#!/bin/bash
# 
# Developed by Fred Weinhaus 8/14/2014 .......... revised 4/6/2019
#
# ------------------------------------------------------------------------------
# 
# 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: cylinderwarp angle displacementfile infile [backgroundfile] outfile
# 
# REQUIRED ARGUMENT:
# 
# angle is the rotation angle in degrees about cylinder axis; mandatory; float;   
# -360<=angle<=360; if angle="", then it will be controlled from the roll 
# argument provided in this file as exported from the cylinderize script
# 
# backgroundfile is an optional background file onto which the cylinderized 
# infile is to be composited at the offset coordinated relative to the 
# center of the backgroundfile
# 
# 
###
# 
# NAME: CYLINDERWARP 
# 
# PURPOSE: To apply a cylinder distortion to an image using a displacement 
# map and arguments provided by the script cylinderize.
# 
# DESCRIPTION: CYLINDERIZE applies a cylinder distortion to an image using 
# a displacement map and arguments provided by the script cylinderize. The 
# arguments must be copied from cylinderize output at the terminal and pasted 
# in the arguments section of this script.
# 
# 
# EXTERNAL ARGUMENTS: 
# 
# angle ... ANGLE is the rotation of the cylinder about its axis. It is   
# a required argument. The values are floats with -360<=angle<=360. If angle="", 
# then it will be controlled from the roll argument provided in this file as 
# exported from the cylinderize script.
# 
# REQUIREMENTS: IM 6.5.3.4 due to the use of -compose displace -composite. 
# Also requires the preprocessing of cylinderize in export mode (-E) to get  
# the displacement image (displace.png) and to get the needed internal   
# arguments that must be pasted in this script below.
# 
# 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 internal arguments here (pasted from the output of cylinderize)




#### end internal arguments

# get external arguments
outfile=""								# initialize in case no background image
angle=`expr "$1" : '\([-.0-9]*\)'`		# get angle
dfile="$2"								# dispacement image
infile="$3"								# input image
bgfile="$4"								# optional background image or if no background image then output image
outfile="$5"							# output image


# set outfile depending upon whether background exists
if [ "$outfile" = "" ]; then 
	outfile="$bgfile"
	bgfile=""
fi

#echo "angle=$angle"
#echo "dfile=$dfile"
#echo "infile=$infile"
#echo "bgfile=$bgfile"
#echo "outfile=$outfile"


# test displacement file
if ! [ -f "$dfile" -a -e "$dfile" -a -r "$dfile" -a -s "$dfile" ]; then
	echo  "--- FILE $dfile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE  ---"
	exit 1
fi

# test infile
if ! [ -f "$infile" -a -e "$infile" -a -r "$infile" -a -s "$infile" ]; then
	echo  "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE  ---"
	exit 1
fi


if [ "$bgfile" != "" ]; then 
	# test backgroundfile
	if ! [ -f "$bgfile" -a -e "$bgfile" -a -r "$bgfile" -a -s "$bgfile" ]; then
		echo  "--- FILE $bgfile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE  ---"
		exit 1
	fi
fi

# set up for rolling
if [ "$angle" = "" -a "$roll" = "" ]; then
	rolling=""
elif [ "$angle" = "" -a "$roll" != "" ]; then
	rolling="-roll $roll"
else
	# set sign of angle for use below in sign of -roll arguments
	sign=`convert xc: -format "%[fx:sign($angle)]" info:`
	[ $sign -lt 0 ] && sign="-" || sign="+"
	if [ "$mode" = "vertical" -a "$angle" != "0" ]; then	
		rollx=`convert xc: -format "%[fx:abs($angle)*$pwidth/360]" info:`
		roll="${sign}${rollx}+0"
		rolling="-roll $roll"
	elif [ "$mode" = "horizontal" -a "$angle" != "0" ]; then
		rolly=`convert xc: -format "%[fx:abs($angle)*$pheight/360]" info:`
		roll="+0${sign}${rolly}"
		rolling="-roll $roll"
	fi
fi
#echo "roll=$roll"
#echo "rolling=$rolling"


# set up resize
if [ "$scale" != "100" -a "$mode" = "vertical" ]; then 
	resizing="-resize 100x${scale}%"
elif [ "$scale" != "100" -a "$mode" = "horizontal" ]; then 
	resizing="-resize ${scale}x100%"
else
	resizing=""
fi
#echo "resizing=$resizing"


# set up for transparency
if [ "$vpmethod" = "transparent" -o "$bgcolor" = "none" ]; then
	channels="-channel rgba -alpha on"
else
	channels="-alpha off"
fi
#echo "channels=$channels"


