#!/usr/bin/env perl
# vchess.wrapper - Launcher for "vchess" main program
# License:  Creative Commons Attribution-NonCommercial-ShareAlike 2.5
# Revision: 080813

# Note:  The license indicated above applies to this file.  It doesn't
# apply to the official Vulcan Chess package,  or to  any file derived
# from that package.

#---------------------------------------------------------------------
#                         license information
#---------------------------------------------------------------------

# This section may not be modified except as approved by the author or
# licensor, or to make non-content changes such as adjustments to par-
# agraph formatting or white space.

# This  version of this software is  distributed  under  the following
# license:
#
#       Creative Commons Attribution-NonCommercial-ShareAlike 2.5

# You may use, modify, and redistribute this software without fees  or
# royalties, but only under the terms and conditions set forth  by the
# license.  In particular, copies and derived works cannot be used for
# commercial purposes.  Additionally, the license propagates to copies
# and derived works. Furthermore, you must provide attribution "in the
# manner  specified  by the  author or licensor".  The latter point is
# discussed below.

# The author [and licensor] hereby specifies that  attribution must be
# handled in the following manner:  a. If the software is interactive,
# any  About or Credits dialog boxes, windows, or output text provided
# by the  original version must be preserved and readily accessible to
# the end user at runtime.  b. If the software is non-interactive,  or
# if it does not  provide  About or Credits dialog boxes, windows,  or
# output text,  the  operating system and/or  desktop environment used
# must provide attribution that is  visible and/or  readily accessible
# to the end user at runtime.

# The following techniques  do not meet the  attribution requirements:
# Attribution through text  files, attribution  through  printed docu-
# mentation,  verbal  attribution, or postings on  external  web sites
# [i.e.,  web  sites  that are not an intrinsic local component of the
# operating system or  desktop environment used].  These  examples are
# provided for illustrative purposes only.

# It should be noted that trademarks are an additional issue.  If this
# software  uses any  trademarks,  trademark-related  restrictions may
# apply.

# This is not a  complete explanation of the  terms and conditions in-
# volved.  For more information, see the Creative Commons Attribution-
# NonCommercial-ShareAlike 2.5 license.

#---------------------------------------------------------------------
#                             explanation
#---------------------------------------------------------------------

# 1. Overview:

# This script performs some setup operations and starts  the main Vul-
# can chess executable [which must be renamed to "vchess.bin"].  Pres-
# ently, the following steps are implemented:
#
#     a. It optionally verifies that multiple instances of the program
#        aren't running.  If the test is done,  and multiple instances
#        are running, a fatal-error message is displayed.
#
#     b. It optionally verifies that the program isn't running through
#        VNC. If the test is done, and the program  is running through
#        VNC, a fatal-error message is displayed.
#
#     c. It optionally verifies that  direct rendering  is  available.
#        If the test is done, and direct rendering isn't available,  a
#        fatal-error message is displayed.
#
#     d. If optionally  checks  for  NVidia graphics hardware.  If the
#        test is done,  and NVidia  graphics hardware  is  present,  a
#        warning message is displayed. Note: The user may exit at this
#        point.

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

# 2. Requirements:

# At the GUI level,  this program requires  Perl 5,  "glxinfo",  Perl-
# Gtk2, and LACSUB.

# These components are standard, except for LACSUB. You should be able
# to obtain LACSUB from  the  same  place as this file.  Note:  LACSUB
# [like this file] is  distributed under a  Creative Commons  license.
# For more information about  license issues,  see the comments at the
# start of this file.

