// by stephan schulz
Vec2D v[],D;
int num=40;
float dist;
float oldTime,newTime,diffTime;

void setup() {
  size(400,400);

  ellipseMode(CENTER_DIAMETER);


  v=new Vec2D[num];

  for(int i=0; i<num; i++) v[i]=new Vec2D();
  v[0].x = 100;
  D=new Vec2D();

  oldTime=0;
  newTime=0;


}

void loop() {
  background(0,140,255);

  newTime=millis()/300;
  diffTime=newTime-oldTime;

  for(int i=num-1; i>0; i--) v[i].set(v[i-1]);//moves array one to right and makes space for new mouse pso
  v[0].set(mouseX,mouseY);
  if (v[0].x==v[num-1].x) oldTime=newTime;;

  for(int i=0; i<num-1; i++) {
    //stroke(0,0,0);
    //line(v[i].x,v[i].y, v[i+1].x,v[i+1].y);// verbindungsline

    //stroke(255,0,0);
    //line(v[i].x,v[i].y,200,400);//stangen

    /*for(int i2=0; i2<num-1; i2++) {
      stroke(0,250,250);
      line(v[i].x,v[i].y,v[i2].x,v[2].y);// spider web
    }*/

    stroke(0,130,145);
    line(v[i].x,0,i*width/num,400);//lightbeams

    D.set(i*width/num,400);
    D.sub(v[i].x,v[i].y);// needs to be somehow adjusted to always be on the lines
    D.div(1);
    
    noFill();
    stroke(0,133,43);
 
    if (i%2==0) ellipse(v[i].x+D.x,0+D.y,8+diffTime,8+diffTime);//bubbles
   
  }
  
}

// General vector class for 2D vectors
class Vec2D {
  float x,y;

  // Constructor with no parameters
  Vec2D() {
    x=0;
    y=0;
  }

  Vec2D(float _x,float _y) {
    x=_x;
    y=_y;
  }

  Vec2D(Vec2D v) {
    x=v.x;
    y=v.y;
  }

  void set(float _x,float _y) {
    x=_x;
    y=_y;
  }

  void set(Vec2D v) {
    x=v.x;
    y=v.y;
  }

  void add(float _x,float _y) {
    x+=_x;
    y+=_y;
  }

  void add(Vec2D v) {
    x+=v.x;
    y+=v.y;
  }

  void sub(float _x,float _y) {
    x-=_x;
    y-=_y;
  }

  void sub(Vec2D v) {
    x-=v.x;
    y-=v.y;
  }

  void mult(float m) {
    x*=m;
    y*=m;
  }

  void div(float m) {
    x/=m;
    y/=m;
  }

  float length() {
    return sqrt(x*x+y*y);
  }

  float angle() {
    return atan2(y,x);
  }

  void normalise() {
    float l=length();
    if(l!=0) {
      x/=l;
      y/=l;
    }
  }

  Vec2D tangent() {
    return new Vec2D(-y,x);
  }

  void rotate(float val) {
    // Due to float not being precise enough, double is used for the calculations
    double cosval=Math.cos(val);
    double sinval=Math.sin(val);
    double tmpx=x*cosval - y*sinval;
    double tmpy=x*sinval + y*cosval;

    x=(float)tmpx;
    y=(float)tmpy;
  }
}