# Objective
Currently text is recomputed unnecessarily on any changes to its color,
which is extremely expensive.
## Solution
Split up `TextStyle` into two separate components `TextFont` and
`TextColor`.
## Testing
I added this system to `many_buttons`:
```rust
fn set_text_colors_changed(mut colors: Query<&mut TextColor>) {
    for mut text_color in colors.iter_mut() {
        text_color.set_changed();
    }
}
```
reports ~4fps on main, ~50fps with this PR.
## Migration Guide
`TextStyle` has been renamed to `TextFont` and its `color` field has
been moved to a separate component named `TextColor` which newtypes
`Color`.
		
	
			
		
			
				
	
	
		
			86 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			86 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
//! Showcase how to use and configure FPS overlay.
 | 
						|
 | 
						|
use bevy::{
 | 
						|
    dev_tools::fps_overlay::{FpsOverlayConfig, FpsOverlayPlugin},
 | 
						|
    prelude::*,
 | 
						|
    text::FontSmoothing,
 | 
						|
};
 | 
						|
 | 
						|
struct OverlayColor;
 | 
						|
 | 
						|
impl OverlayColor {
 | 
						|
    const RED: Color = Color::srgb(1.0, 0.0, 0.0);
 | 
						|
    const GREEN: Color = Color::srgb(0.0, 1.0, 0.0);
 | 
						|
}
 | 
						|
 | 
						|
fn main() {
 | 
						|
    App::new()
 | 
						|
        .add_plugins((
 | 
						|
            DefaultPlugins,
 | 
						|
            FpsOverlayPlugin {
 | 
						|
                config: FpsOverlayConfig {
 | 
						|
                    text_config: TextFont {
 | 
						|
                        // Here we define size of our overlay
 | 
						|
                        font_size: 42.0,
 | 
						|
                        // If we want, we can use a custom font
 | 
						|
                        font: default(),
 | 
						|
                        // We could also disable font smoothing,
 | 
						|
                        font_smoothing: FontSmoothing::default(),
 | 
						|
                    },
 | 
						|
                    // We can also change color of the overlay
 | 
						|
                    text_color: OverlayColor::GREEN,
 | 
						|
                    enabled: true,
 | 
						|
                },
 | 
						|
            },
 | 
						|
        ))
 | 
						|
        .add_systems(Startup, setup)
 | 
						|
        .add_systems(Update, customize_config)
 | 
						|
        .run();
 | 
						|
}
 | 
						|
 | 
						|
fn setup(mut commands: Commands) {
 | 
						|
    // We need to spawn a camera (2d or 3d) to see the overlay
 | 
						|
    commands.spawn(Camera2d);
 | 
						|
 | 
						|
    // Instruction text
 | 
						|
    commands
 | 
						|
        .spawn(NodeBundle {
 | 
						|
            style: Style {
 | 
						|
                width: Val::Percent(100.0),
 | 
						|
                height: Val::Percent(100.0),
 | 
						|
                align_items: AlignItems::Center,
 | 
						|
                justify_content: JustifyContent::Center,
 | 
						|
                ..default()
 | 
						|
            },
 | 
						|
            ..default()
 | 
						|
        })
 | 
						|
        .with_children(|c| {
 | 
						|
            c.spawn(Text::new(concat!(
 | 
						|
                "Press 1 to toggle the overlay color.\n",
 | 
						|
                "Press 2 to decrease the overlay size.\n",
 | 
						|
                "Press 3 to increase the overlay size.\n",
 | 
						|
                "Press 4 to toggle the overlay visibility."
 | 
						|
            )));
 | 
						|
        });
 | 
						|
}
 | 
						|
 | 
						|
fn customize_config(input: Res<ButtonInput<KeyCode>>, mut overlay: ResMut<FpsOverlayConfig>) {
 | 
						|
    if input.just_pressed(KeyCode::Digit1) {
 | 
						|
        // Changing resource will affect overlay
 | 
						|
        if overlay.text_color == OverlayColor::GREEN {
 | 
						|
            overlay.text_color = OverlayColor::RED;
 | 
						|
        } else {
 | 
						|
            overlay.text_color = OverlayColor::GREEN;
 | 
						|
        }
 | 
						|
    }
 | 
						|
    if input.just_pressed(KeyCode::Digit2) {
 | 
						|
        overlay.text_config.font_size -= 2.0;
 | 
						|
    }
 | 
						|
    if input.just_pressed(KeyCode::Digit3) {
 | 
						|
        overlay.text_config.font_size += 2.0;
 | 
						|
    }
 | 
						|
    if input.just_pressed(KeyCode::Digit4) {
 | 
						|
        overlay.enabled = !overlay.enabled;
 | 
						|
    }
 | 
						|
}
 |