float [] px = new float[0]; //temp array
float [] py = new float[0];
float [] gx = {
  -10,10,20,30,40}; //generator data
float [] gy = {
  0, 0,-10, 0, 0};
float [] bx = {
  0,100,200,300,400}; //base data
float [] by = {
  200, 200,100,200, 200};
void setup(){
  size(400,400);
}
void draw(){
  background(200);
  for(int i=1; i<bx.length; i++)
    if(bx[i]!=999 && bx[i-1]!=999) //skip
      line(bx[i-1],by[i-1],bx[i],by[i]);
}
void mousePressed(){
  px = expand (px,0); //empty px
  py = expand (py,0);
  for(int j=0; j<bx.length-1; j++){ //for all base lines
    if(bx[j]!=999 && bx[j+1]!=999) //skip if marked
      for(int i=0; i<gx.length; i++){ //for all generator lines
        float db = dist(bx[j],by[j],bx[j+1],by[j+1]); //get dist of each base segment
        float dg = dist(0,0,gx[gx.length-1],gy[gy.length-1]); //get the distance of the generator
        float x = gx[i] * db/dg; //divide to get the scale factor
        float y = gy[i] * db/dg;
        float angle = atan2(by[j+1]-by[j],bx[j+1]-bx[j]); //angle between origin and each point
        float tempx = x * cos(angle) - y * sin(angle); //rotate
        y = y * cos(angle) + x * sin(angle);
        x = tempx;
        x += bx[j]; //translate
        y += by[j];
        px = append(px,x); //add the newly transformed point
        py = append(py,y);
      }
    px = append(px,999); //mark the end of a polyline sequence with 999
    py = append(py,999);
  }
  //copy p to the base array
  bx = expand (bx,0);
  by = expand (by,0);
  for(int i=0; i<px.length; i++){
    bx = append(bx,px[i]);
    by = append(by,py[i]);
  }
}