Sprite picking does not work correctly with custom viewport

[akimakinai]

Bevy version

0.16.0

What you did

Used sprite picking with custom viewport

Camera {
    viewport: Some(Viewport {
        physical_position: (window_size * 0.125).as_uvec2(),
        physical_size: (window_size * 0.75).as_uvec2(),
        ..default()
    }),
    ..default()
},

What went wrong

• pointer coordinate in sprite picking is incorrect. A sprite is picked in the wrong position.

Potential fix

Sprite picking code subtracts viewport min from cursor coordinate:

bevy/crates/bevy_sprite/src/picking_backend.rs

Lines 143 to 151 in cd67bac

	let viewport_pos = camera
	.logical_viewport_rect()
	.map(|v| v.min)
	.unwrap_or_default();
	let pos_in_viewport = location.position - viewport_pos;
	let Ok(cursor_ray_world) = camera.viewport_to_world(cam_transform, pos_in_viewport) else {
	continue;
	};

However 2d_viewport_to_world example does not.

bevy/examples/2d/2d_viewport_to_world.rs

Lines 35 to 42 in cd67bac

	let Some(cursor_position) = window.cursor_position() else {
	return;
	};
	// Calculate a world position based on the cursor's position.
	let Ok(world_pos) = camera.viewport_to_world_2d(camera_transform, cursor_position) else {
	return;
	};

If I remove the subtraction from sprite picking code as well, it seems to work correctly. (it is redundant as Camera::viewport_to_world already does?)

[Henauxg]

I think that this issue needs PR #18069 to land to be properly fixed.