World (fxgl 0.4.3 API)

java.lang.Object
- com.almasb.fxgl.physics.box2d.dynamics.World

```
public final class World
extends Object
```
The world class manages all physics entities, dynamic simulation, and asynchronous queries. The world also contains efficient memory management facilities.

Author:

Daniel Murphy

Constructor Summary

Constructors
Constructor and Description

World(Vec2 gravity)

Constructors
Constructor and Description
`World(Vec2 gravity)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clearForces()` Call this after you are done with time steps to clear the forces.
`float`	`computeParticleCollisionEnergy()`
`Body`	`createBody(BodyDef def)` Create a rigid body given a definition.
`Joint`	`createJoint(JointDef def)` Create a joint to constrain bodies together.
`int`	`createParticle(ParticleDef def)` Create a particle whose properties have been defined.
`ParticleGroup`	`createParticleGroup(ParticleGroupDef def)` Create a particle group whose properties have been defined.
`void`	`destroyBody(Body body)` Destroy a rigid body.
`void`	`destroyJoint(Joint j)` Destroy a joint.
`void`	`destroyParticle(int index)` Destroy a particle.
`void`	`destroyParticle(int index, boolean callDestructionListener)` Destroy a particle.
`void`	`destroyParticlesInGroup(ParticleGroup group)` Destroy particles in a group without enabling the destruction callback for destroyed particles.
`void`	`destroyParticlesInGroup(ParticleGroup group, boolean callDestructionListener)` Destroy particles in a group.
`int`	`destroyParticlesInShape(Shape shape, Transform xf)` Destroy particles inside a shape without enabling the destruction callback for destroyed particles.
`int`	`destroyParticlesInShape(Shape shape, Transform xf, boolean callDestructionListener)` Destroy particles inside a shape.
`boolean`	`getAutoClearForces()`
`Array<Body>`	`getBodies()` DO NOT MODIFY.
`int`	`getBodyCount()`
`int`	`getContactCount()`
`Contact`	`getContactList()` Get the world contact list.
`DestructionListener`	`getDestructionListener()`
`Vec2`	`getGravity()`
`int`	`getJointCount()`
`Joint`	`getJointList()` Get the world joint list.
`int`	`getParticleBodyContactCount()`
`ParticleBodyContact[]`	`getParticleBodyContacts()`
`ParticleColor[]`	`getParticleColorBuffer()`
`int`	`getParticleContactCount()`
`ParticleContact[]`	`getParticleContacts()`
`int`	`getParticleCount()`
`float`	`getParticleDamping()`
`float`	`getParticleDensity()`
`ParticleDestructionListener`	`getParticleDestructionListener()`
`int[]`	`getParticleFlagsBuffer()` Get the particle data.
`float`	`getParticleGravityScale()`
`ParticleGroup[]`	`getParticleGroupBuffer()`
`int`	`getParticleGroupCount()`
`ParticleGroup[]`	`getParticleGroupList()` Get the world particle group list.
`int`	`getParticleMaxCount()`
`Vec2[]`	`getParticlePositionBuffer()`
`float`	`getParticleRadius()`
`ParticleSystem`	`getParticleSystem()`
`Object[]`	`getParticleUserDataBuffer()`
`Vec2[]`	`getParticleVelocityBuffer()`
`IWorldPool`	`getPool()`
`int`	`getProxyCount()`
`int`	`getTreeBalance()`
`int`	`getTreeHeight()`
`float`	`getTreeQuality()`
`boolean`	`isAllowSleep()`
`boolean`	`isContinuousPhysics()`