#---------------------------------------------------------------------
#                        standard module setup
#---------------------------------------------------------------------

require 5.6.1;
use strict;
use Carp;
use warnings;
                                # Trap warnings
$SIG {__WARN__} = sub { die @_; };

#---------------------------------------------------------------------
#                         add CPAN module[s]
#---------------------------------------------------------------------

use Gtk2 '-init';
use Gtk2::SimpleList;

#---------------------------------------------------------------------
#                        add LACSUB module[s]
#---------------------------------------------------------------------

use LACSUB::GUI
 ( @LACSUB::GUI::EXPORT_OK );

#---------------------------------------------------------------------
#                           basic constants
#---------------------------------------------------------------------

use constant ZERO  => 0;        # Zero
use constant ONE   => 1;        # One

use constant FALSE => 0;        # Boolean FALSE
use constant TRUE  => 1;        # Boolean TRUE

#---------------------------------------------------------------------
#                         program parameters
#---------------------------------------------------------------------

my $DIR_BASE        = '__META_PREFIX__';
my $IE              = 'Internal error';
my $PROGNAME        = 'vchess';
my $REVISION        = '080813'; # Revision [or release] string

my $ALERT_ICON_PATH = "$DIR_BASE/misc/alert.png";
my $NEXT_PROGRAM    = "$DIR_BASE/bin/$PROGNAME.bin";

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

# If this program requires direct-rendering support,  set $FLAG_CHECK_
# DIRECT_RENDERING equal to TRUE.  Otherwise,  set this flag  equal to
# FALSE.

my $FLAG_CHECK_DIRECT_RENDERING = TRUE;

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

# If this program has difficulties with NVidia graphics hardware,  set
# $FLAG_CHECK_NVIDIA equal to TRUE.  Otherwise, set this flag equal to
# FALSE.

my $FLAG_CHECK_NVIDIA = TRUE;

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

# If you'd like  to prohibit  multiple instances,  set $FLAG_PROHIBIT_
# MULTI_INSTANCE to TRUE. Otherwise, set this flag to FALSE.

my $FLAG_PROHIBIT_MULTI_INSTANCE = TRUE;

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

# If this program shouldn't try to run under VNC,  set $FLAG_PROHIBIT_
# VNC equal to TRUE. Otherwise, set this flag equal to FALSE.

my $FLAG_PROHIBIT_VNC = TRUE;

#---------------------------------------------------------------------
#                            main routine
#---------------------------------------------------------------------

sub Main
{

#---------------------------------------------------------------------
# Verify that program isn't already running.

    &VerifyNotRunning
    (
        -icon_path    => $ALERT_ICON_PATH ,
        -name         => $PROGNAME        ,

        -pattern_this =>
            ':\d\d\s(perl |)(\S+/|)' . $PROGNAME . '(|\.wrapper)\s' ,
        -pattern_next =>
            ':\d\d\s(perl |)(\S+/|)' . $PROGNAME . '\.bin\s'
    )
        if $FLAG_PROHIBIT_MULTI_INSTANCE;

#---------------------------------------------------------------------
# Go to user's home directory.

    my $HOME = $ENV {HOME};
    $HOME = '/' unless defined $HOME;
    chdir $HOME;

#---------------------------------------------------------------------
# Handle VNC test (if enabled).

    &AbortIfVNC
    (
        -icon_path => $ALERT_ICON_PATH ,
        -name      => $PROGNAME
    )
        if $FLAG_PROHIBIT_VNC;

#---------------------------------------------------------------------
# Handle direct-rendering test (if enabled).

    &AbortUnlessDRI
    (
        -icon_path => $ALERT_ICON_PATH ,
        -name      => $PROGNAME
    )
        if $FLAG_CHECK_DIRECT_RENDERING;

#---------------------------------------------------------------------
# NVidia-related kludge.

    &CheckNVidia
    (
        -icon_path => $ALERT_ICON_PATH ,
        -name      => $PROGNAME
    )
        if $FLAG_CHECK_NVIDIA;

#---------------------------------------------------------------------
# Wrap it up.

    exec $NEXT_PROGRAM, @ARGV;  # Chain to target program
}

#---------------------------------------------------------------------
#                            main program
#---------------------------------------------------------------------

&Main();                        # Call the main routine
exit ZERO;                      # Normal exit