// EVERY FRAME
// EVERY FRAME
// EVERY FRAME
// EVERY FRAME

struct s_projectile
{
    s_v2 pos;
};
static s_sarray<s_projectile, 1024> projs;
static s_random rng = zero;
if(is_key_pressed(key_space, true))
{
    s_projectile p = zero;
    p.pos.y = rng.randf() * c_world_size.y;
    projs.add(p);
}

foreach(proj_i, proj, projs)
{
    s_v2 size = v2(64);
    draw_rect_ui(proj->pos, 0, size, WHITE);
    proj->pos.x += 400 * delta;
    int emitter = make_trigger_altar_particles(&game->ui_particle_emitters, v3(proj->pos + size / 2, -1), null);
    if(proj->pos.x > 2000)
    {
        projs.remove_and_swap(proj_i--);
    }
}