bevy/examples/window/screenshot.rs

//! An example showing how to save screenshots to disk

use bevy::{
    prelude::*,
    render::view::screenshot::{save_to_disk, Capturing, Screenshot},
    window::SystemCursorIcon,
    winit::cursor::CursorIcon,
};

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, setup)
        .add_systems(Update, (screenshot_on_spacebar, screenshot_saving))
        .run();
}

fn screenshot_on_spacebar(
    mut commands: Commands,
    input: Res<ButtonInput<KeyCode>>,
    mut counter: Local<u32>,
) {
    if input.just_pressed(KeyCode::Space) {
        let path = format!("./screenshot-{}.png", *counter);
        *counter += 1;
        commands
            .spawn(Screenshot::primary_window())
            .observe(save_to_disk(path));
    }
}

fn screenshot_saving(
    mut commands: Commands,
    screenshot_saving: Query<Entity, With<Capturing>>,
    windows: Query<Entity, With<Window>>,
) {
    let Ok(window) = windows.get_single() else {
        return;
    };
    match screenshot_saving.iter().count() {
        0 => {
            commands.entity(window).remove::<CursorIcon>();
        }
        x if x > 0 => {
            commands
                .entity(window)
                .insert(CursorIcon::from(SystemCursorIcon::Progress));
        }
        _ => {}
    }
}

/// set up a simple 3D scene
fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // plane
    commands.spawn((
        Mesh3d(meshes.add(Plane3d::default().mesh().size(5.0, 5.0))),
        MeshMaterial3d(materials.add(Color::srgb(0.3, 0.5, 0.3))),
    ));
    // cube
    commands.spawn((
        Mesh3d(meshes.add(Cuboid::default())),
        MeshMaterial3d(materials.add(Color::srgb(0.8, 0.7, 0.6))),
        Transform::from_xyz(0.0, 0.5, 0.0),
    ));
    // light
    commands.spawn((
        PointLight {
            shadows_enabled: true,
            ..default()
        },
        Transform::from_xyz(4.0, 8.0, 4.0),
    ));
    // camera
    commands.spawn((
        Camera3d::default(),
        Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
    ));

    commands.spawn((
        Text::new("Press <spacebar> to save a screenshot to disk"),
        Style {
            position_type: PositionType::Absolute,
            top: Val::Px(12.0),
            left: Val::Px(12.0),
            ..default()
        },
    ));
}