#!/bin/bash
#
# Developed by Fred Weinhaus 3/18/2013 .......... revised 2/6/2019
#
# ------------------------------------------------------------------------------
# 
# 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: picturefold [-n numfolds] [-a angle] [-h height] [-l location] 
# [-y yoffset] [-s shading] [-t thickness] [-b bdcolor] [-B bgcolor] 
# [-o opacity] [-d distance] [-r ramp] infile outfile
#
# USAGE: picturefold [-help]
#
# OPTIONS:
#
# -n     numfolds       number of folds; integer>=2; default=5
# -a     angle          angle of fold; 0<=integer<=40; default=10
# -h     height         crop height as percent; 5<=integer<=95; default=95
# -l     location       vertical crop location; north, south or center; 
#                       default=center
# -y     yoffset        percent vertical offset from the crop location; 
#                       -100<=integer<=100; default=0
# -s     shading        shading brightness value; 0<=integer<=100; default=70 
# -t     thickness      border thickness; integer>=0; default=0 (off)
# -b     bdcolor        border color; any valid IM color is allowed; 
#                       default=red
# -B     bgcolor        background color; any valid IM color is allowed; 
#                       default=white
# -o     opacity        shadow opacity; 0<=integer<=100; default=0 (off)
# -d     distance       shadow distance; integer>=0; default=5
# -r     ramp           shadow ramping (tapering); integer>=0; default=5
#
###
#
# NAME: PICTUREFOLD 
# 
# PURPOSE: To apply a map-like folded appearance to an image.
# 
# DESCRIPTION: PICTUREFOLD applies a map-like folded appearance to an image.
# A border or shadow optionally may be placed around the image.
# 
# OPTIONS: 
#
# -n numfolds ... NUMFOLDS is the number of folds. Values are integers>=2. 
# The default=5.
# 
# -a angle ... ANGLE of fold. Values are 0<=integer<=40. The default=10.
# 
# -h height ... HEIGHT is the crop height as percent of the image height for 
# desired region. Values are 5<=integers<=95. The default=95.
# 
# -l location ... LOCATION is the desired vertical crop location. Values are: 
# north, south or center. The default=center.
# 
# -y yoffset ... YOFFSET is the percent vertical offset from the crop location.  
# Values are -100<=integer<=100. The default=0.
# 
# -s shading ... SHADING brightness value. Values are 0<=integer<=100. A value 
# of 0 is black and 100 is full image brightness. The default=70.
#  
# -t thickness ... THICKNESS is the border thickness. Values are integers>=0. 
# However, for thickness=1, thickness will be set to 2 for functionality  
# reasons. The default=0 (no border).
# 
# -b bdcolor ... BDCOLOR is the border color. Any valid IM color is allowed.  
# The default=red.
# 
# -B bgcolor ... BGCOLOR is the background color. Any valid IM color is 
# allowed. The default=white.
# 
# -o opacity ... OPACITY is the shadow opacity. Values are 0<=integer<=100. 
# The default=0 (no shadow).
# 
# -d distance ... DISTANCE is the shadow distance (length). Values are 
# integers>=0. The default=5.
# 
# -r ramp ... RAMP is the shadow ramping (tapering). Values are integer>=0. 
# The default=5.
# 
# 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
numfolds=5			# number of folds; integer>=2
angle=10			# angle of fold; 0<=integer<=40
height=95			# percent height of region to use; 5<=height<=95
location=center		# location for region; north, south and center
yoffset=0			# percent vertical offset from location
shading=70			# shading brightness
thick=0				# thickness of border; 0 is off
bdcolor=red			# border color
bgcolor=white		# background color
opacity=0			# shadow opacity; 0 is off; nominal is 80
distance=5			# shadow distance
ramp=5				# shadow ramp

