#!/usr/bin/perl
#
# $Id: graph.png,v 1.7 2002/01/22 15:12:05 minaeibi Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA 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.
#
# LON-CAPA 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 LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/cgi-bin/graph.gif
#
# http://www.lon-capa.org/
#
# The LearningOnline Network with CAPA
# Behrouz Minaei
# YEAR=2001
# 9/13/2001, 9/25/2001, 10/6/2001, 10/9/2001, 12/25/2001
#
# A CGI script that dynamically outputs a graphical chart for lonstatistics.
# 
#### 

use strict;
use GD::Graph::bars3d;
use GD::Graph::colour;
use GD::Graph::Data;

$|=1;   # Autoflush after each print/write
my ($cid, $Tag, $Max, $PNo, $data) = split(/&/,$ENV{'QUERY_STRING'});

my @data1=split(/\,/,$data);
   
my @xlabels;
for (my $nIdx=0; $nIdx<$PNo; $nIdx++ ) {
    $xlabels[$nIdx]=$nIdx+1;
} 
my @data =(\@xlabels,\@data1);

my $Range;
if ( $PNo > 10 ) {$Range = 30*$PNo;}
else { $Range = 300+30*$PNo; }

$Max += (10 - $Max % 10);

my $MyGraph = GD::Graph::bars3d->new($Range, 400);

$MyGraph->set( 
    x_label         => 'Problems #',
    y_label         => $Tag,
    title           => 'LON-CAPA Graphical Chart, Course: '.$cid,
    y_max_value     => $Max,
    y_tick_number   => 10,
    y_label_skip    => 1,
    x_label_skip    => 2,
    
    # colors
    dclrs           => [ qw( green lblue lyellow lpurple cyan lorange)],
    
    # shadows
    bar_spacing     => 4,
    shadow_depth    => 1,
    shadowclr       => 'dred',

    transparent     => 0,
) or warn $MyGraph->error; 

# Tell the server we are sending a gif graphic
print <<END;
Content-type: image/gif

END

my $BinaryData=$MyGraph->plot(\@data)->png;
undef $MyGraph;
binmode(STDOUT);
open IMG,"|pngtopnm|ppmtogif 2>/dev/null"; # convert into a gif image
print IMG $BinaryData; # output image
$|=1; # be sure to flush before closing
close IMG;