=head1 NAME

	Circle

=head1 SYNPOSIS

    use Carp;
	use GD;
	use WWPlot;
	use Fun;


=head1 DESCRIPTION

This module defines a circle which can be inserted as a stamp in a graph (WWPlot) object.

=head2 Command:

	$circle_object = new Circle( $center_pos_x, $center_pos_y, $radius, $border_color, $fill_color);


=head2 Examples:

	Here is the code used to define the subroutines open_circle
	and closed_circle in PGgraphmacros.pl

		sub open_circle {
		    my ($cx,$cy,$color) = @_;
			new Circle ($cx, $cy, 4,$color,'nearwhite');
		}

		sub closed_circle {
		    my ($cx,$cy, $color) = @_;
		    $color = 'black' unless defined $color;
			new Circle ($cx, $cy, 4,$color, $color);
		}

	$circle_object2 = closed_circle( $x_position, $y_position, $color );

	@circle_objects = $graph -> stamps($circle_object2);
	# puts a filled dot at ($x_position, $y_position) on the graph -- using real world coordinates.

=cut


BEGIN {
	be_strict(); # an alias for use strict.  This means that all global variable must contain main:: as a prefix.
}

package Circle;



#use WWPlot;
#Because of the way problem modules are loaded 'use' is disabled.

#use strict;
#use vars qw($AUTOLOAD  @ISA);
@Circle::ISA = qw(WWPlot);

my %fields =(
		colors 			=>	{},
		border_color	=>	 0,
		fill_color		=>	 1,
		radius			=>	 8,
);


sub new {
	my $class 			= shift;
	my $cx				= shift;
	my $cy				= shift;
	my $radius 			= shift;    # radius is in pixels, others are in real world coordinates
	my $border_color	= shift;
	my $fill_color	 	= shift;
	$radius =4 unless defined $radius;
	$border_color		= 	'black' unless defined($border_color);
	$fill_color			=	'black' unless defined($fill_color);

	my $self = { im 		=> 	new GD::Image(2*$radius, 2*$radius),

				 cx			=>	$cx,
				 cy			=>	$cy,
				 radius		=>	$radius,
				 border_color	=>	$border_color,
				 fill_color		=>	$fill_color,

	};

	bless $self, $class;
 	$self ->	_initialize_colors;
	if (defined($self->{'colors'}{$border_color} ) ) {
		$self->{'border_color'} = $self->{'colors'}{$border_color};
	} else {
		$self->{'border_color'} = 'default_color';
	}
	if (defined($self->{'colors'}{$fill_color} ) ) {
		$self->{'fill_color'} = $self->{'colors'}{$fill_color};
	} else {
		$self->{'fill_color'} = 'nearwhite';
	}
    $self->im->transparent($self->{'colors'}{'background_color'});
    $self->im->arc($radius,$radius,2*$radius,2*$radius,0,360,$self->{'border_color'} );
    $self->im->fill($radius,$radius,$self->{'fill_color'});
 	return $self;
}

sub	_initialize_colors {
	my $self 			= shift;
		# allocate some colors
		$self->{'colors'}{'background_color'} 	= 	$self->im->colorAllocate(255,255,255);
	    $self->{'colors'}{'default_color'} 	= 	$self->im->colorAllocate(0,0,0);
		$self->{'colors'}{'white'} 	= 	$self->im->colorAllocate(255,255,255);
	    $self->{'colors'}{'black'} 	= 	$self->im->colorAllocate(0,0,0);
	    $self->{'colors'}{'red'} 	= 	$self->im->colorAllocate(255,0,0);
	    $self->{'colors'}{'green'}	= 	$self->im->colorAllocate(0,255,0);
	    $self->{'colors'}{'blue'} 	= 	$self->im->colorAllocate(0,0,255);
	    $self->{'colors'}{'yellow'}	=	$self->im->colorAllocate(255,255,0);
	    $self->{'colors'}{'orange'}	=	$self->im->colorAllocate(255,100,0);
	    $self->{'colors'}{'gray'}	=	$self->im->colorAllocate(180,180,180);
	    $self->{'colors'}{'nearwhite'}	=	$self->im->colorAllocate(254,254,254);

}

sub size {
	my $s = shift;
	(2*$s->{radius}, 2*$s->{radius});
}
sub height{
	my $s = shift;
	2*$s->{radius};
}
sub width {
	my $s = shift;
	2*$s->{radius};
}
sub radius {
	my $s = shift;
	$s->{radius};
}
sub x {
	my $s = shift;
	$s->{cx};
}
sub y {
	my $s = shift;
	$s->{cy};
}
sub image {
	my $s	= shift;
	$s->{im};
}

sub draw{
	my $self = shift;
	my $g = shift;   # the enclosing graph object
	my $x = $self->x;
	my $y = $self->y;
	my $image = $self->image;
	my $height = $self->height;
	my $width	= $self->width;
	$g->im->copy($image,
				  ($g->ii($x)) - int($width/2),
				  ($g->jj($y)) - int($height/2),
				  0,  0,   $width,   $height);
}
sub DESTROY {
	# doing nothing about destruction, hope that isn't dangerous
}

1;