#!/bin/bash

#
# Poor man's console 3d lib
# Concepts
#  * Everything's an array
#  * Everything's fixed point because bash math is stupid
#  * Unit circle radius=120
#  * Radian SINTABLE 120 in size
#  * Presume -Z extends behind screen
# Notes:
#  Although you can pass an array as a symbolic reference to a function as ary[@] then
#  copy it locally with myary=(${!1}), it's faster just to pass the array around
#  as an expanded list of values "${ary[*]}" and copied locally with myary=($1).
#  It's even faster to pass the array as arguments to the function then consuming
#  with shift.

CSI=$'\e['
SINTABLE=(0 6 12 18 25 31 37 43 49 54 60 65 70 75 80 85 89 93 97 101 104 107 110 112 114 116 117 119 119 120 120 120 119 119 117 116 114 112 110 107 104 101 97 93 89 85 80 75 70 65 60 54 49 43 37 31 25 18 12 6 0 -6 -12 -18 -25 -31 -37 -43 -49 -54 -60 -65 -70 -75 -80 -85 -89 -93 -97 -101 -104 -107 -110 -112 -114 -116 -117 -119 -119 -120 -120 -120 -119 -119 -117 -116 -114 -112 -110 -107 -104 -101 -97 -93 -89 -85 -80 -75 -70 -65 -60 -54 -49 -43 -37 -31 -25 -18 -12 -6)
COSTABLE=(120 120 119 119 117 116 114 112 110 107 104 101 97 93 89 85 80 75 70 65 60 54 49 43 37 31 25 18 12 6 0 -6 -12 -18 -25 -31 -37 -43 -49 -54 -60 -65 -70 -75 -80 -85 -89 -93 -97 -101 -104 -107 -110 -112 -114 -116 -117 -119 -119 -120 -120 -120 -119 -119 -117 -116 -114 -112 -110 -107 -104 -101 -97 -93 -89 -85 -80 -75 -70 -65 -60 -54 -49 -43 -37 -31 -25 -18 -12 -6 0 6 12 18 25 31 37 43 49 54 60 65 70 75 80 85 89 93 97 101 104 107 110 112 114 116 117 119 119 120)

function hex { printf %x $1; }
function aoctopus { printf "\xf0\x9f\x90\x${1:-$(hex $((128+RANDOM%64)))}"; }

P   (){ printf %s $@ ; }
dv  (){ while [ 0 -lt $# ]; do printf '[%6d %6d %6d %6d]\n' $1 $2 $3 $4; shift 4; done; }
dvn  (){ while [ 0 -lt $# ]; do printf '[%6d %6d %6d %6d | %6d]\n' $(($1/$4)) $(($2/$4)) $(($3/$4)) $(($4/$4)) $4; shift 4; done; }
dm4 (){ printf '[%6d %6d %6d %6d]\n' $1 $2 $3 $4 $5 $6 $7 $8 $9 ${10} ${11} ${12} ${13} ${14} ${15} ${16}; }
dm4n (){ printf '[%6d %6d %6d %6d]\n' $(($1/$16)) $(($2/$16)) $(($3/$16)) $(($4/$16)) $(($5/$16)) $(($6/$16)) $(($7/$16)) $(($8/$16)) $(($9/$16)) $(($10/$16)) $(($11/$16)) $(($12/$16)) $(($13/$16)) $(($14/$16)) $(($15/$16)) $(($16/$16)); }
sin (){ P ${SINTABLE[$(($1%120))]} ; }
cos (){ P ${COSTABLE[$(($1%120))]} ; }
G2  (){ P "$CSI$(($1+H/2));$(($2+W/2))H$3"; }
COLORS=('0' '0;31' '0;32' '0;33' '0;34' '0;35' '0;36' '0;37' '1;30' '1;31' '1;32' '1;33' '1;34' '1;35' '1;36' '1;37')
function CL { local c=$1; shift; printf "\e[${COLORS[c]}m$*"; }

# draw a line right and down or down and right
function line {
  local x y m n d dx dy w ws nx ny yyxx e i
  # Make sure line is drawn from left -x to right +x in the temrinal.
  if [ $2 -le $4 ]; then
    x=$2; y=$1; m=$4; n=$3
  else
    x=$4; y=$3; m=$2; n=$1
  fi
  # (x,y) to (m,n) will always go left to right
  dx=$((m-x))
  if [ $1 -lt $3 ]; then dy=$(($3-$1)); else dy=$(($1-$3)); fi

  # Always walk or walk-step

  if [ $dy -lt $dx ]; then # Small slope so walk left and step up or down
    w=''
    if [ $y -lt $n ]; then # walk right and down
       ws=$'\v'
    else                   # walk right and up
       ws=$'\eM'
    fi
    nx=$dx
    ny=$dy
  else # Large slope, so walk up or down and step right
    if [ $y -lt $n ]; then # walk down and right
       w=$'\b\v'
       ws=$'\v'
    else                   # walk up and right
       w=$'\b\eM'
       ws=$'\eM'
    fi
    nx=$dy
    ny=$dx
  fi

  G2 $y $x "$5"
  yy=$((ny + ny))
  yyxx=$((yy - nx - nx))
  e=$((yy - nx))
  i=$nx
  while [ 0 -lt $i ]; do
    #printf "\e7\e[1;1H[$x $y] dx=$dx dy=$dy i=$i e=$e yy=$yy yyxx=$yyxx [$m $n]\e8"
    if [ 0 -le $e ]; then
      printf "$ws$5"
      e=$((e + yyxx))
    else
      printf "$w$5"
      e=$((e + yy))
    fi
    i=$((i-1))
  done
}

# Scan hour, min, sec.  10# forces base 10 parsing of numbers beginning with 0
probetime (){ hour=$((10#$1 * 10)); min=$((10#$2 * 2)); sec=$((10#$3 * 2)); }
probetime $(date +'%H %M %S')

identity=(1 0 0 0  0 1 0 0   0 0 1 0  0 0 0 1)

# Creates
#
# {cos -sin 0 0}[x]
# {sin cos  0 0}[y]
# { 0   0   1 0}[z]
# { 0   0   0 1}[1]
#
function matRotz () { echo -n "${COSTABLE[$(($1%120))]} $((- SINTABLE[$(($1%120))])) 0 0 ${SINTABLE[$(($1%120))]} ${COSTABLE[$(($1%120))]} 0 0 0 0 120 0 0 0 0 120 "; }
function matRoty () { echo -n "${COSTABLE[$(($1%120))]} 0 $((- SINTABLE[$(($1%120))])) 0 0 120 0 0 ${SINTABLE[$(($1%120))]} 0 ${COSTABLE[$(($1%120))]} 0 0 0 0 120 "; }
function matRotx () { echo -n "120 0 0 0 0 ${COSTABLE[$(($1%120))]} ${SINTABLE[$(($1%120))]} 0 0   $((- SINTABLE[$(($1%120))])) ${COSTABLE[$(($1%120))]} 0 0 0 0 120 "; }
function matScale () { echo "$1 0 0 0  0 $1 0 0  0 0 $1 0  0 0 0 1 "; }
function matTrans () { echo "120 0 0 $(($1*120))  0 120 0 $(($2*120))  0 0 120 $(($3*120))  0 0 0 120 "; }

# Give 4xN column vector [x y z 1  x y z 1  ...]
# Pre-Multiply it by 4x$ row vector [a b c d  e f g h  i j k l  m n o p}
#
function matMult () {
 m=($1); shift
 while [ 0 -lt $# ]; do
    echo -n "$((m[0]*$1 + m[1]*$2 + m[2]*$3 + m[3]*$4))  $((m[4]*$1 + m[5]*$2 + m[6]*$3 + m[7]*$4))  $((m[8]*$1 + m[9]*$2 + m[10]*$3 + m[11]*$4))  $((m[12]*$1 + m[13]*$2 + m[14]*$3 + m[15]*$4)) "
    shift 4
 done
}

