offscreen-render.pde

PGraphics pg;

// We need to create variables for the width and height we want to use.
int scaleFactor = 2;
int w = 1080 * scaleFactor;
int h = 1920 * scaleFactor;

// In later versions of Processing, you need to use settings if you want to do any operations on the width and height
void settings(){
  size(w / 8, h / 8);
}

void setup() {
  pg = createGraphics(w, h);
}

void draw() {
  background(150);
  pg.beginDraw();
  pg.background(150);
  pg.ellipse(w/2, h/2, 100, 100);
  pg.endDraw();

  image(pg, 0, 0, width, height);

  if(keyPressed){
    if(key == 's') pg.save("image.png");
  }
}