Hello everybody, i'm trying to work with PGraphics, but something keeps getting wrong. The problem that i can't understand is why processing draws on the screen everything between beginDraw() and endDraw(), but doesn't draw anything when i call the picture back with image(pic, x, y).
It seemed so easy in the beginning but i already wasted 3 nights looking for bugs in my code or common problems in the internet.
Thank you in advance!

1. int pxwidth=2;
2. PGraphics randompic = createGraphics(100, 100, P2D);
3. void setup(){
4.   size(100,100);
5.   noStroke();
6.   background(255);
7. }
8. void draw(){
9.   background(255);
10.   if (keyPressed){
11.     if(key == 'a' || key == 'A'){
12.       randompic.beginDraw();
13.          for (int x=0; x<width/pxwidth; x++){
14.          for (int y=0; y<height/pxwidth; y++){
15.            int colore = (int)random(0,20);
16.            if (colore < 10) {fill(0);} else if (colore >= 10) {fill(255);}
17.            rect(x*pxwidth, y*pxwidth, pxwidth, pxwidth);
18.           }
19.         } 
20.       randompic.endDraw();
21.     }   
22.     if(key == 's' || key == 'S'){
23.       image(randompic, 0, 0);
24.     }
25.   }
26. }