# internal defaults
fuzzval=50			# floodfill fuzz value
blurval=2			# blurval


# 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 26 ]
	then
	errMsg "--- TOO MANY ARGUMENTS WERE PROVIDED ---"
else
	while [ $# -gt 0 ]
		do
			# get parameter values
			case "$1" in
		  	 -help)    # help information
					   echo ""
					   usage2
					   exit 0
					   ;;
				-n)    # get numfolds
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID NUMFOLDS SPECIFICATION ---"
					   checkMinus "$1"
					   numfolds=`expr "$1" : '\([0-9]*\)'`
					   [ "$numfolds" = "" ] && errMsg "--- NUMFOLDS=$numfolds MUST BE A NON-NEGATIVE INTEGER ---"
		   			   testA=`echo "$numfolds < 2" | bc`
					   [ $testA -eq 1 ] && errMsg "--- NUMFOLDS=$numfolds MUST BE AN INTEGER GREATER THAN 1 ---"
					   ;;
				-a)    # get angle
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID ANGLE SPECIFICATION ---"
					   checkMinus "$1"
					   angle=`expr "$1" : '\([0-9]*\)'`
					   [ "$angle" = "" ] && errMsg "--- ANGLE=$angle MUST BE A NON-NEGATIVE INTEGER ---"
		   			   testA=`echo "$angle > 40" | bc`
					   [ $testA -eq 1 ] && errMsg "--- ANGLE=$angle MUST BE AN INTEGER LESS THAN OR EQUAL TO 40 ---"
					   ;;
				-h)    # get height
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID HEIGHT SPECIFICATION ---"
					   checkMinus "$1"
					   height=`expr "$1" : '\([0-9]*\)'`
					   [ "$height" = "" ] && errMsg "--- HEIGHT=$height MUST BE A NON-NEGATIVE INTEGER ---"
		   			   testA=`echo "$height < 5" | bc`
		   			   testB=`echo "$height > 95" | bc`
					   [ $testA -eq 1 -o $testB -eq 1 ] && errMsg "--- HEIGHT=$height MUST BE AN INTEGER BETWEEN 5 AND 95 ---"
					   ;;
				-l)    # location
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID LOCATION SPECIFICATION ---"
					   checkMinus "$1"
					   mode=`echo "$1" | tr "[:upper:]" "[:lower:]"`
					   case "$location" in 
							north|n) location="north" ;;
							center|c) location="center" ;;
							south|s) location="south" ;;
							*) errMsg "--- LOCATION=$location IS AN INVALID VALUE ---" 
					   esac
				   	   ;;
				-y)    # get yoffset
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID YOFFSET SPECIFICATION ---"
					   #checkMinus "$1"
					   yoffset=`expr "$1" : '\([-0-9]*\)'`
					   [ "$yoffset" = "" ] && errMsg "--- YOFFSET=$yoffset MUST BE AN INTEGER ---"
		   			   testA=`echo "$yoffset < -100" | bc`
		   			   testB=`echo "$yoffset > 100" | bc`
					   [ $testA -eq 1 -o $testB -eq 1 ] && errMsg "--- YOFFSET=$yoffset MUST BE AN INTEGER BETWEEN -100 AND 100 ---"
					   ;;
				-s)    # get shading
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID SHADING SPECIFICATION ---"
					   checkMinus "$1"
					   shading=`expr "$1" : '\([0-9]*\)'`
					   [ "$shading" = "" ] && errMsg "--- SHADING=$shading MUST BE A NON-NEGATIVE INTEGER ---"
		   			   testA=`echo "$shading > 100" | bc`
					   [ $testA -eq 1 ] && errMsg "--- SHADING=$shading MUST BE AN INTEGER LESS THAN OR EQUAL TO 100 ---"
					   ;;
				-t)    # get thick
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID THICKNESS SPECIFICATION ---"
					   checkMinus "$1"
					   thick=`expr "$1" : '\([0-9]*\)'`
					   [ "$thick" = "" ] && errMsg "--- THICKNESS=$thick MUST BE A NON-NEGATIVE INTEGER ---"
					   ;;
				-b)    # get bdcolor
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID BDCOLOR SPECIFICATION ---"
					   checkMinus "$1"
					   bdcolor="$1"
					   ;;
				-B)    # get bgcolor
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID bgcolor SPECIFICATION ---"
					   checkMinus "$1"
					   bgcolor="$1"
					   ;;
				-o)    # get opacity
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID OPACITY SPECIFICATION ---"
					   checkMinus "$1"
					   opacity=`expr "$1" : '\([0-9]*\)'`
					   [ "$opacity" = "" ] && errMsg "--- OPACITY=$opacity MUST BE A NON-NEGATIVE INTEGER ---"
		   			   testA=`echo "$opacity < 0" | bc`
		   			   testB=`echo "$opacity > 100" | bc`
					   [ $testA -eq 1 -o $testB -eq 1 ] && errMsg "--- OPACITY=$opacity MUST BE AN INTEGER BETWEEN 0 AND 100 ---"
					   ;;
				-d)    # get distance
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID DISTANCE SPECIFICATION ---"
					   checkMinus "$1"
					   distance=`expr "$1" : '\([0-9]*\)'`
					   [ "$distance" = "" ] && errMsg "--- DISTANCE=$distance MUST BE A NON-NEGATIVE INTEGER ---"
					   ;;
				-r)    # get ramp
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID RAMP SPECIFICATION ---"
					   checkMinus "$1"
					   ramp=`expr "$1" : '\([0-9]*\)'`
					   [ "$ramp" = "" ] && errMsg "--- RAMP=$ramp MUST BE A NON-NEGATIVE INTEGER ---"
					   ;;
				 -)    # 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
	infile="$1"
	outfile="$2"
fi

