
+            ;;
+        s)
+            if is_N "$OPTARG" && ((OPTARG >= 5 && OPTARG <= 15)); then
+                s=$OPTARG
+            else
+                pearg 'must be an integer and from 5 to 15'
+                return 1
+            fi
+            ;;
+        r)
+            if is_N "$OPTARG"; then
+                r=$OPTARG
+            else
+                pearg 'must be a non-negative integer'
+                return 1
+            fi
+            ;;
+        R) RNDSTART=1;;
+        B) BOLD=0;;
+        C) NOCOLOR=1;;
+        K) KEEPCT=1;;
+        h)
+            print_help
+            exit 0
+            ;;
+        v) echo "$(basename -- "$0") $VERSION"
+            exit 0
+            ;;
+        *)
+            return 1
+        esac
+    done
+
+    shift $((OPTIND - 1))
+    if (($#)); then
+        printf "$0: illegal arguments -- $*; no arguments allowed\n" >&2
+        return 1
+    fi
+}
+
+
+cleanup() {
+    # clear out standard input
+    read -t 0.001 && cat </dev/stdin>/dev/null
+
+    tput reset  # fix for konsole, see pipeseroni/pipes.sh#43
+    tput rmcup
+    tput cnorm
+    stty echo
+    printf "$SGR0"
+    exit 0
+}
+
+
+resize() {
+    w=$(tput cols) h=$(tput lines)
+}
+
+
+init_pipes() {
+    # +_CP_init_pipes
+    local i
+
+    ci=$((KEEPCT ? 0 : CN * RANDOM / M))
+    vi=$((KEEPCT ? 0 : VN * RANDOM / M))
+    for ((i = 0; i < p; i++)); do
+        ((
+            n[i] = 0,
+            l[i] = RNDSTART ? RANDOM % 4 : 0,
+            x[i] = RNDSTART ? w * RANDOM / M : w / 2,
+            y[i] = RNDSTART ? h * RANDOM / M : h / 2,
+            v[i] = V[vi]
+        ))
+        c[i]=${E[ci]}
+        ((ci = (ci + 1) % CN, vi = (vi + 1) % VN))
+    done
+    # -_CP_init_pipes
+}
+
+
+init_screen() {
+    stty -echo
+    tput smcup
+    tput civis
+    tput clear
+    trap cleanup HUP TERM
+
+    resize
+    trap resize SIGWINCH
+}
+
+
+main() {
+    # simple pre-check of TERM, tput's error message should be enough
+    tput -T "$TERM" sgr0 >/dev/null || return $?
+
+    # +_CP_init_termcap_vars
+    COLORS=$(tput colors)  # COLORS - 1 == maximum color index for -c argument
+    SGR0=$(tput sgr0)
+    SGR_BOLD=$(tput bold)
+    # -_CP_init_termcap_vars
+
+    parse "$@" || return $?
+
+    # +_CP_init_VC
+    # set default values if not by options
+    ((${#V[@]})) || V=(0)
+    VN=${#V[@]}
+    ((${#C[@]})) || C=(1 2 3 4 5 6 7 0)
+    CN=${#C[@]}
+    # -_CP_init_VC
+
+    # +_CP_init_E
+    # generate E[] based on BOLD (SGR_BOLD), NOCOLOR, and C for each element in
+    # C, a corresponding element in E[] =
+    #   SGR0
+    #   + SGR_BOLD, if BOLD
+    #   + tput setaf C, if !NOCOLOR
+    local i
+    for ((i = 0; i < CN; i++)) {
+        E[i]=$SGR0
+        ((BOLD))    && E[i]+=$SGR_BOLD
+        ((NOCOLOR)) || E[i]+=$(tput setaf ${C[i]})
+    }
+    # -_CP_init_E
+
+    # +_CP_init_SETS
+    local i j
+    for ((i = 0; i < ${#sets[@]}; i++)) {
+        for ((j = 0; j < 16; j++)) {
+            SETS+=("${sets[i]:j:1}")
+        }
+    }
+    unset i j
+    # -_CP_init_SETS
+
+    init_screen
+    init_pipes
+
+    # any key press exits the loop and this script
+    trap 'break 2' INT
+
+    local i
+    while REPLY=; do
+        read -t 0.0$((1000 / f)) -n 1 2>/dev/null
+        case "$REPLY" in
+            P) ((s = s <  15 ? s + 1 : s));;
+            O) ((s = s >   3 ? s - 1 : s));;
+            F) ((f = f < 100 ? f + 1 : f));;
+            D) ((f = f >  20 ? f - 1 : f));;
+            B) ((BOLD = (BOLD + 1) % 2));;
+            C) ((NOCOLOR = (NOCOLOR + 1) % 2));;
+            K) ((KEEPCT = (KEEPCT + 1) % 2));;
+            ?) break;;
+        esac
+        for ((i = 0; i < p; i++)); do
+            # New position:
+            # l[] direction = 0: up, 1: right, 2: down, 3: left
+            # +_CP_newpos
+            ((l[i] % 2)) && ((x[i] += -l[i] + 2, 1)) || ((y[i] += l[i] - 1))
+            # -_CP_newpos
+
+            # Loop on edges (change color on loop):
+            # +_CP_warp
+            ((!KEEPCT && (x[i] >= w || x[i] < 0 || y[i] >= h || y[i] < 0))) \
+            && { c[i]=${E[CN * RANDOM / M]}; ((v[i] = V[VN * RANDOM / M])); }
+            ((x[i] = (x[i] + w) % w,
+              y[i] = (y[i] + h) % h))
+            # -_CP_warp
+
+            # new turning direction:
+            # $((s - 1)) in $s, going straight, therefore n[i] == l[i];
+            # and 1 in $s that pipe makes a right or left turn
+            #
+            #     s * RANDOM / M - 1 == 0
+            #     n[i] == -1
+            #  => n[i] == l[i] + 1 or l[i] - 1
+            # +_CP_newdir
+            ((
+                n[i] = s * RANDOM / M - 1,
+                n[i] = n[i] >= 0 ? l[i] : l[i] + (2 * (RANDOM % 2) - 1),
+                n[i] = (n[i] + 4) % 4
+            ))
+            # -_CP_newdir
+
+            # Print:
+            # +_CP_print
+            printf '\e[%d;%dH%s%s'                      \
+                   $((y[i] + 1)) $((x[i] + 1)) ${c[i]}  \
+                   "${SETS[v[i] * 16 + l[i] * 4 + n[i]]}"
+            # -_CP_print
+            l[i]=${n[i]}
+        done
+        ((r > 0 && t * p >= r)) && tput reset && tput civis && t=0 || ((t++))
+    done
+
+    cleanup
+}
+
+
+# when being sourced, $0 == bash, only invoke main when they are the same
+[[ "$0" != "$BASH_SOURCE" ]] ||  main "$@"