If you run this script and press the mouse to save the pdf then 1 line is vector and the other is made out of pixels.
I need them both out of vectors. I understand that it's pixels because i use the image() method.
This script below is just a simple variant of a more complex thing i do, I understand that in the script below i can easily get the same result in vector by avoiding the pgraphic but that's not an option.

1. import processing.pdf.*;
2. 
   PGraphics pg = createGraphics(400, 400, P2D);
   
   boolean saveOneFrame = false;
   
   
   void setup() {
     size(600, 600);
   }
   
   void draw() {
     if(saveOneFrame == true) {
       beginRecord(PDF, "Line.pdf");
     }
   
     background(255);
     stroke(0, 20);
     strokeWeight(20.0);
     line(mouseX, 0, width-mouseY, height);
   
     pg.beginDraw();
     pg.background(255, 0);
     pg.line(mouseX, 0, width-mouseY, height);
     pg.endDraw();
   
     image(pg, 50, 50);
   
     if(saveOneFrame == true) {
       endRecord();
       saveOneFrame = false;
     }
   }
   
   void mousePressed() {
     saveOneFrame = true;
   }
   

hope there is a simple solution