Rectangle

Rectangles in 3d space

PhilipRBrenan@yahoo.com, 2004, Perl License

Synopsis

Example t/rectangle.t

 #_ Rectangle __________________________________________________________
 # Test 3d rectangles          
 # philiprbrenan@yahoo.com, 2004, Perl License    
 #______________________________________________________________________
 
 use Math::Zap::Rectangle;
 use Math::Zap::Vector;
 use Test::Simple tests=>3;
 
 my ($a, $b, $c, $d) =
  (vector(0,    0, +1),
   vector(0, -1.9, -1),
   vector(0, -2.0, -1),
   vector(0, -2.1, -1)
  );
 
 my $r = rectangle
  (vector(-1,-1, 0),
   vector( 2, 0, 0),
   vector( 0, 2, 0)
  );
 
 ok($r->intersects($a, $b) == 1);
 ok($r->intersects($a, $c) == 1);
 ok($r->intersects($a, $d) == 0);
 

Description

Rectangles in 3d space

Constructors

new

Create a rectangle from 3 vectors:

 a position of any corner
 b first side
 c second side.

Note that vectors b,c must be at right angles to each other.

rectangle

Create a rectangle from 3 vectors - synonym for "new".

Methods

check

Check its a rectangle

is

Test its a rectangle

a,b,c

Components of rectangle

clone

Create a rectangle from another rectangle

accuracy

Get/Set accuracy for comparisons

intersection

Intersect line between two vectors with plane defined by a rectangle

 r rectangle
 a start vector
 b end vector

Solve the simultaneous equations of the plane defined by the rectangle and the line between the vectors:

   ra+l*rb+m*rc         = a+(b-a)*n 
 =>ra+l*rb+m*rc+n*(a-b) = a-ra 

Note: no checks (yet) for line parallel to plane.

intersects

# Test whether a line between two vectors intersects a rectangle # Note: no checks (yet) for line parallel to plane.

visible

# Visibility of a rectangle r hid by other rectangles R from a view # point p. # Rectangle r is divided up into I*J sub rectangles: each sub rectangle # is tested for visibility from point p via the intervening rectangles.

project

# Project rectangle r onto rectangle R from a point p

projectInto

# Project rectangle r into rectangle R from a point p

Exports

Export "rectangle"

Credits

Author

philiprbrenan@yahoo.com

philiprbrenan@yahoo.com, 2004

License

Perl License.