bevy/crates/bevy_ui/src
Rob Parrett 17005b3c8b
Fix blurry text (#12429)
# Objective

Fixes #12064

## Solution

Prior to #11326, the "global physical" translation of text was rounded.

After #11326, only the "offset" is being rounded.

This moves things around so that the "global translation" is converted
to physical pixels, rounded, and then converted back to logical pixels,
which is what I believe was happening before / what the comments above
describe.

## Discussion

This seems to work and fix an obvious mistake in some code, but I don't
fully grok the ui / text pipelines / math here.

## Before / After and test example

<details>
<summary>Expand Code</summary>

```rust
use std::f32::consts::FRAC_PI_2;

use bevy::prelude::*;
use bevy_internal:🪟:WindowResolution;

const FONT_SIZE: f32 = 25.0;
const PADDING: f32 = 5.0;

fn main() {
    App::new()
        .add_plugins(
            DefaultPlugins.set(WindowPlugin {
                primary_window: Some(Window {
                    resolution: WindowResolution::default().with_scale_factor_override(1.0),
                    ..default()
                }),
                ..default()
            }),
            //.set(ImagePlugin::default_nearest()),
        )
        .add_systems(Startup, setup)
        .run();
}

fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.spawn(Camera2dBundle::default());

    let font = asset_server.load("fonts/FiraSans-Bold.ttf");

    for x in [20.5, 140.0] {
        for i in 1..10 {
            text(
                &mut commands,
                font.clone(),
                x,
                (FONT_SIZE + PADDING) * i as f32,
                i,
                Quat::default(),
                1.0,
            );
        }
    }

    for x in [450.5, 700.0] {
        for i in 1..10 {
            text(
                &mut commands,
                font.clone(),
                x,
                ((FONT_SIZE * 2.0) + PADDING) * i as f32,
                i,
                Quat::default(),
                2.0,
            );
        }
    }

    for y in [400.0, 600.0] {
        for i in 1..10 {
            text(
                &mut commands,
                font.clone(),
                (FONT_SIZE + PADDING) * i as f32,
                y,
                i,
                Quat::from_rotation_z(FRAC_PI_2),
                1.0,
            );
        }
    }
}

fn text(
    commands: &mut Commands,
    font: Handle<Font>,
    x: f32,
    y: f32,
    i: usize,
    rot: Quat,
    scale: f32,
) {
    let text = (65..(65 + i)).map(|a| a as u8 as char).collect::<String>();

    commands.spawn(TextBundle {
        style: Style {
            position_type: PositionType::Absolute,
            left: Val::Px(x),
            top: Val::Px(y),
            ..default()
        },
        text: Text::from_section(
            text,
            TextStyle {
                font,
                font_size: FONT_SIZE,
                ..default()
            },
        ),
        transform: Transform::from_rotation(rot).with_scale(Vec2::splat(scale).extend(1.)),
        ..default()
    });
}
```

</details>

Open both images in new tabs and swap back and forth. Pay attention to
the "A" and "ABCD" lines.

<details>
<summary>Before</summary>

<img width="640" alt="main3"
src="https://github.com/bevyengine/bevy/assets/200550/248d7a55-d06d-433f-80da-1914803c3551">

</details>

<details>
<summary>After</summary>

<img width="640" alt="pr3"
src="https://github.com/bevyengine/bevy/assets/200550/26a9d292-07ae-4af3-b035-e187b2529ace">

</details>

---------

Co-authored-by: François Mockers <mockersf@gmail.com>
2024-03-13 08:23:38 +01:00
..
layout Fix #12255 Updating TargetCamera on multi camera scenes not allowing layout to be calculated (#12268) 2024-03-05 22:10:30 +01:00
render Fix blurry text (#12429) 2024-03-13 08:23:38 +01:00
widget Use warn_once where relevant instead of manually implementing a single warn check (#11693) 2024-02-05 21:05:43 +00:00
accessibility.rs resolve all internal ambiguities (#10411) 2024-01-09 19:08:15 +00:00
focus.rs don't attempt to set cursor relative position for zero sized nodes (#12395) 2024-03-10 08:45:13 +01:00
geometry.rs Made the remaining types from bevy_ui to reflect the Default trait if… (#11199) 2024-01-03 18:57:05 +00:00
lib.rs UI Texture 9 slice (#11600) 2024-02-07 20:07:53 +00:00
measurement.rs Change the default for the measure_func field of ContentSize to None. (#9346) 2023-08-07 23:06:40 +00:00
node_bundles.rs Optional ImageScaleMode (#11780) 2024-02-09 20:36:32 +00:00
stack.rs Avoid unconditionally unwrapping the Result - UI Stack System (#11575) 2024-01-29 02:38:41 +00:00
texture_slice.rs Fixed Ui Image slicing (#12047) 2024-02-27 17:17:54 +01:00
ui_material.rs Provide GlobalsUniform in UiMaterial shaders (#10739) 2023-11-28 12:08:28 +00:00
ui_node.rs Rustdoc links in bevy_ui (#11555) 2024-01-28 02:21:39 +00:00
update.rs Avoid panicking with non-UI nodes (#12213) 2024-03-01 00:09:18 +01:00