#!/bin/bash

#

# render_doIdentityImageGrub.sh -- This function provides

# post-rendering action used to produce GRUB 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_doIdentityImageGrub.sh 71 2010-09-18 05:41:11Z al $

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

function render_doIdentityImageGrub {

    local FILE=$1

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

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

    # Define the Netpbm color palettes used when reducing colors.

    # These palettes should be 14 colors based. For more information

    # on this see the GRUB's documentation.

    local PALETTE_PPM=$PALETTES/grub.ppm

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

    # that this is the first time you are rendering GRUB 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

    # GRUB's 14 colors image (splash.png) rendering.  If there is no

    # palette available, do not apply color reduction, show a message,

    # and continue.

    cli_checkFiles $PALETTE_PPM

    # 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-14c.ppm" "AsSavedAsLine"

    pnmremap -verbose -floyd -mapfile=$PALETTE_PPM \

        < $FILE.pnm \

        2>>$FILE.log \

        > $FILE-14c.ppm

    # Create the XPM.GZ file. This is the file we put at

    # /boot/grub/splash.xpm.gz.

    cli_printMessage "$FILE.xpm.gz" "AsSavedAsLine"

    ppmtoxpm \

        < $FILE-14c.ppm \

        2>>$FILE.log \

        > $FILE.xpm \

        && gzip --force $FILE.xpm

}