#!/usr/bin/perl
    use GD;
   #use strict;
   my @x1;
   my @y1;
   my $max1;
   my $max2;
   my $min1;
   my $min2;
   my $i;
    open(FILE1,"fwd.stb");
    while(<FILE1>)
    {
        my @value = split(/\s+/,$_);
        $x1[$i] =  $value[0]-7;
        $y1[$i] = $value[1];

        if($i != 0 && $y1[$i] > $max1)
        {
                $max1 = $y1[$i];
        }

        if($i != 0 && $y1[$i] < $min1)
        {
                $min1 = $y1[$i];
        }

        if($i == 0)
        {
                $min1 = $max1 = $y1[$i];
        }
        $i++;
    }

   my $lines = $i;

    # Define constants
  my    $X1start = 50+20;  # X-axis
  my    $Y1start = 300;    #  X-axis
  my    $X1end   = 450+$lines-400; # X-axis
  my    $Y1end   = 300;  # X-axis
  my    $X2start = 50+20;
  my    $Y2start = 100;
my    $X2end   = 50+20;
  my    $Y2end   = 300;

    # create a new image
  my  $im = new GD::Image($X1end+50,$Y2end+100);

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

    # set the caption for the graph
    $im->string(gdLargeFont,int($lines/2)-50,20,"ENERGY GRAPH",$black);

    # draw the y-axis & x-axis
    $im->line($X2start,$Y2start,$X2end,$Y2end,$black);
    $im->line($X1start,$Y1start,$X1end,$Y1end,$black);

    # set the caption for x-axis and y-axis
    $im->string(gdLargeFont,int($lines/2)-50,335,"NUCLEOTIDE POSITION",$black);
    $im->stringUp(gdLargeFont,5,260,"FREE ENERGY(delta G)",$black);

    $im->string(gdSmallFont,int($lines/2)+100,20," Genomic  Sequence -------",$red);
    $im->string(gdSmallFont,int($lines/2)+100,40," Shuffled Sequence -------",$blue);

    open(FILE2,"total_shuffle.stb");

    $i = 0;
    my @x2;
    my @Y2;
    my $min;
    my $max;

    while(<FILE2>)
    {
        my @value = split(/\s+/,$_);
        $x2[$i] = $value[0]-7;
        $y2[$i] = $value[1];

        if($i != 0 && $y2[$i] > $max2)if($i != 0 && $y2[$i] > $max2)
        {
                $max2 = $y2[$i];
        }

        if($i != 0 && $y2[$i] < $min2)
        {
                $min2 = $y2[$i];
        }

        if($i == 0)
        {
                $min2 = $max2 = $y2[$i];
        }
        $i++;
    }

    if($min1 <= $min2)
    {
        $min = $min1;
    }
    else
    {
        $min = $min2;
    }

    if($max1 >= $max2)
    {
        $max = $max1;
    }
    else
    {
        $max = $max2;
    }

    @y = @y1;
    @x = @x1;
    graph();

    @y = @y2;
    @x = @x2;my  $png_data = $im->png;
    open (DISPLAY,"| display -") || die;
    #open (DISPLAY,">image.jpg") || die;
    binmode DISPLAY;
    print DISPLAY $png_data;
    close DISPLAY;

sub graph
{
    # set min and max energy
   my  $minEnergy = $min;
   my $maxEnergy = $max;

    # set the length of x-axis and y-axis
my   $xLen = $X1end-$X1start;
my   $yLen = $Y2end-$Y2start;

    # Scaling the values
    $Yscale = $yLen/(abs($minEnergy)-abs($maxEnergy));

    $scale = ($minEnergy-$maxEnergy)/5;

    $incEnergy = $maxEnergy;
    while($incEnergy > $minEnergy)  ##### Prob loop####
    {

                $x1 = $X1start-2;
                $y1 = int(((abs($incEnergy)-abs($maxEnergy))*$Yscale)+$Y2start);
                $x2 = $X1start+2;

                $im->line($x1,$y1,$x2,$y1,$black);
                $displayEnergy = sprintf("%2.1f",$incEnergy);
                $im->string(gdSmallFont,$x1-35,$y1-10,$displayEnergy,$black);
                $incEnergy = $incEnergy+$scale;
    }

    # set the length of nucleotide
    $len = @x;

    # mark 10 points on the position axis
    $posSkip = int(@x/10);
# If the length of the fragment is lesser than the x-axis

        $skipPixel = $xLen/$len;

        for($i=0;$i<$len-1;$i++)
        {
                $x1 = int(($i*$skipPixel)+$X1start);
                $y1 = int(((abs($y[$i])-abs($maxEnergy))*$Yscale)+$Y2start);
                $x2 = int((($i+1)*$skipPixel)+$X1start);
                $y2 = int(((abs($y[$i+1])-abs($maxEnergy))*$Yscale)+$Y2start);

                if($call == 0)
                {
                        $im->line($x1,$y1,$x2,$y2,$red);
                }
                else
                {
                        $im->line($x1,$y1,$x2,$y2,$blue);
                }
                $count++;

                if($count == $posSkip)

                {
                        $x1 = int(($i*$skipPixel)+$X1start);
                        $y1 = $Y1end-2;
                        $x2 = int(($i*$skipPixel)+$X1start);
                        $y2 = $Y1end+2;

                        if($call == 0)
                        {
                                $im->line($x1,$y1,$x2,$y2,$black);
                                $im->string(gdSmallFont,$x1,$y1+10,$i+1,$black);
                        }
                        $count = 0;
                }
        }
    $call++;
}