function matMultXform () {
 m=($1); shift
 n=($1);
 o=();
 while shift; do
   o[0]=$((m[0]*n[0] + m[1]*n[4] + m[2]*n[8] + m[3]*n[12]))
    o[1]=$((m[0]*n[1] + m[1]*n[5] + m[2]*n[9] + m[3]*n[13]))
     o[2]=$((m[0]*n[2] + m[1]*n[6] + m[2]*n[10] + m[3]*n[14]))
      o[3]=$((m[0]*n[3] + m[1]*n[7] + m[2]*n[11] + m[3]*n[15]))
   o[4]=$((m[4]*n[0] + m[5]*n[4] + m[6]*n[8] + m[7]*n[12]))
    o[5]=$((m[4]*n[1] + m[5]*n[5] + m[6]*n[9] + m[7]*n[13]))
     o[6]=$((m[4]*n[2] + m[5]*n[6] + m[6]*n[10] + m[7]*n[14]))
      o[7]=$((m[4]*n[3] + m[5]*n[7] + m[6]*n[11] + m[7]*n[15]))
   o[8]=$((m[8]*n[0] + m[9]*n[4] + m[10]*n[8] + m[11]*n[12]))
    o[9]=$((m[8]*n[1] + m[9]*n[5] + m[10]*n[9] + m[11]*n[13]))
     o[10]=$((m[8]*n[2] + m[9]*n[6] + m[10]*n[10] + m[11]*n[14]))
      o[11]=$((m[8]*n[3] + m[9]*n[7] + m[10]*n[11] + m[11]*n[15]))
   o[12]=$((m[12]*n[0] + m[13]*n[4] + m[14]*n[8] + m[15]*n[12]))
    o[13]=$((m[12]*n[1] + m[13]*n[5] + m[14]*n[9] + m[15]*n[13]))
     o[14]=$((m[12]*n[2] + m[13]*n[6] + m[14]*n[10] + m[15]*n[14]))
      o[15]=$((m[12]*n[3] + m[13]*n[7] + m[14]*n[11] + m[15]*n[15]))
   m=(${o[*]})
   n=($1)
 done
 echo "${m[@]} "
}


function isFacing () {
  local c=70

  # Apply perspective
  zz=$(($3*4/$4+c))
  zx=$(($1*8/$4*16/zz))
  zy=$(($2*6/$4*16/zz))

  z2=$(($7*4/$8+c))
  x2=$(($5*8/$8*16/z2))
  y2=$(($6*6/$8*16/z2))

  z3=$((${11}*4/${12}+c))
  x3=$(($9*8/${12}*16/z3))
  y3=$((${10}*6/${12}*16/z3))

  # Check Z component of the normal of the above two vectors
  va0=$((x2-zx))
  va1=$((y2-zy))
  vb0=$((x3-zx))
  vb1=$((y3-zy))
  [ $((va0*vb1 - va1*vb0)) -lt 0 ]
}


function plotLines () {
  local ch=$1; shift  ## character to plot
  local c=70
  while [ 0 -lt $# ]; do
    # Normalize
    x=$(($1*8/$4))
    y=$(($2*6/$4))
    z=$(($3*4/$4+c))
    x1=$(($5*8/$8))
    y1=$(($6*6/$8))
    z1=$(($7*4/$8+c))
    lx=$((x*16/z))
    ly=$((y*16/z))
    lx1=$((x1*16/z1))
    ly1=$((y1*16/z1))
    [ 0 -lt $z ] && [ 0 -lt $z1 ] && {
      line  $ly $lx $ly1 $lx1 "$ch"
    }
    shift 8
  done
}

function plotPoly () {
  local x y z sx sy sz lx ly lz
  local ch=$1; shift  ## character to plot
  local c=70

   #Start point
   x=$(($1*8/$4))
   y=$(($2*6/$4))
   z=$(($3*4/$4+c))
   sx=$((x*16/z))
   sy=$((y*16/z))
   sz=$z
   shift 4