`boolean`	`isLocked()`
`boolean`	`isSleepingAllowed()`
`boolean`	`isSubStepping()`
`boolean`	`isWarmStarting()`
`void`	`joinParticleGroups(ParticleGroup groupA, ParticleGroup groupB)` Join two particle groups.
`void`	`queryAABB(ParticleQueryCallback particleCallback, AABB aabb)` Query the world for all particles that potentially overlap the provided AABB.
`void`	`queryAABB(QueryCallback callback, AABB aabb)` Query the world for all fixtures that potentially overlap the provided AABB.
`void`	`queryAABB(QueryCallback callback, ParticleQueryCallback particleCallback, AABB aabb)` Query the world for all fixtures and particles that potentially overlap the provided AABB.
`void`	`raycast(ParticleRaycastCallback particleCallback, Vec2 point1, Vec2 point2)` Ray-cast the world for all particles in the path of the ray.
`void`	`raycast(RayCastCallback callback, ParticleRaycastCallback particleCallback, Vec2 point1, Vec2 point2)` Ray-cast the world for all fixtures and particles in the path of the ray.
`void`	`raycast(RayCastCallback callback, Vec2 point1, Vec2 point2)` Ray-cast the world for all fixtures in the path of the ray.
`void`	`setAllowSleep(boolean flag)`
`void`	`setAutoClearForces(boolean flag)` Set flag to control automatic clearing of forces after each time step.
`void`	`setContactFilter(ContactFilter filter)` Register a contact filter to provide specific control over collision.
`void`	`setContactListener(ContactListener listener)` Register a contact event listener.
`void`	`setContinuousPhysics(boolean flag)` Enable/disable continuous physics.
`void`	`setDestructionListener(DestructionListener listener)` Register a destruction listener.
`void`	`setGravity(Vec2 gravity)` Change the global gravity vector.
`void`	`setParticleColorBuffer(ParticleColor[] buffer, int capacity)`
`void`	`setParticleDamping(float damping)` Damping is used to reduce the velocity of particles.
`void`	`setParticleDensity(float density)` Change the particle density.
`void`	`setParticleDestructionListener(ParticleDestructionListener listener)`
`void`	`setParticleFlagsBuffer(int[] buffer, int capacity)` Set a buffer for particle data.
`void`	`setParticleGravityScale(float gravityScale)` Change the particle gravity scale.
`void`	`setParticleMaxCount(int count)` Set the maximum number of particles.
`void`	`setParticlePositionBuffer(Vec2[] buffer, int capacity)`
`void`	`setParticleRadius(float radius)` Change the particle radius.
`void`	`setParticleUserDataBuffer(Object[] buffer, int capacity)`
`void`	`setParticleVelocityBuffer(Vec2[] buffer, int capacity)`
`void`	`setSleepingAllowed(boolean sleepingAllowed)`
`void`	`setSubStepping(boolean subStepping)`
`void`	`setWarmStarting(boolean flag)` Enable/disable warm starting.
`void`	`step(float dt, int velocityIterations, int positionIterations)` Take a time step.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - World
```
public World(Vec2 gravity)
```
- Method Detail
  - createBody
```
public Body createBody(BodyDef def)
```
    Create a rigid body given a definition. No reference to the definition is retained. This function is locked during callbacks.
    
