#!/bin/sh
#
#  box_set   output_image
#
# Generate a Perspective 'box' for the ImageMagick software
#

# Generate a Spine Image
convert -size 200x40 xc:lightblue \
  -pointsize 20 -gravity north -annotate +5+0 'IM Examples' \
  -pointsize 10 -gravity south -annotate +0+0 'ImageMagick' \
  -stroke blue -strokewidth 2 -draw 'line 30,0 30,40' \
  -rotate -90 /tmp/spine.png

# Generate the front cover (using a web downloaded logo)
convert -size 150x200 xc:lightblue \
  -fill black -pointsize 20 -gravity north -annotate +0+5 'IM Examples' \
  -fill blue -pointsize 15 -gravity northeast -annotate +5+28 'Box Set' \
  -fill black -pointsize 15 -gravity south -annotate +0+5 'ImageMagick' \
  -stroke blue -strokewidth 2 -draw 'line 0,169 150,169' \
  \( http://imagemagick.org/Usage/images/logo.gif -resize 100x100 \) \
  -gravity center -compose multiply -composite /tmp/front.png

# Distort both images and merge together to produce the final image.
# The images are aligned along two common 'control points' at 0,0 and 0,199
# Note that the spine is placed at a 'negative' x offset!
convert -virtual-pixel transparent \
  \( /tmp/spine.png -virtual-pixel transparent \
     +distort Perspective '0,0 -30,20  0,199 -30,179  39,199 0,199  39,0 0,0' \
  \) \
  \( /tmp/front.png \
     +distort Perspective '0,0 0,0  0,199 0,199  149,199 99,169  149,0 99,30' \
  \) \
  -background black -layers merge  +repage \
  -bordercolor black -border 5 "$1"

# clean up the temporary images.
rm -f /tmp/spine.png /tmp/front.png