The WorldOfParticles is container for particles governed by the common physical laws. More...

Collaboration diagram for WorldOfParticles:

Classes
class	Barrier
	Infinite Potential Barrier (2D-Box) class. More...
interface	RenderingContext
	Provides rendering context interface for the `WorldOfParticles`. More...
Public Member Functions
	WorldOfParticles (RenderingContext context)
	Creates and starts object's (world's) main thread.
boolean	isPaused ()
	Returns indicator whether forces between particles are calculated or not.
void	togglePaused ()
	Turns on/off calculations of forces between particles.
int	getParticleCount ()
	Gets number of particles in our world.
void	incTimeScale (double factor)
	Increments/decrements time scale.
double	getTimeScale ()
	Gets world's time to 'real' world's time ratio.
GraphicsConfiguration	getGraphicsConfiguration ()
	Gets the GraphicsConfiguration associated with parent Component.
Particle	addNewParticle (double M, double Q, double X, double Y, double R, double T)
	Adds one extra particle to the world.
void	removeParticle (Particle p)
	Removes the particle `p` from the world.
void	dump ()
	Dumps internal state for all particles to System.out (for debugging purposes).
void	resetVelocities ()
	Resets velocities for all particles to 0.
void	makeCentripetalVelocities ()
	Makes velocities for all particles to be centripetal to current particles' acceleration.
void	paint (Graphics g, boolean annotate)
	Renders the world on `Graphics`.
Barrier	getBarrier ()
	Gets boundaries of infinite potential barrier keeping particles together.
void	calculateInteractions ()
	Calculates forces acting on particles.
void	run ()
	Main thread that calculates interactions (forces) between all particles in the world.
Private Attributes
ArrayList< Particle >	particles = new ArrayList<Particle> ()
	Collection of `Particles` that belongs to this world.
volatile double	timeScale = 0.5
	World's time to 'real' world's time ratio.
volatile boolean	paused = false
	Indicates whether forces between particles are calculated or not.
volatile boolean	running = true
	Indicates whether to keep world's thread running or not.
Thread	mainThread
	Each object (i.e.
RenderingContext	context
	Particular instance with rendering context interface.

Detailed Description

The WorldOfParticles is container for particles governed by the common physical laws.

Forces acting on particles belonging to this world are calculated in the main thread of the instance. The instance of the WorldOfParticles is rendered inside the Component, which acts as a parent.

Author:: Mikica B Kocic

Definition at line 15 of file WorldOfParticles.java.

Constructor & Destructor Documentation

WorldOfParticles.WorldOfParticles ( RenderingContext context )

Creates and starts object's (world's) main thread.

Parameters:

context instance of the rendering context

Definition at line 87 of file WorldOfParticles.java.

References context, and mainThread.

    {
        this.context = context;

        mainThread = new Thread( this );
        mainThread.start ();
    }

Member Function Documentation

Particle WorldOfParticles.addNewParticle	(	double	M,
		double	Q,
		double	X,
		double	Y,
		double	R,
		double	T
	)

Adds one extra particle to the world.

Parameters:

M	mass of the `Particle`
Q	electrical charge of the `Particle`
X	initial position, x-component
Y	initial position, y-component
R	radius range
T	life-time in seconds

Definition at line 165 of file WorldOfParticles.java.

References context, WorldOfParticles.RenderingContext.onParticleCountChanged(), and particles.

Referenced by JPWorld.actionPerformed(), and JPWorld.createPairOfChargedParticles().

    {
        Particle p = null;
        
        synchronized( this )
        {
            p = new Particle ( this, M, Q, X, Y, R, T );
            
            particles.add ( p );
            
            // Inform parent that particle count has changed
            //
            context.onParticleCountChanged( particles.size () );
        }
        
        return p;
    }

void WorldOfParticles.calculateInteractions ( )

Calculates forces acting on particles.

Definition at line 271 of file WorldOfParticles.java.

References particles.

Referenced by run().

    {
        synchronized( this )
        {
            for ( Particle p : particles ) 
            {
                /* The sum of all forces acting on particle p
                 */
                p.resetForce ();
                
                /* Get sum of forces of interactions with other particles in the world
                 */
                for ( Particle q : particles ) 
                {
                    p.addForceFromParticle( q );
                }

                /* Apply summed forces 
                 */
                p.applyForce ();
                
                /* Relax CPU usage
                 */
                Thread.yield ();                
            }
            
        }
    }

void WorldOfParticles.dump ( )

Dumps internal state for all particles to System.out (for debugging purposes).

Definition at line 202 of file WorldOfParticles.java.

References getParticleCount(), and particles.

Referenced by JPWorld.keyPressed().

    {
        synchronized( this )
        {
            System.out.printf( "%8s %8s %8s %8s %8s %8s %8s\n", 
                    "lifetime", "xPos", "yPos", "vx", "vy", "ax", "ay" );

            for( Particle p : particles ) {
               p.dump ();
            }
            
            System.out.printf( "Total %d particles\n", getParticleCount () );
        }
    }

Barrier WorldOfParticles.getBarrier ( )

Gets boundaries of infinite potential barrier keeping particles together.

Definition at line 263 of file WorldOfParticles.java.

References context, and WorldOfParticles.RenderingContext.getBarrier().

Referenced by Particle.integrateNewtonLaws().

    {
        return context.getBarrier ();
    }

GraphicsConfiguration WorldOfParticles.getGraphicsConfiguration ( )

Gets the GraphicsConfiguration associated with parent Component.

Returns:: the GraphicsConfiguration used by parent's Component or null

Definition at line 151 of file WorldOfParticles.java.

