org.xith3d.physics.simulation
Class SimulationEngine

java.lang.Object
  org.xith3d.physics.simulation.SimulationEngine

All Implemented Interfaces:

org.jagatoo.datatypes.Enableable, Updatable

public abstract class SimulationEngine
extends java.lang.Object
implements Updatable, org.jagatoo.datatypes.Enableable

A simulation engine

Field Summary

protected java.util.ArrayList<SimulationWorld>

worlds

Constructor Summary

protected

SimulationEngine()

Method Summary

void	destroyWorld(SimulationWorld world) Destroys the given SimulationWorld.
long	getMaxStepSize()
long	getStepSize()
java.util.ArrayList<SimulationWorld>	getWorlds()
boolean	isEnabled()
SurfaceParameters	newSurfaceParameters()
abstract SurfaceParameters	newSurfaceParameters(java.lang.String[] paramStrings, java.lang.Object[] paramValues) Creates a new SurfaceParameters with specified params.
SimulationWorld	newWorld() Creates a new Simulation World.
abstract SimulationWorld	newWorldImpl() Creates a new Simulation World.
void	setCollisionResolversManager(CollisionResolversManager collisionResolversManager)
void	setEnabled(boolean enabled) Sets this SimulationEngine enabled/disabled.
void	setMaxStepSize(long micros) Sets the maximum internal step time in microseconds.
void	setStepSize(long micros) Sets the constant internal step time in microseconds.
void	step(long stepMicros) Step the simulation = advance the time
void	update(long gameTime, long frameTime, UpdatingThread.TimingMode timingMode) Updates this Updatable object.

Methods inherited from class java.lang.Object

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

Field Detail

worlds

protected final java.util.ArrayList<SimulationWorld> worlds

Constructor Detail

SimulationEngine

protected SimulationEngine()

Method Detail

getWorlds

public final java.util.ArrayList<SimulationWorld> getWorlds()

Returns:

the list of worlds created and managed by this SimulationEngine.

newWorldImpl

public abstract SimulationWorld newWorldImpl()

Creates a new Simulation World.

Returns:

the newly created World.

newWorld

public final SimulationWorld newWorld()

Creates a new Simulation World.

Returns:

the newly created World.

newSurfaceParameters

public abstract SurfaceParameters newSurfaceParameters(java.lang.String[] paramStrings,
                                                       java.lang.Object[] paramValues)

Creates a new SurfaceParameters with specified params.

Parameters:

paramStrings - the param strings to be specified, e.g. "mu" or "bounce"

paramValues - the values of the params to be specified, e.g. ".1f" or "true"

newSurfaceParameters

public final SurfaceParameters newSurfaceParameters()

Returns:

a new instance of SurfaceParameters filled with default values.

destroyWorld

public void destroyWorld(SimulationWorld world)

Destroys the given SimulationWorld.

Parameters:

world -

setStepSize

public final void setStepSize(long micros)

Sets the constant internal step time in microseconds.

Parameters:

micros -

getStepSize

public final long getStepSize()

Returns:

the constant internal step time in microseconds.

setMaxStepSize

public final void setMaxStepSize(long micros)

Sets the maximum internal step time in microseconds.

Parameters:

micros -

getMaxStepSize

public final long getMaxStepSize()

Returns:

the maximum internal step time in microseconds.

step

public final void step(long stepMicros)

Step the simulation = advance the time

Parameters:

stepMicros - the size of the step which should be taken. Note that 2 steps of .01f isn't equal to 1 step of .02f : the smaller is your stepSize, the more accurate your simulation (but computations take more time). As always, you should find a tradeoff between speed and accuracy (which is the whole point of physic simulation, anyway). Begin with .01f and adjust it later if you don't know what to put. Note : you could also make the stepSize "adaptative", ie proportional to the (real) time that has passed since the last step, but sometimes adaptive stepSize can cause some simulation problems (jumps, instability). If you have these problems you could also try to advance by the right quantity of time by several fixed size steps.

setCollisionResolversManager

public final void setCollisionResolversManager(CollisionResolversManager collisionResolversManager)

setEnabled

public final void setEnabled(boolean enabled)

Sets this SimulationEngine enabled/disabled.
If not enabled, the update() method will do nothing.

Specified by:

setEnabled in interface org.jagatoo.datatypes.Enableable

Parameters:

enabled -

isEnabled

public final boolean isEnabled()

Specified by:

isEnabled in interface org.jagatoo.datatypes.Enableable

Returns:

if this SimulationEngine is enabled.
If not enabled, the update() method will do nothing.

update

public final void update(long gameTime,
                         long frameTime,
                         UpdatingThread.TimingMode timingMode)

Updates this Updatable object.

Specified by:

update in interface Updatable

Parameters:

gameTime - the gameTime in Milliseconds

frameTime - the frameTime in Milliseconds (needed time for the last frame)

timingMode - the TimingMode to use for frameTime.