File Coverage

blib/lib/Rinchi/CIGIPP/EarthReferenceModelDefinition.pm

Criterion	Covered	Total	%
statement	39	66	59.0
branch	5	20	25.0
condition	2	6	33.3
subroutine	11	13	84.6
pod	9	9	100.0
total	66	114	57.8

#
# Rinchi Common Image Generator Interface for Perl
# Class Identifier: f78ae570-200e-11de-bdb3-001c25551abc
# Author: Brian M. Ames
#

package Rinchi::CIGIPP::EarthReferenceModelDefinition;

use 5.006;
use strict;
use warnings;
use Carp;

require Exporter;

our @ISA = qw(Exporter);

# Items to export into callers namespace by default. Note: do not export
# names by default without a very good reason. Use EXPORT_OK instead.
# Do not simply export all your public functions/methods/constants.

# This allows declaration	use Rinchi::CIGI::AtmosphereControl ':all';
# If you do not need this, moving things directly into @EXPORT or @EXPORT_OK
# will save memory.
our %EXPORT_TAGS = ( 'all' => [ qw(

) ] );

our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );

our @EXPORT = qw(

);

our $VERSION = '0.02';

# Preloaded methods go here.

=head1 NAME

Rinchi::CIGIPP::EarthReferenceModelDefinition - Perl extension for the Common
Image Generator Interface - Earth Reference Model Definition data packet.
 data packet.
=head1 SYNOPSIS

  use Rinchi::CIGIPP::EarthReferenceModelDefinition;
  my $erm_def = Rinchi::CIGIPP::EarthReferenceModelDefinition->new();

  $packet_type = $erm_def->packet_type();
  $packet_size = $erm_def->packet_size();
  $custom_erm = $erm_def->custom_erm(Rinchi::CIGIPP->Enable);
  $equatorial_radius = $erm_def->equatorial_radius(6.458);
  $flattening = $erm_def->flattening(32.413);

=head1 DESCRIPTION

The default Earth Reference Model (ERM) used for geodetic positioning is WGS
84. The Host may define another ERM by sending an Earth Reference Model
Definition packet to the IG. This packet defines the equatorial radius and the
flattening of the new reference ellipsoid.

When the IG receives an Earth Reference Model Definition packet, it should set
the Earth Reference Model attribute of the Start of Frame packet to
Host-Defined (1). If, for some reason, the IG cannot support the ERM defined by
the Host, the attribute should be set to WGS 84 (0).

=head2 EXPORT

None by default.

#==============================================================================

=item new $erm_def = Rinchi::CIGIPP::EarthReferenceModelDefinition->new()

Constructor for Rinchi::EarthReferenceModelDefinition.

=cut

sub new {
  my $class = shift;
  $class = ref($class) || $class;

  my $self = {
    '_Buffer'                              => '',
    '_ClassIdent'                          => 'f78ae570-200e-11de-bdb3-001c25551abc',
    '_Pack'                                => 'CCCCIdd',
    '_Swap1'                               => 'CCCCVVVVV',
    '_Swap2'                               => 'CCCCNNNNN',
    'packetType'                           => 19,
    'packetSize'                           => 24,
    '_bitfields1'                          => 0, # Includes bitfields unused31, and customERM.
    'customERM'                            => 0,
    '_unused32'                            => 0,
    '_unused33'                            => 0,
    'equatorialRadius'                     => 0,
    'flattening'                           => 0,
  };

  if (@_) {
    if (ref($_[0]) eq 'ARRAY') {
      $self->{'_Buffer'} = $_[0][0];
    } elsif (ref($_[0]) eq 'HASH') {
      foreach my $attr (keys %{$_[0]}) {
        $self->{"_$attr"} = $_[0]->{$attr} unless ($attr =~ /^_/);
      }
    }
  }

  bless($self,$class);
  return $self;
}

#==============================================================================

=item sub packet_type()

 $value = $erm_def->packet_type();

Data Packet Identifier.

This attribute identifies this data packet as the Earth Reference Model
Definition packet. The value of this attribute must be 19.

