#!/bin/bash

#

# svg_convertPngToSyslinux.sh -- This function provides post-rendition

# action used to produce LSS16 images, the images used by isolinux.

#

# Initially, the color information is defined with GIMP (The GNU Image

# Manipulation Program) as a `.gpl' palette of color. This palette of

# colors contains 16 colors only and is saved in a file named

# `syslinux.gpl.  The `syslinux.gpl' file is used to build two other

# files: the `syslinux.ppm' file and the `syslinux.hex' file. The

# `syslinux.ppm' provides the color information needed to reduce the

# full color PNG image, produced as result of SVG base-rendition, to

# the amount of colors specified (i.e., 16 colors). Later, with the 16

# color PNG image already created, the `syslinux.hex' file is used to

# build the LSS16 image.

#

# In order to produce images in LSS16 format correctly, it is required

# that both the `syslinux.ppm' and `syslinux.hex' files do contain the

# same color information. This is, both `syslinux.ppm' and

# `syslinux.hex' must represent the same color values and in the same

# color index.

#

# In order for this function to work, the `syslinux.gpl' file should

# have a format similar to the following:

#

# GIMP Palette

# Name: CentOS-TreeFlower-4-Syslinux

# Columns: 16

# #

# 32  76 141	204c8d

# 37  82 146	255292

# 52  94 153	345e99

# 73 110 162	496ea2

# 91 124 172	5b7cac

# 108 136 180	6c88b4

# 120 146 186	7892ba

# 131 158 193	839ec1

# 255 255 255	ffffff

# 146 170 200	92aac8

# 162 182 209	a2b6d1

# 183 199 219	b7c7db

# 204 216 230	ccd8e6

# 221 229 238	dde5ee

# 235 241 245	ebf1f5

# 246 251 254	f6fbfe

#

# Copyright (C) 2009-2013 The CentOS Project

#

# 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., 675 Mass Ave, Cambridge, MA 02139, USA.

#

# ----------------------------------------------------------------------

# $Id$

# ----------------------------------------------------------------------

function svg_convertPngToSyslinux {

    # Define number of colors the images will be produced on.

    local COLORS='16'

    # Define options using those passed to actions from pre-rendition

    # configuration script. These options are applied to pnmremap when

    # doing color reduction, so any option available for pnmremap

    # command can be passed to renderSyslinux functionality.

    local OPTIONS=$(render_getConfigOption "$ACTION" '2-')

    # Check options passed to action. This is required in order to

    # aviod using options already used in this script. For example

    # -verbose and -mapfile options.

    for OPTION in $OPTIONS;do

        # Remove anything after equal sign inside option.

        OPTION=$(echo $OPTION | cut -d'=' -f1)

        if [[ "$OPTION" =~ "-(mapfile|verbose)" ]];then

            cli_printMessage "`eval_gettext "The \\\"\\\$OPTION\\\" option is already used."`" --as-error-line

        fi

    done

    # Define default file name prefix for 16 colors images.

    local PREFIX="-${COLORS}c"

    # Re-define 16 colors images default file name prefix using

    # options as reference. This is useful to differenciate final

    # files produced using Floyd-Steinberg dithering and final files

    # which are not.

    if [[ "$OPTIONS" =~ '-floyd' ]];then

        PREFIX="${PREFIX}-floyd"

    fi

    # Define logs' file. Log files are stored in the same place of

    # images and are used to store output information produced by

    # programs when the image files are built up.

    local LOGS=${FILE}${PREFIX}.log

    # Define absolute path to GPL palette. The GPL palette defines the

    # color information used to build syslinux images.  This palette

    # should be set to 16 colors and, as specified in isolinux

    # documentation, the background color should be indexed on

    # position 0 and the forground in position 7 (see

    # /usr/share/doc/syslinux-X.XX/isolinux.doc, for more

    # information.)

    local PALETTE_GPL=${MOTIF_DIR}/Palettes/syslinux.gpl

    # Verify GPL palette existence. If it doesn't exist copy the one

    # provided by the design model through subversion (to keep track

    # of the change) and expand translation markers in the copied

    # instance.

    if [[ ! -f $PALETTE_GPL ]];then

        cli_runFnEnvironment vcs --copy ${MODEL_BASEDIR}/${FLAG_THEME_MODEL}/Palettes/syslinux.gpl ${PALETTE_GPL}

