A potential contact between the children of two Fixture objects. More...

#include <Contact.hpp>

Collaboration diagram for playrho::d2::Contact:

Public Types
enum	: FlagsType { e_touchingFlag = 0x01, e_enabledFlag = 0x02, e_filterFlag = 0x04, e_toiFlag = 0x08, e_dirtyFlag = 0x10, e_sensorFlag = 0x20, e_activeFlag = 0x40, e_impenetrableFlag = 0x80 }
	Flags stored in m_flags. More...

using	substep_type = TimestepIters
	Substep type.

using	FlagsType = std::uint8_t
	Flags type data type.

Public Member Functions
	Contact () noexcept=default
	Default construction not allowed.

	Contact (BodyID bA, FixtureID fA, ChildCounter iA, BodyID bB, FixtureID fB, ChildCounter iB) noexcept
	Initializing constructor. More...

bool	IsTouching () const noexcept
	Is this contact touching? More...

void	SetTouching () noexcept
	Sets the touching flag state. More...

void	UnsetTouching () noexcept
	Unsets the touching flag state.

void	SetEnabled (bool flag) noexcept
	Enables or disables this contact. More...

bool	IsEnabled () const noexcept
	Has this contact been disabled?

void	SetEnabled () noexcept
	Enables this contact.

void	UnsetEnabled () noexcept
	Disables this contact.

BodyID	GetBodyA () const noexcept
	Gets the body-A identifier.

FixtureID	GetFixtureA () const noexcept
	Gets fixture A in this contact.

ChildCounter	GetChildIndexA () const noexcept
	Get the child primitive index for fixture A.

BodyID	GetBodyB () const noexcept
	Gets the body-B identifier.

FixtureID	GetFixtureB () const noexcept
	Gets fixture B in this contact.

ChildCounter	GetChildIndexB () const noexcept
	Get the child primitive index for fixture B.

void	SetFriction (Real friction) noexcept
	Sets the friction value for this contact. More...

Real	GetFriction () const noexcept
	Gets the coefficient of friction. More...

void	SetRestitution (Real restitution) noexcept
	Sets the restitution. More...

Real	GetRestitution () const noexcept
	Gets the restitution.

void	SetTangentSpeed (LinearVelocity speed) noexcept
	Sets the desired tangent speed for a conveyor belt behavior.

LinearVelocity	GetTangentSpeed () const noexcept
	Gets the desired tangent speed.

substep_type	GetToiCount () const noexcept
	Gets the time of impact count.

bool	HasValidToi () const noexcept
	Gets whether a TOI is set. More...

Real	GetToi () const
	Gets the time of impact (TOI) as a fraction. More...

void	FlagForFiltering () noexcept
	Flags the contact for filtering.

bool	NeedsFiltering () const noexcept
	Whether or not the contact needs filtering.

void	FlagForUpdating () noexcept
	Flags the contact for updating.

bool	NeedsUpdating () const noexcept
	Whether or not the contact needs updating.

bool	IsSensor () const noexcept
	Whether or not this contact is a "sensor". More...

void	SetIsSensor () noexcept
	Sets the sensor state of this contact. More...

void	UnsetIsSensor () noexcept
	Unsets the sensor state of this contact.

bool	IsImpenetrable () const noexcept
	Whether or not this contact is "impenetrable". More...

void	SetImpenetrable () noexcept
	Sets the impenetrability of this contact. More...

void	UnsetImpenetrable () noexcept
	Unsets the impenetrability of this contact.

bool	IsActive () const noexcept
	Whether or not this contact is "active". More...

void	SetIsActive () noexcept
	Sets the active state of this contact. More...

void	UnsetIsActive () noexcept
	Unsets the active state of this contact. More...

void	UnflagForFiltering () noexcept
	Flags this contact for filtering. More...

void	UnflagForUpdating () noexcept
	Unflags this contact for updating.

void	SetToi (Real toi) noexcept
	Sets the time of impact (TOI). More...

void	UnsetToi () noexcept
	Unsets the TOI.

void	SetToiCount (substep_type value) noexcept
	Sets the TOI count to the given value.

void	IncrementToiCount () noexcept
	Increments the TOI count.

Private Attributes
BodyID	m_bodyA = InvalidBodyID
	Identifier of body A. More...

BodyID	m_bodyB = InvalidBodyID
	Identifier of body B. More...

FixtureID	m_fixtureA = InvalidFixtureID
	Identifier of fixture A. More...

FixtureID	m_fixtureB = InvalidFixtureID
	Identifier of fixture B. More...

ChildCounter	m_indexA
	Index A. 4-bytes.

ChildCounter	m_indexB
	Index B. 4-bytes.

Real	m_friction = 0
	Mix of frictions of associated fixtures. More...

Real	m_restitution = 0
	Mix of restitutions of associated fixtures. More...

