BoundingSphere Class Reference

Describes a bounding sphere region in 3D space.

#include <Mesh/Geometry/boundingsphere.h>

Inheritance diagram for BoundingSphere:

Public Member Functions
	BoundingSphere ()
	BoundingSphere (const BoundingSphere &sphere)
	BoundingSphere (const Vector3d &center, double radius=0)
BoundingSphere *	clone () const override
BoundingSphere *	cloneRegion () const override
bool	contains (const Vector3d &p) const override
void	destroy () override
void	expand (const Vector3d &p)
void	expandRadius (const Vector3d &p)
bool	getBoundingBox (Vector3d &minimum, Vector3d &maximum) const override
bool	getBoundingSphere (Vector3d &center, double &radius) const override
Vector3d	getCenter () const
double	getRadius () const
bool	isNull () const override
bool	operator!= (const BoundingSphere &v) const
bool	operator== (const BoundingSphere &b) const
void	setCenter (const Vector3d &c)
void	setRadius (double r)
bool	visit (RegionProcessor &processor) override
Public Member Functions inherited from Region
virtual	~Region ()=default
virtual Region *	cloneRegion () const =0
virtual bool	contains (const Vector3d &p) const =0
virtual void	destroy ()=0
virtual bool	getBoundingBox (Vector3d &minimum, Vector3d &maximum) const =0
virtual bool	getBoundingSphere (Vector3d &center, double &radius) const
virtual bool	isNull () const =0
virtual bool	visit (RegionProcessor &processor)=0
Public Member Functions inherited from ObjectGroup
	~ObjectGroup () override
bool	add (const QString &name, DataObject &obj, const QString &preferredWidget=QString())
bool	canSerialize () const override
ObjectGroup *	clone () const override=0
bool	empty () const
void	ensureGroupHasData ()
void	erase (int index)
DataObject *	getChild (const QString &name)
const DataObject *	getChild (const QString &name) const
QString	getChildPreferredWidget (const QString &name) const
DataObject &	getDataObject (int index)
const DataObject &	getDataObject (int index) const
int	getIndex (const QString &name) const
const QString &	getName (int index) const
virtual QString	getPreferedWidget (const QString &name) const
bool	hasData () const
bool	haveName (const QString &name) const
bool	insert (const QString &name, DataObject &obj, int index=-1, const QString &preferredWidget=QString())
bool	load (const QJsonDocument &doc)
bool	load (const SerializedItem &item) override
bool	save (QJsonDocument &doc) const
bool	save (SerializedItem &item) const override
bool	setChildPreferredWidget (const QString &name, const QString &widget)
unsigned	size () const
Public Member Functions inherited from Clonable
virtual	~Clonable ()=default
virtual Clonable *	clone () const =0
Public Member Functions inherited from Serialize
virtual	~Serialize ()=default
virtual bool	canSerialize () const =0
virtual bool	load (const SerializedItem &item)=0
virtual bool	save (SerializedItem &item) const =0

Additional Inherited Members
Protected Member Functions inherited from ObjectGroup
	ObjectGroup ()
void	clear ()
ObjectGroup &	operator= (const ObjectGroup &rhs)
bool	operator== (const ObjectGroup &rhs) const
void	swap (ObjectGroup &rhs)

Constructor & Destructor Documentation

BoundingSphere() [1/3]

BoundingSphere

(

)

Constructs a null bounding sphere.

BoundingSphere() [2/3]

BoundingSphere

(

const BoundingSphere &

sphere

)

Parameters

sphere

The bounding sphere to copy.

BoundingSphere() [3/3]

BoundingSphere	(	const Vector3d &	center,
		double	radius = 0
	)

Parameters

center	The center of the bounding sphere.
radius	The radius of the bounding sphere. It must not be negative.

Member Function Documentation

clone()

BoundingSphere * clone ( ) const

overridevirtual

Returns

A clone of this object.

Note

Subclasses would normally return their own type rather than the Clonable type. The C++ language rules allow a more derived type to be returned from a virtual function and the compiler will still treat it as a valid override.

We redeclare this function only so that the more derived return type is available without casting.

Implements ObjectGroup.

cloneRegion()

BoundingSphere * cloneRegion ( ) const

inlineoverridevirtual

This function should be called clone() but the Visual Studio compilers do not handle covariant return types when multiple inheritance from a virtual base class is involved. Since Region is often combined with other Clonable classes such as ObjectGroup, we don't provide clone() but instead provide cloneRegion() which is effectively doing the same thing, albeit with the annoyance of a different function name.