    Parameters:
    
    def - body definition
    
    Returns:
    
    rigid body
  - destroyBody
```
public void destroyBody(Body body)
```
    Destroy a rigid body. This automatically deletes all associated shapes and joints. This function is locked during callbacks.
    
    Parameters:
    
    body - body to destroy
  - createJoint
```
public Joint createJoint(JointDef def)
```
    Create a joint to constrain bodies together. No reference to the definition is retained. This may cause the connected bodies to cease colliding. This function is locked during callbacks. Note: creating a joint doesn't wake the bodies.
    
    Parameters:
    
    def - joint definition
    
    Returns:
    
    joint
  - destroyJoint
```
public void destroyJoint(Joint j)
```
    Destroy a joint. This may cause the connected bodies to begin colliding. This function is locked during callbacks.
    
    Parameters:
    
    j - joint
  - step
```
public void step(float dt,
                 int velocityIterations,
                 int positionIterations)
```
    Take a time step. This performs collision detection, integration, and constraint solution.
    
    Parameters:
    
    dt - the amount of time to simulate, this should not vary
    
    velocityIterations - for the velocity constraint solver
    
    positionIterations - for the position constraint solver
  - queryAABB
```
public void queryAABB(QueryCallback callback,
                      ParticleQueryCallback particleCallback,
                      AABB aabb)
```
    Query the world for all fixtures and particles that potentially overlap the provided AABB.
    
    Parameters:
    
    callback - a user implemented callback class
    
    particleCallback - callback for particles
    
    aabb - the query box
  - queryAABB
```
public void queryAABB(QueryCallback callback,
                      AABB aabb)
```
    Query the world for all fixtures that potentially overlap the provided AABB.
    
    Parameters:
    
    callback - a user implemented callback class
    
    aabb - the query box
  - queryAABB
```
public void queryAABB(ParticleQueryCallback particleCallback,
                      AABB aabb)
```
    Query the world for all particles that potentially overlap the provided AABB.
    
    Parameters:
    
    particleCallback - callback for particles
    
    aabb - the query box
  - raycast
```
public void raycast(RayCastCallback callback,
                    ParticleRaycastCallback particleCallback,
                    Vec2 point1,
                    Vec2 point2)
```
    Ray-cast the world for all fixtures and particles in the path of the ray. Your callback controls whether you get the closest point, any point, or n-points. The ray-cast ignores shapes that contain the starting point.
    
    Parameters:
    
    callback - a user implemented callback class
    
    particleCallback - the particle callback class
    
    point1 - the ray starting point
    
    point2 - the ray ending point
  - raycast
```
public void raycast(RayCastCallback callback,
                    Vec2 point1,
                    Vec2 point2)
```
    Ray-cast the world for all fixtures in the path of the ray. Your callback controls whether you get the closest point, any point, or n-points. The ray-cast ignores shapes that contain the starting point.
    
    Parameters:
    
    callback - a user implemented callback class
    
    point1 - the ray starting point
    
    point2 - the ray ending point
  - raycast
```
public void raycast(ParticleRaycastCallback particleCallback,
                    Vec2 point1,
                    Vec2 point2)
```
    Ray-cast the world for all particles in the path of the ray. Your callback controls whether you get the closest point, any point, or n-points.
    
    Parameters:
    
    particleCallback - the particle callback class
    
    point1 - the ray starting point
    
    point2 - the ray ending point
  - clearForces
```
public void clearForces()
```
    Call this after you are done with time steps to clear the forces. You normally call this after each call to Step, unless you are performing sub-steps. By default, forces will be automatically cleared, so you don't need to call this function.
    
    See Also:
    
    setAutoClearForces(boolean)
  - createParticle
```
public int createParticle(ParticleDef def)
```
    Create a particle whose properties have been defined. No reference to the definition is retained. A simulation step must occur before it's possible to interact with a newly created particle. For example, DestroyParticleInShape() will not destroy a particle until Step() has been called. This function is locked during callbacks.
    
    Returns:
    
    the index of the particle.
  - destroyParticle
```
public void destroyParticle(int index)
```
    Destroy a particle. The particle is removed after the next step.
    
    Parameters:
    
    index - particle index
  - destroyParticle
```
public void destroyParticle(int index,
                            boolean callDestructionListener)
```
    Destroy a particle. The particle is removed after the next step.
    
    Parameters:
    
    index - of the particle to destroy
    
    callDestructionListener - whether to call the destruction listener just before the particle is destroyed
  - destroyParticlesInShape
```
public int destroyParticlesInShape(Shape shape,
                                   Transform xf)
```
    Destroy particles inside a shape without enabling the destruction callback for destroyed particles. This function is locked during callbacks. For more information see DestroyParticleInShape(Shape&, Transform&,bool). This function is locked during callbacks.
    
    Parameters:
    
    shape - which encloses particles that should be destroyed.
    
    xf - transform applied to the shape.
    
