#! /usr/bin/perl
#########################################################################
#        This Perl script is Copyright (c) 2002, Peter J Billam         #
#               c/o P J B Computing, www.pjb.com.au                     #
#                                                                       #
#     This script is free software; you can redistribute it and/or      #
#            modify it under the same terms as Perl itself.             #
#########################################################################

eval "require 'Math/Evol.pm';";
if ($@) { require 'Evol.pm'; }
import Math::Evol;

eval "require 'Term/Clui.pm';";
if ($@) { require 'Clui'; }
import Term::Clui;

$tmpfile = "/tmp/ps_evol_$$.ps";

sub choose_best_text {
	if (! open (T, "> $tmpfile")) { die "can't open $tmpfile: $!\n"; }
	print T @prolog;
	print T <<EOT;
(Helvetica-Bold) findfont 14 scalefont setfont
gsave 207 289 translate 5 5 moveto (5) show 0.30 dup scale
$_[0]
grestore gsave  20 550 translate 5 5 moveto (1) show 0.30 dup scale
$_[1]
grestore gsave 207 550 translate 5 5 moveto (2) show 0.30 dup scale
$_[2]
grestore gsave 394 550 translate 5 5 moveto (3) show 0.30 dup scale
$_[3]
grestore gsave  20 285 translate 5 5 moveto (4) show 0.30 dup scale
$_[4]
grestore gsave 394 285 translate 5 5 moveto (6) show 0.30 dup scale
$_[5]
grestore gsave  20  20 translate 5 5 moveto (7) show 0.30 dup scale
$_[6]
grestore gsave 207  20 translate 5 5 moveto (8) show 0.30 dup scale
$_[7]
grestore gsave 394  20 translate 5 5 moveto (9) show 0.30 dup scale
$_[8]
grestore showpage
%%EOF
EOT
close T;
	my $preference = &choose('Re-Load. Now which drawing do you prefer ?',
		'1','2','3','4','5','6','7','8','9');
	my $continue   = &confirm('Continue ?');
	if ($preference eq '5') { $preference = 0;
	} elsif ((0+$preference) > 5) { $preference = -1 + $preference;
	} else { $preference = 0 + $preference;
	}
	return ($preference, $continue);
}
while (<>) { push @prolog, $_; if (/EndProlog/) { last; } }
while (<>) { push @prolog, $_; if (/EndPageSetup/) { last; } }
while (<>) { if (/showpage/)  { last; } push @page, $_; }
&inform ("Use GhostView or equivalent to view $tmpfile");
my $new_page = &text_evol(join ('', @page), \&choose_best_text, 8);
print join('', @prolog), $new_page, "showpage\n%%EOF\n";
&confirm("OK to remove $tmpfile ?") && unlink $tmpfile;
exit 0;

__END__

=pod

=head1 NAME

ps_evol - Perl script to fine-tune A4 PostScript drawings

=head1 SYNOPSIS

 vi plant.ps
 ps_evol plant.ps > p2.ps

=head1 DESCRIPTION

I<ps_evol> is mainly intended as a demo script
illustrating the I<text_evol> funtion in Math::Evol.pm.
It assumes you have something like GhostView
which allows you to view PostScript files.

It creates a temporary PostScript file,
then repeatedly generates eight variants of the original file,
scales them smaller, numbers them, and displays them in a 3x3 array.
The original is in the middle, as number 5.
It asks the user which variant they prefer,
then uses that as the original for the next iteration.
When the user decides to call a halt,
the latest preferred variant is written to the standard output.

The parameters to be varied in the PostScript file
must be marked out by special comments, such as

 /gray_sky .87 def % evol step 0.05 min 0.0 max 1.0

See I<perldoc Math::Evol> for more details,
and as an example the PostScript file I<plant.ps>,
included with the distribution.

Version 1.05,
#COMMENT#

=head1 DEPENDENCIES

Uses the CPAN module Term::Clui.pm to dialogue with the user.

=head1 AUTHOR

Peter J Billam, www.pjb.com.au/comp/contact.html

=head1 CREDITS

Based on Math::Evol.pm, and conceptually on
Richard Dawkin's I<Blind Watchmaker> software.

=head1 SEE ALSO

Math::Evol.pm, Term::Clui.pm, http://www.pjb.com.au/, perl(1).

=cut