constructor(x,y,cell){

    this.pos = createVector(x,y);

    this.vec = createVector(random(-1,1),random(-1,1));

    this.size = 10;

    this.curCell = cell;

    this.prevCell = cell;

    this.nearby = [];

    this.viewRange = 40;

  }

  //update cell

  updateCell(cell){

    this.curCell = cell;

  }

  //find particles in nearby cells

  findNearby(){

    let possibleNearby = []; //keep track of all particles nearby

    let range = 1; //how many cells it should check. 1 => 3 x 3 around cell

    //make it wrap around

     for(let i = this.curCell.x-range; i <= this.curCell.x + range; i++){

      for(let j = this.curCell.y-range; j <= this.curCell.y + range; j++){

        //edge case!!!

        //if(i < 0){

        //}

        for(let g of grid[i][j]){

          append(possibleNearby,g);

        }

      }

    }

    this.nearby = possibleNearby;

  }

  connectNearby(){

    for(let n of this.nearby){

      let d = dist(this.pos.x,this.pos.y,n.pos.x,n.pos.y);

      if(d < this.viewRange){

        stroke(255,0,255,50);

        line(this.pos.x,this.pos.y,n.pos.x,n.pos.y);

      }

    }

  }

  update(){

    //check if particle changed cells

    if(this.curCell.x != this.prevCell.x || this.curCell.y != this.prevCell.y){

      changedCell(this);

      this.prevCell = this.curCell;

    }

    //edge check

    if(outOfBorder(this.pos.x,this.pos.y,this.size)){

      this.vec.mult(-1);

    }

    this.pos.add(this.vec);

  }

  show(){

    noStroke();

    //fill(255,0,0);

    //visualize 2x2 grid

    // if(this.curCell.x == 1 && this.curCell.y == 0){

    //   fill(255,0,0)

    // }else if(this.curCell.x == 0 && this.curCell.y == 0){

    //   fill(0,255,0)

    // }else if(this.curCell.x == 0 && this.curCell.y == 1){

    //   fill(0,0,255)

    // }else if(this.curCell.x == 1 && this.curCell.y == 1){

    //   fill(0,255,255)

    // }else{

    //   fill(0);

    // }

    //let clr = color(this.curCell.x*20,this.curCell.y*10,200);

    //fill(clr);

    circle(this.pos.x,this.pos.y,this.size);

  }

​

}

​

​