#!/bin/bash
#
# Developed by Fred Weinhaus 5/27/2010 .......... 12/22/2023
#
# ------------------------------------------------------------------------------
# 
# Licensing:
# 
# Copyright © Fred Weinhaus
# 
# My scripts are available free of charge for non-commercial use, ONLY.
# 
# For use of my scripts in commercial (for-profit) environments or 
# non-free applications, please contact me (Fred Weinhaus) for 
# licensing arrangements. My email address is fmw at alink dot net.
# 
# If you: 1) redistribute, 2) incorporate any of these scripts into other 
# free applications or 3) reprogram them in another scripting language, 
# then you must contact me for permission, especially if the result might 
# be used in a commercial or for-profit environment.
# 
# My scripts are also subject, in a subordinate manner, to the ImageMagick 
# license, which can be found at: http://www.imagemagick.org/script/license.php
# 
# ------------------------------------------------------------------------------
# 
####
#
# USAGE: cone [-s size] [-r radii] [-c center] [-a apex]  [-e ecolors] [-t tcolors] [-b bcolor] [-m mode] [infile] outfile
# USAGE: cone [-help or -h]
#
# OPTIONS:
#
# -s      size         size of background image to create if no input image 
#                      is provided; The size=WIDTHxHEIGHT; Default=300x300
# -r      radii        x,y radii for the ellipse; comma separated list of 
#                      positive integers; The default="50,50" (circle of 
#                      radius=50).
# -c      center       center coordinates for the ellipse part of the cone; 
#                      comma separate list of non-negative integers; 
#                      center="xc,yc"; default="150,100".
# -a      apex         apex coordinates for the triangle tip of the cone;
#                      comma separate list of non-negative integers; 
#                      center="x,y"; default="150,250".
# -e      ecolors      comma separate list of ellipse fill and stroke colors 
#                      and strokewidth; default="white,black,1";
# -t      tcolors      comma separate list of triangle fill and stroke colors 
#                      and strokewidth; default="tan,black,1".
# -b      bcolor       background color for image if no input image is provided;
#                      default="lightblue".
# -m      mode         mode of drawing order; choices are 1 or 2. A value of 1 
#                      draws the triangle over the ellipse; A value of 2 draws 
#                      the ellipse over the triangle; default=1.
#
# If infile is provided, then size and bcolor will be ignored.
# 
###
#
# NAME: CONE 
# 
# PURPOSE: To draw a cone-shaped object on an image.
# 
# DESCRIPTION: CONE draws a cone-shaped object on an image. The cone is 
# composed of two parts an ellipse (or circle) and a triangle. One can 
# specify different colors for each along with stroke colors and strokewidths.
# 
# 
# OPTIONS: 
# 
# -s size ... SIZE of background image to create if no input image is provided.
# The size=WIDTHxHEIGHT; If only one value is provided, the second will be set 
# equal to the first. Default="300x300".
#
# -r radii ... RADII are the x,y radii for the ellipse. Radii are specified as 
# a comma separated list of two positive integers. If only one value is 
# provided, the second will be set equal to the first. The default="50,50" 
# (i.e., circle of radius=50).
# 
# -c center ... CENTER coordinates for the ellipse part of the cone. Center is 
# a comma separate list of two non-negative integers. If only one value is 
# provided, the second will be set equal to the first. The default="150,100".
# 
# -a apex ... APEX coordinates for the triangle tip of the cone. Apex is a 
# comma separate list of two non-negative integers. If only one value is 
# provided, the second will be set equal to the first. The default="150,250".
# 
# -e ecolors ... ECOLORS is a comma separate list of thre values, namely, the 
# ellipse fill and stroke colors and strokewidth. All 3 values must be provided. 
# The default="white,black,1";
# 
# -t tcolors ... TCOLORS is a comma separate list of thre values, namely, the 
# triangle fill and stroke colors and strokewidth. All 3 values must be provided. 
# The default="tan,black,1";
# 
# -b bcolor ... BCOLOR is the background color for image if no input image is 
# provided. The default="lightblue".
# 
# -m mode ... MODE of drawing order. The choices are 1 or 2. A value of 1 
# draws the triangle over the ellipse. A value of 2 draws the ellipse over 
# the triangle. The default=1.
# 
# CAVEAT: No guarantee that this script will work on all platforms, 
# nor that trapping of inconsistent parameters is complete and 
# foolproof. Use At Your Own Risk. 
# 
######
#