# test that infile provided
[ "$infile" = "" ] && errMsg "--- NO INPUT FILE SPECIFIED ---"

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


# setup temporary images
tmpA1="$dir/picturefold_1_$$.mpc"
tmpB1="$dir/picturefold_1_$$.cache"
tmpA2="$dir/picturefold_2_$$.mpc"
tmpB2="$dir/picturefold_2_$$.cache"
trap "rm -f $tmpA1 $tmpB1 $tmpA2 $tmpB2;" 0
trap "rm -f $tmpA1 $tmpB1 $tmpA2 $tmpB2; exit 1" 1 2 3 15
trap "rm -f $tmpA1 $tmpB1 $tmpA2 $tmpB2; exit 1" ERR

# read the input image into the temporary cached image and test if valid
convert -quiet "$infile" +repage "$tmpA1" ||
	echo "--- 1 FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO size  ---"

# get im_version
im_version=`convert -list configure | \
	sed '/^LIB_VERSION_NUMBER */!d; s//,/;  s/,/,0/g;  s/,0*\([0-9][0-9]\)/\1/g' | head -n 1`

# get infile dimensions
ww=`identify -ping -format "%w" $tmpA1`
hh=`identify -ping -format "%h" $tmpA1`

# get specified height
hh2=`convert xc: -format "%[fx:round($height*$hh/100)]" info:`

# adjust thickness for blur and to pad out the image sufficient for the border and blur
#thick1=$((thick-2))  --- problems if thick<3
if [ $thick -eq 1 ]; then
	thick=2
	thick1=3
elif [ $thick -lt 4 ]; then
	thick1=3
else
	thick1=$((thick-2))
fi
thick2=$((thick1*2))
#echo "thick=$thick; thick1=$thick1; thick2=$thick2;"

# get width from numfolds
ww3=`convert xc: -format "%[fx:floor($ww/$numfolds)]" info:`
ww2=`convert xc: -format "%[fx:$numfolds*$ww3]" info:`

# limit hh2
hh2=`convert xc: -format "%[fx:($hh2>$hh-2*$thick2-$ww3*atan($angle*pi/180)?$hh-2*$thick2-$ww3*atan($angle*pi/180):$hh2)]" info:`
#echo "hh=$hh; hh2=$hh2"

# setup geometry and adjust yoffset for negative values
yoffset=`convert xc: -format "%[fx:round($yoffset*$hh/100)]" info:`
offsets=`printf "+0+%d"  $yoffset`

# setup shading
shading="gray$shading"
#echo "$shading"

# center crop image to appropriate width
convert $tmpA1 -gravity center -crop ${ww2}x${hh}+0+$yoffset +repage $tmpA1

# set up alternating repeats for the following processing
proc=""
if [ $numfolds -gt 2 ]; then
	num=$((numfolds-2))
	for ((i=0; i<num; i++)) do
		j=`convert xc: -format "%[fx:mod($i,2)]" info:`
		proc="$proc -clone $j"
	done
fi
#echo "$proc"

