#!/bin/bash

#

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

# action used to produce GRUB images.

#

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

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

# colors contains 14 colors only and is saved in a file named

# `grub.gpl.  The `grub.gpl' file is used to build the `grub.ppm' file

# which provide 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., 14 colors). Later, with the 14 color PNG

# image already created, the `grub.ppm' file is used to build the

# `splash.xpm.gz' file.

#

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

# a format similar to the following:

#

# GIMP Palette

# Name: CentOS-TreeFlower-4-Syslinux

# Columns: 14

# #

# 32  76 141	204c8d

# 36  82 146	245292

# 52  93 152	345d98

# 72 108 162	486ca2

# 102 131 176	6683b0

# 126 153 190	7e99be

# 146 170 200	92aac8

# 161 182 209	a1b6d1

# 182 199 219	b6c7db

# 202 214 228	cad6e4

# 221 230 238	dde6ee

# 235 241 245	ebf1f5

# 246 251 254	f6fbfe

# 254 255 252	fefffc

#

# 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_convertPngToGrub {

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

    local COLORS='14'

    # 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 used already in this script. For example

    # -verbose and -mapfile options.

    for OPTION in $OPTIONS;do

        # Remove anything after equal sign inside option.

        OPTION=$(echo -n $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 file name prefix.

    local PREFIX="-${COLORS}c"

    # Redefine file name prefix using options as reference. This is

    # useful to differenciate final files produced using

    # Floyd-Steinberg dithering and 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.  This palettes should have

    # 14 colors only. For more information on this see the GRUB's

    # documentation.

    local PALETTE_GPL=${MOTIF_DIR}/Palettes/grub.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/grub.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 "grub.ppm")

    # 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"

    # 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}.ppm" --as-savedas-line

    pnmremap -verbose -mapfile=$PALETTE_PPM $OPTIONS \

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

    # Remove PPM palette. It is no longer needed.

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

        rm $PALETTE_PPM

    fi

    # Create the 14 colors xpm.gz file.

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

    ppmtoxpm \

        < ${FILE}${PREFIX}.ppm 2>>${LOGS} > ${FILE}.xpm \

        && gzip --force ${FILE}.xpm \

        && mv ${FILE}.xpm.gz ${FILE}${PREFIX}.xpm.gz

}