# set up for background color
if [ "$vpmethod" = "background" ]; then
	backgroundcolor="-background $bgcolor"
elif [ "$vpmethod" = "black" ]; then
	backgroundcolor="-background black"
elif [ "$vpmethod" = "white" ]; then
	backgroundcolor="-background white"
elif [ "$vpmethod" = "gray" ]; then
	backgroundcolor="-background gray"
elif [ "$vpmethod" = "transparent" -o "$vpmethod" = "none" ]; then
	backgroundcolor="-background none"
else
	backgroundcolor=""
fi
#echo "backgroundcolor=$backgroundcolor"


# set up trimming
if [ "$trim" = "yes" ]; then
	trimming="-fill $bgcolor -trim +repage"
elif [ "$trim" != "yes" -a "$mode" = "vertical" ]; then
	trimming="-gravity center -crop ${width}x${height12}+0+0 +repage"
elif [ "$trim" != "yes" -a "$mode" = "horizontal" ]; then
	trimming="-gravity center -crop ${width12}x${height}+0+0 +repage"
else 
	trimming=""
fi
#echo "trimming=$trimming"


# set up perspective warp
if [ "$coords" != "" ]; then
	pwarp='-gravity northwest -virtual-pixel $vpmethod $backgroundcolor -distort perspective "$coords"'
else
	pwarp=""
fi
#echo "pwarp=$pwarp"
#echo "coords=$coords"


# set up for flipping input when direction of pitch is negative
if [ "$direction" = "negative" -a "$mode" = "vertical" ]; then
	flipping="-flip"
elif [ "$direction" = "negative" -a "$mode" = "horizontal" ]; then
	flipping="-flop"
else
	flipping=""
fi
#echo "flipping=$flipping"


# set up for bgfile
if [ "$bgfile" != "" ]; then
	bgproc1="$flipping -gravity center -background $bgcolor -extent ${wbg}x${hbg} +repage -gravity center -geometry $offsets"
	bgproc2="+swap -compose $compose -composite"
else
	bgproc1="$flipping"
	bgproc2=""
fi
#echo "bgproc1=$bgproc1"
#echo "bgproc2=$bgproc2"


# set up for rotating
if [ "$rotation" != "0" ]; then
	rotating="-background $bgcolor -rotate $rotation"
else
	rotating=""
fi
#echo "rotating=$rotating"


# set up gravity for displacement
if [ "$mode" = "vertical" ]; then
	if [ "$direction" = "both" ]; then
		gravityval="center"
	else
		gravityval="north"
	fi
elif [ "$mode" = "horizontal" ]; then
	if [ "$direction" = "both" ]; then
		gravityval="center"
	else
		gravityval="west"
	fi
fi
#echo "gravityval=$gravityval"


# set up borderize with pad used for direction=both
if [ "$pad" != "0" -a "$mode" = "vertical" ]; then
	borderize="-bordercolor none -border 0x${pad}"
elif [ "$pad" != "0" -a "$mode" = "horizontal" ]; then
	borderize="-bordercolor none -border ${pad}x0"
else
	borderize=""
fi
#echo "borderize=$borderize"



# process image

if [ "$mode" = "vertical" ]; then
#echo "vertical"
	eval 'convert -respect-parenthesis \
	\( "$infile" +repage $rproc $resizing -gravity center -background ${fcolor} -extent ${pwidth}x${pheight} \
		$rolling $flipping -resize 100x${length2}% $backgroundcolor -gravity $gravityval -extent ${pwidth}x${height1} $borderize \) \
	"$dfile" $channels -virtual-pixel $vpmethod $backgroundcolor -gravity northwest \
		-define compose:args=${xc}x${radius2} -compose displace -composite -compose over +channel \
	$trimming '"$pwarp"' $bgproc1 $rotating $bgfile $bgproc2 "$outfile"'


elif [ "$mode" = "horizontal" ]; then
#echo "horizontal"
	eval 'convert -respect-parenthesis \
	\( "$infile" +repage $rproc $resizing -gravity center -background ${fcolor} -extent ${pwidth}x${pheight} \
		$rolling $flipping -resize ${length2}x100% $backgroundcolor -gravity $gravityval -extent ${width1}x${pheight} $borderize \) \
	"$dfile" $channels -virtual-pixel $vpmethod $backgroundcolor -gravity northwest \
		-define compose:args=${radius2}x${yc} -compose displace -composite -compose over +channel \
	$trimming '"$pwarp"' $bgproc1 $rotating $bgfile $bgproc2 "$outfile"'

fi

exit 0