#!/bin/bash # # Developed by Fred Weinhaus 5/14/2013 .......... revised 2/2/2019 # # ------------------------------------------------------------------------------ # # 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: multigradient [-w width] [-h height] [-s stops] [-t type] # [-d direction] [-c center] [-r radii] outfile # # USAGE: multigradient [-help] # # OPTIONS: # # -w width width of desired output image; default=256 # -h height height of desired output image; default=256 # -s stops stops; space separate list of pairs of color and # percent location along the gradient enclosed in double # quotes; default="white black" # -t type type of gradient; choices are linear, circle or ellipse; # default=linear # -d direction direction of gradient; angle or sides or corners; # default=to-bottom for linear and closest-side for circle # or ellipse; angles are measured in degrees clockwise # from the zeroangle direction; -360<=angle<=360 # -c center x and y center coordinates for ellipse or circle; # pair of comma separated floats>=0; # default=(width-2)/2,(height-1)/2 # -r radii x and y radii for ellipse or circle; # pair of comma separated floats>=0; # default is determined by distance from center to # closest-side # -z zeroangle zero angle direction for type=linear; choices are: # to-top or to-right; default=to-top # ### # # NAME: MULTIGRADIENT # # PURPOSE: To create either a linear or radial gradient image with two or more # stops to specify colors and locations along the gradient direction. # # DESCRIPTION: RADIALGRADIENT creates either a linear or radial gradient image # with two or more stops to specify colors and locations along the gradient # direction. Linear gradients may be oriented at any rotation angle or towards # any side or corner. A radial gradient may be either an ellipse or constrained # to a circle. Directions include: closest-side, furthest-side, closest-corner, # or furthest corner. Colors may contain partial transparency and allow any # valid IM color specification, including color names, rgb values or hex values. # This script attempts to simulate many of the features of CSS style gradients. # # # ARGUMENTS: # # -w width ... WIDTH of desired output image. The default=256. # # -h height ... HEIGHT of desired output image. The default=256. # # -s stops ... STOPS are a space separate list of pairs of colors and percent # locations along the gradient enclosed in double quotes. The colors may be color # names, hex colors, rgb colors or a mix. The first and last percent location may # be left off and are then assumed to be 0 and 100 (percent). The first percentage # must be zero if specified. The last percentage may be less than 100 if # specified. In this case, then last color will be use to fill out the gradient. # The default="white black" or "white 0 black 100". # # -t type ... TYPE of gradient. The choices are: linear, circle or ellipse. # The default=linear. # # -d direction ... DIRECTION of gradient. For type=linear, direction may # be either an angle in degrees measured clockwise from the zeroangle in the # range of -360 to 360 or alternately, direction may be any one of the # following: to-top, to-right, to-bottom, to-left, to-topright, # to-bottomright, to-bottomleft or to-topleft for linear. For type=ellipse or # circle, direction may be one of the following: closest-side, furthest-side, # closest-corner, furthest-corner. For type=linear, the default is to-bottom # for zeroangle=to-top and the default is to-right for zeroangle=to-right. For # ellipse or circle the default=closest-side. # # -c center ... x and y CENTER coordinates for ellipse or circle expressed as # a comma separate pair of non-negative floats. The # default=(width-2)/2,(height-1)/2. # # -r radii ... x and y RADII for ellipse or circle expressed as a comma # separate pair of non-negative floats. The default is determined by distance # from the gradient center to the closest-side. # # -z zeroangle ... ZEROANGLE is direction where angle=0 for type=linear. The # choices are: to-top or to-right. The default=to-top # # REFERENCE: http://dev.w3.org/csswg/css-images-3/ # # 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 width=256 height=256 stops="white black" # default: equivalent to gradient: or gradient:"white-black" type="linear" # linear, ellipse, circle direction="" # angle in degrees clockwise from "zeroangle"; or to-top, to-right, to-bottom, to-left, to-topright, to-bottomright, to-bottomleft, to-topleft (for linear); or closest-corner, furthest-corner, closest-side, furthest-side (for ellipse or circle) center="" # ellipse or circle only radii="" # ellipse or circle only zeroangle="to-top" # linear coordinate system zero angle; to-right or to-top # fixed length=65000 length=1000 # 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 15 ] 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 ;; -w) # get width shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID WIDTH SPECIFICATION ---" checkMinus "$1" width=`expr "$1" : '\([0-9]*\)'` [ "$width" = "" ] && errMsg "--- WIDTH=$width MUST BE A NON-NEGATIVE INTEGER ---" testA=`echo "$width <= 0" | bc` [ $testA -eq 1 ] && errMsg "--- WIDTH=$width MUST BE A POSITIVE INTEGER ---" ;; -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 <= 0" | bc` [ $testA -eq 1 ] && errMsg "--- HEIGHT=$height MUST BE A POSITIVE INTEGER ---" ;; -s) # get stops shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID STOPS SPECIFICATION ---" checkMinus "$1" stops="$1" ;; -t) # type shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID TYPE SPECIFICATION ---" checkMinus "$1" type=`echo "$1" | tr "[:upper:]" "[:lower:]"` case "$type" in linear|l) type="linear" ;; circle|c) type="circle" ;; ellipse|e) type="ellipse" ;; *) errMsg "--- TYPE=$type IS AN INVALID VALUE ---" esac ;; -d) # get direction shift # to get the next parameter # test if parameter starts with minus sign #errorMsg="--- INVALID DIRECTION SPECIFICATION ---" #checkMinus "$1" direction=`echo "$1" | tr "[:upper:]" "[:lower:]"` ;; -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" : '\([.0-9]*,[.0-9]*\)'` [ "$center" = "" ] && errMsg "--- CENTER=$center MUST BE A COMMA SEPARATED PAIR OF NON-NEGATIVE FLOATS ---" ;; -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" : '\([.0-9]*,[.0-9]*\)'` [ "$radii" = "" ] && errMsg "--- RADII=$radii MUST BE A COMMA SEPARATED PAIR OF NON-NEGATIVE FLOATS ---" ;; -z) # zeroangle shift # to get the next parameter # test if parameter starts with minus sign errorMsg="--- INVALID ZEROANGLE SPECIFICATION ---" checkMinus "$1" zeroangle=`echo "$1" | tr "[:upper:]" "[:lower:]"` case "$zeroangle" in to-top) ;; to-right) ;; *) errMsg "--- ZEROANGLE=$type IS AN INVALID VALUE ---" esac ;; -) # STDIN and end of arguments break ;; -*) # any other - argument errMsg "--- UNKNOWN OPTION ---" ;; *) # end of arguments break ;; esac shift # next option done # # get outfile outfile="$1" fi # test that outfile provided [ "$outfile" = "" ] && errMsg "--- NO OUTPUT FILE SPECIFIED ---" # setup temporary images tmpA1="$dir/multigradient_1_$$.mpc" tmpB1="$dir/multigradient_1_$$.cache" tmpA2="$dir/multigradient_2_$$.mpc" tmpB2="$dir/multigradient_2_$$.