LinearVelocity	m_tangentSpeed = 0
	Tangent speed. More...

Real	m_toi = 0
	Time of impact. More...

substep_type	m_toiCount = 0
	Count of TOI calculations contact has gone through since last reset.

FlagsType	m_flags = e_enabledFlag \| e_dirtyFlag
	Flags.

Related Functions
(Note that these are not member functions.)
AABB	ComputeIntersectingAABB (const World &world, const Contact &contact)
	Computes the intersecting AABB for the given contact.

WorldManifold	GetWorldManifold (const World &world, const Contact &contact, const Manifold &manifold)
	Gets the world manifold for the given data. More...

BodyID	GetBodyA (const Contact &contact) noexcept
	Gets the body A ID of the given contact.

BodyID	GetBodyB (const Contact &contact) noexcept
	Gets the body B ID of the given contact.

FixtureID	GetFixtureA (const Contact &contact) noexcept
	Gets the fixture A associated with the given contact.

FixtureID	GetFixtureB (const Contact &contact) noexcept
	Gets the fixture B associated with the given contact.

ChildCounter	GetChildIndexA (const Contact &contact) noexcept
	Gets the child index A of the given contact.

ChildCounter	GetChildIndexB (const Contact &contact) noexcept
	Gets the child index B of the given contact.

bool	IsImpenetrable (const Contact &contact) noexcept
	Whether the given contact is "impenetrable".

bool	IsActive (const Contact &contact) noexcept
	Determines whether the given contact is "active".

bool	IsEnabled (const Contact &contact) noexcept
	Gets whether the given contact is enabled or not.

bool	IsTouching (const Contact &contact) noexcept
	Gets whether the given contact is touching or not.

bool	IsSensor (const Contact &contact) noexcept
	Gets whether the given contact is for sensors or not.

auto	GetToiCount (const Contact &contact) noexcept
	Gets the time of impact count.

auto	NeedsFiltering (const Contact &contact) noexcept
	Whether or not the contact needs filtering.

auto	NeedsUpdating (const Contact &contact) noexcept
	Whether or not the contact needs updating.

auto	HasValidToi (const Contact &contact) noexcept
	Gets whether a TOI is set. More...

Real	GetToi (const Contact &contact) noexcept
	Gets the time of impact (TOI) as a fraction. More...

auto	GetFriction (const Contact &contact) noexcept
	Gets the coefficient of friction. More...

void	SetFriction (Contact &contact, Real value) noexcept
	Sets the friction value for the identified contact. More...

auto	GetRestitution (const Contact &contact) noexcept
	Gets the coefficient of restitution. More...

void	SetRestitution (Contact &contact, Real value)
	Sets the restitution value for the identified contact. More...

auto	GetTangentSpeed (const Contact &contact) noexcept
	Gets the desired tangent speed. More...

void	SetTangentSpeed (Contact &contact, LinearVelocity value) noexcept
	Sets the desired tangent speed for a conveyor belt behavior. More...

Detailed Description

A potential contact between the children of two Fixture objects.

The class manages contact between two shapes. A contact exists for each overlapping AABB in the broad-phase (except if filtered). Therefore a contact object may exist that has no actual contact points.

Examples: World.cpp.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum : FlagsType

Flags stored in m_flags.

Enumerator
e_sensorFlag	Indicates whether the contact is to be treated as a sensor or not.
e_activeFlag	Indicates whether the contact is to be treated as active or not.
e_impenetrableFlag	Indicates whether the contact is to be treated as between impenetrable bodies.

Constructor & Destructor Documentation

◆ Contact()

playrho::d2::Contact::Contact	(	BodyID	bA,
		FixtureID	fA,
		ChildCounter	iA,
		BodyID	bB,
		FixtureID	fB,
		ChildCounter	iB
	)

noexcept

Initializing constructor.

Parameters

bA	Identifier of body-A.
fA	Non-invalid identifier to fixture A that must have a shape and may not be the same or have the same body as the other fixture.
iA	Child index A.
bB	Identifier of body-B.
fB	Non-invalid identifier to fixture B that must have a shape and may not be the same or have the same body as the other fixture.
iB	Child index B.

Note: This need never be called directly by a user.

Warning: Behavior is undefined if fA is null.; Behavior is undefined if fB is null.; Behavior is undefined if fA == fB.; Behavior is undefined if both fixture's have the same body.

Member Function Documentation

◆ GetFriction()

Real playrho::d2::Contact::GetFriction ( ) const

inlinenoexcept

Gets the coefficient of friction.

Gets the combined friction of the two fixtures associated with this contact.

Returns: Value of 0 or higher.

See also: SetFriction.

◆ GetToi()

Real playrho::d2::Contact::GetToi ( ) const

inline

Gets the time of impact (TOI) as a fraction.

