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lib/Graph/Chart.pm  view on Meta::CPAN

	this overwrite the png TAG data with the new value and return the new image

=cut

sub png_zEXt
{
    my $self   = shift;
    my $object = shift;
    $self->{ size_tot }->[0] = $self->{ size }->[0] + $self->{ border }->[0] + $self->{ border }->[1];
    $self->{ size_tot }->[1] = $self->{ size }->[1] + $self->{ border }->[2] + $self->{ border }->[3];
    my $tmp = clone( $self );
#     delete $tmp->{ data };
    foreach my $idx (0 .. scalar @{$tmp->{ data }})
    {
    
     next if ( ! defined  $tmp->{ data }[ $idx ] );
    delete $tmp->{ data }[ $idx]{ set};
    }
    delete $tmp->{ img };

    my $obj = Data::Serializer->new( 'compress' => 1 );
    $object->{ 'Graph::Chart' } = $tmp;
    my $tag = $obj->serialize( $object );
    my $png_out;
    my $ihdr;       # IHDR chunk
    my %tEXt;       # tEXt chunks to insert
    my $sig;        # PNG signature
    my $pos;        # position in $png
    my $pngsize;    # Total size of png
    my $text;       # 'string' of all tEXt chunks with CRC, etc.
    my $tchunk;     # content of text chunk
    $tEXt{ data } = $tag;
    ( $sig, $ihdr, $png_out ) = unpack "a8 a25 a*", $self->{ img };
    $png_out =~ /(.*)(....PLTE.*)/s;

    my $old_tag = $1;
    my $end_png = $2;

    foreach my $keyword ( keys %tEXt )
    {

#*    A tEXt chunk contains:
#*
#*       Keyword:            1-79 bytes (character string)
#*       Null separator:     1 byte
#*       Compression method: 1 byte
#*       Compressed text:    n bytes
        my $tbuffer;
        $tbuffer = $tEXt{ $keyword };
        $tbuffer =~ s/\\([tnrfbae])/control_char($1)/eg;
        $tchunk = sprintf "%s%c%s", $keyword, 0, $tbuffer;
        $text .= pack "N A* N", ( length( $tchunk ), 'tEXt' . $tchunk, &crc32( 'tEXt' . $tchunk ) );
        $pngsize += length( $tchunk ) + 8;
    }
    $png_out = $sig . $ihdr . $text . $end_png;
    $self->{ img } = $png_out;
    return $self->{ img };
}

###########################################################################
sub update
{
    my $self   = shift;
    my $object = shift;
#     carp Dumper($self);
     my $image_gd  = GD::Image->new( $self->{img});
#     carp $image_gd;
#     
#      $image->copy($sourceImage,$dstX,$dstY,  $srcX,$srcY,$width,$height)

}




###########################################################################
### 			method to render the Chart 			###
###########################################################################

=head2 render

	render the chart and return a png image


  my $img = $graph->render( \%tag )
   
   
  the hash ref contain data to put in the PNG meta tag.
  the tools img_info.pl allow to see the result.
  the tag is serialized in the png
  
  the returned value could be writted in a file like this:
  my $png_out = $graph->render();
  
    open( my $IMG, '>', $file ) or die $!;
    binmode $IMG;
    print $IMG $png_out;
    close $IMG;
);

=cut

sub render
{
    my $self   = shift;
    my $object = shift;

    my $frame = new GD::Image( $self->{ size }->[0] + $self->{ border }->[0] + $self->{ border }->[1], $self->{ size }->[1] + $self->{ border }->[2] + $self->{ border }->[3] );
    my $bg_color = _color_allocate( $self->{ bg_color }, 'ffffffff', $frame );
    my $bg_color = _color_allocate( $self->{ bg_color }, 'ffffffff', $frame );
    $frame->transparent( $bg_color );
    $frame->interlaced( 'true' );

### plot overlay
    if ( exists $self->{ overlay } )
    {
        foreach my $layer ( @{ $self->{ overlay } } )
        {
            next unless ( ref $layer eq 'HASH' );
            my $col_graph;
            my $frame_over;