    Returns:
    
    Number of particles destroyed.
  - destroyParticlesInShape
```
public int destroyParticlesInShape(Shape shape,
                                   Transform xf,
                                   boolean callDestructionListener)
```
    Destroy particles inside a shape. This function is locked during callbacks. In addition, this function immediately destroys particles in the shape in contrast to DestroyParticle() which defers the destruction until the next simulation step. This function is locked during callbacks.
    
    Parameters:
    
    shape - which encloses particles that should be destroyed.
    
    xf - transform applied to the shape.
    
    callDestructionListener - whether to call the world b2DestructionListener for each particle destroyed.
    
    Returns:
    
    Number of particles destroyed.
  - createParticleGroup
```
public ParticleGroup createParticleGroup(ParticleGroupDef def)
```
    Create a particle group whose properties have been defined. No reference to the definition is retained. This function is locked during callbacks.
    
    Parameters:
    
    def - particle group definition
    
    Returns:
    
    particle group
  - joinParticleGroups
```
public void joinParticleGroups(ParticleGroup groupA,
                               ParticleGroup groupB)
```
    Join two particle groups. This function is locked during callbacks.
    
    Parameters:
    
    groupA - the first group. Expands to encompass the second group.
    
    groupB - the second group. It is destroyed.
  - destroyParticlesInGroup
```
public void destroyParticlesInGroup(ParticleGroup group,
                                    boolean callDestructionListener)
```
    Destroy particles in a group. This function is locked during callbacks.
    
    Parameters:
    
    group - the particle group to destroy.
    
    callDestructionListener - Whether to call the world b2DestructionListener for each particle is destroyed.
  - destroyParticlesInGroup
```
public void destroyParticlesInGroup(ParticleGroup group)
```
    Destroy particles in a group without enabling the destruction callback for destroyed particles. This function is locked during callbacks.
    
    Parameters:
    
    group - the particle group to destroy.
  - getParticleGroupList
```
public ParticleGroup[] getParticleGroupList()
```
    Get the world particle group list. With the returned group, use ParticleGroup::GetNext to get the next group in the world list. A NULL group indicates the end of the list.
    
    Returns:
    
    the head of the world particle group list.
  - getParticleGroupCount
```
public int getParticleGroupCount()
```
    Returns:
    
    the number of particle groups
  - getParticleCount
```
public int getParticleCount()
```
    Returns:
    
    the number of particles
  - getParticleMaxCount
```
public int getParticleMaxCount()
```
    Returns:
    
    the maximum number of particles
  - setParticleMaxCount
```
public void setParticleMaxCount(int count)
```
    Set the maximum number of particles.
    
    Parameters:
    
    count - number
  - setParticleDensity
```
public void setParticleDensity(float density)
```
    Change the particle density.
    
    Parameters:
    
    density - particle density
  - getParticleDensity
```
public float getParticleDensity()
```
    Returns:
    
    the particle density
  - setParticleGravityScale
```
public void setParticleGravityScale(float gravityScale)
```
    Change the particle gravity scale. Adjusts the effect of the global gravity vector on particles. Default value is 1.0f.
    
    Parameters:
    
    gravityScale - gravity scale
  - getParticleGravityScale
```
public float getParticleGravityScale()
```
    Returns:
    
    the particle gravity scale
  - setParticleDamping
```
public void setParticleDamping(float damping)
```
    Damping is used to reduce the velocity of particles. The damping parameter can be larger than 1.0f but the damping effect becomes sensitive to the time step when the damping parameter is large.
    
    Parameters:
    
    damping - particle damping
  - getParticleDamping
```
public float getParticleDamping()
```
    Returns:
    
    damping for particles
  - setParticleRadius
```
public void setParticleRadius(float radius)
```
    Change the particle radius. You should set this only once, on world start. If you change the radius during execution, existing particles may explode, shrink, or behave unexpectedly.
    
    Parameters:
    
    radius - particle radius
  - getParticleRadius
```
public float getParticleRadius()
```
    Returns:
    
    the particle radius
  - getParticleFlagsBuffer
```
public int[] getParticleFlagsBuffer()
```
    Get the particle data. Returns the pointer to the head of the particle data.
    
