#!/bin/bash

#

# render_doIdentityImageSyslinux.sh -- This function provides

# post-rendering action used to produce syslinux images.

#

# Copyright (C) 2009-2010 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: render_doIdentityImageSyslinux.sh 71 2010-09-18 05:41:11Z al $

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

function render_doIdentityImageSyslinux {

    local FILE=$1

    # Define Motif's palette location. We do this relatively.

    local PALETTES=/home/centos/artwork/trunk/Identity/Themes/Motifs/$(cli_getThemeName)/Palettes

    # 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

    # Check syslinux's palettes existence:  If there is no palette

    # assume that this is the first time you are rendering 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)

    # rendering.  If there is no palette available, do not apply color

    # reduction, show a message, and continue.

    cli_checkFiles "$PALETTE_PPM

                $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-16c.pnm" "AsSavedAsLine"

    pnmremap -verbose -floyd -mapfile=$PALETTE_PPM \

        < $FILE.pnm \

        2>>$FILE.log > $FILE-16c.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.lss" "AsSavedAsLine"

    PALETTE_HEX=$(cat $PALETTE_HEX | tr "\n" ' ' | tr -s ' ')

    ppmtolss16 $PALETTE_HEX \

        < $FILE-16c.pnm \

        2>>$FILE.log \

        > $FILE.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-16c.ppm" "AsSavedAsLine"

    lss16toppm -map < $FILE.lss \

       2>>$FILE.log \

       > $FILE.ppm

    # Create the 16 colors PNG image.

    cli_printMessage "$FILE-16c.png" "AsSavedAsLine"

    pnmtopng -verbose -palette=$PALETTE_PPM \

       < $FILE-16c.pnm \

       2>>$FILE.log \

       > $FILE-16c.png

}