class field
{
  sinkp[] sp= new sinkp[15];
  
  field()
  {
    for(int i=0; i< sp.length ; i=i+1)
    {
      sp[i] = new sinkp(random(50,width-50), random(50,height-50),175);
    }
  
  }
  
  float getSPX(int i) {return sp[i].getLOCX();}
  void setSPX(int i, float cx_) {sp[i].setLOCX(cx_);}
  float getSPY(int i) {return sp[i].getLOCY();}
  void setSPY(int i, float cy_) {sp[i].setLOCY(cy_);}
  
  float dirX(float x, float y)
  {
    float sum;
    sum=0;
    
    for(int i=0; i<sp.length; i++)
    {
      sum=sum+sp[i].dirx(x,y);
    }
    return sum;  
  }
  
  float dirY(float x, float y)
  {
    float sum;
    sum=0;
    
    for(int i=0; i<sp.length; i++)
    {
      sum=sum+sp[i].diry(x,y);
    }
    return sum;  
  }
  
  void drawsinks()
  {
    for(int i=0; i<sp.length; i++)
    {
      noStroke(); fill(0,255,0,250);
      ellipse(getSPX(i),getSPY(i),10,10);
    }  
  }
  
  void renderfield()
  {
    for(float i=0; i<width; i=i+20)
    {
      for(float j=0; j<height; j=j+20)
      {
        noStroke(); fill(255,255,255);
        ellipse(i+dirX(i,j),j+dirY(i,j),5,5);
        stroke(255,255,255,150);
        line(i,j, i+dirX(i,j), j+dirY(i,j));     
      }
   }
  }
  
  void wanderfield(float amount)
  {
    float x, y;
    
    for(int i=0; i<sp.length; i++)
    {
      x=sp[i].getLOCX();
      y=sp[i].getLOCY();
      if(x>width || x<0 || y>height || y<0)
      { sp[i].setLOCX(width/2+random(-100,100)); sp[i].setLOCY(width/2+random(100,-100));}
      else
      {sp[i].wandersink(amount);}
    }  
  }
  
}// end of field class