#!/usr/bin/perl -w
use CGI qw/:standard/;    # load standard CGI routines
use GD;		      # load GD library

# create GD image object (width,height)
$image = new GD::Image(900,500);

# allocate some colors
$white = $image->colorAllocate(255,255,255);
$black = $image->colorAllocate(0,0,0);       
$blue = $image->colorAllocate(0,0,255);
$red = $image->colorAllocate(255,0,0);

# make the background transparent 
$image->transparent($white);

# Put a black frame around the picture
$image->rectangle(10,10,890,490,$black);

# Create a paintbrush so we can draw a thicker red line
$mybrush = new GD::Image(4,4);
$brushred = $mybrush->colorAllocate(255,0,0);
# remember, first color is background so this will be a solid rectangle
$mybrush->rectangle(1,1,2,2,$brushred);
# use $mybrush in setBrush for $image which makes this the color gdBrushed
$image->setBrush($mybrush);
# draw the red rectangle
$image->rectangle(20,20,880,480,gdBrushed);

# draw lines with alternating color; note each line is one pixel thick
$image->line(50,50,850,50,$blue);
$image->line(50,51,850,51,$red);
$image->line(50,52,850,52,$black);
$image->line(50,53,850,53,$blue);
$image->line(50,54,850,54,$red);
$image->line(50,55,850,55,$black);
$image->line(50,56,850,56,$blue);
$image->line(50,57,850,57,$red);
$image->line(50,58,850,58,$black);
$image->line(50,59,850,59,$blue);
$image->line(50,60,850,60,$red);
$image->line(50,61,850,61,$black);

#draw a polygon
$mypoly = new GD::Polygon;
$mypoly->addPt(400,100);
$mypoly->addPt(500,173);
$mypoly->addPt(300,173);
#draw the polygon
$image->polygon($mypoly,$black);

#and a blue filled polygon
$mypoly = new GD::Polygon;
$mypoly->addPt(400,246);
$mypoly->addPt(500,173);
$mypoly->addPt(300,173);
$mypoly->addPt(200,150);
#draw the polygon
$image->filledPolygon($mypoly,$blue);

#and a red filled polygon
$mypoly = new GD::Polygon;
$mypoly->addPt(400,247);
$mypoly->addPt(500,320);
$mypoly->addPt(300,320);
#draw the polygon
$image->filledPolygon($mypoly,$red);

#and a polygon
$mypoly = new GD::Polygon;
$mypoly->addPt(400,393);
$mypoly->addPt(500,320);
$mypoly->addPt(300,320);
#draw the polygon
$image->polygon($mypoly,$black);

# draw an arc and a circle
$image->arc(600,220,30,30,0,360,$black) ;
$image->arc(600,320,110,160,180,0,$black) ;

#text normal
$image->string(gdGiantFont,200,200,"GD",$blue); 

#text sideways
$image->stringUp(gdMediumBoldFont,598,400,"COLOR",$red); 

# save image as a PNG file
$pngimage=$image->png;



#open a file for writing; note the address used here
$base = "/var/www/html/images/students_06/username/";
#$base="";
$image_file = $base."snoopy_beagle.gif";
open (PNGOutfile, ">$image_file") or die "Unable to open $image_file: $!";



# make sure we are writing to a binary stream
binmode PNGOutfile;

#write file 
print PNGOutfile $pngimage;
close PNGOutfile;

# create the CGI object and send image
$q = new CGI;                 		
print 
 $q->header('text/html'),                   	
 $q->start_html,
 $q->h1('image test'),
#note path here is different from path to save file; this is because the way #the server is set up, bioed.bu.edu starts at /usr/local/apache2/www
#this will be different on different systems
  $q-> img({-src=>'https://bioed.bu.edu/images/students_06/username/snoopy_beagle.gif'}),
  $q->end_html;