import java.util.*;
ArrayList stars;
void setup() {
  stars = new ArrayList();
  size(600 ,600);
  stroke(255);
  fill(20);
  smooth();
  frameRate(10);
}

void draw() {
  background(20);
  for(int i = 0; i < stars.size(); i++) {
    Star s = (Star)stars.get(i);
    s.draw();
  }
}

void mouseDragged() {
  stars.add(new Star(mouseX, mouseY));
}

void mousePressed() {
  stars.add(new Star(mouseX, mouseY));
}

// floating point point
class FPoint {
  float x;
  float y;
  FPoint(float x, float y) { this.x = x; this.y = y; }
}

class Star {
  FPoint p;
  FPoint d;
  
  ArrayList strands;
  
  Star(int x, int y) {
    p = new FPoint(x, y);
    
    // d is delta x and delta y - velocity vector
    d = new FPoint(0,0);
    strands = new ArrayList();
    
    int s = int(random(2, 7));
    for(int i = 0; i < s; i++) {
      strands.add(new Strand(this, int(random(-20,20)), int(random(-20, 20))));
    }
  }
  
  void draw() {
    
    d.x += random(-1,1);
    d.y += random(-1,1);
    
    if(p.x < 0 || p.x > width) d.x *= -1;
    if(p.y < 0 || p.y > height) d.y *= -1;
    
    if(abs(d.x)>7) d.x /= 2;
    if(abs(d.y)>7) d.y /= 2;
    
    p.x += d.x;
    p.y += d.y;
    
    for(int i = 0; i < strands.size(); i++) {
      Strand s = (Strand) strands.get(i);
      s.draw();
    }  
  }
  

  class Strand {
    FPoint p;
    FPoint d;
    Star s;
    Strand(Star s, int x, int y) {
      this.s = s;
      p = new FPoint(x, y);
      d = new FPoint(0, 0);
    }
    void draw() {
      stroke(255);
      
      
      d.x += random(-1,1);
      d.y += random(-1,1);
    
      if(abs(p.x)>40) d.x *= -1;
      if(abs(p.y)>40) d.y *= -1;
    
      if(abs(d.x)>7) d.x /= 2;
      if(abs(d.y)>7) d.y /= 2;
    
      p.x += d.x;
      p.y += d.y;
      
      line(s.p.x, s.p.y, s.p.x + p.x, s.p.y + p.y);
      stroke(255,0,0);
      float diameter = 4;
     // if(mouseX>width/2) 
      diameter = abs(p.x);
      ellipse(s.p.x + p.x, s.p.y + p.y,diameter,diameter);
    } 
  }
}

void keyPressed() {
  switch(key) {
    case 'c': stars.clear();
       break;
  } 
}