Note that subclasses will need to tell DataExecution::TypedDataFactory about their cloneRegion() implementation explicitly if they do not also inherit from some other Clonable base class as well, since Region does not derive from Clonable (which means the template specializations for TypedDataFactory will not automatically detect cloneRegion()).

Implements Region.

contains()

bool contains ( const Vector3d &  p ) const

overridevirtual

Parameters

p	The point to test.

Returns

True if the point p is contained within the region. If p falls on the boundary of the region, the result returned must also be true. If the region is a null region (ie isNull() returns true), this function must return false.

Implements Region.

destroy()

void destroy ( )

overridevirtual

Destroys the object. This function is usually implemented by calling operator delete on the object.

See also

clone()

Implements Region.

expand()

void expand

(

const Vector3d &

p

)

Parameters

p	The point to test against the bounding sphere.

If p is not within the current bounding sphere, the sphere will be expanded to include it. If the bounding sphere is null at the time of the call, it will be made non-null and will have its center set to p and its radius to zero..

Warning

This function is vulnerable to accumulated roundoff error due to the way the sphere has to be recomputed based on the current center and radius. The class does not retain a list of points added but rather it only retains the last known center and radius. Thus, it is possible that a point that was once inside the sphere might eventually fall just outside it due to rounding inaccuracies. A more robust alternative is to call expandRadius() since it guarantees to always contain whatever it previously contained.

expandRadius()

void expandRadius

(

const Vector3d &

p

)

Parameters

p	The point to test against the bounding sphere.

If p is not within the current bounding sphere, the sphere's radius will be expanded to include it.

Precondition

The center of the sphere must have been set before calling this function. It is okay for the radius to not be set, since it will be assumed to be zero in that case and set to whatever the radius is to p.

See also

expand()

getBoundingBox()

bool getBoundingBox ( Vector3d &  minimum, Vector3d &  maximum  ) const

overridevirtual

Parameters

minimum	If the function returns true, then at exit this will hold the corner of the bounding box corresponding to the minimum values of X, Y and Z.
maximum	If the function returns true, then at exit this will hold the corner of the bounding box corresponding to the maximum values of X, Y and Z.

The bounding box is guaranteed to contain all the regions for which a point passed to contains() will return true. It can be useful as a way of short-circuiting a more expensive test for whether a point is contained in a complex region. How conservative the bounding box is will be determined entirely by the subclass. It is allowable for the subclass to return the entire 3D domain as the bounding box (and indeed some subclasses logically have to do this, such as RegionNegate).

Returns

True if the bounding box could be defined. A return value of false would normally indicate that the region is null.

See also

getBoundingSphere(), isNull()

Implements Region.

getBoundingSphere()

bool getBoundingSphere ( Vector3d &  center, double &  radius  ) const

overridevirtual

Parameters

center	This will hold the center of the bounding sphere if the function is successful. If not successful, the function leaves it unmodified from the passed in value.
radius	This will hold the radius of the bounding sphere if the function is successful. If not successful, the function leaves it unmodified from the passed in value.

If the bounding sphere is not null, this function always succeeds and will be very efficient since the center and radius are both already held internally by the object.

Returns

True if the bounding sphere is not null.

See also

getBoundingBox(), isNull()

Reimplemented from Region.

getCenter()

Vector3d getCenter

(

)

const

Returns

The center of the bounding sphere.

Precondition

The bounding sphere must not be null.

See also

setCenter(), isNull()

getRadius()

double getRadius

(

)

const

Returns

The radius of the bounding sphere.

Precondition

The bounding sphere must not be null.

See also

setRadius(), isNull()

isNull()

bool isNull ( ) const

overridevirtual

Returns

True if the bounding sphere is null. Any call to expand() will make a bounding sphere object non-null, as will the constructors taking Vector3d parameters.

Implements Region.

operator!=()

bool operator!= ( const BoundingSphere &  v ) const

inline

operator==()

bool operator==

(

const BoundingSphere &

b

)

const

setCenter()

void setCenter

(

const Vector3d &

c

)

Parameters

c	The new center of the sphere.

Postcondition

The radius is left unchanged from whatever it was before the call.

See also

getCenter(), setRadius()

setRadius()

void setRadius

(

double

r

)

Parameters

r	The new radius of the sphere.

Postcondition

The center is left unchanged from whatever it was before the call.

See also

getRadius(), setCenter()

visit()

bool visit ( RegionProcessor &  processor )

overridevirtual

Visit the specified region processor, invoking the correct processing function. Subclasses will need to override this to invoke the correct function.

Implements Region.