// by stephan schulz
Vec2D v[],v2[];
int num=10;
float orgSize;

void setup() {
  size(400,200);

  orgSize = (float)width/(float)num;
  v=new Vec2D[num];
  v2=new Vec2D[num];

  for(int i=0; i<num; i++){ //sets the width of all so the same and that they fit on screen
    v[i]=new Vec2D();
    v[i].w= orgSize;
    v[i].h=v[i].w;

    v2[i]=new Vec2D();
    v2[i].w= orgSize;
    v2[i].h=v2[i].w;
  }
  for(int i=0; i<num; i++){

    v[i].w = width/num;
    v[i].h = v[i].w;

    v2[i].w =width/num;
    v2[i].h = v2[i].w;

  }

  for(int i=0; i<num; i++){ //sets the width of all so the same and that they fit on screen

    if(i>0) {
      v[i].x = v[i-1].x + v[i-1].w;
      v[i].y = v[i-1].y;
      v2[i].x = v2[i-1].x + v2[i-1].w;
      v2[i].y = height/2-v2[i].w;

    }
    else {
      v[0].x= 0;
      v[0].y= height/2;
      v2[0].x= 0;
      v2[0].y= height/2-v2[0].h;

    }

  }

}

void loop() {
  background(0,140,255);
  // fill(12);
  //rect(0,0,width,height/2);

  for(int i=0; i<num; i++) {
    fill(29,207-v[i].w,182);
    rect(v[i].x,v[i].y,v[i].w,v[i].h);
    fill(29,170+(v2[i].w),182);
    rect(v2[i].x,v2[i].y,v2[i].w,v2[i].h);
  }

  for(int iSize=0; iSize<num; iSize++) {
    if (v[iSize].w > orgSize) {

      int r = (int)random(num);
      float rand=1; //random(1);
      v[iSize].w = v[iSize].w - rand;
      v[iSize].h = v[iSize].w;
      v[r].w = v[r].w + rand;
      v[r].h = v[r].w;

      for(int iPos=0; iPos<num; iPos++){ //sets the width of all so the same and that they fit on screen

        if(iPos >0) {
          v[iPos].x = v[iPos-1].x + v[iPos-1].w;
          v[iPos].y = v[iPos-1].y;

        }
        else {
          v[0].x= 0;
          v[0].y= height/2;
        }
      }
    }

    if (v2[iSize].w > orgSize) {

      int  r2 = (int)random(num);
      float rand2= 1; //random(-1);
      v2[iSize].w = v2[iSize].w - rand2;
      v2[iSize].h = v2[iSize].w;
      v2[r2].w = v2[r2].w + rand2;
      v2[r2].h = v2[r2].w;

      for(int iPos=0; iPos<num; iPos++){ //sets the width of all so the same and that they fit on screen

        if(iPos >0) {

          v2[iPos].x = v2[iPos-1].x + v2[iPos-1].w;
          v2[iPos].y = height/2-v2[iPos].w;

        }
        else {

          v2[0].x= 0;
          v2[0].y= height/2-v2[0].h;

        }
      }

    }
  }

}

//void mousePressed() {
  void mouseMoved() {

    for(int i=0; i<num; i++){

      int r = (int)random(num-1);
      float rand=random(5,10);

      if( v[r].w+rand<height/2) {
        v[i].w = v[i].w - rand;
        v[i].h = v[i].w;
        v[r].w = v[r].w + rand;
        v[r].h = v[r].w;
      }

      int  r2 = (int)random(num-1);
      float rand2=random(5,10);

      if( v2[r2].w+rand<height/2){
        v2[i].w = v2[i].w - rand2;
        v2[i].h = v2[i].w;
        v2[r2].w = v2[r2].w + rand2;
        v2[r2].h = v2[r2].w;
      }
    //}

    for(int i2=0; i2<num; i2++){ //sets the width of all so the same and that they fit on screen

      if(i2>0) {
        v[i2].x = v[i2-1].x + v[i2-1].w;
        v[i2].y = v[i2-1].y;
        v2[i2].x = v2[i2-1].x + v2[i2-1].w;
        v2[i2].y = height/2-v2[i2].w;

      }
      else {
        v[0].x= 0;
        v[0].y= height/2;
        v2[0].x= 0;
        v2[0].y= height/2-v2[0].h;

      }
    }
  }
}

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

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