# set default values
size="300x300"				# size if no input image
radii="50,50"				# x and y radii
center=150,100				# x,y center of ellipse
apex=150,250				# x,y apex of ellipse
tcolors="tan,black,1"		# fill and outline color of triangle and strokewidth
ecolors="white,black,1"		# fill and outline color of ellipse and strokewidth
bcolor="lightblue"			# background color if no input image
mode=1						# 1=triangle over ellipse, 2=ellipse over triangle

# set directory for temporary files
dir="."    # suggestions are dir="." or dir="/tmp"

# set up functions to report Usage and Usage with Description
PROGNAME=`type $0 | awk '{print $3}'`  # search for executable on path
PROGDIR=`dirname $PROGNAME`            # extract directory of program
PROGNAME=`basename $PROGNAME`          # base name of program
usage1() 
	{
	echo >&2 ""
	echo >&2 "$PROGNAME:" "$@"
	sed >&2 -e '1,/^####/d;  /^###/g;  /^#/!q;  s/^#//;  s/^ //;  4,$p' "$PROGDIR/$PROGNAME"
	}
usage2() 
	{
	echo >&2 ""
	echo >&2 "$PROGNAME:" "$@"
	sed >&2 -e '1,/^####/d;  /^######/g;  /^#/!q;  s/^#*//;  s/^ //;  4,$p' "$PROGDIR/$PROGNAME"
	}


# function to report error messages
errMsg()
	{
	echo ""
	echo $1
	echo ""
	usage1
	exit 1
	}


# function to test for minus at start of value of second part of option 1 or 2
checkMinus()
	{
	test=`echo "$1" | grep -c '^-.*$'`   # returns 1 if match; 0 otherwise
    [ $test -eq 1 ] && errMsg "$errorMsg"
	}

# test for correct number of arguments and get values
if [ $# -eq 0 ]
	then
	# help information
   echo ""
   usage2
   exit 0
elif [ $# -gt 18 ]
	then
	errMsg "--- TOO MANY ARGUMENTS WERE PROVIDED ---"
else
	while [ $# -gt 0 ]
		do
			# get parameter values
			case "$1" in
		   -help|h)    # help information
					   echo ""
					   usage2
					   exit 0
					   ;;
				-s)    # get size
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID SIZE SPECIFICATION ---"
					   checkMinus "$1"
					   size=`expr "$1" : '\([x0-9]*\)'`
					   [ "$size" = "" ] && errMsg "--- SIZE=$size MUST BE TWO X DELIMITED NON-NEGATIVE INTEGERS ---"
 					   ;;
				-r)    # get radii
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID RADII SPECIFICATION ---"
					   checkMinus "$1"
					   radii=`expr "$1" : '\([,0-9]*\)'`
					   [ "$radii" = "" ] && errMsg "--- RADII=$radii MUST BE TWO COMMA DELIMITED NON-NEGATIVE INTEGERS ---"
					   ;;
				-c)    # get center
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID CENTER SPECIFICATION ---"
					   checkMinus "$1"
					   center=`expr "$1" : '\([,0-9]*\)'`
					   [ "$center" = "" ] && errMsg "--- CENTER=$center MUST BE TWO COMMA DELIMITED NON-NEGATIVE INTEGERS ---"
					   ;;
				-a)    # get apex
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID APEX SPECIFICATION ---"
					   checkMinus "$1"
					   apex=`expr "$1" : '\([,0-9]*\)'`
					   [ "$apex" = "" ] && errMsg "--- APEX=$apex MUST BE TWO COMMA DELIMITED NON-NEGATIVE INTEGERS ---"
					   ;;
				-e)    # get ecolors
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID ECOLORS SPECIFICATION ---"
					   checkMinus "$1"
					   ecolors=`expr "$1" : '\([,a-zA-Z0-9]*\)'`
					   [ "$ecolors" = "" ] && errMsg "--- ECOLORS=$ecolors MUST BE THREE COMMA DELIMITED ALPHABETIC OR NUMERIC ITEMS ---"
					   ;;
				-t)    # get tcolors
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID TCOLORS SPECIFICATION ---"
					   checkMinus "$1"
					   tcolors=`expr "$1" : '\([,a-zA-Z0-9]*\)'`
					   [ "$tcolors" = "" ] && errMsg "--- TCOLORS=$tcolors MUST BE THREE COMMA DELIMITED ALPHABETIC OR NUMERIC ITEMS ---"
					   ;;
				-b)    # get bcolor
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID BCOLOR SPECIFICATION ---"
					   checkMinus "$1"
					   bcolor="$1"
					   ;;
				-m)    # get mode
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID MODE SPECIFICATION ---"
					   checkMinus "$1"
					   mode="$1"
					   [ "$mode" != "1" -a "$mode" != "2" ] && errMsg "--- MODE=$mode MUST BE EITHER 1 OR 2 ---"
					   ;;
			 	 -)    # STDIN and end of arguments
					   break
					   ;;
				-*)    # any other - argument
					   errMsg "--- UNKNOWN OPTION ---"
					   ;;
		     	 *)    # end of arguments
					   break
					   ;;
			esac
			shift   # next option
	done
	#
	# get infile and outfile
	if [ $# -eq 2 ]; then
		infile="$1"
		outfile="$2"
	elif [ $# -eq 1 ]; then
		outfile="$1"
		infile=""
	else
		errMsg "--- INCONSISTENT NUMBER OF INPUT AND OUTPUT IMAGES SPECIFIED ---"
	fi
fi

# test that outfile provided
[ "$outfile" = "" ] && errMsg "NO OUTPUT FILE SPECIFIED"

if [ "$infile" != "" ]; then
	# set up temp files
	tmpA1="$dir/cone_A_$$.mpc"
	tmpA2="$dir/cone_A_$$.cache"
	trap "rm -f $tmpA1 $tmpA2;" 0
	trap "rm -f $tmpA1 $tmpA2; exit 1" 1 2 3 15
	trap "rm -f $tmpA1 $tmpA2; exit 1" ERR

	# read the input image and filter image into the temp files and test validity.
	convert -quiet "$infile" +repage "$tmpA1" ||
		errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE  ---"
fi


# extract and test individual argument

apex=`echo "$apex" | sed 's/ //g'`
x1=`echo "$apex" | cut -d, -f 1`
y1=`echo "$apex" | cut -d, -f 2`

center=`echo "$center" | sed 's/ //g'`
xc=`echo "$center" | cut -d, -f 1`
yc=`echo "$center" | cut -d, -f 2`

radii=`echo "$radii" | sed 's/ //g'`
a=`echo "$radii" | cut -d, -f 1`
b=`echo "$radii" | cut -d, -f 2`

tcolors=`echo "$tcolors" | sed 's/ //g'`
tnum=`echo "$tcolors" | tr "," " " | wc -w`
[ $tnum -ne 3 ] && errMsg "--- TCOLORS MUST CONTAIN ONLY 3 VALUES ---"
tcolor=`echo "$tcolors" | cut -d, -f 1`
tstroke=`echo "$tcolors" | cut -d, -f 2`
twidth=`echo "$tcolors" | cut -d, -f 3`
[[ $twidth == [[:digit:]] ]] || echo "--- TWIDTH MUST BE A NON-NEGATIVE INTEGER ---"

ecolors=`echo "$ecolors" | sed 's/ //g'`
enum=`echo "$ecolors" | tr "," " " | wc -w`
[ $enum -ne 3 ] && errMsg "--- ECOLORS MUST CONTAIN ONLY 3 VALUES ---"
ecolor=`echo "$ecolors" | cut -d, -f 1`
estroke=`echo "$ecolors" | cut -d, -f 2`
ewidth=`echo "$ecolors" | cut -d, -f 3`
[[ $ewidth == [[:digit:]] ]] || echo "--- EWIDTH MUST BE A NON-NEGATIVE INTEGER ---"


