GroupFilterTable Class Reference

#include <GroupFilterTable.h>

Inheritance diagram for GroupFilterTable:

Public Member Functions
	GroupFilterTable (uint inNumSubGroups=0)
	Constructs the table with inNumSubGroups subgroups, initially all collision pairs are enabled except when the sub group ID is the same.
	GroupFilterTable (const GroupFilterTable &inRHS)
	Copy constructor.
void	DisableCollision (SubGroupID inSubGroup1, SubGroupID inSubGroup2)
	Disable collision between two sub groups.
void	EnableCollision (SubGroupID inSubGroup1, SubGroupID inSubGroup2)
	Enable collision between two sub groups.
bool	IsCollisionEnabled (SubGroupID inSubGroup1, SubGroupID inSubGroup2) const
	Check if the collision between two subgroups is enabled.
virtual bool	CanCollide (const CollisionGroup &inGroup1, const CollisionGroup &inGroup2) const override
	Checks if two CollisionGroups collide.
virtual void	SaveBinaryState (StreamOut &inStream) const override
	Saves the contents of the group filter in binary form to inStream.
Public Member Functions inherited from GroupFilter
virtual	~GroupFilter () override=default
	Virtual destructor.
Public Member Functions inherited from SerializableObject
virtual	~SerializableObject ()=default
	Destructor.
Public Member Functions inherited from RefTarget< GroupFilter >
	RefTarget ()=default
	Constructor.
	RefTarget (const RefTarget &)
	~RefTarget ()
	assert no one is referencing us
void	SetEmbedded () const
RefTarget &	operator= (const RefTarget &)
	Assignment operator.
uint32	GetRefCount () const
	Get current refcount of this object.
void	AddRef () const
	Add or release a reference to this object.
void	Release () const

Protected Member Functions
virtual void	RestoreBinaryState (StreamIn &inStream) override
	This function should not be called directly, it is used by sRestoreFromBinaryState.
Protected Member Functions inherited from GroupFilter
	GroupFilter ()=default
	Don't allow (copy) constructing this base class, but allow derived classes to (copy) construct themselves.
	GroupFilter (const GroupFilter &)=default
GroupFilter &	operator= (const GroupFilter &)=default
Protected Member Functions inherited from SerializableObject
	SerializableObject ()=default
	Don't allow (copy) constructing this base class, but allow derived classes to (copy) construct themselves.
	SerializableObject (const SerializableObject &)=default
SerializableObject &	operator= (const SerializableObject &)=default

Additional Inherited Members
Public Types inherited from GroupFilter
using	GroupFilterResult = Result<Ref<GroupFilter>>
Static Public Member Functions inherited from GroupFilter
static GroupFilterResult	sRestoreFromBinaryState (StreamIn &inStream)
	Creates a GroupFilter of the correct type and restores its contents from the binary stream inStream.
Static Public Member Functions inherited from RefTarget< GroupFilter >
static int	sInternalGetRefCountOffset ()
	INTERNAL HELPER FUNCTION USED BY SERIALIZATION.
Protected Attributes inherited from RefTarget< GroupFilter >
atomic< uint32 >	mRefCount
	Current reference count.
Static Protected Attributes inherited from RefTarget< GroupFilter >
static constexpr uint32	cEmbedded
	A large value that gets added to the refcount to mark the object as embedded.

Detailed Description

Implementation of GroupFilter that stores a bit table with one bit per sub shape ID pair to determine if they collide or not

The collision rules:

• If one of the objects is in the cInvalidGroup the objects will collide.
• If the objects are in different groups they will collide.
• If they're in the same group but their collision filter is different they will not collide.
• If they're in the same group and their collision filters match, we'll use the SubGroupID and the table below.

For N = 6 sub groups the table will look like:

            sub group 1 --->
sub group 2 x.....
     |      ox....
     |      oox...
     V      ooox..
            oooox.
            ooooox

• 'x' means sub group 1 == sub group 2 and we define this to never collide.
• 'o' is a bit that we have to store that defines if the sub groups collide or not.
• '.' is a bit we don't need to store because the table is symmetric, we take care that group 2 > group 1 by swapping sub group 1 and sub group 2 if needed.

The total number of bits we need to store is (N * (N - 1)) / 2

Constructor & Destructor Documentation

GroupFilterTable() [1/2]

GroupFilterTable::GroupFilterTable ( uint inNumSubGroups = 0 )

inlineexplicit

Constructs the table with inNumSubGroups subgroups, initially all collision pairs are enabled except when the sub group ID is the same.

GroupFilterTable() [2/2]

GroupFilterTable::GroupFilterTable ( const GroupFilterTable & inRHS )

inline

Copy constructor.

Member Function Documentation

CanCollide()

virtual bool GroupFilterTable::CanCollide ( const CollisionGroup & inGroup1, const CollisionGroup & inGroup2 ) const

inlineoverridevirtual

Checks if two CollisionGroups collide.

Implements GroupFilter.

DisableCollision()

void GroupFilterTable::DisableCollision ( SubGroupID inSubGroup1, SubGroupID inSubGroup2 )

inline

Disable collision between two sub groups.

EnableCollision()

void GroupFilterTable::EnableCollision ( SubGroupID inSubGroup1, SubGroupID inSubGroup2 )

inline

Enable collision between two sub groups.

IsCollisionEnabled()

bool GroupFilterTable::IsCollisionEnabled ( SubGroupID inSubGroup1, SubGroupID inSubGroup2 ) const

inline

Check if the collision between two subgroups is enabled.

RestoreBinaryState()

void GroupFilterTable::RestoreBinaryState ( StreamIn & inStream )

overrideprotectedvirtual

This function should not be called directly, it is used by sRestoreFromBinaryState.

Reimplemented from GroupFilter.

SaveBinaryState()

void GroupFilterTable::SaveBinaryState ( StreamOut & inStream ) const

overridevirtual

Saves the contents of the group filter in binary form to inStream.

Reimplemented from GroupFilter.

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The documentation for this class was generated from the following files:

• Jolt/Physics/Collision/GroupFilterTable.h
• Jolt/Physics/Collision/GroupFilterTable.cpp