#!/bin/sh
#
# Unterrainerizer v0.1
# by Anna Wiggins (annabunches@gmail.com)
# Licensed under the GPLv3, see accompanying file LICENSE for terms
#
# Takes any number of terrain RAW files and merges them into a single
# PNG file (or other file type, as configured).
#
# The input files must be named according to this convention:
#
# mapname-nxm.raw
#
# Where mapname is the same for all maps, and n and m are the column and
# row that this image occupies in the final image, starting from the
# top-left.

extension="png"


##### STOP EDITING HERE #####
#############################

# Make a unique random directory
make_tmpdir()
{
    tmpdir=/tmp/unterrainerizer-`uuidgen | perl -pe 's/-.*$//'`
    mkdir $tmpdir
}


clean_up()
{
    echo "Cleaning up"
    rm -rf $tmpdir
}


# Extract the maps into separate files
# Also sets max_x and max_y
extract_maps()
{
    echo "Extracting heightmaps from RAW files"

    # Find the greatest X and Y values
    index=0
    max_x=0
    max_y=0
    for i in $@; do
	x=`echo $i | perl -pe 's/^.*-(.*)x.*.raw/\1/'`
	y=`echo $i | perl -pe 's/^.*-.*x(.*).raw/\1/'`
	if [ $x -gt $max_x ]; then max_x=$x; fi
	if [ $y -gt $max_y ]; then max_y=$y; fi
	out_name=${tmpdir}/${base_name}-${x}x${y}.${extension}
	unterrain_commands[$index]="(un-terrain \"${i}\" \"${out_name}\")"
	index+=1
    done

    # We have to invert the order these are added so that montage will handle them correctly later
    index=0
    for i in $(seq 0 $max_y); do
	for j in $(seq 0 $max_x); do
	    extracted_maps[$index]=${tmpdir}/${base_name}-${j}x${i}.${extension}
	    index+=1
	done
    done

    gimp -id -b - &> /dev/null <<EOF
(define (un-terrain src-filename dest-filename)
  (let* (
	 (src-image (car (file-slraw-load 1 src-filename "")))
	 (dest-image (car (gimp-image-new 256 256 1)))
	 )

    (gimp-edit-copy (car (gimp-image-get-active-drawable src-image)))
    
    (let (
	  (layer (car (gimp-layer-new dest-image 256 256 2 "" 100 0)))
	  )
      (gimp-image-add-layer dest-image layer -1))

    (let* (
	  (pasteable (car (gimp-image-get-active-drawable dest-image)))
	  (floater (car (gimp-edit-paste pasteable 1)))
	  )
      (gimp-floating-sel-anchor floater))
    (gimp-file-save 1
		    dest-image
		    (car (gimp-image-get-active-drawable dest-image))
		    dest-filename
		    "")
    dest-image))

${unterrain_commands[@]}

(gimp-quit 0)
EOF

}


# Recombine the maps into a single final image
build_heightmap()
{
    echo "Combining separate pieces into a single map"
    montage -geometry +0+0 -tile $(($max_x + 1))x$(($max_y + 1)) ${extracted_maps[@]} ${tmpdir}/${base_name}.${extension}
    # fixme: x and y are inverted in the default sort order, apparently... how to fix?  Oy! leftoffhere
}


move_heightmap()
{
    echo "Moving heightmap to current directory"
    mv ${tmpdir}/${base_name}.${extension} ./
}


# Extract the base name of the file.  This is:
# base_name-nxm.extension
base_name=`echo $1 | perl -pe 's/^(.*)-.*x.*.raw/\1/' | perl -pe 's/^.*\/(.*)$/\1/'`

# Run the functions
make_tmpdir
extract_maps $@
build_heightmap
move_heightmap
#clean_up