# Mouse lagging and can't make fullScreen() in 4K

**URL:** https://discourse.processing.org/t/mouse-lagging-and-cant-make-fullscreen-in-4k/41753
**Category:** Beginners
**Created:** [April 18, 2023, 7:58am UTC](https://discourse.processing.org/t/mouse-lagging-and-cant-make-fullscreen-in-4k/41753 "2023-04-18T07:58:04Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![doesThisReallyMatter](https://avatars.discourse-cdn.com/v4/letter/d/ac91a4/32.png) [@doesThisReallyMatter](https://discourse.processing.org/u/doesThisReallyMatter)
#### Post date: [April 18, 2023, 7:58am UTC](https://discourse.processing.org/t/mouse-lagging-and-cant-make-fullscreen-in-4k/41753/1 "2023-04-18T07:58:04Z")

</div>

```auto
void setup(){
  fullScreen();
  noCursor();
}

void draw(){
  background(#f097ff);
  drawCursor(mouseX,mouseY);
  text("("+mouseX+","+mouseY+")",width/2,height/2);
}

void drawCursor(float x,float y){
  final float W = width/1920*11.00, H1 = height/1080*16.00, H2 = sqrt(H1*H1-W*W)*14/13;
  fill(0);
  triangle(x,y,x,y+H1,x+W,y+H2);
}

```

So I’m trying to create a simple alter cursor shape. The problem is the cursor in this program lag severely. That is if I comment the noCursor(),the system’s cursor and the black triangle cursor can’t sync very well.

Also my screen is 3840x2160, but the program only runs under 1080P even with fullScreen().

---

<div class="post-metadata">

### Author: ![josephh](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/josephh/32/210_2.png) [@josephh](https://discourse.processing.org/u/josephh)
#### Post date: [April 18, 2023, 10:00am UTC](https://discourse.processing.org/t/mouse-lagging-and-cant-make-fullscreen-in-4k/41753/2 "2023-04-18T10:00:35Z")

</div>

Hi @doesThisReallyMatter (sometimes yes 😉 )

> [@doesThisReallyMatter](#):
>
> Also my screen is 3840x2160, but the program only runs under 1080P even with fullScreen().

So you have a 4K screen and when you run your sketch it runs fullScreen but the actual resolution is 1920x1080? Did you try to print the `width` and `height` values?

---

<div class="post-metadata">

### Author: ![doesThisReallyMatter](https://avatars.discourse-cdn.com/v4/letter/d/ac91a4/32.png) [@doesThisReallyMatter](https://discourse.processing.org/u/doesThisReallyMatter)
#### Post date: [April 18, 2023, 12:42pm UTC](https://discourse.processing.org/t/mouse-lagging-and-cant-make-fullscreen-in-4k/41753/3 "2023-04-18T12:42:24Z")

</div>

Yeah. The last line inside draw(）is to print mouseX & Y as (x,y) on the screen, and the maximum it can get is (1919,1079).

BTW I put ‘doesThisReallyMatter’ after ‘user name’ when singing up lol.