class Dot{
  PVector pos;
  PVector vel;
  boolean dead=false;
  boolean deadByObstacle=false;
  boolean reachedGoal=false;
  boolean champ=false;
  float fitness;
  Brain brain;
  
  //constructor
  Dot(){
    brain=new Brain(1000);
    
    //start position (bottom center)
    pos=new PVector(width/2, height-10);
    vel=new PVector(0, 0);
  }
  
  //do movement
  void move(){
    PVector accl=brain.next(); //get next acceleration
    if(accl==null){
      dead=true; //we're dead. No solution
    }
    else{
      vel.add(accl); //add acceleration
      vel.limit(20); //limit speed
      pos.add(vel); //update position
    }
    
    //detect if exiting area or is intersecting
    if(pos.x <= 2 || pos.y <= 2 || pos.x >= width-2 || pos.y >= height-2){
      dead=true;
    }
    //check if intersects obstacle
    else if(obstacles.isIntersecting(this)){
      dead=true;
      deadByObstacle=true;
    }
    
    //detect if reached goal
    if(dist(pos.x, pos.y, goal.x, goal.y) < 2){
      reachedGoal=true;
    }
  }
  
  //update point
  boolean update(){
    if(!dead && !reachedGoal){
      move();
      return true;
    }
    else{
      return false;
    }
  }
  
  //calculate fitness
  float calcFitness(){
    if(reachedGoal){
      fitness=10000.0/(brain.step*brain.step);
    }
    else if(!deadByObstacle){
      float distToGoal=dist(pos.x, pos.y, goal.x, goal.y);
      fitness=2.0/(distToGoal*distToGoal);
    }
    else{
      float distToGoal=dist(pos.x, pos.y, goal.x, goal.y);
      fitness=1.0/(distToGoal*distToGoal);
    }
    
    return fitness;
  }
  
  //get children
  Dot getChild(){
    Dot child=new Dot();
    child.brain=brain.clone();
    return child;
  }
  
  //is alive
  boolean alive(){
    return !(dead || reachedGoal);
  }
  
  //display dot
  void display(){
    if(champ){
      fill(0, 255, 0);
      ellipse(pos.x, pos.y, 8, 8);
    }
    else{
      fill(0);
      ellipse(pos.x, pos.y, 4, 4);
    }
  }
}