A `ConeGO.T`

is a geometric object describing a cone.

INTERFACEConeGO ; IMPORT GO, Point3, PointProp, RealProp, SurfaceGO; TYPE T <: Public; Public = SurfaceGO.T OBJECT METHODS init (prec := 30) : T; END;

`cone.init(prec)`

initializes a new cone`cone`

, whose surface is composed of`prec`

triangles, and returns it. The location and radius of the cone is determined by the three properties`Base`

,`Tip`

, and`Radius`

.

VAR Base : PointProp.Name; Tip : PointProp.Name; Radius : RealProp.Name;

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

's:

`Base`

is the name of a property that describes the center of the base of the cone. It associates with a \type{PointProp}{Val}. If no`Base`

property is specified, the base of the cone lies at the origin.

`Tip`

is the name of a property that describes the tip of the cone. It associates with a \type{PointProp}{Val}. If no`Tip`

property is specified, the tip of the cone is at point (1,0,0).

`Radius`

is the name of a property that describes the radius of the cone. It associates with a \type{RealProp}{Val}. If no`Radius`

property is specified, the cone has a radius of 1.

Assume that in a given context and at a given point in time, the property mapping is such that`Base`

maps to a point property value which evaluates to`base`

,`Tip`

maps to a point property value which evaluates to`tip`

, and`Radius`

maps to a real property value which evaluates to`r`

.`base`

,`tip`

, and`r`

define the position and shape of the cone in this c ontext and at this time as shown below: \begin{center} \begin{tabular}{c} \psfig{figure=images/ConeGO.ps,silent=} \end{tabular} \end{center}

PROCEDURE New (base, tip : Point3.T; r : REAL; prec := 30) : T;

The following three procedures provide sugaring to attach`New(base,tip,r,prec)`

creates a new cone, whose surface is composed of`prec`

triangles, and returns it. It also attaches the following properties to the new cone: \begin{verbatim} (Base,PointProp.NewConst(base)) (Tip,PointProp.NewConst(tip)) (Radius,RealProp.NewConst(r)) \end{verbatim}

`Base`

, `Tip`

, and `Radius`

properties with non-animated
property values to geometric objects:
PROCEDURE SetBase (o : GO.T; p : Point3.T);

The expression`SetBase(o,p)`

is equivalent to`o.setProp(Base.bind(PointProp.NewConst(p)))`

.

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

The expression`SetTip(o,p)`

is equivalent to`o.setProp(Tip.bind(PointProp.NewConst(p)))`

.

PROCEDURE SetRadius (o : GO.T; r : REAL);

The expression`SetRadius(o,r)`

is equivalent to`o.setProp(Radius.bind(RealProp.NewConst(r)))`

.

END ConeGO.