com.almasb.fxgl.physics.box2d.dynamics

Class Fixture

java.lang.Object

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

public final 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

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.
AABB	getAABB(int childIndex) This AABB may be enlarged and/or stale.
Body	getBody()
float	getDensity()
Filter	getFilterData()
float	getFriction()
void	getMassData(MassData massData) Get the mass data for this fixture.
float	getRestitution()
Shape	getShape() You can modify the child shape, however you should not change the number of vertices because this will crash some collision caching mechanisms.
ShapeType	getType()
Object	getUserData() The same as in the fixture definition, unless explicitly changed.
boolean	isSensor()
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) This will NOT change the friction of existing contacts.
void	setRestitution(float restitution) This will NOT change the restitution of existing contacts.
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

Method Detail

getBody

public Body getBody()

Returns:

the parent body of this fixture

getShape

public Shape getShape()

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

getType

public ShapeType getType()

Returns:

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

getFilterData

public Filter getFilterData()

Returns:

the contact filtering data

setFilterData

public void setFilterData(Filter filter)

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

Parameters:

filter - filter

getUserData

public Object getUserData()

The same as in the fixture definition, unless explicitly changed. 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

getDensity

public float getDensity()

setDensity

public void setDensity(float density)

getFriction

public float getFriction()

setFriction

public void setFriction(float friction)

This will NOT change the friction of existing contacts.

getRestitution

public float getRestitution()

setRestitution

public void setRestitution(float restitution)

This will NOT change the restitution of existing contacts.

isSensor

public boolean isSensor()

Returns:

true if the fixture / shape is a sensor (non-solid)

setSensor

public void setSensor(boolean sensor)

Set if this fixture is a sensor.

refilter

public void refilter()

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

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.

getAABB

public AABB getAABB(int childIndex)

This AABB may be enlarged and/or stale. If you need a more accurate AABB, compute it using the shape and the body transform.

Returns:

the fixture's 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