NAME
    CAD::Drawing::Manipulate - Manipulate CAD::Drawing objects

Description
    Move, Copy, Scale, Mirror, and Rotate methods for single entities and
    groups of entities.

AUTHOR
      Eric L. Wilhelm
      ewilhelm at sbcglobal dot net
      http://pages.sbcglobal.net/mycroft

COPYRIGHT
    This module is copyright (C) 2003 by Eric L. Wilhelm and A. Zahner Co.

LICENSE
    This module is distributed under the same terms as Perl. See the Perl
    source package for details.

    You may use this software under one of the following licenses:

      (1) GNU General Public License
        (found at http://www.gnu.org/copyleft/gpl.html)
      (2) Artistic License
        (found at http://www.perl.com/pub/language/misc/Artistic.html)

NO WARRANTY
    This software is distributed with ABSOLUTELY NO WARRANTY. The author and
    his employer will in no way be held liable for any loss or damages
    resulting from its use.

Modifications
    The source code of this module is made freely available and
    distributable under the GPL or Artistic License. Modifications to and
    use of this software must adhere to one of these licenses. Changes to
    the code should be noted as such and this notification (as well as the
    above copyright information) must remain intact on all copies of the
    code.

    Additionally, while the author is actively developing this code,
    notification of any intended changes or extensions would be most helpful
    in avoiding repeated work for all parties involved. Please contact the
    author with any such development plans.

Changes
      0.10 First public release
      0.11 Minor changes

Group Methods
    These methods are called with required values, followed by a hash
    reference of option values. Note the difference between this and the
    individual entity manipulation syntax shown below. The absence of an
    \%options hash reference implies everything in the drawing.

    For details about each of the group manipulation methods, see the
    corresponding individual entity manipulation method.

  Options

    The $opts value shown for each of the group manipulation methods is fed
    directly to CAD::Drawing::select_addr(). See the documentation for this
    function for additional details.

    One of the most common methods of selection (after the implicit all) may
    be the explicit list of addresses. This is done by simply passing an
    array reference rather than a hash reference.

  GroupMove

    Move selected entities by @dist.

      $drw->GroupMove(\@dist, $opts);

  GroupCopy

    Returns a list of addresses for newly created entities.

      @new = $drw->GroupCopy(\@dist, $opts);

  GroupClone

    Returns a list of addresses for newly created entities.

      @new = $drw->GroupClone($dest, $opts);

  place

    Clones items from $source into $drw and moves them to @pt. Selects items
    according to %opts and optionally rotates them by $opts{ang} (given in
    radians.)

      $drw->place($source, \@pt, \%opts);

  GroupMirror

    Mirrors the entities specified by %options (see select_addr()) across
    @axis.

      @new = $drw->GroupMirror(\@axis, \%options);

  GroupScale

    Sorry, \@pt is required here.

      $drw->GroupScale($factor, \@pt, \%opts);

  GroupRotate

    Rotates specified entities by $angle. A center point may be specified
    via $opts{pt} = \@pt.

      $drw->GroupRotate($angle, \%opts);

Individual Methods
  Move

    Moves entity at $addr by @dist (@dist may be three-dimensional.)

      $drw->Move($addr, \@dist);

  Copy

      $drw->Copy($addr, \@dist);

  Clone

    Clones the entity at $addr into drawing $dest.

      $drw->Clone($addr, $dest, \%opts);

    %opts may contain:

      to_layer => $layer_name,  # layer to clone into

  Mirror

    Mirrors entity specified by $addr across @axis.

    Returns the address of the manipulated entity. If $opts{copy} is true,
    will clone the entity, otherwise modify in-place.

      $drw->Mirror($addr, \@axis, \%opts);

  Scale

      $drw->Scale($addr, $factor, \@pt);

  Rotate

    Rotates entity specified by $addr by $angle (+ccw radians) about @pt.
    Angle may be in degrees if $angle =~ s/d$// returns a true value (but I
    hope the "d" is the only thing on the end, because I'm not looking for
    anything beyond that.) $angle = "45" . "d" will get converted, but
    $angle = "45" . "bad" will be called 0. Remember, this is Perl:)

      $drw->Rotate($addr, $angle, \@pt);

Internal Functions
  pointrotate

    Internal use only.

      ($x, $y) = pointrotate($x, $y, $ang, $xc, $yc);

  pointmirror

      @point = pointmirror($axis, $pt);

  angle_of

      angle_of(\@segment);

Polygon Methods
    These don't do anything yet and need to be moved to another module
    anyway.

  CutPline

      $drw->CutPline();

  IntPline

      $drw->IntPline();

  intersect_pgon

      intersect_pgon();