com.almasb.fxgl.physics.box2d.dynamics

Class Fixture

java.lang.Object

com.almasb.fxgl.physics.box2d.dynamics.Fixture

public class Fixture
extends Object

A fixture is used to attach a shape to a body for collision detection. A fixture inherits its transform from its parent. Fixtures hold additional non-geometric data such as friction, collision filters, etc. Fixtures are created via Body::CreateFixture. Note: you cannot reuse fixtures.

Author:

daniel

Field Summary

Fields

Modifier and Type	Field and Description
FixtureProxy[]	m_proxies

Method Summary

Modifier and Type	Method and Description
float	computeDistance(Vec2 p, int childIndex, Vec2 normalOut) Compute the distance from this fixture.
boolean	containsPoint(Vec2 p) Test a point for containment in this fixture.
void	createProxies(BroadPhase broadPhase, Transform xf)
AABB	getAABB(int childIndex) Get the fixture's AABB.
Body	getBody() Get the parent body of this fixture.
float	getDensity()
Filter	getFilterData()
float	getFriction()
void	getMassData(MassData massData) Get the mass data for this fixture.
FixtureProxy[]	getProxies()
int	getProxyCount()
float	getRestitution()
Shape	getShape() Get the child shape.
ShapeType	getType() Get the type of the child shape.
Object	getUserData() Get the user data that was assigned in the fixture definition.
boolean	isSensor() Is this fixture a sensor (non-solid)?
boolean	raycast(RayCastOutput output, RayCastInput input, int childIndex) Cast a ray against this shape.
void	refilter() Call this if you want to establish collision that was previously disabled by ContactFilter::ShouldCollide.
void	setDensity(float density)
void	setFilterData(Filter filter) Set the contact filtering data.
void	setFriction(float friction) Set the coefficient of friction.
void	setRestitution(float restitution) Set the coefficient of restitution.
void	setSensor(boolean sensor) Set if this fixture is a sensor.
void	setUserData(Object data) Set the user data.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_proxies

public FixtureProxy[] m_proxies

Method Detail

getType

public ShapeType getType()

Get the type of the child shape. You can use this to down cast to the concrete shape.

Returns:

the shape type

getShape

public Shape getShape()

Get the child shape. You can modify the child shape, however you should not change the number of vertices because this will crash some collision caching mechanisms.

Returns:

child shape

isSensor

public boolean isSensor()

Is this fixture a sensor (non-solid)?

Returns:

true if the shape is a sensor.

setSensor

public void setSensor(boolean sensor)

Set if this fixture is a sensor.

Parameters:

sensor - sensor flag

setFilterData

public void setFilterData(Filter filter)

Set the contact filtering data. This is an expensive operation and should not be called frequently. This will not update contacts until the next time step when either parent body is awake. This automatically calls refilter.

Parameters:

filter - filter

getFilterData

public Filter getFilterData()

Returns:

the contact filtering data

getProxyCount

public int getProxyCount()

getProxies

public FixtureProxy[] getProxies()

refilter

public void refilter()

Call this if you want to establish collision that was previously disabled by ContactFilter::ShouldCollide.

getBody

public Body getBody()

Get the parent body of this fixture.

Returns:

the parent body

setDensity

public void setDensity(float density)

getDensity

public float getDensity()

Returns:

density

getUserData

public Object getUserData()

Get the user data that was assigned in the fixture definition. Use this to store your application specific data.

Returns:

user data

setUserData

public void setUserData(Object data)

Set the user data. Use this to store your application specific data.

Parameters:

data - user data

containsPoint

public boolean containsPoint(Vec2 p)

Test a point for containment in this fixture. This only works for convex shapes.

Parameters:

p - a point in world coordinates

raycast

public boolean raycast(RayCastOutput output,
                       RayCastInput input,
                       int childIndex)

Cast a ray against this shape.

Parameters:

output - the ray-cast results

input - the ray-cast input parameters

getMassData

public void getMassData(MassData massData)

Get the mass data for this fixture. The mass data is based on the density and the shape. The rotational inertia is about the shape's origin.

getFriction

public float getFriction()

Returns:

the coefficient of friction

setFriction

public void setFriction(float friction)

Set the coefficient of friction. This will NOT change the friction of existing contacts.

Parameters:

friction - friction

getRestitution

public float getRestitution()

Returns:

the coefficient of restitution

setRestitution

public void setRestitution(float restitution)

Set the coefficient of restitution. This will NOT change the restitution of existing contacts.

Parameters:

restitution - restitution

getAABB

public AABB getAABB(int childIndex)

Get the fixture's AABB. This AABB may be enlarge and/or stale. If you need a more accurate AABB, compute it using the shape and the body transform.

Returns:

AABB

computeDistance

public float computeDistance(Vec2 p,
                             int childIndex,
                             Vec2 normalOut)

Compute the distance from this fixture.

Parameters:

p - a point in world coordinates.

Returns:

distance

createProxies

public void createProxies(BroadPhase broadPhase,
                          Transform xf)