Function bevy_picking_selection::send_selection_events

pub fn send_selection_events(
    settings: Res<'_, SelectionSettings>,
    pointer_down: EventReader<'_, '_, PointerEvent<Down>>,
    presses: EventReader<'_, '_, InputPress>,
    pointer_click: EventReader<'_, '_, PointerEvent<Click>>,
    pointers: Query<'_, '_, (&PointerId, &PointerMultiselect, &PointerLocation)>,
    no_deselect: Query<'_, '_, &NoDeselect>,
    selectables: Query<'_, '_, (Entity, &PickSelection)>,
    selections: EventWriter<'_, PointerEvent<Select>>,
    deselections: EventWriter<'_, PointerEvent<Deselect>>
)

Determines which entities have been selected or deselected, and sends Select and Deselect events corresponding to these state changes.