Copyright (C) 1994, Digital Equipment Corp.
Created by Marc Najork
MODULE ConeGO EXPORTS ConeGO, ConeGOProxy;
IMPORT GO, GOPrivate, GraphicsBase, GraphicsBasePrivate, Matrix4, Mth, Point3,
PointProp, PointPropPrivate, Prop, RealProp, RealPropPrivate;
REVEAL
T = Public BRANDED OBJECT
prec : INTEGER;
base : Point3.T;
tip : Point3.T;
radius : REAL;
matrix : Matrix4.T; (* transforms unit cone into desired cone *)
OVERRIDES
init := Init;
draw := Draw;
damageIfDependent := DamageIfDependent;
END;
PROCEDURE Init (self : T; prec : INTEGER) : T =
BEGIN
EVAL GO.T.init (self);
self.prec := prec;
self.matrix := Matrix4.Identity ();
self.base := Point3.T {0.0, 0.0, 0.0};
self.tip := Point3.T {0.0, 0.0, 1.0};
self.radius := 1.0;
IF MkProxyT # NIL AND self.proxy = NIL THEN
MkProxyT (self);
END;
RETURN self;
END Init;
PROCEDURE DamageIfDependent (self : T; pn : Prop.Name) =
BEGIN
IF pn = Base OR pn = Tip OR pn = Radius THEN
self.damaged := TRUE;
END;
END DamageIfDependent;
PROCEDURE Draw (self : T; state : GraphicsBase.T) =
BEGIN
state.push (self);
WITH base = Base.getState (state),
tip = Tip.getState (state),
radius = Radius.getState (state) DO
IF base # self.base OR tip # self.tip OR radius # self.radius THEN
self.base := base;
self.tip := tip;
self.radius := radius;
(* Compute a transformation matrix that transforms the prototypical
cone into the desired one. *)
WITH n = Point3.Minus (tip, base),
s = Point3.OrthoVector (n),
t = Point3.CrossProduct (n, s),
a = Point3.Plus (base, Point3.ScaleToLen (s, radius)),
b = Point3.Plus (base, Point3.ScaleToLen (t, radius)) DO
self.matrix := Matrix4.TransformUnitCube (base, a, b, tip);
END;
END;
state.pushMatrix (self.matrix);
state.drawProtoCone (self.prec);
state.popMatrix ();
WITH center = Point3.MidPoint (base, tip),
dist = Point3.Distance (base, tip) / 2.0,
rad = Mth.sqrt (dist * dist + radius * radius) DO
state.growBoundingVolume (center, rad);
END;
END;
self.damaged := FALSE;
state.pop (self);
END Draw;
***************************************************************************
Convenience Procedures
***************************************************************************
PROCEDURE New (base, tip : Point3.T; r : REAL; prec := 30) : T =
VAR
cone := NEW (T).init (prec);
BEGIN
SetBase (cone, base);
SetTip (cone, tip);
SetRadius (cone, r);
RETURN cone;
END New;
PROCEDURE SetBase (o : GO.T; v : Point3.T) =
BEGIN
o.setProp (Base.bind (PointProp.NewConst (v)));
END SetBase;
PROCEDURE SetTip (o : GO.T; v : Point3.T) =
BEGIN
o.setProp (Tip.bind (PointProp.NewConst (v)));
END SetTip;
PROCEDURE SetRadius (o : GO.T; v : REAL) =
BEGIN
o.setProp (Radius.bind (RealProp.NewConst (v)));
END SetRadius;
BEGIN
Base := NEW (PointProp.Name).init (Point3.T {0.0, 0.0, 0.0});
Tip := NEW (PointProp.Name).init (Point3.T {1.0, 0.0, 0.0});
Radius := NEW (RealProp.Name).init (1.0);
END ConeGO.