=cut

sub packet_type() {
  my ($self) = @_;
  return $self->{'packetType'};
}

#==============================================================================

=item sub packet_size()

 $value = $erm_def->packet_size();

Data Packet Size.

This attribute indicates the number of bytes in this data packet. The value of
this attribute must be 24.

=cut

sub packet_size() {
  my ($self) = @_;
  return $self->{'packetSize'};
}

#==============================================================================

=item sub custom_erm([$newValue])

 $value = $erm_def->custom_erm($newValue);

Custom ERM Enable.

This attribute specifies whether the IG should use the Earth Reference Model
(ERM) defined by this packet.

If this attribute is set to Disable (0), the IG will use the WGS 84 reference
model and all other attributes in this packet will be ignored.

    Disable   0
    Enable    1

=cut

sub custom_erm() {
  my ($self,$nv) = @_;
  if (defined($nv)) {
    if (($nv==0) or ($nv==1)) {
      $self->{'customERM'} = $nv;
      $self->{'_bitfields1'} |= $nv &0x01;
    } else {
      carp "custom_erm must be 0 (Disable), or 1 (Enable).";
    }
  }
  return ($self->{'_bitfields1'} & 0x01);
}

#==============================================================================

=item sub equatorial_radius([$newValue])

 $value = $erm_def->equatorial_radius($newValue);

Equatorial Radius.

This attribute specifies the semi-major axis of the ellipsoid.

=cut

sub equatorial_radius() {
  my ($self,$nv) = @_;
  if (defined($nv)) {
    $self->{'equatorialRadius'} = $nv;
  }
  return $self->{'equatorialRadius'};
}

#==============================================================================

=item sub flattening([$newValue])

 $value = $erm_def->flattening($newValue);

Flattening.

This attribute specifies the flattening of the ellipsoid.

=cut

sub flattening() {
  my ($self,$nv) = @_;
  if (defined($nv)) {
    $self->{'flattening'} = $nv;
  }
  return $self->{'flattening'};
}

#==========================================================================

=item sub pack()

 $value = $erm_def->pack();

Returns the packed data packet.

=cut

sub pack($) {
  my $self = shift ;

  $self->{'_Buffer'} = CORE::pack($self->{'_Pack'},
        $self->{'packetType'},
        $self->{'packetSize'},
        $self->{'_bitfields1'},    # Includes bitfields unused31, and customERM.
        $self->{'_unused32'},
        $self->{'_unused33'},
        $self->{'equatorialRadius'},
        $self->{'flattening'},
      );

  return $self->{'_Buffer'};
}

#==========================================================================

=item sub unpack()

 $value = $erm_def->unpack();

Unpacks the packed data packet.

=cut

sub unpack($) {
  my $self = shift @_;

  if (@_) {
     $self->{'_Buffer'} = shift @_;
  }
  my ($a,$b,$c,$d,$e,$f,$g) = CORE::unpack($self->{'_Pack'},$self->{'_Buffer'});
  $self->{'packetType'}                          = $a;
  $self->{'packetSize'}                          = $b;
  $self->{'_bitfields1'}                         = $c; # Includes bitfields unused31, and customERM.
  $self->{'_unused32'}                           = $d;
  $self->{'_unused33'}                           = $e;
  $self->{'equatorialRadius'}                    = $f;
  $self->{'flattening'}                          = $g;

  $self->{'customERM'}                           = $self->custom_erm();

  return $self->{'_Buffer'};
}

#==========================================================================

=item sub byte_swap()

 $obj_name->byte_swap();

Byte swaps the packed data packet.

=cut

sub byte_swap($) {
  my $self = shift @_;

  if (@_) {
     $self->{'_Buffer'} = shift @_;
  } else {
     $self->pack();
  }
  my ($a,$b,$c,$d,$e,$f,$g,$h,$i) = CORE::unpack($self->{'_Swap1'},$self->{'_Buffer'});

  $self->{'_Buffer'} = CORE::pack($self->{'_Swap2'},$a,$b,$c,$d,$e,$g,$f,$i,$h);
  $self->unpack();

  return $self->{'_Buffer'};
}

1;
__END__