// The Cell class
class Cells {
 
// Properties to help tracking and drawing the cells
// Position, growth, which is size, color, direction of movement, velocity and speed
float xpos;
float ypos; 
float xgrowth;
float ygrowth;
color gcolor;
float directionX, directionY;
float velocityX, velocityY;
  
// The constructor for the Cell class
// X and Y positions, growth, which is actually size, color and direction
Cells(float _x, float _y, float _xg, float _yg, color _gcolor, float _directionX, float _directionY) {
  xpos = _x;
  ypos = _y;
  xgrowth = _xg;
  ygrowth = _yg;
  gcolor = _gcolor;
  directionX = _directionX;
  directionY = _directionY;
}
 
// Display function for the cells
// Nostroke, color and draw an ellipse
void display() {
  noStroke();
  fill(color(gcolor));
  ellipse(xpos,ypos,xgrowth,ygrowth);
}
 
// Move function for the cells 
// X and Y velocity set by velocity, which is direction and speed
// Which in turns gives us an X and Y position
void move(){
  velocityX = directionX;
  velocityY = directionY;
  xpos += velocityX;
  ypos += velocityY;
} 
 
// Grow and shrink function for the cells 
// Growth per frame circle set, if the cells grow bigger than 150 pixels we invert the growth
// This means its a negative number when they shrink, which is important to remember
void grow() {
  xgrowth = xgrowth +0.05;
  ygrowth = ygrowth +0.05;
    if (xgrowth > 150) {
      xgrowth = - xgrowth;
      ygrowth = - ygrowth;
    }
  }
}