Note: This is only valid if a TOI has been set.

See also: void SetToi(Real toi).

Returns: Time of impact fraction in the range of 0 to 1 if set (where 1 means no actual impact in current time slot), otherwise undefined.

◆ HasValidToi()

bool playrho::d2::Contact::HasValidToi ( ) const

inlinenoexcept

Gets whether a TOI is set.

Returns: true if this object has a TOI set for it, false otherwise.

Referenced by GetToi().

◆ IsActive()

bool playrho::d2::Contact::IsActive ( ) const

inlinenoexcept

Whether or not this contact is "active".

Note: This should be true whenever body A or body B are "awake".

◆ IsImpenetrable()

bool playrho::d2::Contact::IsImpenetrable ( ) const

inlinenoexcept

Whether or not this contact is "impenetrable".

Note: This should be true whenever body A or body B are impenetrable.

◆ IsSensor()

bool playrho::d2::Contact::IsSensor ( ) const

inlinenoexcept

Whether or not this contact is a "sensor".

Note: This should be true whenever fixture A or fixture B is a sensor.

◆ IsTouching()

bool playrho::d2::Contact::IsTouching ( ) const

inlinenoexcept

Is this contact touching?

Touching is defined as either:

This contact's manifold has more than 0 contact points, or
This contact has sensors and the two shapes of this contact are found to be overlapping.
Returns
true if this contact is said to be touching, false otherwise.

◆ SetEnabled()

void playrho::d2::Contact::SetEnabled ( bool flag )

inlinenoexcept

Enables or disables this contact.

Note: This can be used inside the pre-solve contact listener. The contact is only disabled for the current time step (or sub-step in continuous collisions).

◆ SetFriction()

void playrho::d2::Contact::SetFriction ( Real friction )

inlinenoexcept

Sets the friction value for this contact.

Override the default friction mixture.

Note: You can call this in "pre-solve" listeners.; This value persists until set or reset.

Warning: Behavior is undefined if given a negative friction value.

Parameters

friction Co-efficient of friction value of zero or greater.

See also: GetFriction.

◆ SetImpenetrable()

void playrho::d2::Contact::SetImpenetrable ( )

inlinenoexcept

Sets the impenetrability of this contact.

Attention: Call this if body A or body B are impenetrable.

◆ SetIsActive()

void playrho::d2::Contact::SetIsActive ( )

inlinenoexcept

Sets the active state of this contact.

Attention: Call this if body A or body B are "awake".

◆ SetIsSensor()

void playrho::d2::Contact::SetIsSensor ( )

inlinenoexcept

Sets the sensor state of this contact.

Attention: Call this if fixture A or fixture B is a sensor.

◆ SetRestitution()

void playrho::d2::Contact::SetRestitution ( Real restitution )

inlinenoexcept

Sets the restitution.

This override the default restitution mixture.

Note: You can call this in "pre-solve" listeners.; The value persists until you set or reset.

Referenced by playrho::d2::SetRestitution().

◆ SetToi()

void playrho::d2::Contact::SetToi ( Real toi )

inlinenoexcept

Sets the time of impact (TOI).

After returning, this object will have a TOI that is set as indicated by HasValidToi().

Note: Behavior is undefined if the value assigned is less than 0 or greater than 1.

See also: Real GetToi() const.; HasValidToi.

Parameters

toi	Time of impact as a fraction between 0 and 1 where 1 indicates no actual impact in the current time slot.

◆ SetTouching()

void playrho::d2::Contact::SetTouching ( )

inlinenoexcept

Sets the touching flag state.

Note

This should only be called if either:

The contact's manifold has more than 0 contact points, or
The contact has sensors and the two shapes of this contact are found to be overlapping.

See also: IsTouching().

◆ UnflagForFiltering()

void playrho::d2::Contact::UnflagForFiltering ( )

inlinenoexcept

Flags this contact for filtering.

Note: Filtering will occur the next time step.

◆ UnsetIsActive()

void playrho::d2::Contact::UnsetIsActive ( )

inlinenoexcept

Unsets the active state of this contact.

Attention: Call this if neither body A nor body B are "awake".

Friends And Related Function Documentation

◆ GetFriction()

auto GetFriction ( const Contact & contact )

See also: SetFriction.

◆ GetRestitution()

auto GetRestitution ( const Contact & contact )

See also: SetRestitution.

◆ GetTangentSpeed()

auto GetTangentSpeed ( const Contact & contact )

Exceptions

std::out_of_range If given an invalid contact identifier.

See also: SetTangentSpeed.

◆ GetToi()

Real GetToi ( const Contact & contact )

Note: This is only valid if a TOI has been set.

See also: void SetToi(Real toi).

Returns: Time of impact fraction in the range of 0 to 1 if set (where 1 means no actual impact in current time slot), otherwise undefined.

