anim3D/src/BoxGO.i3

 Copyright (C) 1993, Digital Equipment Corporation                         
 All rights reserved.                                                      
 See the file COPYRIGHT for a full description.                            
                                                                           
 Created by Marc Najork                                                    
 Last modified on Mon Jun 13 10:05:10 PDT 1994 by najork                   




 A BoxGO.T is a geometric object describing a parallelopiped. 




INTERFACE BoxGO;

IMPORT GO, Point3, PointProp, SurfaceGO;

TYPE
  T <: Public;
  Public = SurfaceGO.T OBJECT
  METHODS
    init () : T;
  END;

 box.init()  initializes a new parallelopiped box and returns it.
   The sides of the parallelopiped are axis-aligned, its corners are
   determined by the Corner1 and Corner2 properties. 


VAR
  Corner1 : PointProp.Name;
  Corner2 : PointProp.Name;

 In addition to the properties observed by all \type{GO}{T}'s and
   \type{SurfaceGO}{T}'s, there are two additional properties that
   are observed by BoxGO.T's:


   Corner1 and Corner2 are the names of two point properties that
   describe the two cornerpoints of the box. They associate with
   \type{PointProp}{Val}s. If they are not specified, (0,0,0) and (1,1,1)
   are used as cornerpoints. 


PROCEDURE New (a, b : Point3.T) : T;

 New(a,b) creates a new box and returns it. It also attaches the following
   properties to the new box:
   \begin{verbatim}
     (Corner1,PointProp.NewConst(a))
     (Corner2,PointProp.NewConst(b))
   \end{verbatim}

 The following two procedures provide sugaring to attach Corner1 and
   Corner2 properties with non-animated property values to geometric
   objects: 


PROCEDURE SetCorner1 (o : GO.T; p : Point3.T);

 The expression SetCorner1(o,p) is equivalent to
   o.setProp(Corner1.bind(PointProp.NewConst(p))). 

PROCEDURE SetCorner2 (o : GO.T; p : Point3.T);

 The expression SetCorner2(o,p) is equivalent to
   o.setProp(Corner2.bind(PointProp.NewConst(p))). 

END BoxGO.