Function update_cursor_overlay_on_move

src/plot_widget.rs:1333–1370

(
    widget: &PlotWidget,
    state: &PlotState,
    effects: &mut UpdateEffects,
)

fn clear_hover_effect(widget: &PlotWidget, state: &mut PlotState, effects: &mut UpdateEffects) {
    let should_clear_hover =
        state.picking.last_hover_cache.is_some() || !widget.hovered_points.is_empty();

    if effects.hover_pick.is_none() && should_clear_hover {
        state.picking.last_hover_cache = None;
        effects.hover_pick = Some(HoverPickEvent::ClearHover);
    }
}

fn maybe_submit_hover_request(
    widget: &PlotWidget,
    state: &mut PlotState,
    effects: &mut UpdateEffects,
) {
    if !state.hover_enabled || state.pan.active || state.selection.active {
        return;
    }
    if !state.cursor_inside() {
        clear_hover_effect(widget, state, effects);
        return;
    }

    if effects.hover_pick.is_some() {
        return;
    }

    let PlotState {
        picking: pick_state,
        cursor_position,
        hover_radius_px,
        points,
        series,
        camera,
        bounds,
        ..
    } = state;
    let force_cpu_picking = widget.render_strategy.force_cpu_picking();

    match pick_state.request_hover(
        widget.instance_id,
        *cursor_position,
        *hover_radius_px,