int nsides = 4;
int trailLength = 15;
int nForms = 2;
 
int bright = 0;
 
Vector forms = new Vector();
 
 
void setup(){
 
  size(550,700,P3D);
 
  makeForms();
  frameRate(30);
  background(0);
  colorMode(HSB,100);
}
 
void makeForms(){
  forms = new Vector();
  for (int i =0; i < nForms; i++){
    forms.add(new Form());  
  }  
 
}
 
void draw(){
 
   
  noStroke();
  
  fill(0,0,100*bright,trailLength);
  rect(0,0,width,height);
  
  
  noFill();
  Form form;
  Point pt;
  float x=0,y=0;
  
  for (int i =0; i < forms.size(); i++){
  
    form = (Form)forms.elementAt(i);
    form.shift();
    stroke(form.c);  
    beginShape();
    
    for (int j =0; j < form.points.size(); j++){
 
      pt = (Point)form.points.elementAt(j);
      if (j == 0){
        x = pt.x;
        y = pt.y;
      }
      vertex(pt.x,pt.y);
      pt.physics();
            
    }      
 
      vertex(x,y);
 
 
    endShape();
    
  }
 
}
 
 
void keyPressed(){
 
  if (key =='a') trailLength ++;
  else if (key =='z') trailLength --;  
  constrain(trailLength,0,50);
 
  if (key == 's' || key == 'x'){
    if (key =='s') nsides ++;
    else if (key =='x') nsides--;  
    if (nsides < 3) nsides = 3;
    makeForms();
  }
 
  if (key == 'd' || key == 'c'){
    if (key =='d') nForms ++;
    else if (key =='c') nForms--;  
    if (nsides < 1) nsides = 1;
    makeForms();
  }
 
  if (key == ' ') bright = 1- bright;
 
}
 
class Form{
 
  color c;
  
  float h = random(0,100);
  float s = random(0,100);
  float b = 100;
  
  Vector points;
  float dh = random(-2,2);
  float ds = random(-2,2);
  
  //colorshifting
  void shift(){
    
    b = 100 - 50*bright;
    h += dh;
    if (h < 0 || h > 100) dh = -dh;
 
    s += ds;
    if (s < 0 || s > 100) ds = -ds;
 
    c = color(h,s,b);
  
  }
  
  
  Form(){
    
    c = color(h,s,b);
    points = new Vector();
    
    for (int i = 0; i < nsides; i++){
      points.add(new Point(random(0,width), random(0,height),random(-7,7),random(-7,7)));
    
    }
  
  }
 
}
 
class Point{
  float x,y,dx,dy;
  
  Point(float x, float y, float dx, float dy){
    this.x = x;
    this.y = y;
    this.dx = dx;
    this.dy = dy;
  
  }
  
  void physics(){
    x += dx;
    y += dy;
    
    //dy += 1;    
    if (x > width || x < 0) dx = -dx;
    if (y > height || y < 0) dy = -dy;   
        
  }
 
}