Package toxi.physics2d

Class VerletPhysics2D

java.lang.Object

toxi.physics2d.VerletPhysics2D

public class VerletPhysics2D
extends Object

3D particle physics engine using Verlet integration based on: http://en.wikipedia.org/wiki/Verlet_integration http://www.teknikus.dk/tj/gdc2001.htm

Field Summary

Fields

Modifier and Type	Field	Description
final List<ParticleBehavior2D>	behaviors
final List<ParticleConstraint2D>	constraints
ArrayList<VerletParticle2D>	particles	List of particles
ArrayList<VerletSpring2D>	springs	List of spring/stick connectors

Constructor Summary

Constructors

Constructor	Description
VerletPhysics2D()	Initializes a Verlet engine instance using the default values.
VerletPhysics2D(Vec2D gravity, int numIterations, float drag, float timeStep)	Initializes an Verlet engine instance with the passed in configuration.

Method Summary

Modifier and Type	Method	Description
void	addBehavior(ParticleBehavior2D behavior)
void	addConstraint(ParticleConstraint2D constraint)
static void	addConstraintToAll(ParticleConstraint2D c, List<VerletParticle2D> list)
VerletPhysics2D	addParticle(VerletParticle2D p)	Adds a particle to the list
VerletPhysics2D	addSpring(VerletSpring2D s)	Adds a spring connector
VerletPhysics2D	clear()
Rect	getCurrentBounds()
float	getDrag()
SpatialIndex<Vec2D>	getIndex()
int	getNumIterations()
VerletSpring2D	getSpring(Vec2D a, Vec2D b)	Attempts to find the spring element between the 2 particles supplied
float	getTimeStep()
Rect	getWorldBounds()
boolean	removeBehavior(ParticleBehavior2D c)
boolean	removeConstraint(ParticleConstraint2D c)
static void	removeConstraintFromAll(ParticleConstraint2D c, List<VerletParticle2D> list)
boolean	removeParticle(VerletParticle2D p)	Removes a particle from the simulation.
boolean	removeSpring(VerletSpring2D s)	Removes a spring connector from the simulation instance.
boolean	removeSpringElements(VerletSpring2D s)	Removes a spring connector and its both end point particles from the simulation
void	setDrag(float drag)
void	setIndex(SpatialIndex<Vec2D> index)
void	setNumIterations(int numIterations)
void	setTimeStep(float timeStep)
VerletPhysics2D	setWorldBounds(Rect world)	Sets bounding box
VerletPhysics2D	update()	Progresses the physics simulation by 1 time step and updates all forces and particle positions accordingly

Methods inherited from class java.lang.Object

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

Field Details

particles

public ArrayList<VerletParticle2D> particles

List of particles

springs

public ArrayList<VerletSpring2D> springs

List of spring/stick connectors

behaviors

public final List<ParticleBehavior2D> behaviors

constraints

public final List<ParticleConstraint2D> constraints

Constructor Details

VerletPhysics2D

public VerletPhysics2D()

Initializes a Verlet engine instance using the default values.

VerletPhysics2D

public VerletPhysics2D(Vec2D gravity,
 int numIterations,
 float drag,
 float timeStep)

Initializes an Verlet engine instance with the passed in configuration.

Parameters:

gravity - 3D gravity vector

numIterations - iterations per time step for verlet solver

drag - drag value 0...1

timeStep - time step for calculating forces

Method Details

addConstraintToAll

public static void addConstraintToAll(ParticleConstraint2D c,
 List<VerletParticle2D> list)

removeConstraintFromAll

public static void removeConstraintFromAll(ParticleConstraint2D c,
 List<VerletParticle2D> list)

addBehavior

public void addBehavior(ParticleBehavior2D behavior)

addConstraint

public void addConstraint(ParticleConstraint2D constraint)

addParticle

public VerletPhysics2D addParticle(VerletParticle2D p)

Adds a particle to the list

Parameters:

p -

Returns:

itself

addSpring

public VerletPhysics2D addSpring(VerletSpring2D s)

Adds a spring connector

Parameters:

s -

Returns:

itself

clear

public VerletPhysics2D clear()

getCurrentBounds

public Rect getCurrentBounds()

getDrag

public float getDrag()

getIndex

public SpatialIndex<Vec2D> getIndex()

Returns:

the index

getNumIterations

public int getNumIterations()

Returns:

the numIterations

getSpring

public VerletSpring2D getSpring(Vec2D a,
 Vec2D b)

Attempts to find the spring element between the 2 particles supplied

Parameters:

a - particle 1

b - particle 2

Returns:

spring instance, or null if not found

getTimeStep

public float getTimeStep()

Returns:

the timeStep

getWorldBounds

public Rect getWorldBounds()

Returns:

the worldBounds

removeBehavior

public boolean removeBehavior(ParticleBehavior2D c)

removeConstraint

public boolean removeConstraint(ParticleConstraint2D c)

removeParticle

public boolean removeParticle(VerletParticle2D p)

Removes a particle from the simulation.

Parameters:

p - particle to remove

Returns:

true, if removed successfully

removeSpring

public boolean removeSpring(VerletSpring2D s)

Removes a spring connector from the simulation instance.

Parameters:

s - spring to remove

Returns:

true, if the spring has been removed

removeSpringElements

public boolean removeSpringElements(VerletSpring2D s)

Removes a spring connector and its both end point particles from the simulation

Parameters:

s - spring to remove

Returns:

true, only if spring AND particles have been removed successfully

setDrag

public void setDrag(float drag)

setIndex

public void setIndex(SpatialIndex<Vec2D> index)

Parameters:

index - the index to set

setNumIterations

public void setNumIterations(int numIterations)

Parameters:

numIterations - the numIterations to set

setTimeStep

public void setTimeStep(float timeStep)

Parameters:

timeStep - the timeStep to set

setWorldBounds

public VerletPhysics2D setWorldBounds(Rect world)

Sets bounding box

Parameters:

world -

Returns:

itself

update

public VerletPhysics2D update()

Progresses the physics simulation by 1 time step and updates all forces and particle positions accordingly

Returns:

itself