   #last point
   lx=$sx
   ly=$sy
   lz=$sz

  while [ 0 -lt $# ]; do
    # next point
    x=$(($1*8/$4))
    y=$(($2*6/$4))
    z=$(($3*4/$4+c))
    nx=$((x*16/z))
    ny=$((y*16/z))
    [ 0 -lt $lz ] && [ 0 -lt $z ] && {
      line  $ly $lx $ny $nx "$ch"
    }
    # last point
    lx=$nx
    ly=$ny
    lz=$z
    shift 4
  done
  [ 0 -lt $sz ] && [ 0 -lt $lz ] && {
    line  $sy $sx $ly $lx "$ch"
  }
}

function plotPoints () {
  local x y z
  ch=$1; shift # character to plot
  local c=70
  while [ 0 -lt $# ]; do
     # Normalize
     x=$(($1*8/$4))
     y=$(($2*6/$4))
     z=$(($3*4/$4+c))
     nx=$((x*16/z))
     ny=$((y*16/z))
     if [ 0 -lt $z ]; then
       G2 $ny $nx "$ch"
     fi
    shift 4
  done
}

function resetAnimals {
  animal1=$(aoctopus)
  animal2=$(aoctopus)
  animal3=$(aoctopus)
}

function makeHand { echo 0 -$1 0 1  0 -$2 0 1; }

# makeLine mat a b c x y z
function transformPoints {
  mat="$1"; shift
  matMult "$mat" $*
}

# Object descriptor and vertex stores
glables=()
gpoints=()

# Keep track of sets of points
function makePoints {
  local len=${#gpoints[*]}
  glabels=("${glabels[@]}" "$1 $2 $3 $4 $len $((len+$#-3))")
  shift 4
  gpoints=(${gpoints[@]} $*)
}

r=8
facea=$(matMultXform "$(matRoty 0)"  "$(matTrans 0 0 -$r)")
faceb=$(matMultXform "$(matRoty 30)" "$(matTrans 0 0 -$r)")
facec=$(matMultXform "$(matRoty 60)" "$(matTrans 0 0 -$r)")
faced=$(matMultXform "$(matRoty 90)" "$(matTrans 0 0 -$r)")
facee=$(matMultXform "$(matRotx 30)" "$(matTrans 0 0 -$r)")
facef=$(matMultXform "$(matRotx 90)" "$(matTrans 0 0 -$r)")

box="-$r $r 0 1    $r $r 0 1    -$r -$r 0 1     $r -$r 0 1    -$r -$r 0 1    -$r $r 0 1    $r $r 0 1"
boxa=$(transformPoints "$facea" $box)
boxb=$(transformPoints "$faceb" $box)
boxc=$(transformPoints "$facec" $box)
boxd=$(transformPoints "$faced" $box)
boxe=$(transformPoints "$facee" $box)
boxf=$(transformPoints "$facef" $box)

# Create the clock vertices
function makeClock {

  twelve="$(echo  -$r $r 0 1 $r $r 0 1 -$r -$r 0 1; makeHand 2 7)"
  myclock="$(echo -$r $r 0 1 $r $r 0 1 -$r -$r 0 1; for s in 10 20 30 40 50 60 70 80 90 100 110; do transformPoints "$(matRotz s)" $(makeHand 2 7); done )"
  mymin="$(echo   -$r $r 0 1 $r $r 0 1 -$r -$r 0 1; transformPoints "$(matRotz              $min)" $(makeHand 0 7))"
  myhour="$(echo  -$r $r 0 1 $r $r 0 1 -$r -$r 0 1; transformPoints "$(matRotz  $((hour+min/12)))" $(makeHand 1 4))"
  mysec="$(echo   -$r $r 0 1 $r $r 0 1 -$r -$r 0 1; transformPoints "$(matRotz              $sec)" $(makeHand 6 7))"

  makePoints A        \# 9 y $boxa
  makePoints twelve   \. 15 l $(transformPoints "$facea" $twelve)
  makePoints clock    \. 8 l $(transformPoints "$facea" $myclock)
  makePoints handmin  $animal1 6 l $(transformPoints "$facea" $mymin)
  makePoints handhour $animal2 2 l $(transformPoints "$facea" $myhour)
  makePoints handsec  $animal3 5 l $(transformPoints "$facea" $mysec)

  makePoints B        \# 10 y $boxb
  makePoints twelve   \. 15 l $(transformPoints "$faceb" $twelve)
  makePoints clock    \. 8  l $(transformPoints "$faceb" $myclock)
  makePoints handmin  $animal1 6  l $(transformPoints "$faceb" $mymin)
  makePoints handhour $animal2 2  l $(transformPoints "$faceb" $myhour)
  makePoints handsec  $animal3 5  l $(transformPoints "$faceb" $mysec)

