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.IX Title "CAD::Drawing::Calculate 3"
.TH CAD::Drawing::Calculate 3 "2008-01-04" "perl v5.8.8" "User Contributed Perl Documentation"
.SH "NAME"
CAD::Drawing::Calculate \- Calculations for CAD::Drawing
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This module provides calculation functions for the CAD::Drawing family
of modules.
.SH "AUTHOR"
.IX Header "AUTHOR"
Eric L. Wilhelm <ewilhelm at cpan dot org>
.PP
http://scratchcomputing.com
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
This module is copyright (C) 2004\-2006 by Eric L. Wilhelm.  Portions
copyright (C) 2003 by Eric L. Wilhelm and A. Zahner Co.
.SH "LICENSE"
.IX Header "LICENSE"
This module is distributed under the same terms as Perl.  See the Perl
source package for details.
.PP
You may use this software under one of the following licenses:
.PP
.Vb 4
\&  (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)
.Ve
.SH "NO WARRANTY"
.IX Header "NO WARRANTY"
This software is distributed with \s-1ABSOLUTELY\s0 \s-1NO\s0 \s-1WARRANTY\s0.  The author,
his former employer, and any other contributors will in no way be held
liable for any loss or damages resulting from its use.
.SH "Modifications"
.IX Header "Modifications"
The source code of this module is made freely available and
distributable under the \s-1GPL\s0 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.
.PP
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.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
.Vb 3
\&  CAD::Drawing
\&  CAD::Calc
\&  Math::Vec
.Ve
.SH "Methods"
.IX Header "Methods"
.SH "Extents Calculations"
.IX Header "Extents Calculations"
.Sh "OrthExtents"
.IX Subsection "OrthExtents"
Calculates the extents of a group of objects (selected according to \fIselect_addr()\fR) and returns an array: [xmin,xmax],[ymin,ymax].
.PP
.Vb 1
\&  @extents = $drw->OrthExtents(\e%opts);
.Ve
.Sh "getExtentsRec"
.IX Subsection "getExtentsRec"
Alias to \fIOrthExtents()\fR which returns a polyline-form array of points
(counter clockwise from lower\-left) describing a rectangle.
.PP
.Vb 1
\&  @rec = $drw->getExtentsRec(\e%opts);
.Ve
.Sh "EntOrthExtents"
.IX Subsection "EntOrthExtents"
Gets the orthographic extents of the object at \f(CW$addr\fR.  Returns 
[\e@xpts,\e@y_pts] (leaving you to sort through them and find which 
is min or max.)
.PP
.Vb 1
\&  @extents = $drw->EntOrthExtents($addr);
.Ve
.Sh "@orthfunc"
.IX Subsection "@orthfunc"
List of hash references containing code references to reduce
duplication and facilitate natural flow (rather than ifififif
statements.)
.SH "Planar Geometry Methods"
.IX Header "Planar Geometry Methods"
.Sh "offset"
.IX Subsection "offset"
Intended as any-object offset function (not easy).
.PP
$dist is negative to offset outward
.PP
.Vb 1
\&  $drw->offset($object, $dist);
.Ve
.Sh "divide"
.IX Subsection "divide"
.Vb 1
\&  $drw->divide();
.Ve
.Sh "area"
.IX Subsection "area"
.Vb 1
\&  $drw->area($addr);
.Ve
.SH "Line Manipulations"
.IX Header "Line Manipulations"
.Sh "pline_to_ray"
.IX Subsection "pline_to_ray"
Transforms a polyline with a nubbin into a ray (line with direction.)
.PP
.Vb 1
\&  $line_addr = $drw->pline_to_ray($pline_addr);
.Ve
.Sh "trim_both"
.IX Subsection "trim_both"
Trims two lines to their intersection.
.PP
.Vb 1
\&  $drw->trim_both($addr1, $addr2, $tol, \e@keep_ends);
.Ve
.PP
See \fICAD::Calc::line_intersection()\fR
.SH "Coordinate Transforms"
.IX Header "Coordinate Transforms"
Switch between coordinate system representations.
.Sh "to_ocs"
.IX Subsection "to_ocs"
Change the objects coordinates into the object coordinate system.
.PP
Both of these are relatively quick.  A simple test shows that one point
can be taken back and forth at about 2KHz, so don't be afraid to use
them.
.PP
.Vb 1
\&  $drw->to_ocs($addr);
.Ve
.Sh "to_wcs"
.IX Subsection "to_wcs"
Change the object's coordinates into the world coordinate system.
.PP
.Vb 1
\&  $drw->to_wcs($addr);
.Ve
.Sh "flatten"
.IX Subsection "flatten"
Puts the object in the wcs, zeros all z\-coordinates and deletes the
normal vector.  Note that this is fine for projecting polylines and
lines, but may not be what you want if you are trying to make a circle
into an ellipse (at least not yet.)
.PP
.Vb 1
\&  $drw->flatten($addr);
.Ve
.SH "Functions"
.IX Header "Functions"
Non-OO internal-use functions.
.Sh "_ocs_axes"
.IX Subsection "_ocs_axes"
Returns the x,y, and z axes for the ocs described by \f(CW@normal\fR.  These
will have arbitrary lengths.
.PP
.Vb 1
\&  @local_axes = _ocs_axes(@normal);
.Ve
.Sh "_wcs_axes"
.IX Subsection "_wcs_axes"
Returns the x,y, and z axes for the world coordinate system in terms of
the \f(CW@ocs_axes\fR.
.PP
.Vb 1
\&  @trs_axes = _wcs_axes(@ocs_axes);
.Ve