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 function linearGradient { # creates appropiately rotated grayscale gradient angle=$1 cos=`convert xc: -format "%[fx:cos($angle*pi/180)]" info:` sin=`convert xc: -format "%[fx:sin($angle*pi/180)]" info:` cx=`convert xc: -format "%[fx:($width-1)/2]" info:` cy=`convert xc: -format "%[fx:($height-1)/2]" info:` # dist corresponds to 2*distance along a line from the center at the specified angle -- # to the intersection with a perpendicular line from the corner # abs needed so that it works for all quadrants not just first quadrant dist=`convert xc: -format "%[fx:abs($width*$cos)+abs($height*$sin)]" info:` # echo "dist=$dist; phase=$phase; angle=$angle" # slow pure fx approach # convert -size ${width}x${height} xc: \ # -fx "xx=((i-$cx)*$cos+(j-$cy)*$sin)/$rx; yy=((i-$cx)*$sin-(j-$cy)*$cos)/$ry; 1-hypot(xx,yy)" \ # faster hybrid approach (same speed if use gradient:) a=`convert xc: -format "%[fx:$cos*($width-1)/$dist]" info:` b=`convert xc: -format "%[fx:$sin*($height-1)/$dist]" info:` c=`convert xc: -format "%[fx:0.5-($cos*$cx+$sin*$cy)/$dist]" info:` # note: possible error --- the following should perhaps be before the c computation and the cos, sin computations if [ "$angle" = "180" -o "$angle" = "360" ]; then ang=0 else ang=`convert xc: -format "%[fx:mod($angle,90)]" info:` fi convert \ \( -size ${width}x1 xc: -fx "i/(w-1)" -scale ${width}x${height}! \) \ \( -size 1x${height} xc: -fx "j/(h-1)" -scale ${width}x${height}! \) \ +swap -define compose:args="0,$a,$b,$c" -compose mathematics -composite $tmpA1 } function radialGradient { cx=$1 cy=$2 rx=$3 ry=$4 # echo "cx=$cx; cy=$cy; rx=$rx; ry=$ry" # slow pure fx approach # convert -size ${width}x1 xc: \ # -fx "xx=(i-$cx)/$rx; yy=(j-$cy)/$ry; hypot(xx,yy)" $tmpA1 # faster hybrid approach # choose not to use 1D gradient: and -solarize -level 0x50% -evaluate pow 2 # comparison with -fx shows slight differences and I trust -fx results more convert \ \( -size ${width}x1 xc: -fx "xx=(i-$cx)/$rx; xx*xx" -scale ${width}x${height}! \) \ \( -size 1x${height} xc: -fx "yy=(j-$cy)/$ry; yy*yy" -scale ${width}x${height}! \) \ -compose plus -composite -evaluate pow 0.5 $tmpA1 } function distSides { rleft=$cx rtop=$cy rright=`convert xc: -format "%[fx:$width-1-$cx]" info:` rbottom=`convert xc: -format "%[fx:$height-1-$cy]" info:` } function distCorners { rtopleft=`convert xc: -format "%[fx:hypot($cx,$cy)]" info:` rtopright=`convert xc: -format "%[fx:hypot($width-1-$cx,$cy)]" info:` rbottomright=`convert xc: -format "%[fx:hypot($width-1-$cx,$height-1-$cy)]" info:` rbottomleft=`convert xc: -format "%[fx:hypot($cx,$height-1-$cy)]" info:` } function cornerCoords { rad=$1 if [ $(convert xc: -format "%[fx:$rad==$rtopleft?1:0]" info:) -eq 1 ]; then xx=0 yy=0 elif [ $(convert xc: -format "%[fx:$rad==$rtopright?1:0]" info:) -eq 1 ]; then xx=$((width-1)) yy=0 elif [ $(convert xc: -format "%[fx:$rad==$rbottomright?1:0]" info:) -eq 1 ]; then xx=$((width-1)) yy=$((height-1)) elif [ $(convert xc: -format "%[fx:$rad==$rbottomleft?1:0]" info:) -eq 1 ]; then xx=0 yy=$((height-1)) fi } # set up linear coordinate system if [ "$type" = "linear" -a "$zeroangle" = "to-top" ]; then phase=-90 [ "$direction" = "" ] && direction="to-bottom" elif [ "$type" = "linear" -a "$zeroangle" = "to-right" ]; then phase=0 [ "$direction" = "" ] && direction="to-right" elif [ "$type" = "circle" -o "$type" = "ellipse" ]; then [ "$direction" = "" ] && direction="closest-side" fi # trap on direction angletest="false" if [ "$type" = "linear" ]; then if [ "$(echo "$direction" | grep -E '^[-+]?[0-9]+\.?[0-9]*$')" != "" ]; then # direction is angle dtest=`convert xc: -format "%[fx:($direction<-360 || $direction>360)?0:1 ]" info:` [ $dtest -eq 0 ] && errMsg "---DIRECTION ANGLE MUST BE BETWEEN 0 AND 360 ---" angletest="true" # echo "dir=$direction; dtest=$dtest; angletest=$angletest" else # direction is not an angle case "$direction" in to-top) ;; to-right) ;; to-bottom) ;; to-left) ;; to-topright) ;; to-bottomright) ;; to-bottomleft) ;; to-topleft) ;; *) errMsg "--- DIRECTION=$direction IS AN INVALID VALUE FOR TYPE=LINEAR ---" esac fi else case "$direction" in closest-side) ;; furthest-side) ;; closest-corner) ;; furthest-corner) ;; *) errMsg "--- DIRECTION=$direction IS AN INVALID VALUE FOR TYPE=ELLIPSE OR TYPE=CIRCLE ---" esac fi if [ "$type" = "linear" ]; then # create linear grayscale gradient from black to white for different directions if [ "$angletest" = "true" ]; then angle=`convert xc: -format "%[fx:$direction+$phase]" info:` linearGradient $angle elif [ "$direction" = "to-right" ]; then convert -size "${height}x${width}" gradient: -rotate 90 $tmpA1 elif [ "$direction" = "to-left" ]; then convert -size "${height}x${width}" gradient: -rotate -90 $tmpA1 elif [ "$direction" = "to-bottom" ]; then convert -size "${width}x${height}" gradient: -rotate 180 $tmpA1 elif [ "$direction" = "to-top" ]; then convert -size "${width}x${height}" gradient: $tmpA1 elif [ "$direction" = "to-bottomright" ]; then angle=`convert xc: -format "%[fx:(180/pi)*atan2($height,$width)]" info:` linearGradient $angle elif [ "$direction" = "to-bottomleft" ]; then angle=`convert xc: -format "%[fx:90+(180/pi)*atan2($height,$width)]" info:` linearGradient $angle elif [ "$direction" = "to-topleft" ]; then angle=`convert xc: -format "%[fx:180+(180/pi)*atan2($height,$width)]" info:` linearGradient $angle elif [ "$direction" = "to-topright" ]; then angle=`convert xc: -format "%[fx:270+(180/pi)*atan2($height,$width)]" info:` linearGradient $angle fi elif [ "$type" = "circle" ]; then # create radial grayscale gradient from black to white different directions # get center if [ "$center" = "" ]; then cx=`convert xc: -format "%[fx:($width-1)/2]" info:` cy=`convert xc: -format "%[fx:($height-1)/2]" info:` else cx=`echo "$center" | cut -d, -f1` cy=`echo "$center" | cut -d, -f2` fi if [ "$radii" != "" ]; then rx=`echo "$radii" | cut -d, -f1` ry=$rx radialGradient "$cx" "$cy" "$rx" "$ry" elif [ "$direction" = "closest-side" ]; then distSides rx=`convert xc: -format "%[fx:min($rleft,(min($rtop,(min($rright,$rbottom)))))]" info:` ry=$rx radialGradient "$cx" "$cy" "$rx" "$ry" elif [ "$direction" = "furthest-side" ]; then distSides rx=`convert xc: -format "%[fx:max($rleft,(max($rtop,(max($rright,$rbottom)))))]" info:` ry=$rx radialGradient "$cx" "$cy" "$rx" "$ry" elif [ "$direction" = "closest-corner" ]; then distCorners rx=`convert xc: -format "%[fx:min($rtopleft,(min($rtopright,(min($rbottomleft,$rbottomright)))))]" info:` ry=$rx radialGradient "$cx" "$cy" "$rx" "$ry" elif [ "$direction" = "furthest-corner" ]; then distCorners rx=`convert xc: -format "%[fx:max($rtopleft,(max($rtopright,(max($rbottomleft,$rbottomright)))))]" info:` ry=$rx radialGradient "$cx" "$cy" "$rx" "$ry" fi elif [ "$type" = "ellipse" ]; then # create radial grayscale gradient from black to white different directions # get center if [ "$center" = "" ]; then cx=`convert xc: -format "%[fx:($width-1)/2]" info:` cy=`convert xc: -format "%[fx:($height-1)/2]" info:` else cx=`echo "$center" | cut -d, -f1` cy=`echo "$center" | cut -d, -f2` fi if [ "$radii" != "" ]; then rx=`echo "$radii" | cut -d, -f1` ry=`echo "$radii" | cut -d, -f2` radialGradient "$cx" "$cy" "$rx" "$ry" elif [ "$direction" = "closest-side" ]; then distSides rx=`convert xc: -format "%[fx:min($rleft,$rright)]" info:` ry=`convert xc: -format "%[fx:min($rtop,$rbottom)]" info:` radialGradient "$cx" "$cy" "$rx" "$ry" elif [ "$direction" = "furthest-side" ]; then distSides rx=`convert xc: -format "%[fx:max($rleft,$rright)]" info:` ry=`convert xc: -format "%[fx:max($rtop,$rbottom)]" info:` radialGradient "$cx" "$cy" "$rx" "$ry" elif [ "$direction" = "closest-corner" ]; then distCorners rmin=`convert xc: -format "%[fx:min($rtopleft,(min($rtopright,(min($rbottomleft,$rbottomright)))))]" info:` cornerCoords "$rmin" ry=`convert xc: -format "%[fx:sqrt(($height/$width)^2*($xx-$cx)^2 + ($yy-$cy)^2)]" info:` rx=`convert xc: -format "%[fx:($width/$height)*$ry]" info:` radialGradient "$cx" "$cy" "$rx" "$ry" elif [ "$direction" = "furthest-corner" ]; then distCorners rmax=`convert xc: -format "%[fx:max($rtopleft,(max($rtopright,(max($rbottomleft,$rbottomright)))))]" info:` cornerCoords "$rmax" ry=`convert xc: -format "%[fx:sqrt(($height/$width)^2*($xx-$cx)^2 + ($yy-$cy)^2)]" info:` rx=`convert xc: -format "%[fx:($width/$height)*$ry]" info:` radialGradient "$cx" "$cy" "$rx" "$ry" fi fi # process stops to separate into colorArr and percentArr stops=`echo "$stops" | sed 's/, /,/g; s/[ ][ ]*/ /g'` #echo "stops=$stops" stopsArr=($stops) num=${#stopsArr[*]} numm1=$((num-1)) #echo "$num" # test for even number of entries test=`convert xc: -format "%[fx:mod($num,2)]" info:` [ $test != 0 ] && errMsg "--- NUMBER OF STOP ENTRIES MUST BE EVEN ---" && exit 1 # test if first stop is numeric and quit first=${stopsArr[0]} [ "$(echo "$first" | grep -E '^[0-9][0-9]*\.?[0-9]*$')" != "" ] && errMsg "--- FIRST ENTRY IN STOPS LIST IS NUMERIC ---" && exit 1 # test if last stop is numeric (percent) or non-numeric (color) last=${stopsArr[$numm1]} if [ "$(echo "$last" | grep -E '^[0-9][0-9]*\.?[0-9]*$')" = "" ]; then # not numeric - process stops for firstcolor secondcolor second percent ... lastcolor format if [ $num -eq 2 ]; then colorArr=($first $last) percentArr=(0 100) num=2 numm1=1 # echo "$numm1" else #remove first and last entries from stops and then get color and percent arrays pos=1 len=$((num-2)) stopsArr2=(${stopsArr[@]:$pos:$len}) num=${#stopsArr2[*]} # echo "$num" # echo "stops=${stopsArr2[*]}" # get remaining entries separated into color and percent arrays colorArr=($(for ((i=0; i