Window size use logical size by default + inconsistent unit + `WindowDescriptor.resizable` not working

[iacore]

Bevy version

db55bf5

Operating system & version

Linux 5.13.19-2-MANJARO

What you did

First, I tried to set window size to 900 x 600;

use bevy::prelude::*;

fn main() {    
    let window = WindowDescriptor {
        width: 900.0,
        height: 600.0,
        ..Default::default()
    };

    App::build()
        .insert_resource(window)
        .add_plugins(DefaultPlugins)
        .insert_resource(ClearColor(Color::rgb(0.9, 0.9, 0.9)))
        .add_system(bevy::input::system::exit_on_esc_system.system())
        .run();
}

However, the window was near 1080px tall, not 600.

So I set scale_factor_override: Some(1.0), and the window size was correct.

Then, I tried to make window fixed size with resizable: false. That didn't work either.

So I set window.resize_constraints to 900 x 600. However, the actual window was now 1.75 times bigger than expected.

[iacore]

In other words, window.width use physical unit times scale_factor, where window.resize_constraints uses logical unit.

[bjorn3]

I think it makes sense that resize_constraints uses logical units. I think a minimum size should only be used when below the given size the interface/game becomes unusable/unplayable. This size depends on logical units, not physical units. Imagine it like this: What if the user has a (near) infinite dpi screen, the scale factor needs to be (near) infinite too in that case to see anything at all. The minimum physical size would then be (near) 0x0 if it were to be based on physical units instead of logical units. I can guarantee you that a window size of 0x0 makes any game unplayable.