Particle3D[] tracers;
Attractor attractor;
Repulsor[] repulsors;
Vec3D light;

float MAX_STEER=.01f;
float MAX_VEL=1.0f;
int NUM_REPULSORS = 40;
int NUM_TRACERS = 100;

void setup(){
  size(800,800);
  background(150);
  noStroke();
  randomTracers();
  Vec3D target = new Vec3D(0,0,0);
  attractor = new Attractor(target,100f,1f);
  randomRepulsors();
  light = randomLight();
  smooth();

}

void draw(){

  translate(400,400); 
  for (int t=0;t<NUM_TRACERS;t++){

      Vec3D steer = new Vec3D();
      steer = steer.add(attractor.steeringForce(tracers[t]));
              stroke(120,0,0,2);
      for(int i=0;i<NUM_REPULSORS;i++){

        steer = steer.add(repulsors[i].steeringForce(tracers[t]));
      }
      noStroke();
      if (steer.size > MAX_STEER) steer = steer.mul(MAX_STEER / steer.size);
      tracers[t].update(steer); 
      fill(255,120);
      ellipse(tracers[t].pos.x+light.x,tracers[t].pos.y+light.y,3,3);
      fill(0,120);
      ellipse(tracers[t].pos.x,tracers[t].pos.y,3,3);
      if(tracers[t].vel.size<.1f){
       tracers[t].age++;
     }
       else{
         tracers[t].age=0;
         }
        if (tracers[t].age>20) tracers[t]=randomTracer();
  }
  



}


Particle3D randomTracer(){
  Vec3D pos = new Vec3D(random(-1f,1f),random(-1f,1f),0);
  pos = pos.normalize();
  pos = pos.mul(random(0.5f,1.5f)*300f);
   //Vec3D vel = new Vec3D(random(-1f,1f),random(-1f,1f),random(-1f,1f));
  Vec3D vel= pos.normalize();
  //vel = vel.normalize();
  vel = vel.mul(-MAX_VEL);
  return new Particle3D(pos, vel); 

}

Vec3D randomLight(){
  Vec3D pos = new Vec3D(random(-1f,1f),random(-1f,1f),0);
  pos = pos.normalize();  
  return pos; 

}

void randomRepulsors(){
  repulsors = new Repulsor[NUM_REPULSORS];
  for(int i=0;i<NUM_REPULSORS;i++){
    Vec3D pos = new Vec3D(random(-1f,1f),random(-1f,1f),0);
    pos = pos.normalize();
    pos = pos.mul((random(100f)<50f)?200f:100f);
    repulsors[i] = new Repulsor(pos,50f,1f);
  }


}

void randomTracers(){
  tracers = new Particle3D[NUM_TRACERS];
  for(int i=0;i<NUM_TRACERS;i++){
    tracers[i] = randomTracer();
  }


}

void mousePressed(){
  background(150);
  randomTracers();
  randomRepulsors();
  light = randomLight();

}