#!/bin/bash
#
# identity_renderImageSyslinux.sh -- This function provides
# post-rendition action used to produce syslinux images.
#
# Copyright (C) 2009-2011 Alain Reguera Delgado
# 
# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
# USA.
# 
# ----------------------------------------------------------------------
# $Id$
# ----------------------------------------------------------------------

function identity_renderImageSyslinux {

    local FILE="$1"
    local ACTION="$2"
    local OPTIONS=''

    # Define 16 colors images default file name prefix.
    local PREFIX='-16c'

    # 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.
    OPTIONS=$(identity_getConfigOption "$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 $OPTION | cut -d'=' -f1)
        if [[ "$OPTION" =~ "-(mapfile|verbose)" ]];then
            cli_printMessage "`eval_gettext "The \\\$OPTION option is already used."`"
            cli_printMessage "$(caller)" "AsToKnowMoreLine"
        fi
    done

    # 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 motif's palette location.
    local PALETTES=$(cli_getRepoTLDir)/Identity/Themes/Motifs/$(cli_getPathComponent '--theme')/Colors
   
    # Define the Netpbm color palette used when reducing colors. This
    # palette should be 16 colors based. For more information on this
    # see the isolinux documentation.
    local PALETTE_PPM=$PALETTES/syslinux.ppm

    # Define hexadecimal color information used by ppmtolss16.  Color
    # information and order used on PALETTE_HEX and PALETTE_PPM should
    # match exactly.
    local PALETTE_HEX=$PALETTES/syslinux.hex

    # Print which palette of colors centos-art.sh script is using to
    # produce grub content. This is relevant in order to know if we
    # are using whether trunk or branches palette of colors.
    cli_printMessage "$PALETTE_PPM" 'AsPaletteLine'
    cli_printMessage "$PALETTE_HEX" 'AsPaletteLine'

    # Check syslinux's palettes existence:  If there is no palette
    # assume that this is the first time you are rendition syslinux
    # images. If that is the case the script will provide you with the
    # PNG format which should be used as base to produce (using GIMP)
    # the .gpl palette.  The .gpl palette information is used to
    # produced (using GIMP) the colormap (.ppm) which is used to
    # automate the syslinux's 16 colors image (syslinux-splash.png)
    # rendition.  If there is no palette available, do not apply color
    # reduction, show a message, and continue.
    cli_checkFiles $PALETTE_PPM
    cli_checkFiles $PALETTE_HEX

    # Create Netpbm superformat (PNM). PNM file is created from the
    # PNG image rendered previously. PNM is a common point for image
    # manipulation using Netpbm tools.
    cli_printMessage "${FILE}.pnm" "AsSavedAsLine"
    pngtopnm -verbose \
        < ${FILE}.png 2>${FILE}.log > ${FILE}.pnm
   
    # Reduce colors. Here we use the Netpbm color $PALETTE_PPM to
    # enforce the color position in the image index and the
    # Floyd-Steinberg dithering in order to improve color reduction.
    cli_printMessage "${FILE}${PREFIX}.pnm" "AsSavedAsLine"
    pnmremap -verbose -mapfile=$PALETTE_PPM $OPTIONS \
        < ${FILE}.pnm 2>> ${FILE}.log > ${FILE}${PREFIX}.pnm

    # Create LSS16 image. As specified in isolinux documentation the
    # background color should be indexed on position 0 and forground
    # in position 7 (see /usr/share/doc/syslinux-X.XX/isolinux.doc).
    # This order of colors is specified in $PALETTE_PPM and redefined
    # here again for the LSS16 image format. Both $PALETTE_PPM and
    # LSS16 color map redefinition ($PALETTE_HEX) should have the same
    # colors and index order. PALETTE_HEX should return just one line
    # with the color information as described in isolinux
    # documentation (i.e #RRGGBB=0 #RRGGBB=1 ... [all values in the
    # same line]).
    cli_printMessage "${FILE}${PREFIX}.lss" "AsSavedAsLine"
    PALETTE_HEX=$(cat $PALETTE_HEX | tr "\n" ' ' | tr -s ' ')
    ppmtolss16 $PALETTE_HEX \
        < ${FILE}${PREFIX}.pnm 2>>${FILE}.log > ${FILE}${PREFIX}.lss
     
    # Create the 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" "AsSavedAsLine"
    lss16toppm -map \
        < ${FILE}${PREFIX}.lss 2>>${FILE}.log > ${FILE}${PREFIX}.ppm
      
    # Create the 16 colors PNG image.
    cli_printMessage "${FILE}${PREFIX}.png" "AsSavedAsLine"
    pnmtopng -verbose -palette=$PALETTE_PPM \
        < ${FILE}${PREFIX}.pnm 2>>${FILE}.log > ${FILE}${PREFIX}.png
   
}