import traer.physics.*;

import processing.opengl.*;
Particle repel, attract;
Particle[] particles;
Attraction[] attractArray;
Attraction[] repelArray;
PVector[] position;

int grid = 4;

ParticleSystem physics;

float velocitySample = 0;
int amount;
int index = 0;

void setup()
{
  size( 512, 512, P3D);
  frameRate( 60 );
  amount = (( width * height ) / grid ) / grid;

  ellipseMode( CENTER );
  background( 0x22222222 );
  stroke(0x03FF6600);

  position = new PVector[ amount ];

  physics = new ParticleSystem( 0, 0, 0, 0 );
  physics.setIntegrator( ParticleSystem.MODIFIED_EULER );
  particles = new Particle[ amount];
  attractArray = new Attraction[amount];
  repelArray = new Attraction[amount];
  repel = physics.makeParticle( 5, width * 0.2, height * 0.5, 0 );

  for( int i = 0; i < width; i += grid )
  {
    for( int j = 0; j < height; j += grid)
    {
      particles[ index ] = physics.makeParticle( 1, i, j, 0);
      repelArray[ index ] = physics.makeAttraction(repel, particles[ index ], -4, 10); 
      position[ index ] = new PVector( i, j );
      index++;
    }
  }
  println( index );
}

void draw()
{
  fill( 0x04222222 );
  rect( 0, 0, width, height );  
  repel.position().set( (float)mouseX, (float)mouseY, 0 );
  index = 0;

  Particle p;
  for(int k = 0; k < amount; k++)
  {
    p = particles[ k ];
    float posX = p.position().x();
    float posY = p.position().y();
    if( posX > width || posX < 0 || posY > height || posY < 0 )
    {
      p.position().set( position[ k ].x, position[ k ].y, 0 );
      p.velocity().set( 0, 0, 0 );      
    }  
    point(particles[ k ].position().x(), particles[ k ].position().y());    
  }
  physics.tick();
}