# create alternating bright and dark modulations of the cropped image
#
# create white horizontal line and gray70 horizontal line of fold width
# add alternate copies and append them all, scale to full height and center extend with black to input size
# multiply mask by image
convert \( -size ${ww3}x1 xc:white \) \( -size ${ww3}x1 xc:$shading \) \
	\( $proc \) +append -scale ${ww2}x${hh}! \
	$tmpA1 -compose multiply -composite $tmpA1


if [ "$opacity" != "0" -o "$thickness" != "0" ]; then
	maskwrite="+write $tmpA2"
else
	maskwrite=""
fi


# create and apply alternating sheared masks to intensity modulated image
#
# create sheared white mask of size of fold on transparent background
# clone and horizontal flop it, add alternate copies, and append them all
# make a transparent image of the size of the 
# composite the mask at the proper location in the transparent image
# put the b/w mask as the alpha channel for the image and trim
# add -alpha off after shear as it leaves an alpha channel that IM 7 thresholds to white as fully transparent (IM 7 change of behavior with alpha)
# add -alpha off after -extent or IM 7 introduces transparency when it should not om border command below
convert \( -size ${ww3}x${hh2} xc:white -background black -shear 0x-$angle -alpha off \) \
	\( +clone -flop \) \( $proc \) +append -gravity center -background black -extent ${ww}x${hh} -alpha off $maskwrite \
	\( -size ${ww2}x${hh} xc:black \) \
	+swap -gravity $location -geometry $offsets -compose over -composite \
	$tmpA1 +swap -alpha off -compose copy_opacity -composite $tmpA1



# add border
# note that borner in IM 7 will be slightly thinner than in IM 6
if [ "$thick" != "0" ]; then
fuzzval2=`convert xc: -format "%[fx:$fuzzval/2]" info:`
# add border to image
# add border to mask, threshold to remove antialiasing, convert to outer edge, blur and level
# compose image with mask using mask
# remove tmps, do fuzzy trim
convert $tmpA1 -background black -alpha background -alpha off -bordercolor black -border $thick2 \
	\( $tmpA2 -bordercolor black -border $thick2 -threshold 0 \
		-morphology edgeout octagon:$thick -blur 0x$blurval -level 0x50% \) \
	\( -clone 1 -fuzz $fuzzval2% -fill "$bdcolor" -opaque white \) \
	\( -clone 0 -clone 2 -clone 1 -compose over -composite \) \
	-delete 0,1,2 $tmpA1
fi

# set up floodfill
if [ "$im_version" -ge "07000000" ]; then
	matte_alpha="alpha"
else
	matte_alpha="matte"
fi
#echo "matte_alpha=$matte_alpha"

# add shadow
if [ "$opacity" != "0" ]; then
	if [ "$thick" != "0" ]; then
		# clone input, add black border
		# floodfill outer black with none, convert opaque to white and transparent to black for new mask
		# blur, level and shave so mask is back to size of input
		# put mask in alpha channel of input
		# create shadow
		# composite shadow over input
		convert $tmpA1 \( -clone 0 -bordercolor black -border $thick1 \
			-fuzz $fuzzval% -fill none -draw "$matte_alpha 0,0 floodfill" \
			-fill white +opaque none -fill black -opaque none -alpha off \
			-blur 0x$blurval -level 50x100% -shave $thick1 \) \
			-alpha off -compose copy_opacity -composite \
			\( +clone -background black -shadow ${opacity}x${ramp}+${distance}+${distance} \) \
			+swap -background none -compose over -layers merge +repage \
			$tmpA1
	else
		# blur mask image, and level
		# put mask in alpha channel of input
		# create shadow
		# composite shadow over input
		convert $tmpA1 \( $tmpA2 -blur 0x$blurval -level 50x100% \) \
			-alpha off -compose copy_opacity -composite \
			\( +clone -background black -shadow ${opacity}x${ramp}+${distance}+${distance} \) \
			+swap -background none -compose over -layers merge +repage \
			$tmpA1
	fi
fi


# add background color
if [ "$thick" = "0" -o "$opacity" != "0" ]; then
	convert $tmpA1 +repage -background $bgcolor -flatten "$outfile"
else
	convert $tmpA1 +repage -bordercolor black -border 2 \
		-fuzz $fuzzval% -fill none -draw "$matte_alpha 0,0 floodfill" \
		-background $bgcolor -flatten "$outfile"
fi

exit 0