1//! Utilities for handling mouse events.
2
3/// Recorded mouse delta designed to filter out noise.
4pub struct Delta<T> {
5 x: T,
6 y: T,
7}
8
9impl<T: Default> Default for Delta<T> {
10 fn default() -> Self {
11 Self { x: Default::default(), y: Default::default() }
12 }
13}
14
15impl<T: Default> Delta<T> {
16 pub(crate) fn set_x(&mut self, x: T) {
17 self.x = x;
18 }
19
20 pub(crate) fn set_y(&mut self, y: T) {
21 self.y = y;
22 }
23}
24
25macro_rules! consume {
26 ($this:expr, $ty:ty) => {{
27 let this = $this;
28 let (x, y) = match (this.x.abs() < <$ty>::EPSILON, this.y.abs() < <$ty>::EPSILON) {
29 (true, true) => return None,
30 (false, true) => (this.x, 0.0),
31 (true, false) => (0.0, this.y),
32 (false, false) => (this.x, this.y),
33 };
34
35 Some((x, y))
36 }};
37}
38
39impl Delta<f32> {
40 pub(crate) fn consume(self) -> Option<(f32, f32)> {
41 consume!(self, f32)
42 }
43}
44
45impl Delta<f64> {
46 pub(crate) fn consume(self) -> Option<(f64, f64)> {
47 consume!(self, f64)
48 }
49}
50