See also: HasValidToi

◆ GetWorldManifold()

WorldManifold GetWorldManifold	(	const World &	world,
		const Contact &	contact,
		const Manifold &	manifold
	)

Note: This is a convenience function that in turn calls the GetWorldManifold(const Manifold&, const Transformation&, const Real, const Transformation& xfB, const Real) function.

Parameters

world	World that the result is to be relative to.
contact	Contact to return a world manifold for.
manifold	The manifold to covert to a world manifold.

Returns: World manifold value for the given inputs which will have the same number of points as the given manifold has. The returned world manifold points will be the mid-points of the contact's intersection.

◆ HasValidToi()

auto HasValidToi ( const Contact & contact )

See also: GetToi.

Examples: World.cpp.

◆ SetFriction()

void SetFriction	(	Contact &	contact,
		Real	value
	)

Overrides the default friction mixture.

Note: This value persists until set or reset.

Warning: Behavior is undefined if given a negative friction value.

Parameters

contact	The contact whose friction should be set.
value	Co-efficient of friction value of zero or greater.

Exceptions

std::out_of_range If given an invalid contact identifier.

See also: GetFriction.

◆ SetRestitution()

void SetRestitution	(	Contact &	contact,
		Real	value
	)

This override the default restitution mixture.

Note: You can call this in "pre-solve" listeners.; The value persists until you set or reset.

Exceptions

std::out_of_range If given an invalid contact identifier.

See also: GetRestitution.

◆ SetTangentSpeed()

void SetTangentSpeed	(	Contact &	contact,
		LinearVelocity	value
	)

Exceptions

std::out_of_range If given an invalid contact identifier.

See also: GetTangentSpeed.

Member Data Documentation

◆ m_bodyA

BodyID playrho::d2::Contact::m_bodyA = InvalidBodyID

private

Identifier of body A.

Note: Field is 2-bytes.

Warning: Should only be body of fixture A.

Referenced by GetBodyA().

◆ m_bodyB

BodyID playrho::d2::Contact::m_bodyB = InvalidBodyID

private

Identifier of body B.

Note: Field is 2-bytes.

Warning: Should only be body of fixture B.

Referenced by GetBodyB().

◆ m_fixtureA

FixtureID playrho::d2::Contact::m_fixtureA = InvalidFixtureID

private

Identifier of fixture A.

Note: Field is 2-bytes.

Referenced by GetFixtureA().

◆ m_fixtureB

FixtureID playrho::d2::Contact::m_fixtureB = InvalidFixtureID

private

Identifier of fixture B.

Note: Field is 2-bytes.

Referenced by GetFixtureB().

◆ m_friction

Real playrho::d2::Contact::m_friction = 0

private

Mix of frictions of associated fixtures.

Note: Field is 4-bytes (with 4-byte Real).

See also: MixFriction.

Referenced by GetFriction(), and SetFriction().

◆ m_restitution

Real playrho::d2::Contact::m_restitution = 0

private

Mix of restitutions of associated fixtures.

Note: Field is 4-bytes (with 4-byte Real).

See also: MixRestitution.

Referenced by GetRestitution(), and SetRestitution().

◆ m_tangentSpeed

LinearVelocity playrho::d2::Contact::m_tangentSpeed = 0

private

Tangent speed.

Note: Field is 4-bytes (with 4-byte Real).

Referenced by GetTangentSpeed(), and SetTangentSpeed().

◆ m_toi

Real playrho::d2::Contact::m_toi = 0

private

Time of impact.

Note: This is a unit interval of time (a value between 0 and 1).; Only valid if m_flags & e_toiFlag.

Referenced by GetToi(), and SetToi().

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

Contact.hpp
AABB.hpp
WorldManifold.hpp
Contact.cpp

Public Types

Public Member Functions

Private Attributes

Related Functions

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ Contact()

Member Function Documentation

◆ GetFriction()

◆ GetToi()

◆ HasValidToi()

◆ IsActive()

◆ IsImpenetrable()

◆ IsSensor()

◆ IsTouching()

◆ SetEnabled()

◆ SetFriction()

◆ SetImpenetrable()

◆ SetIsActive()

◆ SetIsSensor()

◆ SetRestitution()

◆ SetToi()

◆ SetTouching()

◆ UnflagForFiltering()

◆ UnsetIsActive()

Friends And Related Function Documentation

◆ GetFriction()

◆ GetRestitution()

◆ GetTangentSpeed()

◆ GetToi()

◆ GetWorldManifold()

◆ HasValidToi()

◆ SetFriction()

◆ SetRestitution()

◆ SetTangentSpeed()

Member Data Documentation

◆ m_bodyA

◆ m_bodyB

◆ m_fixtureA

◆ m_fixtureB

◆ m_friction

◆ m_restitution

◆ m_tangentSpeed

◆ m_toi