Module org.dyn4j

Package org.dyn4j.world

Package containing the dynamics engine.

The dynamics engine is an impulse based rigid body physics simulator. The simulation by default uses SI (m/kg/s) units. This can be changed, but all settings within the Settings singleton must be set to the new units. Instead its recommended to use the UnitConversion class to convert all values to MKS.

A constraint based approach is used to solving contacts and joints.

Create a World object to gain access the dynamics engine. Create Bodys and add them to the World. Add the AbstractPhysicsWorld.update(double) method to your game loop (notice the AbstractPhysicsWorld.update(double) method requires the elapsed time to be in seconds).

Upon creating a World a Bounds object may be supplied. The Bounds will determine when Bodys go out of bounds and deactivate them. Using the World() constructor will create a world that has no bounds, in which case the AbstractCollisionWorld.getBounds() method will return null.

A World object also contains a number listeners that can be used to respond to events that happen within the world, contact for instance.

• BoundsListener for responding to out of bounds bodies
• DestructionListener for responding to bodies and joints that are implicitly destroyed by some other action
• StepListener for performing logic at the end/beginning of a time step
• CollisionListener for responding to collision detection events
• ContactListener for responding to contact events
• TimeOfImpactListener for responding to time of impact events

Please read the respective documentation on each listener. Certain operations on the World object may not be allowed inside the listener methods.

The gravity of the World object can be changed, and can be in any direction via the AbstractPhysicsWorld.setGravity(org.dyn4j.geometry.Vector2) method.

The dynamics engine may require some configuration. The defaults should cover most applications, however, they can be changed using the Settings class on the World. Any setting can be changed at runtime so that no source code modification is needed. Refer to the source of Settings and the Sandbox for details on what each individual setting controls.

Since:

4.0.0

Version:

4.0.0

Author:

William Bittle

Interface Summary

Interface	Description
BroadphaseCollisionData<T extends CollisionBody<E>,E extends Fixture>	Represents a broadphase collision.
BroadphaseCollisionDataFilter<T extends CollisionBody<E>,E extends Fixture>	Represents a class that defines rules to ignore results from BroadphaseDetector.
CoefficientMixer	Deprecated. Deprecated in 4.2.0.
CollisionData<T extends CollisionBody<E>,E extends Fixture>	Represents a container for all the collision information between a CollisionPair.
CollisionWorld<T extends CollisionBody<E>,E extends Fixture,V extends CollisionData<T,E>>	Represents a world where CollisionBodys are added to participate in collision detection.
ContactCollisionData<T extends PhysicsBody>	Interaface for collision data that contains a ContactConstraint.
ManifoldCollisionData<T extends CollisionBody<E>,E extends Fixture>	Represents a manifold collision.
NarrowphaseCollisionData<T extends CollisionBody<E>,E extends Fixture>	Represents a narrowphase collision.
PhysicsWorld<T extends PhysicsBody,V extends ContactCollisionData<T>>	Represents a CollisionWorld that resolves collision using Newton's laws of physics.
ValueMixer	Interface used to customize the way friction and restitution coefficients are mixed.

Class Summary

Class	Description
AbstractCollisionWorld<T extends CollisionBody<E>,E extends Fixture,V extends CollisionData<T,E>>	Abstract implementation of the CollisionWorld interface.
AbstractPhysicsWorld<T extends PhysicsBody,V extends ContactCollisionData<T>>	Abstract implementation of the PhysicsWorld interface.
BroadphaseCollisionDataFilterAdapter<T extends CollisionBody<E>,E extends Fixture>	Helper class to avoid having to override all the methods of the BroadphaseCollisionDataFilter interface.
CollisionBodyBroadphaseCollisionDataFilter<T extends CollisionBody<E>,E extends Fixture>	The default filter for CollisionWorlds that filters Fixtures by their Filters and their enable flags.
ConstraintGraph<T extends PhysicsBody>	Represents an undirected graph of constraints involving PhysicsBodys with the desire to split the simulation into smaller, solvable chunks.
ConstraintGraphNode<T extends PhysicsBody>	Represents a node in the constraint graph.
DetectFilter<T extends CollisionBody<E>,E extends Fixture>	Represents the filters for queries against a CollisionWorld.
Island<T extends PhysicsBody>	Used to solve the contact constraints and joints for a group of interconnected bodies.
PhysicsBodyBroadphaseCollisionDataFilter<T extends PhysicsBody>	Encapsulates logic used to filter the broadphase pairs based on filters, body state, etc.
PhysicsBodySweptAABBProducer<T extends PhysicsBody>	AABBProducer specifically for CollisionBodys producing swept AABBs via the PhysicsBody.computeSweptAABB(AABB) methods.
World<T extends PhysicsBody>	Full implementation of both the CollisionWorld and PhysicsWorld interfaces.
WorldCollisionData<T extends PhysicsBody>	Represents the collision data for the World class.