Getting the size of an object in the viewport?

There's a bounding box function somewhere in the code archives I think. It may contain what you're looking for. Actually, here it is:

Function targetBox(ent)
	If ent=0 Return 0
	If EntityInView(ent,cam)=0 Return 0
	CameraProject cam,EntityX(ent),EntityY(ent),EntityZ(ent)
	leftmost#=ProjectedX()
	rightmost#=ProjectedX()
	topmost#=ProjectedY()
	bottommost#=ProjectedY()
	For i=1 To CountSurfaces(ent)
		s=GetSurface(ent,1)
		For v=0 To CountVertices(s)-1
			TFormPoint VertexX(s,v),VertexY(s,v),VertexZ(s,v),ent,0
			CameraProject cam,TFormedX(),TFormedY(),TFormedZ()
			If ProjectedX()<leftmost leftmost=ProjectedX()
			If ProjectedX()>rightmost rightmost=ProjectedX()
			If ProjectedY()<topmost topmost=ProjectedY()
			If ProjectedY()>bottommost bottommost=ProjectedY()
		Next
	Next
	color 200,200,200
	Rect leftmost,topmost,rightmost-leftmost,bottommost-topmost,0
End Function