// Metaball Class

class Metaball{
  // Shape Members
  float x,y;
  float radius;
  color value;
  // Motion Members
  float mspeedx, msizex, mcenterx;
  float mspeedy, msizey, mcentery;
  
  // Constructor
  Metaball (float cw, float ch){
    mspeedx = random(1,20);
    mspeedy = random(1,20);
    msizex = random(cw/32,cw/3);
    msizey = random(ch/32,ch/3);
    mcenterx = random(msizex, cw-msizex);
    mcentery = random(msizey, ch-msizey);
    radius = random((cw+ch)/16,(cw+ch)/8);
    colorMode(HSB,1.0);
    value = color(random(1.0),random(0.75,1.0),random(0.75,1.0));
    Move(0.0);
    
  }
  
  // motion control
  void Move (float t){
    x = (cos(time*d2r*mspeedx) * msizex) + mcenterx;
    y = (cos(time*d2r*mspeedy) * msizey) + mcentery;
  }
  
  // influence
  float Influence(float a, float b){
    float d = sqrt(((a-x)*(a-x)) + ((b-y)*(b-y)));
    if (d<radius){
      float dd = (0.707*d)/radius;
      float g = ((dd*dd*dd*dd) - (dd*dd) + 0.25);
      return (4*g);
    }else {
      return 0.0;
    }
  }
  
  // draw 
  void Draw(){
    stroke(value);
    fill(value,32);
    ellipse(x,y,radius*2,radius*2);
    noFill();
    ellipse(x,y,radius*2,radius*2);
    ellipse(x,y,4,4);
  }
  
  color GetColor(){
    return value;
  }
}