Enum FillEndpoint

src/plot_state.rs:923–927

        let cursor_render_before = self.camera.screen_to_render(
            DVec2::new(self.cursor_position.x as f64, self.cursor_position.y as f64),
            viewport,
        );

        if zoom_x {
            self.camera.half_extents.x *= zoom_factor;
        }
        if zoom_y {
            self.camera.half_extents.y *= zoom_factor;