bevy/examples/2d/2d_viewport_to_world.rs
Pablo Reinhardt d96a9d15f6
Migrate from Query::single and friends to Single (#15872)
# Objective

- closes #15866

## Solution

- Simply migrate where possible.

## Testing

- Expect that CI will do most of the work. Examples is another way of
testing this, as most of the work is in that area.
---

## Notes
For now, this PR doesn't migrate `QueryState::single` and friends as for
now, this look like another issue. So for example, QueryBuilders that
used single or `World::query` that used single wasn't migrated. If there
is a easy way to migrate those, please let me know.

Most of the uses of `Query::single` were removed, the only other uses
that I found was related to tests of said methods, so will probably be
removed when we remove `Query::single`.
2024-10-13 20:32:06 +00:00

38 lines
936 B
Rust

//! This example demonstrates how to use the `Camera::viewport_to_world_2d` method.
use bevy::{color::palettes::basic::WHITE, prelude::*};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, draw_cursor)
.run();
}
fn draw_cursor(
camera_query: Single<(&Camera, &GlobalTransform)>,
windows: Query<&Window>,
mut gizmos: Gizmos,
) {
let (camera, camera_transform) = *camera_query;
let Ok(window) = windows.get_single() else {
return;
};
let Some(cursor_position) = window.cursor_position() else {
return;
};
// Calculate a world position based on the cursor's position.
let Ok(point) = camera.viewport_to_world_2d(camera_transform, cursor_position) else {
return;
};
gizmos.circle_2d(point, 10., WHITE);
}
fn setup(mut commands: Commands) {
commands.spawn(Camera2d);
}