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#!/bin/bash
#
# render_doSyslinux.sh -- This function provides post-rendition
# action used to produce LSS16 images, the images used by isolinux.
#
# This function uses three different formats to handle the same color
# information. Initially, the color information is defined with GIMP
# (The GNU Image Manipulation Program) as a 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'
# file is used to reduce a full color PNG image to the amount of
# colors it specifies (i.e., 16 colors). Later, with the 16 color
# 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 needed
# that both the `syslinux.ppm' and `syslinux.hex' files contain the
# same color information. This is, both `syslinux.ppm' and
# `syslinux.hex' shoud represent the same color values and the same
# color index.
#
# This function save you the work of preparing both `syslinux.ppm' and
# `syslinux.hex'. Instead, you only need to prepare the `syslinux.gpl'
# file with the color information you want to produce images.
#
# In order for this function to work, the `syslinux.gpl' file should
# have a format similar to the following:
#
# GIMP Palette
# Name: TreeFlower-4-Syslinux
# Columns: 16
# #
# 10 22 40 0a1628
# 9 28 52 091c34
# 16 34 63 10223f
# 20 37 67 142543
# 15 39 74 0f274a
# 12 45 85 0c2d55
# 20 43 78 142b4e
# 255 255 255 ffffff
# 21 51 95 15335f
# 41 52 70 293446
# 32 76 141 204c8d
# 77 90 107 4d5a6b
# 143 154 167 8f9aa7
# 128 179 255 80b3ff
# 194 200 202 c2c8ca
# 231 241 255 e7f1ff
#
# Copyright (C) 2009, 2010, 2011 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 render_doSyslinux {
# Define number of colors the images will be produced on.
local COLOR_NUMBER='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="-${COLOR_NUMBER}c"
# Re-define 16 colors images default file name prefix using
# options as reference. This is useful to differenciate final
# files produced using Floyd-Steinberg dithering and final files
# which are not.
if [[ "$OPTIONS" =~ '-floyd' ]];then
PREFIX="${PREFIX}-floyd"
fi
# Define theme-specific palettes directory.
local PALETTES=$(cli_getRepoTLDir)/Identity/Images/Themes/$(cli_getPathComponent '--theme')/Palettes
# Define absolute path to GPL palette. The GPL palette defines the
# color information used to build syslinux images. This palette
# should be set to 16 colors and, as specified in isolinux
# documentation, the background color should be indexed on
# position 0 and the forground in position 7 (see
# /usr/share/doc/syslinux-X.XX/isolinux.doc, for more
# information.)
local PALETTE_GPL=${PALETTES}/syslinux.gpl
# Verify GPL palette existence.
cli_checkFiles $PALETTE_GPL
# Define absolute path to PPM palette. The PPM palette is built
# from source palette (PALETTE_GPL) and provides the color
# information understood by `ppmremap', the program used to
# produce images in a specific amount of colors.
local PALETTE_PPM=$(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 \
< ${FILE}.png 2>${FILE}.log > ${FILE}.pnm
# Print the path to GPL palette.
cli_printMessage "$PALETTE_GPL" --as-palette-line
# Create PPM palette using GPL palette.
render_convertGplToPpm "$PALETTE_GPL" "$PALETTE_PPM" "$COLOR_NUMBER"
# Create HEX palette using GPL palette.
render_convertGplToHex "$PALETTE_GPL" "$PALETTE_HEX" "$COLOR_NUMBER"
# 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>> ${FILE}.log > ${FILE}${PREFIX}.pnm
# Create LSS16 image.
cli_printMessage "${FILE}${PREFIX}.lss" --as-savedas-line
ppmtolss16 $(cat $PALETTE_HEX) \
< ${FILE}${PREFIX}.pnm 2>>${FILE}.log > ${FILE}${PREFIX}.lss
# Remove HEX palette. It is no longer needed.
if [[ -f ${PALETTE_HEX} ]];then
rm $PALETTE_HEX
fi
# 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" --as-savedas-line
lss16toppm -map \
< ${FILE}${PREFIX}.lss 2>>${FILE}.log > ${FILE}${PREFIX}.ppm
# Create the 16 colors PNG image.
cli_printMessage "${FILE}${PREFIX}.png" --as-savedas-line
pnmtopng -verbose -palette=$PALETTE_PPM \
< ${FILE}${PREFIX}.pnm 2>>${FILE}.log > ${FILE}${PREFIX}.png
# Remove PPM palette. It is no longer needed.
if [[ -f ${PALETTE_PPM} ]];then
rm $PALETTE_PPM
fi
}