#!/bin/bash

# This program auto-generates colorized textures for all 89 of the Unified 
# Dyes colors, based on one or two input files.

# Copyright (C) 2012-2013, Vanessa Ezekowitz
# Email: vanessaezekowitz@gmail.com
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

if [ -z "`which convert`" ] ; then {
	echo "Please install Imagemagick."
	exit 1
} fi

if [ -z "`which bc`" ] ; then {
	echo "Please install GNU bc."
	exit 1
} fi

if [ $1 = "-t" ] ; then {
	TINT_OVERLAY=$1
	BASE=$2
	COMPOSITE=$3
} else {
	TINT_OVERLAY=""
	BASE=$1
	COMPOSITE=$2
} fi

if [ -z $1 ] || [ $1 == "--help" ] || [ $1 == "-h" ] || [[ $1 == "-t" && -z $3 ]] ; then {

	echo -e "\nUsage:
\ngentextures.sh basename [overlay_filename]
gentextures.sh -t basename overlay_filename
\nThis script requires up to three parameters which supply the base filename
of the textures, an optional overlay, and possibly the '-t' switch.  The
'basename' is the first part of the filename that your textures will use when
your mod is done, which should almost always be the same as the one-word name
of your mod.  For example, if you supply the word 'mymod', this script will
produce filenames like mymod_red.png or 'mymod_dark_blue_s50.png'.  The
texture that this script will read and recolor is derived from this parameter,
and will be of the form 'basename_base.png', i.e. 'mymod_base.png'.
\nYou can also supply an optional overlay image filename.  This image will be
composited onto the output files after they have been colorized, but without
being modified.  This is useful when you have some part of your base image
that will either get changed undesirably (for example, the mortar among
several bricks, or the shading detail of a stone pattern).  Simply draw two
images: one containing the whole image to be colored, and one containing the
parts that should not be changed, with either full or partial alpha
transparency where the re-colored base image should show through.  Skilled use
of color and alpha on this overlay can lead to some interesting effects.
\nIf you add '-t' as the first parameter, the script will switch to 'tint
overlay' mode.  For this mode to work, you must also supply the base name as
usual, and you must include an overlay image filename.  Rather than re-color
the base texture, the script will alter the hue/saturation/value of the
overlay texture file instead, and leave the base texture unchanged.  When
using this mode, the base texture should be drawn in some neutral color, but
any color is fine if it results in what you wanted.\n"
	exit 1
} fi

if [[ ! -e $BASE"_base.png" ]]; then {
	echo -e "\nThe basename '"$BASE"_base.png' was not found."
        echo -e "\nAborting.\n"
	exit 1
} fi

if [[ ! -z $COMPOSITE && ! -e $COMPOSITE ]]; then {
	echo -e "\nThe requested composite file '"$COMPOSITE"' was not found."
        echo -e "\nAborting.\n"
	exit 1
} fi

convert $BASE"_base.png" -modulate 1,2,3 tempfile.png 1>/dev/null 2>/dev/null

if (( $? )) ; then {
	echo -e "\nImagemagick failed while testing the base texture file."
	echo -e "\nEither the base file '"$BASE"_base.png' isn't an image,"
	echo "or it is broken, or Imagemagick itself just didn't work."
	echo -e "\nPlease check and correct your base image and try again."
	echo -e "\nAborting.\n"
	exit 1
} fi

if [ ! -z $COMPOSITE ] ; then {
	convert $BASE"_base.png" -modulate 1,2,3 $COMPOSITE -composite tempfile.png 1>/dev/null 2>/dev/null

	if (( $? )) ; then {
		echo -e "\nImagemagick failed while testing the composite file."
		echo -e "\nEither the composite file '"$COMPOSITE"' isn't an image"
		echo "or it is broken, or Imagemagick itself just didn't work."
		echo -e "\nPlease check and correct your composite image and try again."
		echo -e "\nAborting.\n"
		exit 1
	} fi
} fi

rm tempfile.png

base_colors="red orange yellow lime green aqua cyan skyblue blue violet magenta redviolet"

echo -e -n "\nGenerating filenames based on "$BASE"_base.png"
if [ ! -z $COMPOSITE ] ; then {
	echo ","
	echo -n "using "$COMPOSITE" as an overlay"
} fi

if [ ! -z $TINT_OVERLAY ] ; then {
	echo ","
	echo -n "and tinting the overlay instead of the base texture"
} fi

echo -e "...\n"

mkdir -p generated-textures

function generate_texture () {
	name=$1
	h=$2
	s=$3
	v=$4
	if [ -z $TINT_OVERLAY ]; then {
		if [ -z $COMPOSITE ]; then {
			convert $BASE"_base.png" -modulate $v,$s,$h "generated-textures/"$BASE"_"$name".png"
		} else {
			convert $BASE"_base.png" -modulate $v,$s,$h $COMPOSITE -composite "generated-textures/"$BASE"_"$name".png"
		} fi
	} else {
		convert $COMPOSITE -modulate $v,$s,$h MIFF:- | composite MIFF:- $BASE"_base.png" "generated-textures/"$BASE"_"$name".png"
	} fi
}

hue=0
for color_name in $base_colors ; do
	hue2=`echo "scale=10; ("$hue"*200/360)+100" |bc`
	echo $color_name "("$hue" degrees)"
	echo "     dark"
	generate_texture "dark_"$color_name $hue2 100 33
	echo "     medium"
	generate_texture "medium_"$color_name $hue2 100 66
	echo "     full"
	generate_texture $color_name $hue2 100 100
	echo "     light"
	generate_texture "light_"$color_name $hue2 100 150
	echo "     dark, 50% saturation"
	generate_texture "dark_"$color_name"_s50" $hue2 50 33
	echo "     medium, 50% saturation"
	generate_texture "medium_"$color_name"_s50" $hue2 50 66
	echo "     full, 50% saturation"
	generate_texture $color_name"_s50" $hue2 50 100 
	hue=$((hue+30))
done

echo "greyscales"
echo "     black"
generate_texture black 0 0 15
echo "     dark grey"
generate_texture darkgrey 0 0 50
echo "     medium grey"
generate_texture grey 0 0 100
echo "     light grey"
generate_texture lightgrey 0 0 150
echo "     white"
generate_texture white 0 0 190