# Objective
Text2d doesn't respond to changes to the window scalefactor.
Fixes#16223
## Solution
In `update_text2d_layout` store the previous scale factor in a `Local`
instead and check against the current scale factor to detect changes.
It seems like previously the text wasn't updated because of a bug with
the `WindowScaleFactorChanged` event and it isn't emitted after changes
to the scale factor. That needs to be looked into, but this will work
for now.
## Testing
Really simple app that draws a big message in the middle of the window:
```
use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.run();
}
fn setup(mut commands: Commands) {
commands.spawn(Camera2d);
commands.spawn((
Text2d::new("Hello"),
TextFont {
font_size: 400.,
..Default::default()
},
));
}
```
Looks fine:
<img width="500" alt="hello1"
src="https://github.com/user-attachments/assets/5320746b-687e-4682-9e4c-bc43ab7ff9d3">
On main, after changing the monitor's scale factor:
<img width="500" alt="hello2"
src="https://github.com/user-attachments/assets/486cea16-fc44-4d66-9468-6f68905d4196">
With this PR the text maintains the same size and position after the
scale factor is changed.
c0fbadbc4c