#!/bin/bash
#
# Developed by Fred Weinhaus 4/27/2010 .......... 5/7/2015
#
# ------------------------------------------------------------------------------
# 
# 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: wavemap [-c cycles] [-p phase] infile outfile
# USAGE: wavemap [-h or -help]
#
# OPTIONS:
#
# -c      cycles       number of cycles in sinusiodal wave transform;
#                      float>=0; default=0.5
# -p      phase        phase shift from cosine function; 0<=float<=360;
#                      default=0
#
###
#
# NAME: WAVEMAP 
# 
# PURPOSE: To transform the graylevels in each RGB channel according to a 
# sinusoidal wave function.
# 
# DESCRIPTION: WAVEMAP transform the graylevels in each RGB channel according 
# to a sinusoidal wave function. This is similar to GIMP's Alien Map.
# 
# 
# OPTIONS: 
# 
# -c cycle ... CYCLES is the number of cycles in the sinusoidal wave transform. 
# Values are floats>=0. One or three comma delimited values may be provided, 
# one for each of the RGB channels. If only the one value is provided, the other 
# two will be set to the same value. The default=0.5 (which is the same as 
# 0.5,0.5,0.5). With phase=0, this produces a nearly linear transform. 
#
# -p phase ... PHASE is the phase shift in degrees from a cosine wave. Values 
# are in the range 0<=float<=360. One or three comma delimited values may be 
# provided, one for each of the RGB channels. If only the one value is provided, 
# the other two will be set to the same value. The default=0 (or 0,0,0) will 
# produce a cosine wave. See 
# http://www.imagemagick.org/Usage/transform/#function_sinusoid.
# In wavemap, we will add 90 degrees to the phase value so that the sinusoid 
# will be shifted from a sine to a cosine wave as the default. With cycles=0.5, 
# this produces a nearly linear transform.
# 
# REQUIREMENT: IM version 6.4.8-9 or higher due to the use of -function sinusoid.
#
# 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
cycles="0.5"
phase="0"

# 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 6 ]
	then
	errMsg "--- TOO MANY ARGUMENTS WERE PROVIDED ---"
else
	while [ $# -gt 0 ]
		do
			# get parameter values
			case "$1" in
		  -h|-help)    # help information
					   echo ""
					   usage2
					   exit 0
					   ;;
				-c)    # get cycles
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID CYCLES SPECIFICATION ---"
					   checkMinus "$1"
					   cycles=`expr "$1" : '\([,.0-9]*\)'`
					   [ "$cycles" = "" ] && errMsg "--- CYCLES=$cycles MUST BE FROM ONE TO THREE COMMA DELIMITED NON-NEGATIVE FLOATS ---"
 					   ;;
				-p)    # get phase
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID PHASE SPECIFICATION ---"
					   checkMinus "$1"
					   phase=`expr "$1" : '\([,.0-9]*\)'`
					   [ "$phase" = "" ] && errMsg "--- PHASE=$phase MUST BE FROM ONE TO THREE COMMA DELIMITED NON-NEGATIVE FLOATS ---"
					   ;;
			 	-)    # 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"

# 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`

# colorspace RGB and sRGB swapped between 6.7.5.5 and 6.7.6.7 
# though probably not resolved until the latter
# then -colorspace gray changed to linear between 6.7.6.7 and 6.7.8.2 
# then -separate converted to linear gray channels between 6.7.6.7 and 6.7.8.2,
# though probably not resolved until the latter
# so -colorspace HSL/HSB -separate and -colorspace gray became linear
# but we need to use -set colorspace RGB before using them at appropriate times
# so that results stay as in original script
# The following was determined from various version tests using wavemap
# with IM 6.7.4.10, 6.7.6.10, 6.7.9.1
if [ "$im_version" -lt "06070607" -o "$im_version" -gt "06070707" ]; then
	setcspace="-set colorspace RGB"
else
	setcspace=""
fi
if [ "$im_version" -lt "06070606" -o "$im_version" -gt "06070707" ]; then
	cspace="RGB"
else
	cspace="sRGB"
fi
# no need for setcspace for grayscale or channels after 6.8.5.4
if [ "$im_version" -gt "06080504" ]; then
	setcspace=""
	cspace="sRGB"
fi


