class Ball {
  float x,y,vx,vy,freq;
   float diam, opac,grav,b,speed;
   boolean sizeDecrease;
   
   Ball(float xpos, float ypos){
   x = xpos;
   y = ypos;
  // grav = .05;
  speed = random(.1);
   //bounce back 80%

   //random velocity
   vx = random(-1,1);
   vy = random(-1,1);
   freq = .02;
   diam = random(10,30);
   opac = random(100,255);
   sizeDecrease = false;
 }
 
 void display(){
    noStroke();
    fill(255,opac);
    ellipse(x,y,diam,diam);
  }
  void move(){
 
 
     x+= vx;
     y+= vy;
     
     //check for left edge
     if(x < diam){
       vx = vx*-1;
       x = diam+1;
     }
     //check right edge
     if(x > width-diam){
       vx = vx*-1;
       x = width-diam-1;
     }
     if(y < diam){
       vy *= -1;
       y=diam+1; 
     }
    
  }
  
  void change(){
    if(diam < 95 && sizeDecrease == false){
    diam += random(1,8);
    }
    else{
      sizeDecrease = true;
      diam -= random(1,8);
    }
    if(diam <= 10){
     sizeDecrease = false; 
    }
  }
}