Squash n Stretch based on Velocity

function s_cursor:update()
    local last_coords = self.coords:copy()

    -- get inputs
    self:handle_inputs()

    -- update state
    if self.coords ~= last_coords then
        self.target = mgr_game.layout:get_screen_coords_for_level(self.coords)
        self.animator = _gfx.animator.new(150, self.current, self.target, playdate.easingFunctions.outCirc)
    end

    if self.current ~= self.target then
        -- animate towards our target
        local last_coords = self.current:copy()
        self.current = self.animator:currentValue()

        -- determine delta
        self.delta.x = self.current.x - last_coords.x
        self.delta.y = self.current.y - last_coords.y

        -- squash and stretch based on velocity
        -- magic numbers 1.75, 0.57 are chosen to prevent the square from becoming a 1-pixel line
        -- 1.75 x 0.57 is approximately 1, preserving the visual volume of the square
        if (math.abs(self.delta.x) - math.abs(self.delta.y)) > 0 then
            self.scale.x = math.min(1 + math.abs(self.delta.x / g_box_size), 1.75)
            self.scale.y = math.max(1 - math.abs(self.delta.x / g_box_size), 0.57)
        else
            self.scale.x = math.max(1 - math.abs(self.delta.y / g_box_size), 0.57)
            self.scale.y = math.min(1 + math.abs(self.delta.y / g_box_size), 1.75)
        end

        local grid_size = g_box_size + g_padding
        local cx = (self.current.x + grid_size/2) - (grid_size * self.scale.x / 2) + 1
        local cy = (self.current.y + grid_size/2) - (grid_size * self.scale.y / 2) + 1
        local cwidth = (g_box_size * self.scale.x)
        local cheight = (g_box_size * self.scale.y)

        self:setBounds(cx, cy, cwidth, cheight)
    end

    -- if we've run out of animation, reset to nil
    if self.animator and self.animator:ended() then
        self.animator = nil
        self.current = self.target:copy()
        self.delta = _gtry.point.new(0, 0)
        self.scale = _gtry.point.new(1, 1)

        self:setBounds(self.current.x, self.current.y, g_box_size, g_box_size)
    end

    self:markDirty()
end