# extract channel cycles
cr=`echo "$cycles" | cut -d, -f 1`
cg=`echo "$cycles" | cut -d, -f 2`
cb=`echo "$cycles" | cut -d, -f 3`
[ "$cr" = "" -o "$cg" = "" -o "$cb" = "" ] && errMsg "--- CYCLES=$cycles MUST BE THREE COMMA DELIMITED NON-EMPTY VALUES ---"
testr=`echo "$cr < 0" | bc`
testg=`echo "$cr < 0" | bc`
testb=`echo "$cr < 0" | bc`
[ $testr -eq 1 -o $testg -eq 1 -o $testr -eq 1 ] && errMsg "--- CYCLES=$cycles MUST BE FROM ONE OR THREE COMMA DELIMITED NON-NEGATIVE FLOATS ---"

# extract channel phases
pr=`echo "$phase" | cut -d, -f 1`
pg=`echo "$phase" | cut -d, -f 2`
pb=`echo "$phase" | cut -d, -f 3`
[ "$pr" = "" -o "$pg" = "" -o "$pb" = "" ] && errMsg "--- PHASE=$phase MUST BE THREE COMMA DELIMITED NON-EMPTY VALUES ---"
phasetestR1=`echo "$pr < 0" | bc`
phasetestR2=`echo "$pr > 360" | bc`
[ $phasetestR1 -eq 1 -a $phasetestR2 -eq 1 ] && errMsg "--- RED PHASE=$pr MUST BE A FLOAT BETWEEN 0 AND 360 ---"
phasetestG1=`echo "$pg < 0" | bc`
phasetestG2=`echo "$pg > 360" | bc`
[ $phasetestG1 -eq 1 -a $phasetestG2 -eq 1 ] && errMsg "--- GREEN PHASE=$pg MUST BE A FLOAT BETWEEN 0 AND 360 ---"
phasetestB1=`echo "$pb < 0" | bc`
phasetestB2=`echo "$pb > 360" | bc`
[ $phasetestB1 -eq 1 -a $phasetestB2 -eq 1 ] && errMsg "--- BLUE PHASE=$pb MUST BE A FLOAT BETWEEN 0 AND 360 ---"

# shift the phases by 90 for use with -function sinusoid to make cosine function
pr=`convert xc: -format "%[fx:$pr-90]" info:`
pg=`convert xc: -format "%[fx:$pg-90]" info:`
pb=`convert xc: -format "%[fx:$pb-90]" info:`


# set up temp files
tmpR1="$dir/wavemap_R_$$.mpc"
tmpR2="$dir/wavemap_R_$$.cache"
tmpG1="$dir/wavemap_G_$$.mpc"
tmpG2="$dir/wavemap_G_$$.cache"
tmpB1="$dir/wavemap_B_$$.mpc"
tmpB2="$dir/wavemap_B_$$.cache"
trap "rm -f $tmpR1 $tmpR2 $tmpG1 $tmpG2 $tmpB1 $tmpB2;" 0
trap "rm -f $tmpR1 $tmpR2 $tmpG1 $tmpG2 $tmpB1 $tmpB2; exit 1" 1 2 3 15
trap "rm -f $tmpR1 $tmpR2 $tmpG1 $tmpG2 $tmpB1 $tmpB2; exit 1" ERR

# assumes image is sRGB/RGB

# test input image
convert -quiet "$infile" $setcspace -channel red -separate +channel +repage "$tmpR1" ||
	errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE  ---"
convert -quiet "$infile" $setcspace -channel green -separate +channel +repage "$tmpG1" ||
	errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE  ---"
convert -quiet "$infile" $setcspace -channel blue -separate +channel +repage "$tmpB1" ||
	errMsg "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE  ---"


# process channels
convert $tmpR1 -function sinusoid "$cr,$pr" $tmpR1
convert $tmpG1 -function sinusoid "$cg,$pb" $tmpG1
convert $tmpB1 -function sinusoid "$cb,$pb" $tmpB1

# recombine
convert $tmpR1 $tmpG1 $tmpB1 -set colorspace $cspace -combine -colorspace $cspace "$outfile"

exit 0