class sinkp
{
  float locx;
  float locy;
  float strength;
  
  sinkp(float locx_, float locy_, float strength_)
  {
    locx=locx_;
    locy=locy_;
    strength=strength_;
  }
  
  float getLOCX() {return locx;}
  void setLOCX(float locx_) {locx = locx_;}
  float getLOCY() {return locy;}
  void setLOCY(float locy_) {locy = locy_;}
  float getS() {return strength;}
  void setS(float strength_) {strength = strength_;}
  
  float dirx(float x, float y)
  {
    float mx, my, distm, an;

       mx=x-locx; // positive if 1 to the right of 2
       my=y-locy; //positive if 1 below 2
       distm=sqrt(mx*mx+my*my);

       an=atan2(my,mx);
       //return -1*strength*cos(an);
       return -1*strength*(1/(sqrt(distm)+1))*cos(an);      
  }
  
  float diry(float x, float y)
  {
    float mx, my, distm, an;

       mx=x-locx; // positive if 1 to the right of 2
       my=y-locy; //positive if 1 below 2
       distm=sqrt(mx*mx+my*my);

       an=atan2(my,mx);
       return -1*strength*(1/(sqrt(distm)+1))*sin(an);       
  }
  
  void rendersinkfield()
  {
    for(float i=0; i<width; i=i+20)
    {
      for(float j=0; j<height; j=j+20)
      {
         line(i,j, i+dirx(i,j), j+diry(i,j));      
      }
    }
  }
  
  void wandersink(float amount)
  {
    setLOCX( getLOCX() + random(-1*amount, amount));
    setLOCY( getLOCY() + random(-1*amount, amount));
  
  }

} // class sinkpoint