docs/bevy/examples/stress_tests/many_glyphs.rs 3.2 K · 112 lines · raw · history

1 //! Simple text rendering benchmark.
2 //!
3 //! Creates a text block with a single span containing `100_000` glyphs,
4 //! and renders it with the UI in a white color and with Text2d in a red color.
5 //!
6 //! To recompute all text each frame run
7 //! `cargo run --example many_glyphs --release recompute-text`
8 use argh::FromArgs;
9 use bevy::{
10 color::palettes::basic::RED,
11 diagnostic::{FrameTimeDiagnosticsPlugin, LogDiagnosticsPlugin},
12 prelude::*,
13 text::{LineBreak, TextBounds},
14 window::{PresentMode, WindowResolution},
15 winit::WinitSettings,
16 };
17
18 #[derive(FromArgs, Resource)]
19 /// `many_glyphs` stress test
20 struct Args {
21 /// don't draw the UI text.
22 #[argh(switch)]
23 no_ui: bool,
24
25 /// don't draw the Text2d text.
26 #[argh(switch)]
27 no_text2d: bool,
28
29 /// whether to force the text to recompute every frame by triggering change detection.
30 #[argh(switch)]
31 recompute_text: bool,
32 }
33
34 fn main() {
35 // `from_env` panics on the web
36 #[cfg(not(target_arch = "wasm32"))]
37 let args: Args = argh::from_env();
38 #[cfg(target_arch = "wasm32")]
39 let args = Args::from_args(&[], &[]).unwrap();
40
41 let mut app = App::new();
42 app.add_plugins((
43 DefaultPlugins.set(WindowPlugin {
44 primary_window: Some(Window {
45 present_mode: PresentMode::AutoNoVsync,
46 resolution: WindowResolution::new(1920, 1080).with_scale_factor_override(1.0),
47 ..default()
48 }),
49 ..default()
50 }),
51 FrameTimeDiagnosticsPlugin::default(),
52 LogDiagnosticsPlugin::default(),
53 ))
54 .insert_resource(WinitSettings::continuous())
55 .add_systems(Startup, setup);
56
57 if args.recompute_text {
58 app.add_systems(Update, force_text_recomputation);
59 }
60
61 app.insert_resource(args).run();
62 }
63
64 fn setup(mut commands: Commands, args: Res<Args>) {
65 warn!(include_str!("warning_string.txt"));
66
67 commands.spawn(Camera2d);
68 let text_string = "0123456789".repeat(10_000);
69 let text_font = TextFont {
70 font_size: FontSize::Px(4.),
71 ..Default::default()
72 };
73 let text_block = TextLayout {
74 justify: Justify::Left,
75 linebreak: LineBreak::AnyCharacter,
76 };
77
78 if !args.no_ui {
79 commands
80 .spawn(Node {
81 width: percent(100),
82 align_items: AlignItems::Center,
83 justify_content: JustifyContent::Center,
84 ..default()
85 })
86 .with_children(|commands| {
87 commands
88 .spawn(Node {
89 width: px(1000),
90 ..Default::default()
91 })
92 .with_child((Text(text_string.clone()), text_font.clone(), text_block));
93 });
94 }
95
96 if !args.no_text2d {
97 commands.spawn((
98 Text2d::new(text_string),
99 text_font.clone(),
100 TextColor(RED.into()),
101 bevy::sprite::Anchor::CENTER,
102 TextBounds::new_horizontal(1000.),
103 text_block,
104 ));
105 }
106 }
107
108 fn force_text_recomputation(mut text_query: Query<&mut TextLayout>) {
109 for mut block in &mut text_query {
110 block.set_changed();
111 }
112 }