First version.

vcg/space/sphere3.h

@@ -0,0 +1,107 @@
+/****************************************************************************
+* VCGLib                                                            o o     *
+* Visual and Computer Graphics Library                            o     o   *
+*                                                                _   O  _   *
+* Copyright(C) 2004                                                \/)\/    *
+* Visual Computing Lab                                            /\/|      *
+* ISTI - Italian National Research Council                           |      *
+*                                                                    \      *
+* All rights reserved.                                                      *
+*                                                                           *
+* This program is free software; you can redistribute it and/or modify      *   
+* it under the terms of the GNU General Public License as published by      *
+* the Free Software Foundation; either version 2 of the License, or         *
+* (at your option) any later version.                                       *
+*                                                                           *
+* This program is distributed in the hope that it will be useful,           *
+* but WITHOUT ANY WARRANTY; without even the implied warranty of            *
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             *
+* GNU General Public License (http://www.gnu.org/licenses/gpl.txt)          *
+* for more details.                                                         *
+*                                                                           *
+****************************************************************************/
+/****************************************************************************
+  History
+
+$Log: not supported by cvs2svn $
+
+****************************************************************************/
+
+#ifndef VCG_SPHERE_H
+#define VCG_SPHERE_H
+
+#include <vcg/point3.h>
+
+namespace vcg {
+
+/** \addtogroup space */
+/*@{*/
+/** 
+Templated class for 3D sphere.
+  This is the class for definition of a sphere in 3D space. It is stored just as a Point3 and a radius
+	@param T (template parameter) Specifies the type of scalar used to represent coords.
+  Various policy could be added to improve efficience (keeping square of radius for instance).
+*/
+
+template <class T> class Sphere {
+protected:
+  Point3<T> _center;
+	T _radius;
+public:
+	Sphere(): radius(-1) {}
+  Sphere(const Point3<T> &center, T radius): _center(center), _radius(radius) {}
+
+  T &Radius() { return _radius; }
+  const T &Radius() const { return _radius; }
+  Point3<T> &Center() { return _center; }
+  const Point3<T> &Center() const { return _center; }
+
+	bool IsEmpty() const { return _radius < 0; }
+  ///return true if @param p - Center() <= Radius() 
+  bool IsIn(const Point3<T> &p) const;
+
+  void Add(Point3<T> &p);
+	void Add(const Sphere &sphere);
+  	
+};
+
+template <class T> void Sphere<T>::Add(const Sphere<T> &sphere) {
+  if(IsEmpty()) {
+			*this = sphere;
+			return;
+		}
+		Point3<T> dist = sphere.center - _center;
+    float distance = dist.Norm();
+		float fartest = distance + sphere.Radius();
+
+		if(fartest <= _radius) 
+      return;
+    if(distance == 0) 
+      _radius = sphere.Radius();
+    else {
+	    _center += dist * ((fartest - _radius) / (dist.Norm() * 2));
+		  _radius = (_radius + fartest)/2;
+    }
+}
+
+template <class T> void Sphere<T>::Add(Point3<T> &p) {
+	if(IsEmpty()) {
+		_center = p;
+		_radius = 0;
+	}
+	Point3<T> dist = p - _center;
+	float fartest = dist.Norm();
+	if(fartest <= _radius) return;
+	_center += dist * ((fartest - _radius) / (fartest*2));
+	_radius = (_radius + fartest)/2;
+}  
+
+template <class T> bool Sphere<T>::IsIn(const Point3<T> &p) const {
+	Point3<T> dist = p - _center;
+	return dist.Norm() <= _radius;
+}
+
+} //namespace
+
+
+#endif