# do calculations

# calc horizontal ellipse points relative to center
x2=`convert xc: -format "%[fx:($xc-$a)]" info:`
y2=$yc
x3=`convert xc: -format "%[fx:$xc+$a]" info:`
y3=$yc

# calc distance from apex (x1,y1) to center
len=`convert xc: -format "%[fx:hypot(($y1-$yc),($x1-$xc))]" info:`

# calc angle from apex to center
angle=`convert xc: -format "%[fx:(180/pi)*atan2(($x1-$xc),($yc-$y1))]" info:`

# compute tangent points as if ellipse at origin and apex vertically above
# ellipse (x/a)^2 + (y/b)^2 = 1, where a and b are semi-major and semi-minor radii
# differentiate: dy/dx = slope at tangent = -(x*b^2)/(y*a^2)
# tangent line to apex (x1,y1): y-y1=-(x-x1)*(x*b^2)/(y*a^2)
# solve for y and substitute into equation of ellipse to find x from quadratic equation

# compute ellipse points and apex point when ellipse at center and apex directly above
x4=0
y4=-$len
x5=$x2
y5=0
x6=$x3
y6=0

A=`convert xc: -format "%[fx:$a*$a*$y4*$y4 + $b*$b*$x4*$x4]" info:`
B=`convert xc: -format "%[fx:-2*$a*$a*$b*$b*$x4]" info:`
C=`convert xc: -format "%[fx:$a*$a*$a*$a*($b*$b-($y4*$y4))]" info:`
x7=`convert xc: -format "%[fx:(-$B-sqrt($B*$B-(4*$A*$C)))/(2*$A)]" info:`
x8=`convert xc: -format "%[fx:(-$B+sqrt($B*$B-(4*$A*$C)))/(2*$A)]" info:`
y7=`convert xc: -format "%[fx:($a*$a*$b*$b-$b*$b*$x4*$x7)/($a*$a*$y4)]" info:`
y8=`convert xc: -format "%[fx:($a*$a*$b*$b-$b*$b*$x4*$x8)/($a*$a*$y4)]" info:`

# rotate and translate tangent points relative to apex and true ellipse center
x9=`convert xc: -format "%[fx:($x7)*cos(pi*$angle/180)-($y7+$len)*sin(pi*$angle/180)+$x1]" info:`
y9=`convert xc: -format "%[fx:($x7)*sin(pi*$angle/180)+($y7+$len)*cos(pi*$angle/180)+$y1]" info:`
x10=`convert xc: -format "%[fx:($x8)*cos(pi*$angle/180)-($y8+$len)*sin(pi*$angle/180)+$x1]" info:`
y10=`convert xc: -format "%[fx:($x8)*sin(pi*$angle/180)+($y8+$len)*cos(pi*$angle/180)+$y1]" info:`

if [ "$infile" != "" ]; then
	input="$tmpA1"
else
	input="-size $size xc:$bcolor"
fi

# draw circle and tangent lines
if [ $mode -eq 1 ]; then
	convert $input \
		-fill $ecolor -stroke $estroke -strokewidth $ewidth -draw "translate $xc,$yc rotate $angle ellipse 0,0 $a,$b 0,360" \
		-fill $tcolor -stroke $tstroke -strokewidth $twidth -draw "polygon $x1,$y1 $x9,$y9 $x10,$y10" \
		"$outfile"
elif [ $mode -eq 2 ]; then
	convert $input \
		-fill $tcolor -stroke $tstroke -strokewidth $twidth -draw "polygon $x1,$y1 $x9,$y9 $x10,$y10" \
		-fill $ecolor -stroke $estroke -strokewidth $ewidth -draw "translate $xc,$yc rotate $angle ellipse 0,0 $a,$b 0,360" \
		"$outfile"
fi

exit 0