#!/bin/bash -x
#
# perspective output name must be .gif
pfile=perspective_animation.gif


##file number to start with
COUNT=1

##checks only the size of the first file
checksize=$1/001.png
function imagesize
	{
	width=`identify -format %w $checksize`
	height=`identify -format %h $checksize`
	}
imagesize

## total number of original files
OTOTAL=`ls $1 | wc -l`

## sloppy addition so that the angle doesn't change too slowly
if [ $OTOTAL -lt 180 ]; then
    OANG=$OTOTAL
elif [ $OTOTAL -lt 360 ]; then
    OANG=`expr $OTOTAL / 2` 
elif [ $OTOTAL -lt 720 ]; then
    OANG=`expr $OTOTAL / 4`

## more than this number of files will take forever, so might as well break if there are more
else exit 0
fi

# provide the frame delay in the gif animation
delay=10

# note - choose anginc and initang to keep from having a frame looking directly edge on
# otherwise get a blank white picture!
##got rid of this. angle is calculated later on, so that the number of files is taken into account
#anginc=10

initang=5
tmp="perspective_animate_$$.png"
trap "rm -f $tmp; exit 0" 0
trap "rm -f $tmp; exit 1" 1 2 3 15

##added this because two angle arguments are required one with and one without floating points
ang1=$initang
ang2=$initang
xx=x

##added this so that different file names are called up
while [ $COUNT -le $OTOTAL ]; do

VAR=`printf "%03d" $COUNT`.png

##moved this down here so that ifile is changed during while loop. 
##input directory now first argument on the commandline
ifile=$1/$VAR

##got rid of this to take greater file numbers into account
#while [ $ang -le 360 ]
#	do
	if [ $ang2 -gt 180 ] 
		then
		newang=`expr $ang2 - 360`
	else
		newang=$ang1
	fi
#   animate pan
#	3Drotate pan=$newang zoom=-1.5 $ifile $tmp
#   animate tilt
#	3Drotate tilt=$newang zoom=-1.5 $ifile $tmp
#   animate roll
#	3Drotate roll=$newang zoom=-1.5 $ifile $tmp
#	animate pan about tilt=45
#	3Drotate pan=$newang tilt=45 zoom=-1.5 $ifile $tmp
#   tilt=30 animate pan
#
#   set the fixed angle(s) and the animated angle
	3Drotate tilt=$newang pan=$newang zoom=-1.5 $ifile $tmp

	if [ $ang2 -eq $initang ]
		then
		convert $tmp -delay $delay $pfile
	else
		convert -delay $delay $pfile -page $width$xx$height+0+0 $tmp -page $width$xx$height $pfile
	fi

##changed from $ang to $newang so that the angle doesn't go over 180
	ang1=$(echo "scale=2; $newang + $(echo "scale=2; 360 / $OANG" | bc)" | bc)

##added this because decimals don't work in if statements
	ang2=$(echo $ang1 | awk '{printf "%.0f",$1}')

##added sloppily so that gif file isn't created more than once
	initang=195

let COUNT=COUNT+1

echo $COUNT


done
convert $pfile -loop 0 $pfile