dvd-thing/crates/domain/tests/motion.rs

mod common;

use common::{
    EDGE_ONLY, ROOMY, SNUG, TINY, advance, bottom_right, logo_sprite, scene_in, sprite_count,
};

#[test]
fn hitting_a_corner_bursts_sparkles_at_that_corner() {
    let mut scene = scene_in(SNUG);

    advance(&mut scene, SNUG, 1);

    let corner = bottom_right(SNUG);

    assert!(scene.sprites().any(|sprite| sprite.position() == corner));
    assert!(sprite_count(&scene) > 1);
}

#[test]
fn hitting_a_single_edge_recolours_but_does_not_burst() {
    let mut scene = scene_in(EDGE_ONLY);
    let before = logo_sprite(&scene).color();

    advance(&mut scene, EDGE_ONLY, 1);

    assert_ne!(logo_sprite(&scene).color(), before);
    assert_eq!(sprite_count(&scene), 1);
}

#[test]
fn sparkles_expire_so_the_scene_reaches_a_steady_size() {
    let mut scene = scene_in(SNUG);

    advance(&mut scene, SNUG, 64);
    let steady = sprite_count(&scene);
    advance(&mut scene, SNUG, 512);

    assert_eq!(sprite_count(&scene), steady);
}

#[test]
fn the_sparkle_buffer_holds_the_worst_case_without_dropping_any() {
    let mut scene = scene_in(SNUG);

    advance(&mut scene, SNUG, 256);

    assert_eq!(sprite_count(&scene), 12 * 9 + 1);
}

#[test]
fn bounds_shrinking_below_the_logo_neither_recolours_nor_bursts() {
    let mut scene = scene_in(ROOMY);
    let before = logo_sprite(&scene).color();

    advance(&mut scene, TINY, 64);

    assert_eq!(logo_sprite(&scene).color(), before);
    assert_eq!(sprite_count(&scene), 1);
}

#[test]
fn the_logo_never_leaves_the_bounds() {
    let mut scene = scene_in(ROOMY);

    for _ in 0..2048 {
        advance(&mut scene, ROOMY, 1);

        let logo = logo_sprite(&scene);
        let (position, size) = (logo.position(), logo.dimensions());

        assert!(position.x() >= 0.0 && position.y() >= 0.0);
        assert!(position.x() + size.width() as f32 <= ROOMY.width() as f32);
        assert!(position.y() + size.height() as f32 <= ROOMY.height() as f32);
    }
}