    Returns:
    
    particle flags buffer
  - getParticlePositionBuffer
```
public Vec2[] getParticlePositionBuffer()
```
  - getParticleVelocityBuffer
```
public Vec2[] getParticleVelocityBuffer()
```
  - getParticleColorBuffer
```
public ParticleColor[] getParticleColorBuffer()
```
  - getParticleGroupBuffer
```
public ParticleGroup[] getParticleGroupBuffer()
```
  - getParticleUserDataBuffer
```
public Object[] getParticleUserDataBuffer()
```
  - setParticleFlagsBuffer
```
public void setParticleFlagsBuffer(int[] buffer,
                                   int capacity)
```
    Set a buffer for particle data.
    
    Parameters:
    
    buffer - is a pointer to a block of memory.
    
    capacity - is the number of values in the block.
  - setParticlePositionBuffer
```
public void setParticlePositionBuffer(Vec2[] buffer,
                                      int capacity)
```
  - setParticleVelocityBuffer
```
public void setParticleVelocityBuffer(Vec2[] buffer,
                                      int capacity)
```
  - setParticleColorBuffer
```
public void setParticleColorBuffer(ParticleColor[] buffer,
                                   int capacity)
```
  - setParticleUserDataBuffer
```
public void setParticleUserDataBuffer(Object[] buffer,
                                      int capacity)
```
  - getParticleContacts
```
public ParticleContact[] getParticleContacts()
```
    Returns:
    
    contacts between particles
  - getParticleContactCount
```
public int getParticleContactCount()
```
  - getParticleBodyContacts
```
public ParticleBodyContact[] getParticleBodyContacts()
```
    Returns:
    
    contacts between particles and bodies
  - getParticleBodyContactCount
```
public int getParticleBodyContactCount()
```
  - computeParticleCollisionEnergy
```
public float computeParticleCollisionEnergy()
```
    Returns:
    
    the kinetic energy that can be lost by damping force
  - getBodies
```
public Array<Body> getBodies()
```
    DO NOT MODIFY.
    
    Returns:
    
    all world bodies
  - getJointList
```
public Joint getJointList()
```
    Get the world joint list. With the returned joint, use Joint.getNext to get the next joint in the world list. A null joint indicates the end of the list.
    
    Returns:
    
    the head of the world joint list.
  - getContactList
```
public Contact getContactList()
```
    Get the world contact list. With the returned contact, use Contact.getNext to get the next contact in the world list. A null contact indicates the end of the list. Contacts are created and destroyed in the middle of a time step. Use ContactListener to avoid missing contacts.
    
    Returns:
    
    the head of the world contact list.
  - isSleepingAllowed
```
public boolean isSleepingAllowed()
```
  - setSleepingAllowed
```
public void setSleepingAllowed(boolean sleepingAllowed)
```
  - setWarmStarting
```
public void setWarmStarting(boolean flag)
```
    Enable/disable warm starting. For testing.
    
    Parameters:
    
    flag - warm starting flag
  - isWarmStarting
```
public boolean isWarmStarting()
```
  - setContinuousPhysics
```
public void setContinuousPhysics(boolean flag)
```
    Enable/disable continuous physics. For testing.
    
    Parameters:
    
    flag - continuous physics flag
  - isContinuousPhysics
```
public boolean isContinuousPhysics()
```
  - getProxyCount
```
public int getProxyCount()
```
    Returns:
    
    the number of broad-phase proxies
  - getBodyCount
```
public int getBodyCount()
```
    Returns:
    
    the number of bodies
  - getJointCount
```
public int getJointCount()
```
    Returns:
    
    the number of joints
  - getContactCount
```
public int getContactCount()
```
    Returns:
    
    the number of contacts (each may have 0 or more contact points)
  - getTreeHeight
```
public int getTreeHeight()
```
    Returns:
    
    the height of the dynamic tree
  - getTreeBalance
```
public int getTreeBalance()
```
    Returns:
    
    the balance of the dynamic tree
  - getTreeQuality
```
public float getTreeQuality()
```
    Returns:
    
    the quality of the dynamic tree
  - setGravity
```
public void setGravity(Vec2 gravity)
```
    Change the global gravity vector.
    
