=head1 NAME

Box2D::b2MouseJoint - Make a point on a body track a specified point.

=head1 SYNOPSIS

  my $joint = $world->CreateJoint( $joint_def );
  $joint->SetTarget( $target );

=head1 DESCRIPTION

A mouse joint is used to make a point on a body track a specified world
point. This a soft constraint with a maximum force. This allows the
constraint to stretch and without applying huge forces.

NOTE: this joint is not documented in the manual because it was
developed to be used in the testbed. If you want to learn how to use
the mouse joint, look at the testbed.

=head1 METHODS

=head2 GetAnchorA()

Implements C<Box2D::b2Joint>.

Returns a C<Box2D::b2Vec2>

=head2 GetAnchorB()

Implements C<Box2D::b2Joint>.

Returns a C<Box2D::b2Vec2>

=head2 GetDampingRatio()

Returns a C<float32>

=head2 GetFrequency()

Returns a C<float32>

=head2 GetMaxForce()

Returns a C<float32>

=head2 GetReactionForce( $inv_dt )

Implements C<Box2D::b2Joint>.

Parameters:

=over 4

=item * C<float32> C<$inv_dt>

=back

Returns a C<Box2D::b2Vec2>

=head2 GetReactionTorque( $inv_dt )

Implements C<Box2D::b2Joint>.

Parameters:

=over 4

=item * C<float32> C<$inv_dt>

=back

Returns a C<float32>

=head2 GetTarget()

Returns a C<Box2D::b2Vec2>

=head2 SetDampingRatio( $ratio )

Set/get the damping ratio (dimensionless).

Parameters:

=over 4

=item * C<float32> C<$ratio>

=back

=head2 SetFrequency( $hz )

Set/get the frequency in Hertz.

Parameters:

=over 4

=item * C<float32> C<$hz>

=back

=head2 SetMaxForce( $force )

Set/get the maximum force in Newtons.

Parameters:

=over 4

=item * C<float32> C<$force>

=back

=head2 SetTarget( $target )

Use this to update the target point.

Parameters:

=over 4

=item * C<Box2D::b2Vec2> C<$target>

=back

=head1 SEE ALSO

=over 4

=item * L<Box2D>

=item * L<Box2D::b2MouseJointDef>

=item * L<Box2D::b2Joint>

=item * L<Box2D::b2World>

=back

=head1 BUGS

See L<Box2D/BUGS>

=head1 AUTHORS

See L<Box2D/AUTHORS>

=head1 COPYRIGHT & LICENSE

See L<Box2D/"COPYRIGHT & LICENSE">

=cut