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		8e3db957c5
		
			
		
	
	
	
	
		
			
			# Objective - Fixes #10720 - Adds the ability to control font smoothing of rendered text ## Solution - Introduce the `FontSmoothing` enum, with two possible variants (`FontSmoothing::None` and `FontSmoothing::AntiAliased`): - This is based on `-webkit-font-smoothing`, in line with our practice of adopting CSS-like properties/names for UI; - I could have gone instead for the [`font-smooth` property](https://developer.mozilla.org/en-US/docs/Web/CSS/font-smooth) that's also supported by browsers, but didn't since it's also non-standard, has an uglier name, and doesn't allow controlling the type of antialias applied. - Having an enum instead of e.g. a boolean, leaves the path open for adding `FontSmoothing::SubpixelAntiAliased` in the future, without a breaking change; - Add all the necessary plumbing to get the `FontSmoothing` information to where we rasterize the glyphs and store them in the atlas; - Change the font atlas key to also take into account the smoothing setting, not only font and font size; - Since COSMIC Text [doesn't support controlling font smoothing](https://github.com/pop-os/cosmic-text/issues/279), we roll out our own threshold-based “implementation”: - This has the downside of **looking ugly for “regular” vector fonts** ⚠️, since it doesn't properly take the hinting information into account like a proper implementation on the rasterizer side would. - However, **for fonts that have been specifically authored to be pixel fonts, (a common use case in games!) this is not as big of a problem**, since all lines are vertical/horizontal, and close to the final pixel boundaries (as long as the font is used at a multiple of the size originally intended by the author) - Once COSMIC exposes this functionality, we can switch to using it directly, and get better results; - Use a nearest neighbor sampler for atlases with font smoothing disabled, so that you can scale the text via transform and still get the pixelated look; - Add a convenience method to `Text` for setting the font smoothing; - Add a demonstration of using the `FontSmoothing` property to the `text2d` example. ## Testing - Did you test these changes? If so, how? - Yes. Via the `text2d`example, and also in my game. - Are there any parts that need more testing? - I'd like help from someone for testing this on devices/OSs with fractional scaling (Android/Windows) - How can other people (reviewers) test your changes? Is there anything specific they need to know? - Both via the `text2d` example and also by using it directly on your projects. - If relevant, what platforms did you test these changes on, and are there any important ones you can't test? - macOS --- ## Showcase ```rust commands.spawn(Text2dBundle { text: Text::from_section("Hello, World!", default()) .with_font_smoothing(FontSmoothing::None), ..default() }); ```  <img width="740" alt="image" src="https://github.com/user-attachments/assets/b881b02c-4e43-410b-902f-6985c25140fc"> ## Migration Guide - `Text` now contains a `font_smoothing: FontSmoothing` property, make sure to include it or add `..default()` when using the struct directly; - `FontSizeKey` has been renamed to `FontAtlasKey`, and now also contains the `FontSmoothing` setting; - The following methods now take an extra `font_smoothing: FontSmoothing` argument: - `FontAtlas::new()` - `FontAtlasSet::add_glyph_to_atlas()` - `FontAtlasSet::get_glyph_atlas_info()` - `FontAtlasSet::get_outlined_glyph_texture()`
		
			
				
	
	
		
			82 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
| //! Text pipeline benchmark.
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| //!
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| //! Continuously recomputes a large `Text` component with 100 sections.
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| 
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| use bevy::{
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|     color::palettes::basic::{BLUE, YELLOW},
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|     diagnostic::{FrameTimeDiagnosticsPlugin, LogDiagnosticsPlugin},
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|     prelude::*,
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|     text::{BreakLineOn, TextBounds},
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|     window::{PresentMode, WindowResolution},
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|     winit::{UpdateMode, WinitSettings},
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| };
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| 
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| fn main() {
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|     App::new()
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|         .add_plugins((
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|             DefaultPlugins.set(WindowPlugin {
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|                 primary_window: Some(Window {
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|                     present_mode: PresentMode::AutoNoVsync,
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|                     resolution: WindowResolution::new(1920.0, 1080.0)
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|                         .with_scale_factor_override(1.0),
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|                     ..default()
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|                 }),
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|                 ..default()
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|             }),
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|             FrameTimeDiagnosticsPlugin,
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|             LogDiagnosticsPlugin::default(),
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|         ))
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|         .insert_resource(WinitSettings {
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|             focused_mode: UpdateMode::Continuous,
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|             unfocused_mode: UpdateMode::Continuous,
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|         })
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|         .add_systems(Startup, spawn)
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|         .add_systems(Update, update_text_bounds)
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|         .run();
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| }
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| 
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| fn spawn(mut commands: Commands, asset_server: Res<AssetServer>) {
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|     warn!(include_str!("warning_string.txt"));
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| 
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|     commands.spawn(Camera2dBundle::default());
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|     let sections = (1..=50)
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|         .flat_map(|i| {
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|             [
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|                 TextSection {
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|                     value: "text".repeat(i),
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|                     style: TextStyle {
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|                         font: asset_server.load("fonts/FiraMono-Medium.ttf"),
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|                         font_size: (4 + i % 10) as f32,
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|                         color: BLUE.into(),
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|                     },
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|                 },
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|                 TextSection {
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|                     value: "pipeline".repeat(i),
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|                     style: TextStyle {
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|                         font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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|                         font_size: (4 + i % 11) as f32,
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|                         color: YELLOW.into(),
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|                     },
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|                 },
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|             ]
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|         })
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|         .collect::<Vec<_>>();
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|     commands.spawn(Text2dBundle {
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|         text: Text {
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|             sections,
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|             justify: JustifyText::Center,
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|             linebreak_behavior: BreakLineOn::AnyCharacter,
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|             ..default()
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|         },
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|         ..Default::default()
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|     });
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| }
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| 
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| // changing the bounds of the text will cause a recomputation
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| fn update_text_bounds(time: Res<Time>, mut text_bounds_query: Query<&mut TextBounds>) {
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|     let width = (1. + ops::sin(time.elapsed_seconds())) * 600.0;
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|     for mut text_bounds in text_bounds_query.iter_mut() {
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|         text_bounds.width = Some(width);
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|     }
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| }
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