        cli_expandTMarkers ${PALETTE_GPL}

    fi

    # Define absolute path to PPM palette. The PPM palette is built

    # from source palette (PALETTE_GPL) and provides the color

    # information understood by `ppmremap', the program used to

    # produce images in a specific amount of colors.

    local PALETTE_PPM=$(cli_getTemporalFile "syslinux.ppm")

    # Define the HEX palette. The HEX palette is built from source

    # palette (PALETTE_GPL) and provides the color information in the

    # format understood by `ppmtolss16', the program used to produce

    # images in LSS16 format.  The HEX palette stores just one line

    # with the color information as described in isolinux

    # documentation (i.e #RRGGBB=0 #RRGGBB=1 ... [all values in the

    # same line])

    local PALETTE_HEX=$(cli_getTemporalFile "syslinux.hex")

    # Create image in Netpbm superformat (PNM). The PNM image file is

    # created from the PNG image rendered previously as centos-art

    # base-rendition output. The PNM image is an intermediate format

    # used to manipulate images through Netpbm tools.

    cli_printMessage "${FILE}.pnm" --as-savedas-line

    pngtopnm -verbose \

        < ${FILE}.png 2>${LOGS} > ${FILE}.pnm

    # Print the path to GPL palette.

    cli_printMessage "$PALETTE_GPL" --as-palette-line

    # Create PPM palette using GPL palette.

    svg_convertGplToPpm "$PALETTE_GPL" "$PALETTE_PPM" "$COLORS"

    # Create HEX palette using GPL palette.

    svg_convertGplToHex "$PALETTE_GPL" "$PALETTE_HEX" "$COLORS"

    # Reduce colors as specified in PPM palette.  Here we use the PPM

    # palette to enforce the color position in the image index and the

    # Floyd-Steinberg dithering in order to improve color reduction.

    cli_printMessage "${FILE}${PREFIX}.pnm" --as-savedas-line

    pnmremap -verbose -mapfile=$PALETTE_PPM $OPTIONS \

        < ${FILE}.pnm 2>> ${LOGS} > ${FILE}${PREFIX}.pnm

    # Create LSS16 image. 

    cli_printMessage "${FILE}${PREFIX}.lss" --as-savedas-line

    ppmtolss16 $(cat $PALETTE_HEX) \

        < ${FILE}${PREFIX}.pnm 2>>${LOGS} > ${FILE}${PREFIX}.lss

    # Remove HEX palette. It is no longer needed.

    if [[ -f ${PALETTE_HEX} ]];then

        rm $PALETTE_HEX

    fi

    # Create PPM image indexed to 16 colors. Also the colormap used in

    # the LSS16 image is saved on ${FILE}.log; this is useful to

    # verify the correct order of colors in the image index.

    cli_printMessage "${FILE}${PREFIX}.ppm" --as-savedas-line

    lss16toppm -map \

        < ${FILE}${PREFIX}.lss 2>>${LOGS} > ${FILE}${PREFIX}.ppm

    # Create PNG image indexed to 16 colors.

    cli_printMessage "${FILE}${PREFIX}.png" --as-savedas-line

    pnmtopng -verbose \

        < ${FILE}${PREFIX}.pnm 2>>${LOGS} > ${FILE}${PREFIX}.png

    # Remove PPM palette. It is no longer needed.

    if [[ -f ${PALETTE_PPM} ]];then

        rm $PALETTE_PPM

    fi

}