  makePoints C        \# 12 y $boxc
  makePoints twelve   \. 15 l $(transformPoints "$facec" $twelve)
  makePoints clock    \. 8  l $(transformPoints "$facec" $myclock)
  makePoints handmin  $animal1 6  l $(transformPoints "$facec" $mymin)
  makePoints handhour $animal2 2  l $(transformPoints "$facec" $myhour)
  makePoints handsec  $animal3 5  l $(transformPoints "$facec" $mysec)

  makePoints D        \# 14 y $boxd
  makePoints twelve   \. 15 l $(transformPoints "$faced" $twelve)
  makePoints clock    \. 8  l $(transformPoints "$faced" $myclock)
  makePoints handmin  $animal1 6  l $(transformPoints "$faced" $mymin)
  makePoints handhour $animal2 2  l $(transformPoints "$faced" $myhour)
  makePoints handsec  $animal3 5  l $(transformPoints "$faced" $mysec)

  makePoints E        \# 11 y $boxe
  makePoints twelve   \. 15 l $(transformPoints "$facee" $twelve)
  makePoints clock    \. 8  l $(transformPoints "$facee" $myclock)
  makePoints handmin  $animal1 6  l $(transformPoints "$facee" $mymin)
  makePoints handhour $animal2 2  l $(transformPoints "$facee" $myhour)
  makePoints handsec  $animal3 5  l $(transformPoints "$facee" $mysec)

  makePoints F        \# 13 y $boxf
  makePoints twelve   \. 15 l $(transformPoints "$facef" $twelve)
  makePoints clock    \. 8  l $(transformPoints "$facef" $myclock)
  makePoints handmin  $animal1 6  l $(transformPoints "$facef" $mymin)
  makePoints handhour $animal2 2  l $(transformPoints "$facef" $myhour)
  makePoints handsec  $animal3 5  l $(transformPoints "$facef" $mysec)
}

# Over every set, dump set name and values
function plotGpoints {
  for l in "${glabels[@]}"; do
    read n c k t a b <<<$l
    if isFacing $(matMult "${gm[*]}" ${gpoints[*]:$a:12}); then
      CL $k
      case $t in 
       (y) plotPoly   "$c" $(matMult "${gm[*]}" ${gpoints[*]:$a+12:$b-$a-1-12}) ;;
       (l) plotLines  "$c" $(matMult "${gm[*]}" ${gpoints[*]:$a+12:$b-$a-1-12}) ;;
       (p) plotPoints "$c" $(matMult "${gm[*]}" ${gpoints[*]:$a+12:$b-$a-1-12}) ;;
      esac
    fi
  done
}

gtick=0 # Final plotting scale

# Global transformation matrix
gm=()

renderclock () {
  read H W <<<$(stty size)
  #if [ $sec == 0 ] || [ $# == 1 ];then resetAnimals; fi
  glabels=()
  gpoints=()
  makeClock
  gm=($(matMultXform "$(matRotx $((gtick/2)))" "$(matRoty $gtick)"))
  P $(
    P $CSI 2J
    plotGpoints
  )
}

main () {
  P $CSI?25l # Disable cursor
  resetAnimals
  trap 'renderclock i' SIGWINCH
  case $1 in
  (a)
  while [ ! -e k ]; do
    if [ "$currentTick" != $(date +%s) ]; then
      probetime $(date +'%H %M %S')
      renderclock
      currentTick=$(date +%s)
    fi
    sleep .9
  done
  ;;
  (b)
  while [ ! -e k ]; do
    gtick=$((gtick+1))
    #probetime $(date -r $gtick +'%H %M %S')
    probetime $(date +'%H %M %S')
    renderclock
  done
  ;;
  esac
  k=$(cat k)
  rm k
  main $k
}

mainFast () {
  P $CSI?25l # Disable cursor
  resetAnimals
  trap 'renderclock i' SIGWINCH
  while :; do 
    probetime $(date -r $gtick +'%H %M %S')
    renderclock
  done
}

main b