References context, and WorldOfParticles.RenderingContext.getGraphicsConfiguration().

Referenced by Particle.createParticleImage().

    {
        return context.getGraphicsConfiguration ();
    }

int WorldOfParticles.getParticleCount ( )

Gets number of particles in our world.

Returns:: number of particles

Definition at line 116 of file WorldOfParticles.java.

References particles.

Referenced by JPWorld.actionPerformed(), JPWorld.createPairOfChargedParticles(), dump(), and JPWorld.paintComponent().

    {
        synchronized( this )
        {
            return particles.size ();
        }
    }

double WorldOfParticles.getTimeScale ( )

Gets world's time to 'real' world's time ratio.

Returns:: time scale; slower if less then 1.

Definition at line 141 of file WorldOfParticles.java.

References timeScale.

Referenced by JPWorld.paintComponent(), and Particle.run().

    {
        return timeScale;
    }

void WorldOfParticles.incTimeScale ( double factor )

Increments/decrements time scale.

Parameters:

factor delta time

Definition at line 129 of file WorldOfParticles.java.

References timeScale.

Referenced by JPWorld.keyPressed().

    {
        timeScale += factor;
        timeScale = Math.min( timeScale, 2.0 );
        timeScale = Math.max( timeScale, 0.1 );
    }

boolean WorldOfParticles.isPaused ( )

Returns indicator whether forces between particles are calculated or not.

Definition at line 98 of file WorldOfParticles.java.

References paused.

Referenced by Particle.run().

    {
        return paused;
    }

void WorldOfParticles.makeCentripetalVelocities ( )

Makes velocities for all particles to be centripetal to current particles' acceleration.

Definition at line 234 of file WorldOfParticles.java.

References particles.

Referenced by JPWorld.keyPressed().

    {
        synchronized( this )
        {
            for( Particle p : particles ) {
                p.makeCentripetalVelocity ();
             }
        }
    }

void WorldOfParticles.paint	(	Graphics	g,
		boolean	annotate
	)

Renders the world on Graphics.

Parameters:

g	where to render
annotate	annotate particle accelerations

Definition at line 250 of file WorldOfParticles.java.

References particles.

Referenced by JPWorld.paintComponent().

    {
        synchronized( this )
        {
            for( Particle p : particles ) {
                p.paint( g, annotate );
             }
        }
    }

void WorldOfParticles.removeParticle ( Particle p )

Removes the particle p from the world.

Parameters:

p	instance of the `Particle` to be removed

Definition at line 188 of file WorldOfParticles.java.

References context, WorldOfParticles.RenderingContext.onParticleCountChanged(), and particles.

Referenced by Particle.run().

    {
        synchronized( this )
        {
            particles.remove( p );
            
            /* Inform parent that number of particles has been changed
             */
            context.onParticleCountChanged( particles.size () );
        }
    }

void WorldOfParticles.resetVelocities ( )

Resets velocities for all particles to 0.

Definition at line 220 of file WorldOfParticles.java.

References particles.

Referenced by JPWorld.keyPressed().

    {
        synchronized( this )
        {
            for( Particle p : particles ) {
                p.resetVelocity ();
             }
        }
    }

void WorldOfParticles.run ( )

Main thread that calculates interactions (forces) between all particles in the world.

Definition at line 305 of file WorldOfParticles.java.

References calculateInteractions(), paused, and running.

    {
        final int sleepMillis = 5; // ~200 Hz
        
        while( running )
        {
            try { 
                Thread.sleep( sleepMillis );
            }
            catch( InterruptedException ie ) {
            }

            if ( ! paused ) {
                calculateInteractions ();
            }
        }
    }

void WorldOfParticles.togglePaused ( )

Turns on/off calculations of forces between particles.

Definition at line 106 of file WorldOfParticles.java.

References paused.

Referenced by JPWorld.keyPressed().

    { 
        paused = ! paused; 
    }

Member Data Documentation

RenderingContext WorldOfParticles.context [private]

Particular instance with rendering context interface.

Definition at line 78 of file WorldOfParticles.java.

Referenced by addNewParticle(), getBarrier(), getGraphicsConfiguration(), removeParticle(), and WorldOfParticles().

Thread WorldOfParticles.mainThread [private]

Each object (i.e.

world) has it's own physical rules. Forces between particles in our world are are calculated in object's main thread.

Definition at line 73 of file WorldOfParticles.java.

Referenced by WorldOfParticles().

ArrayList<Particle> WorldOfParticles.particles = new ArrayList<Particle> () [private]

Collection of Particles that belongs to this world.

Definition at line 51 of file WorldOfParticles.java.

Referenced by addNewParticle(), calculateInteractions(), dump(), getParticleCount(), makeCentripetalVelocities(), paint(), removeParticle(), and resetVelocities().

volatile boolean WorldOfParticles.paused = false [private]

Indicates whether forces between particles are calculated or not.

The velocities of the particles are freezed if forces are not calculated.

Definition at line 62 of file WorldOfParticles.java.

Referenced by isPaused(), run(), and togglePaused().

volatile boolean WorldOfParticles.running = true [private]

Indicates whether to keep world's thread running or not.

Definition at line 67 of file WorldOfParticles.java.

Referenced by run().

volatile double WorldOfParticles.timeScale = 0.5 [private]

World's time to 'real' world's time ratio.

Slower if less then 1.

Definition at line 56 of file WorldOfParticles.java.

Referenced by getTimeScale(), and incTimeScale().

The documentation for this class was generated from the following file:

WorldOfParticles.java

WorldOfParticles Class Reference

Classes

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation