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 10:38:22 PDT 1994 by najork                   

A MarkerGO.T is a geometric object describing a marker.


IMPORT Color, ColorProp, GO, MarkerTypeProp, Point3, PointProp, RealProp;

  T <: Public;
  Public = GO.T OBJECT
    init () : T;
m.init() initializes m, and returns it. The location of the marker is determined by the property Center.

  Center : PointProp.Name;
  Colour : ColorProp.Name;
  Scale  : RealProp.Name;
  Type   : MarkerTypeProp.Name;
In addition to the properties observed by all \type{GO}{T}'s, there are some additional properties that are observed by MarkerGO.T's:

Center is the name of a point property that describes the point indicated by the marker. If no Center property is specified, the marker is drawn at the origin.

Colour is the name of a color property that describes the color of the marker. If no Colour property is specified, the marker is drawn in white.

Scale is the name of a real property that describes the scale of the marker. If no Scale property is specified, the marker is drawn with scale 1.

Type is the name of a marker type property that describes the type of the marker (dot, cross, circle, asterisk, or X). If no Type property is specified, the marker is drawn as an asterisk.

PROCEDURE New (p : Point3.T) : T;
New(p) creates a new marker and returns it. It also attaches the property (Center,PointProp.NewConst(p)) to the new marker.
 The following four procedures provide sugaring to attach the
   Center, Colour, Scale, and Type properties to geometric objects: 

PROCEDURE SetCenter (o : GO.T; v : Point3.T);
The expression SetCenter(o,p)is equivalent to o.setProp(Center.bind(PointProp.NewConst(p))).

PROCEDURE SetColour (o : GO.T; v : Color.T);
The expression SetColour(o,c) is equivalent to o.setProp(Colour.bind(ColorProp.NewConst(c))).

PROCEDURE SetScale (o : GO.T; v : REAL);
The expression SetScale(o,r) is equivalent to o.setProp(Scale.bind(RealProp.NewConst(r))).

PROCEDURE SetType (o : GO.T; v : MarkerTypeProp.Kind);
The expression SetType(o,t) is equivalent to o.setProp(Type.bind(MarkerTypeProp.NewConst(t))).

END MarkerGO.