    Parameters:
    
    gravity - gravity vector
  - getGravity
```
public Vec2 getGravity()
```
    Returns:
    
    global gravity vector
  - getPool
```
public IWorldPool getPool()
```
  - getDestructionListener
```
public DestructionListener getDestructionListener()
```
  - setDestructionListener
```
public void setDestructionListener(DestructionListener listener)
```
    Register a destruction listener. The listener is owned by you and must remain in scope.
    
    Parameters:
    
    listener - destruction listener
  - getParticleDestructionListener
```
public ParticleDestructionListener getParticleDestructionListener()
```
  - setParticleDestructionListener
```
public void setParticleDestructionListener(ParticleDestructionListener listener)
```
  - isAllowSleep
```
public boolean isAllowSleep()
```
  - setAllowSleep
```
public void setAllowSleep(boolean flag)
```
  - setSubStepping
```
public void setSubStepping(boolean subStepping)
```
  - isSubStepping
```
public boolean isSubStepping()
```
  - getParticleSystem
```
public ParticleSystem getParticleSystem()
```
  - setAutoClearForces
```
public void setAutoClearForces(boolean flag)
```
    Set flag to control automatic clearing of forces after each time step.
    
    Parameters:
    
    flag - automatically clear forces flag
  - getAutoClearForces
```
public boolean getAutoClearForces()
```
    Returns:
    
    the flag that controls automatic clearing of forces after each time step
  - setContactFilter
```
public void setContactFilter(ContactFilter filter)
```
    Register a contact filter to provide specific control over collision. Otherwise the default filter is used (_defaultFilter). The listener is owned by you and must remain in scope.
    
    Parameters:
    
    filter - contact filter
  - setContactListener
```
public void setContactListener(ContactListener listener)
```
    Register a contact event listener. The listener is owned by you and must remain in scope.
    
    Parameters:
    
    listener - contact listener
  - isLocked
```
public boolean isLocked()
```
    Returns:
    
    is the world locked (in the middle of a time step)

Class World

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

World

Method Detail

createBody

destroyBody

createJoint

destroyJoint

step

queryAABB

queryAABB

queryAABB

raycast

raycast

raycast

clearForces

createParticle

destroyParticle

destroyParticle

destroyParticlesInShape

destroyParticlesInShape

createParticleGroup

joinParticleGroups

destroyParticlesInGroup

destroyParticlesInGroup

getParticleGroupList

getParticleGroupCount

getParticleCount

getParticleMaxCount

setParticleMaxCount

setParticleDensity

getParticleDensity

setParticleGravityScale

getParticleGravityScale

setParticleDamping

getParticleDamping

setParticleRadius

getParticleRadius

getParticleFlagsBuffer

getParticlePositionBuffer

getParticleVelocityBuffer

getParticleColorBuffer

getParticleGroupBuffer

getParticleUserDataBuffer

setParticleFlagsBuffer

setParticlePositionBuffer

setParticleVelocityBuffer

setParticleColorBuffer

setParticleUserDataBuffer

getParticleContacts

getParticleContactCount

getParticleBodyContacts

getParticleBodyContactCount

computeParticleCollisionEnergy

getBodies

getJointList

getContactList

isSleepingAllowed

setSleepingAllowed

setWarmStarting

isWarmStarting

setContinuousPhysics

isContinuousPhysics

getProxyCount

getBodyCount

getJointCount

getContactCount

getTreeHeight

getTreeBalance

getTreeQuality

setGravity

getGravity

getPool

getDestructionListener

setDestructionListener

getParticleDestructionListener

setParticleDestructionListener