This is an easing library available for macroquad

Quick start

Add quad-tween as a dependency to Cargo.toml:

[dependencies]
macroquad  = "0.4.5"
quad-tween = { git = "https://github.com/xLin7648/quad-tween.git" }

use quad_tween::*;
use macroquad::prelude::*;

#[macroquad::main("BasicShapes")]
async fn main() {
    request_new_screen_size(1280., 720.);

    let mut points = Vec::new();

    points.push(vec2(400. , 600.));
    points.push(vec2(800. , 600.));
    points.push(vec2(1200., 200.));
    points.push(vec2(800. , 200.));

    let mut tween: Tween<Vec2> = Tween::<Vec2>::new(
        Ease::InOutExpo,
        true, // isloop?
        1.5,  // total time,
        points
    );

    loop {
        clear_background(BLUE);

        tween.update(get_frame_time(), |tw| {
            draw_circle(tw.points[0].x , tw.points[0].y , 20., BLACK);
            draw_circle(tw.points[1].x , tw.points[1].y , 20., WHITE);
            draw_circle(tw.points[2].x , tw.points[2].y , 20., BLACK);
            draw_circle(tw.points[3].x , tw.points[3].y , 20., WHITE);
            draw_circle(tw.result.x    , tw.result.y    , 20., GREEN);
        });

        next_frame().await
    }
}