#!/bin/bash

# number to start with to call the original files (usually not changed)
COUNT=1
# number to start with to name the new files (usually not changed)
COUNT2=1
# total number of original files
OTOTAL=99
# total number of end files
ETOTAL=200
# Top Y position of masked line
YVALUE=-40
# Left X position of masked line
XVALUE=-40
# Bottom Y position
YVALUE2=520
# Right X position
XVALUE2=760



while [ $COUNT -le $OTOTAL ]; do
if [ $COUNT -lt $OTOTAL ]; then
    VAR=`printf "%03d" $COUNT`
elif [ $COUNT -eq $OTOTAL ]; then
    COUNT=0
    VAR=0$OTOTAL
fi

# create an image animation where lines move across the screen which will be used as masks.
# an animation shows through the masked line animation on a third animation. 
convert -size 720x480 xc:black -stroke white -strokewidth 40 -draw "line 0,$YVALUE 720,$YVALUE" -draw "line $XVALUE,0 $XVALUE,480" -draw "line $XVALUE2,0 $XVALUE2,480" -draw  "line 0,$YVALUE2 720,$YVALUE2" $VAR.png &&
composite platte720x480png/$VAR.png agfa720x480png/$VAR.png $VAR.png  -compose src-over movie/$VAR2.png

echo $VAR2
let COUNT=COUNT+1

#add to x position to move the line mask
XVALUE=$(echo "scale=2; $XVALUE + ( 800 / $ETOTAL )" | bc)

#add to y position to move the line mask
YVALUE=$(echo "scale=2; $YVALUE + ( 560 / $ETOTAL )" | bc)

#subtract from x position of the second line mask
XVALUE2=$(echo "scale=2; $XVALUE2 - ( 800 / $ETOTAL )" | bc)

#subtract from y position of the second line mask
YVALUE2=$(echo "scale=2; $YVALUE2 - ( 560 / $ETOTAL )" | bc)


# creates the names for the end files
if [ $COUNT2 -le $ETOTAL ]; then
    VAR2=`printf "%04d" $COUNT2`
elif [ $COUNT2 -gt $ETOTAL ]; then
break
fi

let COUNT2=COUNT2+1
done